This document discusses various abnormalities seen on electrocardiograms related to enlargement of the heart's chambers and thickening of the ventricular walls. It describes how right and left atrial enlargement manifest as changes to the P wave, including tall, wide P waves in specific leads. Right and left ventricular hypertrophy are described by their characteristic patterns in the right and left chest leads, including tall R waves and deep S waves. Common causes of each type of cardiac abnormality are provided.

1. ATRIAL AND VENTRICULAR
ENLARGEMENT

2. CARDIAC ENLARGEMENT
1. DILATION
a. STRETCHED
b. E.G. CONGESTIVE HEART FAILURE
2. HYPERTROPHY
a. INCREASE SIZE OF HEART MUSCLE FIBERS
b. E.G. AORTIC STENOSIS

3. RIGHT ATRIAL ABNORMALITY
• OVERLOAD OF THE RIGHT ATRIA
• DILATION
• HYPERTROPHY
• ALSO KNOWN AS P PULMONALE
• HOW WOULD THIS CHANGE THE P WAVE?

4. RIGHT ATRIAL ABNORMALITY
• NORMAL P WAVE IS LESS THAN 2.5 MM TALL AND 0.10 SECONDS WIDE.
• WITH RIGHT ATRIAL HYPERTROPHY, P WAVES ARE TYPICALLY TALLER
THAN 2.5 MM BUT NOT WIDER THAN 0.10SEC.

5. RIGHT ATRIAL ABNORMALITY
CRITERIA
• TALL P WAVES IN LEAD II
• (OR III, AVF AND SOMETIMES V1)

6. RIGHT ATRIAL ABNORMALITY
• CAUSES:
• PULMONARY DISEASE
• CONGENITAL HEART DISEASE

7. LEFT ATRIAL ABNORMALITY
•ALSO KNOWN AS P MITRALE
•LEFT ATRIA NORMALLY DEPOLARIZES AFTER THE RIGHT
ATRIA.
•HOW WOULD THIS AFFECT THE P WAVE?
•WIDER; LEFT ATRIAL ENLARGEMENT SHOULD PROLONG THE
P WAVE > 0.10 SEC.

8. LEFT ATRIAL ABNORMALITY
• II: WIDE P WAVE
•V1: NEGATIVE P WAVE IS “1 BOX WIDE, 1 BOX DEEP”

9. ATRIAL ENLARGEMENT

10. LEFT ATRIAL ABNORMALITY
• LEAD II (AND I) SHOW
WIDE P WAVES
• (SECOND HUMP DUE TO
DELAYED
DEPOLARIZATION OF THE
LEFT ATRIUM)
• (P MITRALE: MITRAL
VALVE DISEASE)
• V1 MAY SHOW A BI-
PHASIC P WAVE
• 1 BOX WIDE, 1 BOX DEEP
• (BIPHASIC SINCE RIGHT
ATRIA IS ANTERIOR TO
THE LEFT ATRIA)

11. LEFT ATRIAL ABNORMALITY
• CAUSES:
• VALVE DISEASE (MITRAL AND AORTIC)
• HYPERTENSIVE HEART DISEASE
• CARDIOMYOPATHIES
• CORONARY ARTERY DISEASE

12. VENTRICULAR HYPERTROPHY

13. Frontal Plane
Transverse
Plane
12 LEADS

14. NORMAL QRS

15. RIGHT VENTRICULAR HYPERTROPHY
• CONSIDER RIGHT VENTRICULAR HYPERTROPHY AND V1
• HOW WOULD V1 BE DIFFERENT?
Normal Hypertrophy

16. RIGHT VENTRICULAR HYPERTROPHY

17. RIGHT VENTRICULAR HYPERTROPHY
CRITERIA
1.IN V1, R WAVE IS GREATER THAN THE S WAVE - OR - R
IN V1 GREATER THAN 7 MM
1. RIGHT AXIS DEVIATION
2. IN V1, T WAVE INVERSION (REASON UNKNOWN)
3. S WAVES IN V5 AND V6

18. RIGHT VENTRICULAR HYPERTROPHY
• CAUSES OF RVH
• PULMONARY DISEASE
• CONGENITAL HEART DISEASE
• (EMPHYSEMA MAY MASK SIGNS OF RVH)
• POSTERIOR WALL MI MAY ALSO SHOW TALL R WAVES IN V1

19. Fig 6.8
R wave and T
wave in V1?
What about the
axis?

20. Fig 6.9
R wave in V1.
P waves in II, III, & V1
T wave inversion
PR interval

21. LEFT VENTRICULAR HYPERTROPHY
• WITH LVH, THE ELECTRICAL BALANCE IS TIPPED EVEN FURTHER TO THE
LEFT.
• TALL R WAVES IN THE LEFT CHEST LEADS
• PREDOMINATE S WAVES IN THE RIGHT CHEST LEADS

22. LEFT VENTRICULAR HYPERTROPHY

23. LEFT VENTRICULAR
HYPERTROPHY CRITERIA
•SOKOLOW-LYON VOLTAGE CRITERIA
•IF S WAVE IN V1 + R WAVE IN V5 OR V6 ≥
35 MM (≥ 50 FOR UNDER 35 YRS OF
AGE)
•R WAVE > 11 MM IN AVL OR I...
•ALSO
•LVH IS MORE LIKELY WITH A “STRAIN PATTERN”
OR ST SEGMENT CHANGES
•LEFT AXIS DEVIATION
•LEFT ATRIAL ABNORMALITY

24. LEFT VENTRICULAR HYPERTROPHY
• CAUSES:
• HYPERTENSION
• AORTIC STENOSIS
• NOT ALWAYS PATHOLOGICAL
• RISKS OF LVH
• CONGESTIVE HEART FAILURE
• ARRHYTHMIAS

25. LEFT VENTRICULAR HYPERTROPHY
• HIGH VOLTAGE CAN BE SEEN IN NORMAL PEOPLE, ESPECIALLY ATHLETES
• WITH HYPERTROPHY IN BOTH VENTRICLES, THE ECG WILL SHOW MORE
EVIDENCE OF LVH

26. ST STRAIN PATTERNS

27. LVH with ST strain pattern and LAE Fig 6.10

28. Fig 6.11
LVH (in 20 yr old) without ST strain or LAE

29. RVH

30. Left atrial enlargement

31. Left ventricular hypertrophy (S wave V2 plus R wave
of V5 greater than 35mm) and left atrial enlargement
(II and V1).

32. LVH

33. Right atrial enlargement

34. LVH

35. RVH

36. Tall R waves in V4 and V5 with down sloping ST segment depression and T wave inversion are
suggestive of left ventricular hypertrophy (LVH) with strain pattern. LVH with strain pattern usually
occurs in pressure overload of the left ventricle as in systemic hypertension or aortic stenosis.
Similar pattern may also occur in long standing severe aortic regurgitation, though the usual pattern
in aortic regurgitation is left ventricular volume overload.
Negative P waves in lead V1 is indicative of left atrial overload. Shallow T wave inversions are seen
in inferior leads. Two supra ventricular ectopic beats are also seen in the rhythm strip. They are
characterized by their premature nature, a P wave of different morphology preceding the QRS (in this
case merging with the T wave of the previous beat), narrow QRS complex and an incomplete
compensatory pause.

37. Right atrial overload (P pulmonale) and right ventricular hypertrophy. Right atrial overload (enlargement) is
manifest as tall sharp P waves in lead II and V1. The cut off values are P wave amplitude more than 0.25 mV in lead II
and 0.1 mV or more in V1. Dominant R waves in V1 and deep S waves in V6 indicate right ventricular hypertrophy (RVH).
Sokolow-Lyon for RVH criteria mentions that R wave in V1 + S wave in V5/V6 should be 1.1 mV or more. There is also a
clockwise rotation in the QRS pattern between V1 to V6. QRS axis is around +120 degrees (aVR biphasic and lead III
showing tallest QRS complex). Right axis deviation is also due to right ventricular hypertrophy. T wave inversion in inferior
leads and V1 could be due to right ventricular hypertrophy itself. RVH in this case is type A with dominant R in V1 and
deep S in V6. This type is seen in pulmonary stenosis. Type B RVH shows dominant R waves in V1 without deep S in V6.
Deep S in V6 without dominant R in V1 seen in chronic obstructive lung disease with cor-pulmonale is called type C RVH.
(Strictly speaking the types are classified depending upon vector cardiographic features and not based on scalar ECG)