Significance of right bundle-branch block patterns during pervenous ventricular pacing.

Abstract

Despite the widespread use of pervenous right ventricular pacing, there are relatively few reports concerning the occurrence of a right bundle-branch block pattern during apparent right ventricular pacing (Siddons and Sowton, 1967;Mower, Aranaga, and Tabatznik, 1967). This communication presents our observations of these patterns during pervenous ventricular pacing and analyses their clinical and electrophysiological implications. (Gordon, 1965) before and during the withdrawal of the catheter, suggested that it had been located in the coronary sinus (Fig. 2) block with a 0 13 sec. QRS complex with a left bundlebranch block pattern. A temporary bipolar pacing catheter was inserted into what was considered to be the outflow tract of the right ventricle, and ventricular pacing was achieved at a threshold of about 4-5 mA. Several days later when the threshold had risen to 22 mA and the chest x-ray suggested that the catheter was in the coronary sinus, the significance of the right bundlebranch block pattern recorded in the electrocardiogram (Fig. 3) became evident. The catheter was withdrawn and replaced by another which was positioned in the outflow tract of the right ventricle where a left bundlebranch block pattern was recorded during pacing (Fig. 3).Case 3. Cardiac catheterization demonstrated no abnormality in a 16-year-old boy who had been referred for the investigation of a cardiac murmur and incomplete right bundle-branch block in the electrocardiogram. At the end of the study, a bipolar pacing catheter was manipulated, in turn, to the outflow tract, apex, and inflow tract of the right ventricle, and surface electrocardiograms were obtained during pacing at these sites (Fig. 4, 5, and 6). The pacing rate, which was faster than the control rate, and voltage used for pacing were identical for all the three sites. A right bundle-branch block pattern was recorded during pacing of the apex of the right ventricle and retrograde ventriculo-atrial conduction with reciprocal (echo) beating was also observed (Fig. 7). Electrograms before pacing at all the sites demonstrated intraventricular morphology, and the threshold for ventricular pacing was under 1-5 mA at all sites.Case 4. An 86-year-old man was admitted with congestive heart failure and the electrocardiogram demonstrated atrial fibrillation and complete heart block with a 0-13 sec. QRS complex exhibiting a right bundlebranch block pattern. When he became compensated, a permanent pervenous pacemaker was implanted with the tip of the catheter wedged in the apex of the right ventricle where the threshold for pacing was 0 5 mA, and the electrogram displayed an intraventricular QRS complex. After operation the electrocardiogram showed 285

Sinus venosus atrial septal defect: a rare cause of misplacement of pacemaker leads

“…Hence the presence of a right bundle branch block pattern after implantation should raise suspicion for a misplacement of leads, as was the case in our patient. However, one should remember that this right bundle branch block pattern can also be seen in the case of lead placement in the coronary sinus10,11 or even occasionally in the apical region of the right ventricle 12,13. Chest X-ray with posterior-anterior and lateral views can provide supplementary diagnostic arguments, as was the case in our patient.…”

A change in QRS morphology in right ventricular apical pacing: is it a red flag sign?

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Paradoxical Right Bundle Branch Block Morphology in Right Ventricular Apical Pacing- Is it Really Concerning?

“…They also proposed that if the screw tip is deeper into the septal plane then it could activate LV early [7]. Barold et al [8] said that combination of RV activation delay due to severe disease of RV conduction system and early penetration of electrical impulse into LV system could be responsible for this effect.…”