“Stable” Asystole In A Patient With Left Ventricular Assist Device

Abstract

The use of Left Ventricular assist devices (LVADs) for mechanical circulatory support has become a standard therapy for some patients with end-stage heart failure. Although presentation and consequences of ventricular arrhythmias (VA) in LVAD supported patients are well described and often stabilized by the mechanical support, presence of asystole is less commonly reported. Our patient is a 75-year-old male with advanced ischemic cardiomyopathy requiring cardiac resynchronization therapy-defibrillator (CRT-D) and ultimately HeartMate II LVAD. Post implantation, his CRT-D was abandoned after it reached the elective replacement indicator as he had no VAs and was not pacer dependent. He now presented with a new onset of low flow alarms that started earlier in the day. He appeared stable, pleasant and in a humorous mood. He reported lightheadedness but denied syncope. While in the ED, the patient was noted to be asystolic. His mean arterial pressure was in the 50s. Physical exam was unremarkable with the expected LVAD hum and lack of pulses. LVAD parameters revealed decreased Flow (2.5 from baseline 5.1) and Pulsatility Index (2.7 from baseline 4.9). Patient subsequently underwent implantation of a new battery with reactivation of his previously abandoned pacemaker leads with resultant hemodynamic improvement. Ultimately, he was discharged home in stable condition. Discussion: Very few cases of asystolic LVAD patients without immediate hemodynamic collapse are described. Similarly to ventricular arrhythmias, the hypothesized physiology for stability is this quasi-Fontan circulation, where low pulmonary vascular resistance with elevated central venous pressure allows pulmonary vasculature perfusion and left atrial filling. In this case, low flow alarms and decreased PI were due to decreased left ventricular preload in the setting of asystole. Ventricular arrhythmias remain common after LVAD implantation, asystole, as in the present case can equally be an issue. This is particularly true as many of LVAD supported patients have CRT-Ds implanted in the setting of pre-existent left bundle branch blocks, which can progress to complete heart block or asystole. Thus, It might not always be the case that LVAD supported patients don't benefit from maintaining ICD function. Conclusion: Traditionally unstable asystole and ventricular arrhythmia can be well tolerated in the LVAD population due to quasi-Fontan physiology. ICD role in LVAD patients is currently unclear, and should be a part of shared decision making with the patient. Yes, there may be such a thing as, "stable" asystole.