Clinical case description
A 42 years-old patient presented, one week after a surgical valve replacement, presented in the emergency room due to episodes of syncope. The patient had a past medical history of rheumatic valvular heart disease and had been submitted to three valvular surgeries. At the first surgery (22 years before) a mitral and tricuspid valvuloplasty was performed, and 6 years later, due to progressive valvular stenosis, a mechanical prosthetic mitral valve and bioprosthetic tricuspid valve was implanted. As a consequence of the second surgery, a high degree AV block occurred, and a right infraclavicular dual-chamber pacemaker (PM) was implanted\sout. Owing to the presence of the prosthetic tricuspid valve, the ventricular pacing lead (unipolar) was placed through the coronary sinus in the anterior vein.
A week before the current hospital admission, the patient had a third valvular surgery. At this time, he had a replacement of the tricuspid mechanical valve and was submitted to an aortic mechanical valve implantation. The immediate post-operative period was uncomplicated. Regarding heart rhythm, the patient had previously developed a permanent Atrial Fibrillation (AF) and had the PM reprogrammed to VVI mode.
One week after discharge he had 3 episodes of syncope and recurred to the emergency department. The admission ECG revealed AF and pacing spikes without ventricular capture and prolonged ventricular asystole (figure 1).