If there is a large R wave in lead V1, what does it typically indicate?

If there is a large R wave in lead V1, what does it typically indicate?

• A. Left atrial enlargement
• B. Right ventricular hypertrophy
• C. Left ventricular hypertrophy
• D. Heart block

Answer: (B)

A large R wave in lead V1 typically indicates right ventricular hypertrophy (RVH). This is due to the positioning of the electrodes and the heart's orientation in the thoracic cavity. In the case of right ventricular hypertrophy, the right ventricle becomes enlarged and produces a stronger electrical signal. This increased signal manifests as a prominent R wave in lead V1, which is positioned over the right side of the heart.

In contrast, left atrial enlargement, left ventricular hypertrophy, and heart block do not generally lead to a large R wave in lead V1. For example, left atrial enlargement primarily affects lead II and V1 by showing changes in the P wave rather than a prominent R wave. Left ventricular hypertrophy, on the other hand, typically presents with larger R waves in leads that are oriented toward the left ventricle, such as V5 and V6. Heart block can show varying patterns on the EKG, but a large R wave in V1 is not characteristic of this condition, and other features would be more prominent instead.

Therefore, the presence of a large R wave in lead V1 points towards right ventricular hypertrophy, highlighting the importance of understanding lead-specific findings in interpreting EKGs