Coronary sinus fistula: A reason not to implant a transvenous left ventricular lead

Abstract

A 40-year-old woman referred for biventricular implantable cardioverter-defibrillator (ICD) implantation with an ejection fraction of 30%, New York Heart Association class III symptoms, and left bundle branch block QRS duration of 160 ms (patient had nonischemic cardiomyopathy and no evidence of occlusive coronary artery disease by nuclear perfusion imaging). Occlusive venography (Figure 1) demonstrated a coronary artery‐to‐coronary venous fistula. The left anterior descending artery is seen anteriorly (along the interventricular septal region) in the right anterior oblique image. There is no evidence of coronary sinus dilation, and the proximal coronary sinus was a relatively narrow vessel with no significant lateral branches. A shunt assessment demonstrated no significant left-to-right shunt. Based on the findings, the decision was made not to place a coronary sinus lead due to risk of thrombus formation and embolization to the coronary arteries. Additionally, there was a lack of suitable lateral branches to provide an optimal pacing vector. A decision to consider a surgically implanted lead was made. A follow-up coronary computed tomography (CT) scan interestingly did not document a fistula, likely because the image resolution of the 64-slice CT was not sufficient to visualize a small fistula.