1. Bundle Branch Blocks and Chamber Enlargement All EKGs in this presentation have been borrowed from: The Alan E. Lindsay ECG Learning Center ; http://medstat.med.utah.edu/kw/ecg/http://medstat.med.utah.edu/kw/ecg/ http://hastaneciyiz.blogspot.com

2. Outline 1. Left Bundle Branch Block 2. Right Bundle Branch Block 3. Left Atrial Enlargement 4. Right Atrial Enlargement 5. Left Ventricular Enlargement 6. Right Ventricular Enlargement 7. Examples

3. Left Bundle Branch Block Criteria QRS duration ≥ 120ms Broad R wave in I and V 6 Prominent QS wave in V 1 Absence of q waves (including physiologic q waves) in I and V 6

4. Left Bundle Branch Block

5. Right Bundle Branch Block Criteria QRS duration ≥ 110ms rSR’ pattern or notched R wave in V 1 Wide S wave in I and V 6

6. Right Bundle Branch Block

7. Conduction Blocks and Secondary Repolarization Abnormalities LBBBRBBB

8. Left Atrial Enlargement Criteria P wave duration in II ≥120ms or Negative component of biphasic P wave in V 1 ≥ 1 “small box” in area

9. Right Atrial Enlargement Criteria P wave height in II ≥ 2.4mm or Positive component of biphasic P wave in V 1 ≥ 1 “small box” in area

10. Left Ventricular Hypertrophy Many sets of criteria for diagnosing LVH have been proposed: SensitivitySpecificity The sum of the S wave in V 1 and the R wave in either V 5 or V 6 > 35 mm 43%95% Sum of the largest precordial R wave and the largest precordial S wave > 45 mm 45%93% Romhilt-Estes Point System50-54%95-97%

11. Romhilt-Estes Point System for LVH CriterionPoints Amplitude (any of the following: Largest R or S wave in any limb lead ≥ 20mm S in V 1 or V 2 ≥ 30mm R in V 5 or V 6 ≥ 30mm 3 ST depressions or T wave inversions in lateral precordial leads, I, and/or aVL 3 Left atrial enlargement3 Left axis deviation2 QRS duration ≥ 90 ms1 Intrinsicoid deflection in V 5 or V 6 ≥ 50 ms1 4 points  Probable LVH5 points  Definite LVH

12. Left Ventricular Hypertrophy

13. Right Ventricular Hypertrophy Right axis deviation Right atrial enlargement Downsloping ST depressions in V 1 -V 3 (a.k.a. RV strain pattern) Tall R wave in V 1 Although there is no widely accepted criteria for detecting the presence of RVH, any combination of the following EKG features is suggestive of its presence:

14. Right Ventricular Hypertrophy

15. Examples

16. Left Ventricular Hypertrophy

17. Right Bundle Branch Block

18. Right Atrial Enlargement

19. Left Bundle Branch Block

20. Left Atrial Enlargement

21. Right Ventricular Hypertrophy

22. Left Ventricular Hypertrophy (with frequent PVCs)