VENTRICULAR-TACHYCARDIA IN VALVULAR HEART-DISEASE - FACILITATION OF SUSTAINED BUNDLE-BRANCH REENTRY BY VALVE SURGERY

Background The clinical characteristics of sustained monomorphic ventr icular tachycardia (SMVT), when it develops after valve surgery, have not been described. Methods and Results Between 1985 and 1996, 31 pati ents (30 men and 1 woman) who had undergone valve surgery were found t o have inducible SMVT. Nine patients (29%) had sustained VT due to bun dle-branch reentry (BBR) (group 1). Four of these patients had normal left ventricular function, and VT with a right bundle-branch morpholog y was inducible in 4 patients. Group 2 included 20 patients with induc ible myocardial (ie, non-BBR) VT. Coronary artery disease was present in 15 group 2 patients (75%) due to atherosclerotic (n=12) and nonathe rosclerotic (n=3) causes. Two patients had both inducible sustained BB R and myocardial VT (group 3). Sustained BBR VT occurred significantly earlier after valve surgery (median, 10 days) than the onset of posto perative myocardial VT (median, 72 months; P<.005). Conclusions Myocar dial VT was the most common type of inducible SMVT in patients with va lvular heart disease. The majority of these patients had underlying co ronary artery disease and significant left ventricular dysfunction. Ho wever, in almost one;third of the patients, sustained BBR VT was the o nly type of inducible SMVT. This type of VT was facilitated by the val ve procedure occurring within 4 weeks after surgery in most patients. In these patients, left ventricular function was relatively well prese rved, and the right bundle-branch block type of BBR was frequently ind uced. Because a curative therapy can be offered to these patients (ie, bundle-branch ablation), BBR should be seriously considered as the me chanism of VT in patients with valvular heart disease, particularly if the arrhythmia occurs soon after valve surgery.