This document provides guidance on electrocardiogram (ECG) interpretation. It begins with descriptions of normal ECG appearances and measurements. It then discusses approaches to reading an ECG, including evaluating the patient details, heart rate, rhythm, axis, and conduction abnormalities. Various abnormalities are described such as arrhythmias, conduction blocks, abnormal P waves, QRS complexes, ST segments, and T waves. Causes and indications of different abnormalities are provided. The document concludes with descriptions of myocardial infarction patterns on ECG over time.
This document provides guidance on electrocardiogram (ECG) interpretation. It begins with descriptions of normal ECG appearances and measurements. It then discusses approaches to reading an ECG, including evaluating heart rate, rhythm, axis, and abnormalities. Common conduction abnormalities and what parts of the heart different abnormalities indicate are defined. The document concludes with descriptions of abnormalities in various ECG components like ST segments, T waves, and Q waves as well as the typical evolution of a myocardial infarction on ECG.
1. The document describes various EKG abnormalities including early repolarization, pericarditis, fascicular blocks, ventricular hypertrophy, electrolyte abnormalities, prolonged QT interval, and more.
2. Key details are provided on differentiating early repolarization from anterior MI and pericarditis. Stages of pericarditis are outlined.
3. Fascicular blocks are described along with their characteristic axis deviations and block locations. Different forms of ventricular hypertrophy and their EKG patterns are also summarized.
The document provides information about electrocardiography (ECG), including its history, how an ECG machine works, how to perform an ECG, electrode placement, the different leads, and how to interpret an ECG. It discusses normal ECG waves and intervals as well as various arrhythmias and abnormalities that can be seen on an ECG. Modern ECG machines produce computerized readings but interpretation should still be done carefully by a medical professional. A proper ECG involves correctly placing the electrodes on the patient's limbs and chest to measure the heart's electrical activity from multiple angles.
1. The document discusses electrocardiographic (ECG) interpretation including determining cardiac rate and rhythm, identifying conduction disturbances, myocardial ischemia or infarction, and other abnormalities.
2. It provides details on properly placing ECG leads and determining the cardiac axis. Common rhythms, conduction blocks, hypertrophy, and other ECG findings are explained.
3. A mnemonic device, RRAHIM, is presented to guide the systematic interpretation of an ECG, covering rate, rhythm, axis, hypertrophy, ischemia/infarction, and other findings.
The document discusses electrocardiography (ECG). It defines ECG as the graphical recording of electrical activity of the heart from body surface electrodes. It notes ECG is immediately available, non-invasive, and inexpensive. The document outlines uses of ECG including assessing heart rate, arrhythmias, blocks, chamber enlargement, electrolyte imbalance, and drug effects. It discusses key aspects of ECG like waves, intervals, axis, and ST segment elevation. Overall, the document provides an overview of ECG, its uses, principles, and how to interpret common findings.
This document provides an introduction to electrocardiograms (ECGs) and EKG monitoring. It discusses ECG basics like standardized methods and devices, the components and measurements of the ECG complex, and how to analyze ECGs. The objectives are to learn how to properly apply ECG leads, define what a lead is, learn the anatomy of a normal ECG, define normal sinus rhythm, and quantify the various components of a normal ECG. Various cardiac rhythms and abnormalities are also explained such as sinus bradycardia, sinus tachycardia, atrial fibrillation, ventricular fibrillation, and myocardial infarction.
The electrocardiogram (ECG or EKG) measures and records the electrical activity of the heart. It was developed in 1893 by Willem Einthoven, who received the Nobel Prize for his work. An ECG works by detecting the tiny electrical changes on the skin that occur with each heartbeat. It shows the heart's rate and rhythm, as well as any damage to heart muscle. A standard 12-lead ECG provides multiple views of the heart and can help diagnose conditions like heart attacks.
This document provides guidance on electrocardiogram (ECG) interpretation. It begins with descriptions of normal ECG appearances and measurements. It then discusses approaches to reading an ECG, including evaluating heart rate, rhythm, axis, and abnormalities. Common conduction abnormalities and what parts of the heart different abnormalities indicate are defined. The document concludes with descriptions of abnormalities in various ECG components like ST segments, T waves, and Q waves as well as the typical evolution of a myocardial infarction on ECG.
1. The document describes various EKG abnormalities including early repolarization, pericarditis, fascicular blocks, ventricular hypertrophy, electrolyte abnormalities, prolonged QT interval, and more.
2. Key details are provided on differentiating early repolarization from anterior MI and pericarditis. Stages of pericarditis are outlined.
3. Fascicular blocks are described along with their characteristic axis deviations and block locations. Different forms of ventricular hypertrophy and their EKG patterns are also summarized.
The document provides information about electrocardiography (ECG), including its history, how an ECG machine works, how to perform an ECG, electrode placement, the different leads, and how to interpret an ECG. It discusses normal ECG waves and intervals as well as various arrhythmias and abnormalities that can be seen on an ECG. Modern ECG machines produce computerized readings but interpretation should still be done carefully by a medical professional. A proper ECG involves correctly placing the electrodes on the patient's limbs and chest to measure the heart's electrical activity from multiple angles.
1. The document discusses electrocardiographic (ECG) interpretation including determining cardiac rate and rhythm, identifying conduction disturbances, myocardial ischemia or infarction, and other abnormalities.
2. It provides details on properly placing ECG leads and determining the cardiac axis. Common rhythms, conduction blocks, hypertrophy, and other ECG findings are explained.
3. A mnemonic device, RRAHIM, is presented to guide the systematic interpretation of an ECG, covering rate, rhythm, axis, hypertrophy, ischemia/infarction, and other findings.
The document discusses electrocardiography (ECG). It defines ECG as the graphical recording of electrical activity of the heart from body surface electrodes. It notes ECG is immediately available, non-invasive, and inexpensive. The document outlines uses of ECG including assessing heart rate, arrhythmias, blocks, chamber enlargement, electrolyte imbalance, and drug effects. It discusses key aspects of ECG like waves, intervals, axis, and ST segment elevation. Overall, the document provides an overview of ECG, its uses, principles, and how to interpret common findings.
This document provides an introduction to electrocardiograms (ECGs) and EKG monitoring. It discusses ECG basics like standardized methods and devices, the components and measurements of the ECG complex, and how to analyze ECGs. The objectives are to learn how to properly apply ECG leads, define what a lead is, learn the anatomy of a normal ECG, define normal sinus rhythm, and quantify the various components of a normal ECG. Various cardiac rhythms and abnormalities are also explained such as sinus bradycardia, sinus tachycardia, atrial fibrillation, ventricular fibrillation, and myocardial infarction.
The electrocardiogram (ECG or EKG) measures and records the electrical activity of the heart. It was developed in 1893 by Willem Einthoven, who received the Nobel Prize for his work. An ECG works by detecting the tiny electrical changes on the skin that occur with each heartbeat. It shows the heart's rate and rhythm, as well as any damage to heart muscle. A standard 12-lead ECG provides multiple views of the heart and can help diagnose conditions like heart attacks.
- LVH is characterized by tall QRS complexes on ECG due to increased electrical forces moving through the thickened myocardium.
- Criteria exists to diagnose LVH using a 12-lead ECG, such as the R wave in V5 or V6 plus the S wave in V1 or V2 exceeding 35 mm.
- The document compares a normal ECG to one with LVH and explains how echocardiogram can also detect LVH by showing increased ventricular wall thickness.
This document provides an overview of key topics in electrocardiography (ECG). It begins with definitions of an ECG and electrode leads. It then covers normal ECG wave patterns and measurements. Various abnormal ECG patterns are discussed including sinus bradycardia/tachycardia, ventricular hypertrophy, myocardial infarction in different regions, and more. Diagrams are provided to illustrate normal and abnormal ECG findings. The document serves as a guide to interpreting ECGs and recognizing common cardiac conditions.
This document provides an overview of ECG interpretation, including conduction pathways, a systematic method of interpretation, and common abnormalities seen in critical care. It discusses supraventricular and ventricular arrhythmias, bundle branch blocks, heart block, and life-threatening arrhythmias such as ventricular tachycardia, ventricular fibrillation, and asystole. It also covers the basics of 12-lead ECG interpretation including lead placement and axis.
This document provides a 100 step guide to electrocardiogram (ECG) interpretation written by Dr. S. Aswini Kumar. It begins with basic definitions of an ECG, the machine used to record it, and how the paper is formatted. It then explains how to analyze various aspects of the ECG including heart rate, rhythm, electrical axis, P wave, PR interval, QRS duration, ST segment, T wave, and conditions like myocardial infarction. The document provides criteria for interpreting abnormalities and identifying conditions. It concludes with examples of analyzing ECG findings and providing an impression.
This document provides an overview of basics of electrocardiography (ECG or EKG). It discusses the history of ECG development from 1842 to modern use. Key aspects of ECG are described, including the cardiac cycle waveform known as PQRST, conduction system, normal values, and interpretation of abnormalities. Common uses of ECG include identifying arrhythmias, ischemia, infarction and other cardiac conditions. Proper placement of ECG leads and use of rules to evaluate a normal tracing are also outlined.
The document provides an overview of electrocardiography (ECG) including the basic components and waves of an ECG tracing as well as the 12-lead ECG system. It describes the P wave, QRS complex, ST-T wave, and U wave. It also defines common intervals such as the PR interval, QRS duration, and QT interval. Additionally, it explains that the 12-lead ECG provides spatial information about the heart's electrical activity in three orthogonal planes and lists the leads that measure activity in each plane. Finally, it includes 10 review questions related to ECG interpretation.
This document provides an overview of electrocardiography (ECG). It defines an ECG as a tracing of the heart's electrical activity. The objectives are to learn how to perform an ECG, interpret the results, and recognize various pathologies. Key points covered include electrode placement, components of the ECG wave, the physiology of cardiac conduction, interpreting the rate, rhythm, axis, and analyzing P, QRS, and T waves. Causes of axis deviations and details on analyzing the P wave are also summarized.
The document provides an overview of electrocardiography (ECG) basics including lead positions, ECG paper and timing, standardization, the normal ECG waves including P, PR, QRS, ST segments, T waves, and QT interval, and abnormalities. Key findings of right and left ventricular hypertrophy, atrial enlargement, bundle branch blocks, myocardial infarction, and various degrees of atrioventricular block are also summarized.
This document provides a guide for medical students to interpret electrocardiograms (ECGs). It aims to enable students to determine normal ECG features, assess rate and rhythm, and identify myocardial infarctions. The guide outlines how to present ECG findings in a logical order, covering rate and rhythm, conduction intervals, cardiac axis, QRS complexes, and ST segments and T waves. Key normal and abnormal ECG patterns are defined. The guide is intended to help standardize ECG interpretation training for medical students.
This document discusses various abnormalities that can be seen on electrocardiograms (ECGs). It covers rate abnormalities like tachycardia and bradycardia. It also discusses atrial and ventricular enlargements and the patterns they produce. Various rhythm abnormalities are outlined like junctional rhythm, idioventricular rhythm, and atrioventricular blocks. Bundle branch blocks and fascicular blocks are also described. The document then covers electrolyte disturbances and various arrhythmias including supraventricular arrhythmias, ventricular tachycardias, ventricular fibrillation, and patterns seen in myocardial infarction. It concludes by emphasizing the importance of ECG in identifying many heart conditions and changes.
1. The document describes the anatomy and physiology of the heart, including its chambers, valves, conduction system, blood flow, and heart sounds.
2. Key aspects covered are the structure and function of the heart, cardiac cycle, electrocardiography, cardiac arrhythmias, murmurs, and approach to cardiac patients.
3. Details are provided on abnormalities like bundle branch blocks, hypertrophies, conduction disorders, and various arrhythmias that can be identified on ECG.
ECG localization of accessory pathways slideshareCardiology
This presentation is simplified view of accessory pathways in heart and their localization with help of algorithms and ECG examples. Try to read this PPT in power point to see full effects and animations.
This document provides a tutorial on electrocardiography (ECG). It discusses the basics of ECG including standard calibration and electrical impulse generation. It describes the anatomical locations associated with different ECG leads. Key components of the ECG like the P wave, QRS complex, ST segment, T wave, and QT interval are explained. Common ECG findings related to conditions like myocardial infarction, hypertrophy, axis deviation, and arrhythmias are presented. Calculation of heart rate and cardiac axis are demonstrated. Recommended resources for further ECG learning are provided at the end.
The document provides an overview of electrocardiogram (ECG) interpretation. It discusses the key steps including assessing quality, rate, rhythm, axis, P wave, PR interval, QRS duration and morphology, ST segment, T wave, QT interval, and identifying common abnormalities. Examples of important ECG patterns are also shown, such as lateral myocardial infarction, left bundle branch block, ventricular tachycardia, and Wolff-Parkinson-White syndrome. The overall document aims to develop a structured approach for interpreting ECGs in clinical practice.
This document outlines a standardized method for interpreting 12-lead electrocardiograms (ECGs). The method involves analyzing six major sections in a specific order: heart rate, PR interval, QRS duration, QT interval, QRS axis, and waveforms. Each section is analyzed to identify any abnormalities, including intervals outside normal ranges or irregular waveforms. After following this method, the interpreter provides an overall interpretation of the ECG as normal or abnormal, listing any findings.
Electrocardiography is a technique that records the electrical activity of the heart over time via electrodes placed on the skin. Dr. Wilhelm Einthoven invented the first practical ECG in 1903. An ECG provides information to support cardiac diagnoses by detecting abnormal cardiac rhythms and electrical changes associated with heart muscle contraction and relaxation. A normal ECG shows distinct P, QRS, and T waves representing atrial depolarization, ventricular depolarization, and ventricular repolarization, respectively. Key intervals like the PR and QT intervals are also measured to identify conduction abnormalities.
This document provides an overview of ECG samples and diagnosis for medical students. It discusses the basics of ECG interpretation, normal sinus rhythm, intervals, waveforms, abnormalities, myocardial infarction, bundle branch blocks, ventricular hypertrophy, atrial fibrillation, and more. Examples of various abnormal ECG patterns are presented along with explanations. Sources include textbooks and online resources for ECG learning. The document is intended for educational presentation purposes.
This document discusses the analysis of a 12-lead EKG. It begins by describing the components that should be assessed, including rhythm, rate, axis, and grouped lead analysis. Specific abnormalities are then discussed in detail such as ST segment changes, bundle branch blocks, Q waves, and more. The overall goal is to systematically analyze all aspects of the 12-lead EKG to evaluate for any cardiac abnormalities.
This document provides a comprehensive overview of EKG interpretation. It defines the various EKG waves, intervals, segments and complexes. It describes normal values as well as abnormalities related to conditions like myocardial infarction, hypertrophy, conduction blocks, electrolyte imbalances, hypothermia and more. Causes of variations in waves, intervals and complexes are discussed in detail. Commonly seen arrhythmias and their mechanisms are also explained.
- LVH is characterized by tall QRS complexes on ECG due to increased electrical forces moving through the thickened myocardium.
- Criteria exists to diagnose LVH using a 12-lead ECG, such as the R wave in V5 or V6 plus the S wave in V1 or V2 exceeding 35 mm.
- The document compares a normal ECG to one with LVH and explains how echocardiogram can also detect LVH by showing increased ventricular wall thickness.
This document provides an overview of key topics in electrocardiography (ECG). It begins with definitions of an ECG and electrode leads. It then covers normal ECG wave patterns and measurements. Various abnormal ECG patterns are discussed including sinus bradycardia/tachycardia, ventricular hypertrophy, myocardial infarction in different regions, and more. Diagrams are provided to illustrate normal and abnormal ECG findings. The document serves as a guide to interpreting ECGs and recognizing common cardiac conditions.
This document provides an overview of ECG interpretation, including conduction pathways, a systematic method of interpretation, and common abnormalities seen in critical care. It discusses supraventricular and ventricular arrhythmias, bundle branch blocks, heart block, and life-threatening arrhythmias such as ventricular tachycardia, ventricular fibrillation, and asystole. It also covers the basics of 12-lead ECG interpretation including lead placement and axis.
This document provides a 100 step guide to electrocardiogram (ECG) interpretation written by Dr. S. Aswini Kumar. It begins with basic definitions of an ECG, the machine used to record it, and how the paper is formatted. It then explains how to analyze various aspects of the ECG including heart rate, rhythm, electrical axis, P wave, PR interval, QRS duration, ST segment, T wave, and conditions like myocardial infarction. The document provides criteria for interpreting abnormalities and identifying conditions. It concludes with examples of analyzing ECG findings and providing an impression.
This document provides an overview of basics of electrocardiography (ECG or EKG). It discusses the history of ECG development from 1842 to modern use. Key aspects of ECG are described, including the cardiac cycle waveform known as PQRST, conduction system, normal values, and interpretation of abnormalities. Common uses of ECG include identifying arrhythmias, ischemia, infarction and other cardiac conditions. Proper placement of ECG leads and use of rules to evaluate a normal tracing are also outlined.
The document provides an overview of electrocardiography (ECG) including the basic components and waves of an ECG tracing as well as the 12-lead ECG system. It describes the P wave, QRS complex, ST-T wave, and U wave. It also defines common intervals such as the PR interval, QRS duration, and QT interval. Additionally, it explains that the 12-lead ECG provides spatial information about the heart's electrical activity in three orthogonal planes and lists the leads that measure activity in each plane. Finally, it includes 10 review questions related to ECG interpretation.
This document provides an overview of electrocardiography (ECG). It defines an ECG as a tracing of the heart's electrical activity. The objectives are to learn how to perform an ECG, interpret the results, and recognize various pathologies. Key points covered include electrode placement, components of the ECG wave, the physiology of cardiac conduction, interpreting the rate, rhythm, axis, and analyzing P, QRS, and T waves. Causes of axis deviations and details on analyzing the P wave are also summarized.
The document provides an overview of electrocardiography (ECG) basics including lead positions, ECG paper and timing, standardization, the normal ECG waves including P, PR, QRS, ST segments, T waves, and QT interval, and abnormalities. Key findings of right and left ventricular hypertrophy, atrial enlargement, bundle branch blocks, myocardial infarction, and various degrees of atrioventricular block are also summarized.
This document provides a guide for medical students to interpret electrocardiograms (ECGs). It aims to enable students to determine normal ECG features, assess rate and rhythm, and identify myocardial infarctions. The guide outlines how to present ECG findings in a logical order, covering rate and rhythm, conduction intervals, cardiac axis, QRS complexes, and ST segments and T waves. Key normal and abnormal ECG patterns are defined. The guide is intended to help standardize ECG interpretation training for medical students.
This document discusses various abnormalities that can be seen on electrocardiograms (ECGs). It covers rate abnormalities like tachycardia and bradycardia. It also discusses atrial and ventricular enlargements and the patterns they produce. Various rhythm abnormalities are outlined like junctional rhythm, idioventricular rhythm, and atrioventricular blocks. Bundle branch blocks and fascicular blocks are also described. The document then covers electrolyte disturbances and various arrhythmias including supraventricular arrhythmias, ventricular tachycardias, ventricular fibrillation, and patterns seen in myocardial infarction. It concludes by emphasizing the importance of ECG in identifying many heart conditions and changes.
1. The document describes the anatomy and physiology of the heart, including its chambers, valves, conduction system, blood flow, and heart sounds.
2. Key aspects covered are the structure and function of the heart, cardiac cycle, electrocardiography, cardiac arrhythmias, murmurs, and approach to cardiac patients.
3. Details are provided on abnormalities like bundle branch blocks, hypertrophies, conduction disorders, and various arrhythmias that can be identified on ECG.
ECG localization of accessory pathways slideshareCardiology
This presentation is simplified view of accessory pathways in heart and their localization with help of algorithms and ECG examples. Try to read this PPT in power point to see full effects and animations.
This document provides a tutorial on electrocardiography (ECG). It discusses the basics of ECG including standard calibration and electrical impulse generation. It describes the anatomical locations associated with different ECG leads. Key components of the ECG like the P wave, QRS complex, ST segment, T wave, and QT interval are explained. Common ECG findings related to conditions like myocardial infarction, hypertrophy, axis deviation, and arrhythmias are presented. Calculation of heart rate and cardiac axis are demonstrated. Recommended resources for further ECG learning are provided at the end.
The document provides an overview of electrocardiogram (ECG) interpretation. It discusses the key steps including assessing quality, rate, rhythm, axis, P wave, PR interval, QRS duration and morphology, ST segment, T wave, QT interval, and identifying common abnormalities. Examples of important ECG patterns are also shown, such as lateral myocardial infarction, left bundle branch block, ventricular tachycardia, and Wolff-Parkinson-White syndrome. The overall document aims to develop a structured approach for interpreting ECGs in clinical practice.
This document outlines a standardized method for interpreting 12-lead electrocardiograms (ECGs). The method involves analyzing six major sections in a specific order: heart rate, PR interval, QRS duration, QT interval, QRS axis, and waveforms. Each section is analyzed to identify any abnormalities, including intervals outside normal ranges or irregular waveforms. After following this method, the interpreter provides an overall interpretation of the ECG as normal or abnormal, listing any findings.
Electrocardiography is a technique that records the electrical activity of the heart over time via electrodes placed on the skin. Dr. Wilhelm Einthoven invented the first practical ECG in 1903. An ECG provides information to support cardiac diagnoses by detecting abnormal cardiac rhythms and electrical changes associated with heart muscle contraction and relaxation. A normal ECG shows distinct P, QRS, and T waves representing atrial depolarization, ventricular depolarization, and ventricular repolarization, respectively. Key intervals like the PR and QT intervals are also measured to identify conduction abnormalities.
This document provides an overview of ECG samples and diagnosis for medical students. It discusses the basics of ECG interpretation, normal sinus rhythm, intervals, waveforms, abnormalities, myocardial infarction, bundle branch blocks, ventricular hypertrophy, atrial fibrillation, and more. Examples of various abnormal ECG patterns are presented along with explanations. Sources include textbooks and online resources for ECG learning. The document is intended for educational presentation purposes.
This document discusses the analysis of a 12-lead EKG. It begins by describing the components that should be assessed, including rhythm, rate, axis, and grouped lead analysis. Specific abnormalities are then discussed in detail such as ST segment changes, bundle branch blocks, Q waves, and more. The overall goal is to systematically analyze all aspects of the 12-lead EKG to evaluate for any cardiac abnormalities.
This document provides a comprehensive overview of EKG interpretation. It defines the various EKG waves, intervals, segments and complexes. It describes normal values as well as abnormalities related to conditions like myocardial infarction, hypertrophy, conduction blocks, electrolyte imbalances, hypothermia and more. Causes of variations in waves, intervals and complexes are discussed in detail. Commonly seen arrhythmias and their mechanisms are also explained.
This document discusses various non-coronary causes of ST-elevation on electrocardiograms (ECGs) including ventricular aneurysms, pericarditis, early repolarization patterns, left ventricular hypertrophy, left bundle branch block, hypothermia, cardioversion, intraventricular hemorrhage, hyperkalemia, Brugada pattern, type 1C antiarrhythmic drugs, hypercalcemia, pulmonary embolism, hypothermia, myocarditis, and tumor invasion of the left ventricle. It then discusses left ventricular aneurysms, early repolarization, acute pericarditis, hyperkalemia, hypothermia, increased intracranial pressure, Brugada syndrome, Tak
This document provides an overview of ECG abnormalities, including abnormal rhythms, conduction blocks, hypertrophies, and ischemic changes. Key points include definitions of sinus bradycardia, sinus tachycardia, sinus arrhythmia, various types of atrioventricular and bundle branch blocks, signs of ventricular hypertrophy, ST segment changes indicating ischemia or injury, and abnormal T waves associated with conditions like hyperkalemia. Criteria for interpreting and describing normal ECG findings are also outlined.
This document provides a history of the electrocardiogram (EKG/ECG) and describes how it is used to evaluate cardiac electrical activity and identify various cardiac conditions. Some key points:
- The EKG was developed in the late 19th/early 20th century, with scientists like Matteucci, Marey, and Einthoven contributing to its invention and clinical use.
- An EKG records the heart's electrical activity through electrodes on the skin and can be used to detect arrhythmias, ischemia, infarction, and other conditions.
- It analyzes the P wave, QRS complex, ST segment, and T wave to evaluate conduction and identify abnormalities.
The document outlines a systematic 7+2 step approach for interpreting electrocardiograms (ECGs) that involves analyzing the rhythm, rate, conduction, axes, wave morphologies, segment changes, and comparing to previous ECGs to form a clinical conclusion. The 7 steps examine the rhythm, rate, conduction intervals, axes, P wave, QRS, and ST-T wave morphologies. The +2 steps involve comparing the ECG to previous tracings and formulating a concluding statement.
This document provides a 10 step process for interpreting ECGs:
1. Identify patient information and ensure proper calibration
2. Analyze rhythm, rate, axis
3. Examine PR interval and segments
4. Assess QRS morphology, duration, and amplitude
5. Evaluate ST segments and T waves
6. Measure QT interval
7. Interpret signs of ischemia, injury, or infarction
8. Consider additional conditions like electrolyte imbalances or cardiac abnormalities
9. Review dysrhythmia examples
10. Note any miscellaneous findings like pericarditis or right bundle branch block
The document discusses the electrocardiogram (ECG), providing definitions and discussing its uses, components, and interpretation. Some key points:
- ECG records and amplifies the heart's electrical signals to evaluate heart rate, rhythm, and detect conditions like ischemia, infarction, and conduction abnormalities.
- It has several waves that are analyzed including P, QRS, T, and ST segments. Intervals like PR and QT are also measured.
- Abnormalities in wave amplitude, duration, morphology can indicate conditions like hypertrophy, ischemia, infarction, and conduction blocks.
- A 12-lead ECG provides the most comprehensive evaluation of the heart's electrical activity.
- The document describes normal ECG values and intervals. It then discusses abnormalities seen in right and left atrial and ventricular enlargement, right and left bundle branch blocks, and myocardial infarction. Specific ECG patterns are provided for each condition. For example, right atrial enlargement shows tall, narrow P waves in certain leads, while left bundle branch block results in a wide QS complex in lead V1 and tall R wave without Q wave in lead V6. The document serves as a guide for interpreting ECG findings in various cardiopulmonary conditions.
A 61-year-old man with a history of hypertension and congestive heart failure presented to the emergency department with shortness of breath after eating breakfast. His ECG showed sinus tachycardia, a normal PR interval, left ventricular hypertrophy, and no left bundle branch block. He was diagnosed with worsening congestive heart failure causing pulmonary edema and improved with standard therapy.
This document provides an overview of electrocardiography (ECG) including:
- What an ECG measures and the cardiac cycle waveform
- How ECGs can identify various cardiac conditions like arrhythmias, ischemia, and chamber abnormalities
- The basics of cardiac impulse conduction and the components of a normal ECG waveform including the P wave, QRS complex, T wave, and segments
- How to determine heart rate using the 300/1500 rule or 10 second rule
- Factors that can affect the QRS axis and how it is determined using the quadrant or equiphasic approaches
- Types of bradyarrhythmias like sinus bradycardia, junctional rhythm
This document provides a summary of basics of electrocardiography (ECG/EKG). It discusses the history and development of ECG technology. It describes the components of a normal ECG waveform including the P, QRS, and T waves. It explains how to determine heart rate from an ECG and identify different arrhythmias based on the waveform. Key anatomical structures involved in heart's electrical conduction system are also outlined.
The document discusses the basics of electrocardiography (ECG), including the 12-lead ECG system and cardiac rhythms. It explains that a standard ECG uses 6 limb leads (I, II, III, aVR, aVL, aVF) and 6 precordial/chest leads (V1-V6). It describes Einthoven's triangle and law. It discusses normal sinus rhythm, cardiac intervals, axis determination, hypertrophy, ischemia, blocks, arrhythmias, and bundle branch blocks. Key points are made about rate, regularity, P waves, PR interval, and QRS duration for interpreting rhythms.
This document provides a summary of the basics of electrocardiography (ECG). It discusses the history and development of ECG technology. It describes the normal cardiac conduction system and the waves that make up a normal ECG, including the P, QRS, and T waves. It outlines the 12 standard ECG leads and how they are positioned on the body. It reviews criteria for interpreting common cardiac abnormalities based on ECG findings such as hypertrophy, infarction, and arrhythmias.
This document provides an overview of electrocardiography (ECG/EKG) including its history, components, and how to interpret common rhythms. Some key points:
- ECG records electrical activity of the heart and was invented in the late 19th century. It helps diagnose arrhythmias, ischemia, infarction and other cardiac conditions.
- The ECG tracing has components (P wave, PR interval, QRS complex, ST segment, T wave) that reflect different stages of the cardiac cycle.
- Common arrhythmias arise from problems in the sinus node, atria, AV node or ventricles. These include sinus bradycardia, sinus tachycardia, premature
The 11-step method provides a systematic approach to reading EKGs:
1. Gather data such as heart rate, intervals, and axis.
2. Diagnose rhythm, conduction blocks, enlargement, and infarction by applying specific criteria.
3. Potential diagnoses are identified through disturbances of rhythm, conduction, hypertrophy, and ischemia. The relationship between P waves and QRS complexes helps determine block types.
The 11-step method provides a systematic approach to reading EKGs:
1. Gather data such as heart rate, intervals, and axis.
2. Diagnose rhythm, conduction blocks, enlargement, and infarction by applying specific criteria.
3. Potential diagnoses are identified through disturbances of rhythm, conduction, hypertrophy, and ischemia. The four questions framework is used to characterize rhythms.
The document provides information about electrocardiograms (ECGs), including what an ECG is, the types of pathology that can be identified from ECGs, ECG paper specifications, heart anatomy and the normal ECG signal, ECG leads, determining heart rate from ECGs, common rhythms, P waves, the PR interval, the QRS complex, identifying left and right bundle branch block, identifying left and right ventricular hypertrophy, Q waves, the ST segment and T waves. Key details are provided about normal ECG measurements and the signs of various cardiac conditions.
1. Brown-Séquard syndrome was first described in 1850 based on observations of machete injuries in sugar cane farmers, with key features being ipsilateral motor paralysis and mixed sensory loss below the level of the spinal cord lesion.
2. Understanding the anatomy of ascending and descending spinal tracts is important for explaining the clinical features of Brown-Séquard syndrome and other spinal cord injuries.
3. Injuries can disrupt motor or sensory tracts differently, causing varying neurological deficits depending on whether the lesion involves upper or lower motor neurons.
The document discusses several inflammatory arthropathies known as spondylarthropathies. They are commonly associated with the HLA B27 gene and involve entheses, synovium, and the spine. Major types include ankylosing spondylitis, psoriatic arthropathy, reactive arthritis, and enteropathic arthritis. They often present with enthesitis, uveitis, and spondylitis and are treated with NSAIDs, DMARDs, anti-TNF drugs, or surgery depending on the specific condition and symptoms.
Lung cancer is classified into two main types - non-small cell lung carcinoma (NSCLC) and small cell lung carcinoma (SCLC). NSCLC makes up about 80% of cases and can be further divided into squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. SCLC accounts for 10-15% of lung cancers and grows more quickly. The main symptoms are cough, chest pain, and coughing up blood. Risk factors include smoking, asbestos exposure, and radiation exposure. Diagnosis involves tests such as sputum analysis, biopsies, CT scans, and PET scans to determine the cancer type and stage. Treatment options depend on the cancer type and stage but may include surgery, chemotherapy
Eczema herpeticum is a potentially life-threatening herpes infection that occurs when herpes simplex virus infects disrupted skin in patients with pre-existing skin conditions like eczema or atopic dermatitis. It presents with clusters of vesicles and punched-out erosions that spread and become hemorrhagic and crusted. Diagnosis involves identifying characteristic lesions along with fever and pain, and can be confirmed with tests like Tzanck smear, viral culture, or antibody testing. Aggressive treatment with IV acyclovir is required to prevent complications like herpes keratitis, which can lead to blindness. Early recognition and effective antiviral therapy are important given the potential severity of eczema her
The vagus nerve connects organs in the neck and below to the brainstem. It has both sensory and motor functions and helps control the heart rate, digestion, and other involuntary processes. Stimulation of the vagus nerve has been shown to reduce seizures, experimental pain, and inflammation, and may help treat conditions like epilepsy, obesity, and heart disease. Damage to the vagus nerve or its connections in the brainstem can impact swallowing, heart rate variability, and level of consciousness.
Poor water and sanitation are responsible for a huge global burden of disease, with contaminated water alone contributing to about 2.4 million preventable deaths per year, mainly in children. While progress has been made in increasing access to safe water and improved sanitation, current rates of progress will not meet the Millennium Development Goal targets. Water and sanitation remain a low priority on international development agendas despite their importance for health and achieving the MDGs. Coordinated efforts are still needed to address this critical issue.
This document discusses medical student electives in developing countries. It notes potential benefits like exposure to rare diseases and personal growth, but also flags ethical issues. Electives could exploit local health systems and raise false expectations. They may perpetuate neo-colonial practices by benefiting students and health systems in wealthy countries more than local populations. The document also examines how non-governmental organizations can undermine public health systems and calls for electives to minimize harm, respect local needs, and establish long-term exchange programs to provide mutual benefit.
This document provides an overview of global health by defining key terms, outlining major players and organizations, and summarizing the history and evolution of the field from 1945 to the present day. It describes how global health has shifted from a focus on infectious disease control to addressing social determinants of health and health issues that transcend national borders. Major milestones discussed include the founding of the UN and WHO, the Alma-Ata Declaration, structural adjustment policies, the Millennium Declaration and MDGs, debt relief campaigns, and the establishment of the Global Fund. The summary highlights the ongoing tension between disease-specific and comprehensive primary healthcare approaches.
The document discusses how international organizations like the WTO and treaties it has established like TRIPS and GATS impact healthcare. The WTO aims to liberalize trade and its dispute process enforces agreements. TRIPS established intellectual property standards that require drug patenting, raising prices. Some countries like Brazil and South Africa have issued compulsory licenses to produce cheaper generics, facing opposition from pharmaceutical companies but helping improve access to treatment.
Global health examines influences on health across borders, including issues like globalization, poverty, and human rights. It draws from multiple disciplines. Globalization refers to reducing barriers between countries, leading to increased trade, investment, and communication. This has effects like economic growth but also rising inequalities. Agreements like TRIPS have increased pharmaceutical patent protection globally, raising concerns about access to medicines, especially in developing countries. Networks of both commercial and civil society actors have been important in debates over balancing intellectual property with public health.
Migration of health care workers has both positive and negative effects on health. It reduces the availability of health services in source countries while increasing access in destination countries. This unequal distribution of health workers is driven by push factors like low pay and poor working conditions in source countries and pull factors like higher wages in destination countries. As a result, source countries experience worse health outcomes due to lack of health workers, while destination countries receive an indirect subsidy through the receipt and employment of trained medical professionals from poorer nations. Proposed policy responses aim to strengthen health systems in source countries, implement ethical recruitment practices, and foster partnerships between nations to promote more equitable health worker distribution.
Global institutions play major roles in health financing and policy. The key players discussed are the World Health Organization (WHO), World Bank, International Monetary Fund (IMF), and World Trade Organization (WTO). The WHO is the UN agency for health, working with 192 member states. The World Bank aims to reduce poverty through loans and policy advice to developing countries. The IMF promotes international monetary cooperation and provides temporary financial assistance. The WTO, formed in 1995, ensures trade flows freely through treaties and enforcement mechanisms, which some criticize can undermine public health systems.
Haemochromatosis is an autosomal recessive condition characterized by excessive iron accumulation in the body. It affects around 0.5% of Caucasians and usually presents in the 40s-50s with a triad of pigmentation, diabetes mellitus, and hepatomegaly. Diagnosis involves blood tests showing elevated serum iron, transferrin saturation over 50%, and elevated serum ferritin. Liver biopsy can confirm iron deposition and damage. Treatment aims to reduce iron stores through weekly venesection of 1 unit of blood for 6-12 months followed by maintenance venesection.
Ascites is an abnormal collection of fluid in the peritoneal cavity, commonly caused by portal hypertension due to cirrhosis. It results from sodium and water retention triggered by vasodilation and activation of the renin-angiotensin system, as well as increased hydrostatic pressure and transudation of fluid from the liver and spleen into the peritoneal cavity. Hypoalbuminemia due to decreased liver function also contributes by reducing plasma oncotic pressure. Spironolactone is used as treatment as it is an aldosterone antagonist. Management involves dietary sodium restriction, diuretics, stopping alcohol, monitoring for complications, and procedures such as paracentesis or shunts.
The liver has two lobes, separated by veins, and is divided into sections supplied by individual blood vessels. Blood flows through hepatic arteries and portal veins into sinusoids, where waste is filtered by Kupffer cells in the space of Disse before draining into hepatic veins. The liver performs many functions including synthesizing proteins, metabolizing carbohydrates and lipids, and detoxifying hormones and drugs. Liver function can be assessed through blood tests of enzymes and proteins.
Antidepressants such as SSRIs, TCAs, and MAOIs work by increasing levels of serotonin, norepinephrine, or both in the brain. SSRIs are generally first-line treatment and safer in overdose than TCAs, but TCAs may be better for severe depression. Both classes of drugs can cause side effects like dry mouth, nausea, and sexual dysfunction. Antidepressants may take 10-20 days to work and should be continued for at least 6 months after symptoms improve to prevent relapse. Combining certain antidepressants can be dangerous due to increased serotonin levels.
Gout is caused by deposition of uric acid crystals in the joints, which leads to acute inflammation. It typically presents as sudden severe pain, swelling and redness in one joint, most commonly the big toe. Diagnosis is made based on symptoms and identification of crystals in joint fluid under polarized microscopy. Treatment involves medications to reduce symptoms during acute attacks as well as long-term drugs like allopurinol or probenecid to lower uric acid levels and prevent future episodes. Without treatment, gout can progress to a chronic stage with multiple joint involvement and growth of tophi deposits in the tissues.
Review of orthopaedic services: Prepared for the Auditor General for Scotland...meducationdotnet
1. Orthopaedics is a large specialty that treats musculoskeletal conditions through surgery, medication, and rehabilitation. It accounts for a significant portion of NHS spending and activity in Scotland.
2. Waiting times for orthopaedic services have reduced in recent years through changes to service delivery and additional funded activity. However, further improvements to meet 18-week referral targets will be challenging to sustain.
3. There is variation in orthopaedic efficiency across Scotland that is not fully explained by resources or procedures. The report finds opportunities to use existing resources more efficiently through measures like increasing day surgery and reducing hospital length of stay.
This document discusses the use of muscle relaxants in anesthesia and the potential role of sugammadex as a reversal agent. It provides background on why muscle relaxants are used, types of muscle relaxants, and current problems with reversal agents. It then summarizes research on sugammadex, which appears to be a more effective reversal agent than anticholinesterases, allowing faster recovery from neuromuscular blockade. Sugammadex may allow safer use of muscle relaxants and replace agents like suxamethonium, but economic factors will also influence its adoption.
This document contains a series of slides related to ophthalmology. It tests the reader's knowledge on topics like visual acuity measurements, refractive errors, eye abnormalities, causes of vision loss, and eye examination techniques. The slides include images showing conditions like cataracts, glaucoma, retinal detachments, and more. Key details are provided about diagnoses, symptoms, investigations, and treatments.
1. A Guide on ECG Interpretation
Normal Appearances
Normal appearances in precordial leads
P waves: Upright in V4-V6 though can be biphasic (both positive an negative) in V1-V2
(negative component should be smaller if biphasic)
QRS complexes: V1 can show an rS pattern ,V6 shows a qR pattern. The size of the r wave
should increase progressively from V1 to V6
Normal appearances in limb leads
T waves: In the normal ECG, the T wave is always upright in leads I, II, V3-6, and always
inverted in lead aVR.
Normal Dimensions
• At least one R wave in the precordial leads must exceed 8 mm
• The tallest R wave in the precordial leads must not exceed 27 mm
• The deepest S wave in the precordial leads must not exceed 30 mm
• Precordial q waves must never have a depth greater than one quarter of the height of
the R wave which follows them.
• ST segments: Must not deviate above or below the isoelectric line by more than 1
mm. Normal ST segment elevation occurs in leads with large S waves (e.g. V1-3),
and the normal configuration is concave upward.
ECG: A Methodical Approach
Patient and ECG Details
Read the name, date and time on the top of the ECG. Make sure they all correlate with the
patient you are dealing with.
Heart Rate
(Number of QRS complexes in 30 squares) multiplied by 10.
Abnormalities in Heart Rate:
1. Tachycardia > 100bpm
Anaemia, anxiety, exercise, pain, increased temperature, sepsis, hypovolaemia, heart
failure, PE, pregnancy, thyrotoxicosis, beri beri (Thiamine (vitamin B1) deficiency),
CO2 retention, autonomic neuropathy, sympathomimetics (caffeine etc).
2. Bradycardia < 60bpm
Physical fitness, vasovagal attacks, sick sinus syndrome, acute MI (particularly
inferior), drugs (beta-blockers, digoxin), hypothyroidism, hypothermia, raised ICP,
cholectasis (flow of bile from liver blocked).
Heart Rhythm
Here we look at the rhythm strip. NSR is of regular pattern and has following features:
2. • The P wave is upright in leads I and II
• Each P wave is usually followed by a QRS complex
• The heart rate is 60-99 beats/min
Young, athletic people may display various other rhythms, particularly during sleep. Sinus
arrhythmia is the variation in the heart rate that occurs during inspiration and expiration.
There is “beat to beat” variation in the R-R interval, the rate increasing with inspiration. It is a
vagally mediated response to the increased volume of blood returning to the heart during
inspiration. The most common arrythmias are outlined below:
Supraventricular Arrhythmias Ventricular Arrhythmias
1. Premature atrial complexes. 1. Abnormal VT due to abnormal
tissues in ventricle generation:
• Regular
• 180-190bpm
• QRS prolonged (excitation
spread through abnormal
path in ventricle)
1. Atrial fibrillation due to disorganised
electrical signals:
• Irregularly irregular pattern
• 100-160bpm
• QRS normal
• Absent P waves
2. Ventricular fibrillation:
• Irregular rhythm
• 300bpm +
• QRS not recognisable
• Absent P wave
3. Atrial flutter:
• Regular
• Atrial rate 300bpm and
ventricles 110bpm
• P waves replaced by
(sawtooth like ) F (flutter)
waves
4. Paroxymal SV tachycardia:
tachycardia that begins and ends
suddenly. Type of PSVT is WPW
syndrome, due to accessory pathway
between atria and ventricles causing:
• Regular
• Short PR interval
• Slurred upstroke of QRS
3. (Delta wave)
(See diagram below)
More rhythms outlined at http://www.ambulancetechnicianstudy.co.uk/rhythms.html
Cardiac Axis
An accurate estimate of the axis can be achieved if all six limb leads are examined. The axis
is determined as follows:
1. Choose the limb lead closest to being equiphasic. The axis lies about 90° to the right
or left of this lead
2. With reference to the hexaxial diagram, inspect the QRS complexes in the leads
adjacent to the equiphasic lead. If the lead to the left side is positive, then the axis is
90° to the equiphasic lead towards the left. If the lead to the right side is positive, then
the axis is 90° to the equiphasic lead towards the right.
See notes for abnormalities
Conduction Abnormalities
1. PR interval: normal range 120 – 200 ms (3 – 5 small squares on ECG paper).
2. QRS duration: normal range up to 120 ms (3 small squares on ECG paper).
3. QT interval: normal range up to 440 ms (though varies with heart rate and may be
slightly longer in females)
The most common conduction abnormalities are outlined below:
Sinus node block is failure of the sinus node to depolarise or conduct to the atria. Seen
during anaesthesia (due to vagal reflexes); during digoxin, quinidine or phenylephrine
therapy; MI or infarction.
1. An absent P wave and often an absent QRS complex are seen.
2. Manifested by a gradual shortening of the P-P intervals until a pause occurs (i.e. the
blocked sinus impulse fails to reach the atria).
Sick sinus syndrome is a term used for a number of disorders that involve dysfunction of
sinus node.
Atrioventricular (AV) blocks occur at a number of points and involve lack of conduction
from atria to ventricles
1st degree AV block
This may be seen in healthy individuals. ECG features include:
1. Prolonged PR interval - i.e. PR interval >0.20 s.
2. All P waves are conducted to the ventricles.
4. 2nd degree AV block
Here, all of the atrial impulses are not conducted to the ventricles. Divided into two types
with corresponding ECG features:
1. Mobitz Type I or Wenckebach phenomenon: the PR interval lengthens gradually until
a P wave which fails to conduct to the ventricles occurs. The block in this case is
almost always located in the AV node and may be caused by right coronary artery
occlusion causing inferior wall infarctions.
2. Mobitz Type II: Involves an intermittent block in conduction of the P wave into the
ventricles, but the PR interval in surrounding beats is unaltered. Type II AV block is
almost always located in the bundle branches and can result from anterior wall
infarctions. These blocks are generally permanent, with a greater risk of progressing
to complete heart block.
3rd degree /complete heart block
This involves total disruption of conduction between the atria and ventricles. In this situation,
life is maintained by a spontaneous escape rhythm. ECG features include:
1. Slow rate
2. QRS prolonged with unrelated P wave
Intraventricular blocks involve altered conduction of the cardiac impulse within the
ventricles.
Right bundle branch block (RBBB)
This involves total failure of conduction in the right bundle branch proximally. It can be seen
in a variety of disorders, including severe ischaemic heart disease, hypertension, pulmonary
embolism, cardiomyopathy, myocarditis, pericarditis, rheumatic heart disease, Chagas disease
and congenitally in association with atrial septal defect and Fallot’s tetralogy. ECG features
include:
1. "Complete" RBBB has a QRS duration >0.12secs
2. M pattern (rSR) (form of QRS see page) in V1
3. Dominant R wave in V1
4. W (QS) pattern in V6
5. Inverted T waves V1-V3
6. Deep S wave in V6
Left bundle branch block (LBBB)
This involves total failure of conduction in the left bundle branch system. LBBB always
indicates significant cardiac disease. It is seen most commonly in severe ischaemic heart
5. disease (seen in angina, acute coronary syndromes, cardiac failure etc), hypertension, aortic
stenosis and fibrous degeneration of the conducting tissue. It may also occur in congestive
and hypertrophic cardiomyopathy, myocarditis, acute rheumatic fever, syphilis, cardiac
tumours, post-cardiac surgery and in congenital heart disease. ECG:
1. Total QRS duration >0.12 s
2. M pattern (rsR) V5 and W pattern V1.
3. Inverted T waves in I, V5-V5.
To differentiate between the two we have 16 William Morrows:
Bifascicular block is the combination of RBBB and LB fasicular block (hemiblock) and
manifests as an axis deviation
Trifasicular bundle branch block is combination of bifasicular block and 1st
degree heart block
Abnormalities of the P Wave
P wave height = 2.5 mm
P wave duration = 0.12 s
This waveform is best seen in leads II and V1 and its abnormalities include:
1. Peaked P wave (P Pulmonale):
Demonstrated in anything that causes the right atrium to become hypertrophied
(including tricuspid valve stenosis and pulmonary hypertension).
2. Notched (bifid) and broad P wave (P Mitrale):
Demonstrated in left atrial hypertrophy.
Abnormalities of QRS Complex
1. Right Ventricular Hypertrophy
Dominant R wave in V1 (>25mm).
This is usually accompanied by recipricol deep S wave in V6, right axis deviation,
peaked P wave (with right atrial hypertrophy) and in severe cases inverted T waves in
leads V1- V4 (ventricular hypertrophy).
6. A Special Case: Pulmonary Embolism
As pulmonary embolism can cause pulmonary hypertension and thus an increased afterload
on the right ventricle, the ECG may show features of right ventricular hypertrophy.
2. Left Ventricular Hypertrophy
Dominant R wave in V6 (>25mm).
Usually accompanied by recipricol deep S wave in lead V1, left axis deviation, P
mitrale possible though not as common (left atrial hypertrophy due to increased
afterload), and in severe cases inverted T waves in V5-V6.
Q Wave Abnormalities
Q waves greater than one square in width and at least 2mm deep indicate a myocardial
infarction and the leads in which these waves appear give an indication of the part of the heart
that has been damaged. The waves may appear as QR or QS.
1. Anterior surface of heart: V1-V4 (Septal V2-V3). Caused by occlusion of left
descending coronary artery.
2. Anterolateral: V1-V6, aVL. Most commonly caused by circumflex CA occlusions.
3. Lateral surface of the heart: I, aVL. Caused by occlusion of left circumflex coronary
artery.
4. Inferior surface: II, III and aVF. Commonly caused by right coronary artery.
5. Posterior surface: Not common but can produce a true posterior MI with occlusion of
right CA. When it does occur the result is a dominant R wave in approximately V1
along with a deep S wave in V1.
The presence of a Q wave gives no indication of the age of an infarction but once developed it
is usually permanent.
Abnormalities in ST Segment
7. 1. Elevation of ST Segment is an indication of acute myocardial injury, usually due to
recent MI or pericarditis:
In myocardial infarction with ST segment elevation (STEMI), the leads in which
elevation occurs indicates which part of the heart has been damaged as above.
In addition to the primary changes that occur in the ECG leads facing the infracted
myocardium, "reciprocal changes" may occur in leads opposite to the site of
infarction. The changes are just the inverse of the primary changes.
Thus, if you have a left lateral MI (V5, V6, I, aVL), you would expect changes in
aVR, and sometimes V1 and V2 (depending on how lateral, lead placement, etc). A
right sided infarct (rV4, aVR) would show reciprocal changes to the left lateral leads.
Inferior events would show reciprocal changes in the anterior(septal) leads (V1-V4).
Here we see inferior MI with segment elevation in leads III and VF and V6
(suggesting some lateral wall involvement). There is reciprocal ST segment
depression in leads V1-V3.
Pericarditis is usually not a localised event, however, and causes ST elevation in most
leads.
2. Horizontal depression of the ST Segment is usually a sign of ischemia.
The ECG at rest is usually normal (unless severe angina) however when exerted and
ischemia thus occurs, this abnormality appears, particularly with angina (pain due to
ischemia). Commonly seen with T wave inversion (also indicator of ischemia).
3. Downsloping of ST Segment.
Caused by treatment with digoxin.
Abnormalities of the T Wave
1. Inversion of T wave occurs in the following circumstances:
• Normality: Commonly inverted in VR and V1, V2 in young people, and V3
in some black people.
• Ischemia
• Ventricular hypertrophy.
• Bundle branch block due to abnormal path of repolarization.
• Administration of digoxin.
• No significance.
2. T Wave Abnormalities associated with Electrolyte Status:
• Low potassium level causes T wave flattening and the appearance of a hump
on the ned of the T wave called a “U” wave.
8. • A high potassium level or abnormal magnesium levels causes peaked T
waves, commonly with the disappearance of the ST segment and prolonged
QRS duration.
• Low plasma calcium level causes prolongation of QT interval and high
plasma level shortens it.
3. Other T wave Abnormalities will be seen later (MI etc)
Evolution of A Standard MI
Usual ECG evolution of a STEMI; not all of the following patterns may be seen; the time
from onset of MI to the final pattern is quite variable and related to the size of MI, the rapidity
of reperfusion (if any), and the location of the MI.
1. Normal ECG prior to MI
2. Within hours of transmural infarction we see hyperacute T wave changes - increased
T wave amplitude and width; with ST elevation or new LBBB.
3. Over hours to days we see the development of pathologic Q waves with T wave
inversion (necrosis) (Pathologic Q waves are usually defined as duration >0.04 s or
>25% of R-wave amplitude)
4. T waves begin to flatten and eventually become upright T waves (fibrosis) after
months.