This document provides information about cardiac cells, the cardiac conduction system, components of the ECG, ECG paper format, normal ECG intervals, dysrhythmias, and heart blocks. It describes the two main types of cardiac cells - myocardial and pacemaker cells. It explains the cardiac conduction system including the sinoatrial node. It outlines the key components of the ECG including the P wave, PR interval, QRS complex, ST segment, and T wave. It provides details on normal ECG intervals and how to analyze rhythms and determine heart rate. It discusses various dysrhythmias including sinus tachycardia, sinus bradycardia, premature atrial contractions, atrial flutter, atrial fib

1. ECG
PATEL.YASH.GIRISHBHAI (KAPC)

2. TYOES IF CARDIAC CELLS
 MAYOCARDIAL CELLS
Working or mechanical cells
Contain contractile filaments
 PACEMAKER CAELLS
-specialized cell of the electrical conduction system
- Responsible for the spontaneous generation and conduction
of electrical impulses

3. Cardiac
Conduction

4. From Basic ECG Module - AACN
SA Node

5. Cardiac Cycle & the ECG
Isometric line
ST Segment

6. Lead Placement –
6 lead system
From Basic ECG Module - AACN

7. ECG Paper
 ECG paper is graph paper made
up of small and larger, heavy-
lined squares
 Smallest squares are 1 mm wide and 1 mm high
 5 small squares between the heavier black lines
 25 small squares within each large square

8. What Does the ECG Measure?
V
O
L
T
A
G
E
T I M E

9. PR INTERVAL
 Normal P wave – small, round,
Upright
PR INTERVAL:
Begins with the onset of the P
Wave and ends with the inset of QRS
Complex normally measures 0.12
To 0.20 seconds
5 small boxes

10. QRS COMPLEX
 A QRS complex normally
Follows each P wave
Consists of Q wave, R wave,
And S wave
Represents the spread of electrical
Impulse through the ventricles
normal – 0.04- 0.12 seconds

11. ST SEGMENT
 ST – segment
Begins with the end of the QRS complex and ends with the of
the onset of the T wave and is on the same line as the PR
interval
ST segment depression of more than 1 mm is suggestive of
myocardial ischemia
ST segment elevation of more then 1 mm is suggestive of
myocardial injury or pericarditis.

12. T WAVE
 T WAVE :
Represent ventricular repolarization
The beginning of the T wave the slope of the ST segment
appears to become abruptly or gradually steeper
The T wave ends when it returns to the baseline

13. ST Segment
 The ST segment is considered:
 “Elevated” if the segment deviates above the baseline of the
PR segment
 “Depressed” if the segment deviates below it

14. STEPS OF RHYTHM ANLAYSIS
1. What is ate ?
Ventricular
Atrial
2 is the rhythm regular or irregular?
Is there 1 P wave before each QRS?
Is the PR interval (.12- .20)?
Is the QRS narrow or wide(.04- .10)

15. Determining the Rate
 1500 ÷ No of small boxes within an RR interval (regular rhythms)
 300 ÷ No of Large boxes within an RR interval (regular rhythms)
 10 x No of R complexes in 6 seconds(30 large box)
 10 x No of R complexes in 6 seconds

16. Rhythm: Regular / Irregular
 Distance between the ‘R’ waves

17. Normal Sinus Rhythm
 Ventricular rate: 60-100; Regular rhythm
 Atrial: Same as ventricular
 P consistent shape – always positive
 P-R interval: 0.12-0.20
 QRS complex: 0.04-0.10
 1 P wave for every QRS

18. DYSRHYTHMIAS
 Disorders of electrical impulse:
Formation
Conduction
 Named by
Site of origin of impulse
Mechanism of formation or conduction involved

19. DYSRTHMIAS
 Site of origin
SA node
Bradycardia, tachycardia
AYRIAL tissue
Flutter, fibrillation
AV node
blocks

20. SINUS TACHYCARDIA
 ETIOLOGY
↑ CNS response : anxiety; pain; fever; anemia
INTERVANTION
Identify cause, select best treatment
Goal : ↓ HR to normal levels
β-blockers, ACE Inhibitors

21. Sinus Tachycardia
 Ventricular rate: > 100 (up to180);
Regular rhythm
 Atrial: Same as ventricular
 P consistent shape
 P wave for every QRS
 QRS complex: Normal
Sinus Tachycardia

22. Sinus Bradycardia
 Ventricular rate:< 60; regular rhythm
 Atrial: same as ventricular
 P consistent shape
 P wave for every QRS
 QRS complex: Normal

23. Sinus Bradycardia
 Etiology
 PNS dominant; Excessive vagal (Valsalva) stimulation to the heart (↓ SA node
discharge = ↓ HR, ↓ conduction)
 Interventions
 Atropine = Tx of choice
 Pacemaker placement

24. PAC (premature atraial
contractions):
Irregular P-R rhythms
 Premature, irregular P waves (sometimes “lost” in the T
Wave.

25. Premature Atrial Contractions:
 Triggered by: Alcohol, nicotine, anxiety, fatigue, fever, and
infections
 Clinical Manifestations: Palpitations or “skipped beats”

26. Flutter and Fibrillation

27. Atrial Flutter
 Etiology
 AV node selectively blocks # impulses that reach
ventricles (protective mechanism)
 Rheumatic Heart disease, CHF, AV valve disease, post
cardiac surgery
 Clinical manifestations dependent upon ventricular
response

28. Atrial Flutter
 Ventricular rate: Variable,
 Atrial: 250-300/minute
 P shape – “sawtooth” formation
 P-R interval: Absent
 No P wave
 QRS complex:
Normal

29. Atrial Fibrillation
 Etiology
 Most common dysrhythmia in US
 Aging, MI, MS, Cardiomyopathy
 Multiple, rapid impulses many atrial foci;
Atrial depolarization disorganized

30. Atrial Fibrillation
 Commonly seen after cardiac
surgery (transient)
 Can be intermittent or chronic
 Symptoms:
 SOB
 Fatigue
 Weakness,
 Distended neck veins
 Anxiety
 Palpitations
 Chest discomfort
 Irregular pulse

31. Atrial Fibrillation
 Ventricular rate: < 100 (controlled)
 Atrial: Unable to determine (>350)
 No P waves (fibrillatory waves)
 P-R interval: Absent
 QRS complex: Normal

32. Atrial Fibrillation

33. Premature Ventricular Contractions
 Etiology
 Early ventricular complexes, followed by pause
 Ventricular contraction originating in an ectopic
focus outside ventricles
 Aging, MI, Caffeine, ↓ K+

34. Premature Ventricular Contractions
 No P wave
 QRS wide and unusual
 ST segment often slops in the opposite direction
PVC

35. Ventricular Tachycardia
 Etiology
 Repetitive firing of an irritated ventricular ectopic
focus
 Intermittent
 Sustained: > 15-30 sec

36. Ventricular Tachycardia (V Tach)
 Unable to determine rhythm
 No P waves present
 QRS complex > 0.10 sec

37. Ventricular Fibrillation
 Cardiac arrest
 Etiology
 Ventricles quiver, consume lots of O2, No cardiac output, no perfusion
 AMI, ↓ K+, ↓ Mg+
 Rapidly fatal (3-5 min)
 No proper QRS Complex is noted

38. Ventricular Fibrillation
 Assessment
 LOC, Absence of Pulse
 Apnea
 Seizures
 Development of respiratory & metabolic acidosis
 Treatment
 CPR (ACLS)
 Defibrillation

39. Ventricular Fibrillation (V Fib)
Coarse
Fine

40. Heart Blocks
 Occur when there is a delay in the conduction of the impulse
through the AV node
 PR is > 0.20 seconds
 SA node function is normal

41. Heart Block Overview
 1st degree –
 PR interval > 0.20 seconds
 All impulses reach the ventricles
 2nd degree – (2 types)
 Mobitz I – each impulses takes longer to conduct
until 1 is blocked and a QRS complex is dropped and
a pause occurs; then cycle repeats
 Mobitz II – None conduction to ventricles.2-4 p
waves between QRS.
 3rd degree –
 None of the atrial impulses reach the ventricles
 Activity of the atria and ventricles is ‘divorced’
 Results in inadequate cardiac output
 Requires pacemaker

42. 2nd degree Type 1
1st degree

43. 3rd degree
2nd degree Type II

44. Pacemakers