Download to read offline
![ECG & Heart block [doctors online]](https://cdn.slidesharecdn.com/ss_thumbnails/ecgheartblockdoctorsonline-131111054313-phpapp01-thumbnail.jpg?width=640&height=640&fit=bounds)
![Understanding Parkinson’s Disease: Causes, Symptoms, and Treatment [2025]](https://cdn.slidesharecdn.com/ss_thumbnails/understandingparkinson-251208102525-80ba3223-thumbnail.jpg?width=640&height=640&fit=bounds)
EKG POWERPOINT NC emergency care in the streets
- 1.
- 2. Topics • Electrocardiographic Monitoring •Dysrhythmias
- 3. Cardiac Physiology • CardiacConductive System • Properties • Excitability • Conductivity • Automaticity • Contractility
- 4.
- 5. Conduction System • Eachcomponent of the conductive system has its own intrinsic rate of self- excitation. • SA node = 60–100 beats per minute • AV node = 40–60 beats per minute • Purkinje system = 15–40 beats per minute
- 6.
- 7. Electrocardiographic Monitoring • Electrocardiogram (ECG)is a graphic record of the heart’s electrical activity. • Tells you nothing about the heart’s pumping ability, which you must evaluate by pulse and blood pressure. • The body acts as a giant conductor of electricity. • The heart is its largest generator • Electrodes on the skin can detect the total electrical activity within the heart.
- 8. Electrocardiographic Monitoring • Electrical Impulses •Positive impulses • Deflect upward • Negative impulses • Deflect downward • The isoelectric line • Absence of deflection • Artifact
- 9. The Electrocardiogram ECGLeads Bipolar (Limb) ▪ Einthoven’s Triangle ▪ Leads I, II, III ▪ Provide only one view of the heart Augmented (Unipolar) ▪ aVR, aVL, aVF Precordial ▪ V1 – V6 ▪ Measure electrical cardiac activity on a horizontal axis ▪ Help in viewing the left ventricle and septum
- 10. The Electrocardiogram • RoutineMonitoring • Routine ECG monitoring generally uses only one lead • Most common monitoring leads are either lead II or the modified chest lead 1 (MCL1) • Einthoven’s triangle offers a basis for placing the leads • Place the electrodes on the chest wall • Lead placement
- 11. Single Lead Monitoring •Information from a single lead shows: • Rate • Regularity • Time to conduct an impulse • Single lead cannot show: • Presence of an infarct • Axis deviation or chamber enlargement • Right-to-left differences in conduction • Quality or presence of pumping action
- 12. The Electrocardiogram • ECGPaper • Speed • A standard speed of 25 mm/sec • Amplitude and Deflection • Should deflect two large boxes when 1 mV is present • Calibration
- 13. The Electrocardiogram • Relationshipof the ECG to Electrical Events in the Heart • ECG Components • P Wave • QRS Complex • T Wave • U Wave
- 14.
- 15.
- 16.
- 17.
- 18.
- 19.
- 20.
- 21. The Electrocardiogram • TimeIntervals • PR Interval (PRI) or PQ Interval (PQI) • 0.12–0.20 seconds • QRS Interval • 0.08–0.12 seconds • ST Segment • QT Interval • 0.33–0.42 seconds
- 22. The Electrocardiogram RefractoryPeriods The all-or-none nature of myocardial depolarization results in an interval when the heart cannot be restimulated Absolute ▪ Cannot accept stimulus Relative ▪ If stimulus is strong enough, will cause depolarization
- 23. The Electrocardiogram • STSegment Changes • The ST segment is usually an isoelectric line • Ischemia causes deflections • Infarctions usually follow this sequence: • Ischemia • ST segment depression or an inverted T wave • Injury • Elevates the ST segment • Necrosis • Significant Q wave presents
- 24. The Electrocardiogram • Interpretationof Rhythm Strips • Basic Criteria • Always be consistent and analytical • Memorize the rules for each dysrhythmia • Analyze a given rhythm strip according to a specific format • Compare your analysis to the rules for each dysrhythmia • Identify the dysrhythmia by its similarity to established rules
- 25. The Electrocardiogram • Five-StepProcedure • Analyze the rate • Analyze the rhythm • Analyze the P waves • Analyze the PR interval • Analyze the QRS complex
- 26. The Electrocardiogram • AnalyzingRate • Six-Second Method • Heart Rate Calculator Rulers • RR Interval • Triplicate Method
- 27. The Electrocardiogram • AnalyzingRate • Six-Second Method
- 28. The Electrocardiogram • AnalyzingRate • RR Interval • Count the number of large boxes from R-R, and divide number of boxes into 300
- 29. The Electrocardiogram • AnalyzingRate • Triplicate Method • Count the large boxes from R to R • 300, 150, 100, 75, 60, 50
- 30. The Electrocardiogram • AnalyzingRhythm • Regular • Occasionally Irregular • Regularly Irregular • Irregularly Irregular
- 31. The Electrocardiogram • AnalyzingP Waves • Are P waves present? • Are the P waves regular? • Is there one P wave for each QRS complex? • Are the P waves upright or inverted? • Do all the P waves look alike? • Analyzing the PR Interval • Normal PR interval is 0.12–0.20 sec • Analyzing the QRS Complex • Do all the QRS complexes look alike? • What is the QRS duration? • Usually 0.04–0.12 sec
- 32.
- 33.
- 34.
- 35.
- 36.
- 37.
- 38. Cardiac Rhythms • NormalSinus Rhythm • Rate • 60–100 • Rhythm • Regular • P waves • Normal, upright, only before each QRS complex • PR Interval • 0.12–0.20 seconds • QRS Complex • Normal, duration of <0.12 seconds
- 39.
- 40.
- 41. Dysrhythmias • Dysrhythmia • Anydeviation from the heart’s normal electrical rhythm
- 42. Causes of Dysrhythmias •Myocardial Ischemia, Necrosis, or Infarction • Autonomic Nervous System Imbalance • Distention of the Chambers of the Heart • Blood Gas Abnormalities • Electrolyte Imbalances
- 43. Causes of Dysrhythmias •Trauma to the Myocardium • Drug Effects and Drug Toxicity • Electrocution • Hypothermia • CNS Damage • Idiopathic Events • Normal Occurrences
- 44. Dysrhythmias • Mechanism ofImpulse Formation • Ectopic Foci • Result of enhanced automaticity • Cells other than the pacemaker cells automatically depolarize • PVC’s, PAC’s, and PJC’s • Reentry • Ischemia or another disease process alters two branches of a conduction pathway • Can result in rapid rhythms such as paroxysmal supraventricular tachycardia or atrial fibrillation
- 45. Dysrhythmias • Classification ofDysrhythmias • Nature of Origin • Magnitude • Severity • Site of Origin
- 46. Dysrhythmias • Classification bySite of Origin • Originating in the SA Node • Originating in the Atria • Originating within the AV Junction (AV Blocks) • Originating in the AV Junction • Originating in the Ventricles • Resulting from Disorders of Conduction
- 47. Dysrhythmias Originating in theSA Node • Sinus Bradycardia • Sinus Tachycardia
- 48. Dysrhythmias Originating in theSA Node Normal QRS Normal PRI Upright and normal P Waves SA node Pacemaker Site Regular Rhythm Less than 60 Rate Sinus Bradycardia Rules of Interpretation
- 49. Normal QRS Normal PRI Upright and normal PWaves SA node Pacemaker Site Regular Rhythm Greater than 100 Rate Sinus Tachycardia Rules of Interpretation Dysrhythmias Originating in the SA Node
- 50.