Recurrent symptomatic bilateral bundle branch block in a 74-year-old patient with a prosthetic aortic valve: A description of a case and review of the literature

This report concerns a 74-year-old patient who had undergone aortic valve replacement 11 years earlier. On admission, the patient complained of shortness of breath when climbing two flights of stairs; there was no history of dizziness, fainting or sensations of arrhythmias. An ECG at rest showed first-degree atrioventricular (A-V) block together with left bundle branch block (LBBB). On bicycle ergometry, there was a fall in blood pressure and in heart rate due to a second-degree (2:1) A-V block along with the LBBB. After termination of exercise, the PR interval increased further from 0.24 s to >0.3 s, together with right bundle branch block (RBBB) and 1:1 A-V conduction instead of LBBB. Finally, at a constant atrial rate of 98/min, the RBBB disappeared, LBBB recurred, again with 2:1 A-V conduction. The diagnosis was bilateral BBB together with first degree A-V block at rest and higher-degree A-V block on effort. The patient underwent pacemaker implantation and was discharged shortly thereafter free of symptoms.