13 July 2026
: Case report 
Exercise-Induced Complete Heart Block and Sinoatrial Exit Block in Baseline Bifascicular Block
Unusual or unexpected effect of treatment, Rare disease
Asher Gorantla ABEF 1, Peter Cwalina
DEF 2*, Aleksander Łuniewski BE 3, Ahmad Jallad DE 4, Natalia Turkiewicz ABCDEF 5, Adam S. Budzikowski ADEF 4
DOI: 10.12659/AJCR.949566
Am J Case Rep 2026; 27:e949566
Figure 3 (A) Stress EKG showing Stage 1 Bruce protocol with PVC inducing CHB [green arrow]. (B) During the post-exercise period, second-degree Type II AV block was observed with LBBB. (C) At recovery, bifascicular block was observed with development of new second-degree Type I block. AV, atrioventricular; CHB, complete heart block; EKG, electrocardiogram; LBBB, left bundle branch block; PVC, premature ventricular contraction; RBBB, right bundle branch block.