Persistent left superior vena cava and associated structural and functional considerations.

Potentially significant associations are presented between anomalous systemic venous return (including both left superior vena cava and left hepatic venous drainage to the coronary sinus), a history of atrial fibrillation and a forme fruste of cor triatriatum in an elderly woman. Lack of associated structural defects or functional deficits makes it difficult to assess the frequency of occurrence in the general population of bilateral superior venae cavae in association with a persistent left hepatic vein draining into the coronary sinus. However, the potential for these systemic venous anomalies needs to be considered when unexplained arrhythmias are encountered. More specifically, the size of the coronary sinus needs to be assessed in patients with arrhythmia.