RBBB with Amputated Primary R Wave

Report:

Sinus rhythm 95/min

Right axis deviation

Right bundle branch block

Recent anterior infarct

Comment:

The QR complex in V1 is still RBBB since the delay is all in the RV territory. Before the infarction it was an rSr’ of normal duration (not shown); with acute infarction, it became an rR’ complex (Fig 65a below) while its companions to the left were typical “tombstones”. Now the Q waves have evolved and the primary R wave is lost.

The marked RAD is also new – perhaps due to LPHB but more likely due to the loss of anterior R waves, an equivalent to Q waves. There is some persistent ST segment elevation in the anterior leads, along with reciprocal depression in the inferior leads. This patient’s outlook is not good.

There is, however, a cosmetic improvement in the inferior leads which previously recorded an old inferior infarct: their Q waves are now largely gone because the inferior “cavity leads” are now balanced by the anterior ones. Similarly cosmetic was the resurrected R wave in V1 (see next, the same patient as Case 266).

Fig 65a. Acute extensive anterior infarction with RBBB 10 days previously. The inferior Q waves are still present.

Fig 66. Same patient as Case 65, a week earlier (three days after a myocardial infarction at a country hospital).