Duration of right ventricular pressure curve in transient right bundle branch block: Observations during catheterization in man

Abstract

The duration of the right ventricular pressure curve in transient right bundle branch block has not previously been studied. During approximately 2,000 consecutive heart catheterizations, right bundle branch block was produced in 37 patients. In 4 of the 37, transient right bundle branch block was recorded. These 4 patients had different hemodynamic conditions. Photographic superimposition and amplification of the tracings shows that after right bundle branch block (1) the duration of the S-T interval is shortened because the end of S is inscribed much later than the end of T, and (2) the duration of the right ventricular pressure curve is shortened because the upstroke is delayed while the downstroke is not. In the presence of an obvious delay in the onset, no obvious change is seen in the velocity of inscription of the systolic rising phase of the ventricular pressure pulse after right bundle branch block. These observations indicate that only the presystolic slope pressure (the foot before the onset of ventricular contraction) shows the effects of the altered right ventricular activation when right bundle branch block is produced during catheterization in man.