Idiopathic Central Diabetes Insipidus as an Etiology of Left Ventricular Suction and Ventricular Arrhythmias

Abstract

<h3>Introduction</h3> Left ventricular assist device (LVAD) implantation has increased in patients with end-stage heart failure. Left ventricular suction is a known complication of LVAD therapy, with etiologies including hypovolemia, sepsis and ventricular arrhythmias. Prompt recognition of the underlying cause is crucial in the management and prevention of suction events. <h3>Case Report</h3> A 59-year-old male with non-ischemic cardiomyopathy status post LVAD and ventricular tachycardia (VT) presented with shocks from his implantable defibrillator. He noted 2-3 weeks of low flow alarms and daily suction events with associated lightheadedness and dizziness. On admission, device interrogation revealed two episodes of successfully terminated VT. His antiarrhythmic therapy and device settings were adjusted by the electrophysiology team. On day two of hospitalization, he had ventricular fibrillation associated with a suction event. He was noted to have increased urine output despite holding diuresis. LVAD speed was decreased and he was given intravenous fluids, however right heart catheterization revealed very low filling pressures despite these interventions. He continued to have polyuria despite liberalization of fluid intake and suction alarms with associated ventricular ectopy. Urine studies revealed low urine osmolality of 266 mOsm/Kg and urine sodium of 41 mmol/L. Hypertonic saline challenge resulted in hypernatremia and improved but suboptimal urine concentration. Workup for causes of nephrogenic diabetes insipidus (DI) was unrevealing. Computed tomography of the sella did not reveal any pituitary abnormalities. He was started on desmopressin and urine output appropriately decreased. He had no further ventricular arrhythmias, though he continued to have intermittent suction alarms associated with positional changes. <h3>Summary</h3> Treatment of left ventricular suction events includes correction of underlying etiology, maintaining preload, reducing LVAD speed and management of complications including ventricular arrhythmias. Our patient's suction events and ventricular arrhythmias were presumed secondary to hypovolemia in the setting of central DI and polyuria, which improved with treatment with desmopressin. In review of literature, this is the first documented case of diabetes insipidus resulting in suction events and ventricular arrhythmias.