MALIGNANT VENTRICULAR ARRHYTHMIAS ARE WELL TOLERATED IN PATIENTS RECEIVING LONG-TERM LEFT-VENTRICULAR ASSIST DEVICES

Objectives. We sought to quantitate the incidence of malignant ventric ular arrhythmias and to identify subsequent hemodynamic changes and un toward events in patients who have received an implantable left ventri cular circulatory assist device as an extended bridge to heart transpl antation. Background. Implantable long-term mechanical circulatory ass ist devices have been used clinically with increasing frequency and su ccess for the past 4 years. Previous investigators have suggested that patients with malignant ventricular arrhythmias receiving a left vent ricular assist device will require both left and right ventricular ass istance to maintain vital organ perfusion. Methods. We reviewed our 4 year experience with 21 patients who underwent implantation of a left ventricular assist device. Device flows and mean arterial pressure wer e used to assess systemic perfusion; central venous pressure provided a gauge of right ventricular function. Charts were screened for eviden ce of end organ injury resulting from malignant ventricular arrhythmia s. Results. Malignant ventricular arrhythmias occurred in 4 patients ( 19%) before device placement and in 9 patients (43%) during device sup port. The latter nine patients formed the final study group; their arr hythmias occurred 0 to 186 days after device implantation and had a du ration of 10 min to 12 days. The patients reported weakness or palpita tion; however, none reported syncope or dyspnea. Mean arterial pressur e and central venous pressure were insignificantly changed by the arrh ythmias. Device flow decreased by 1.4 +/- 0.6 liters/min (p < 0.05) at the onset of the arrhythmias but returned to normal after cardioversi on. No thromboembolic events or significant end organ dysfunction occu rred.Conclusion. Absence of right ventricular contraction during malig nant ventricular arrhythmias is well tolerated in recipients of a left ventricular assist device. The diagnosis of malignant arrhythmia shou ld be suspected if an unexplained decrease in left ventricular assist device how occurs. Early electrical cardioversion is warranted to avoi d both thrombus formation in the native heart and right ventricular my ocardial injury from prolonged fibrillation.