B-PO05-213 REVERSAL OF HYPOCALCEMIA-INDUCED DILATED CARDIOMYOPATHY TREATED WITH CRT-D

Abstract

Hypocalcemia is a rare cause of dilated cardiomyopathy (DCM). Pathophysiology involves decreased myocyte contractility and prolongation of QTc interval. CRT-D is a proven therapy in patients with DCM. We present a novel case of hypocalcemic DCM and syncope that was refractory to GDM, including calcium replacement, that responded to CRT. N/A A 52-year-old woman with DCM and chronic hypocalcemia secondary to hypoparathyroidism presented for biventricular ICD placement. Hypocalcemia began after hemithyroidectomy. She was first diagnosed with heart failure after 10 years of hypocalcemia (mean 6.6 +/- .92 mg/dL). ECG was sinus rhythm with left bundle branch block (QRS 146 ms). TTE showed LVEF of 20% and 4-chamber enlargement. Cardiac catheterization did not show coronary artery disease. After 3 months of GDM and correction of calcium, she continued to have NYHA class III symptoms without change in EF. She was hospitalized for syncope concerning for malignant arrhythmia. QTc was 524 ms (JTc = 378 ms). Cardiac MR did not show evidence of fibrosis or scar. She had class 1b indication for CRT due to LVEF <35% and LBBB and underwent successful placement of Biotronik BiV ICD with LV lead placed into posterolateral branch. At 3-month follow-up she had 100% biventricular pacing. Her LVEF increased from 20% to 35%, LVIDd and LVIDs decreased by 15% (6.76 to 5.73 cc) and 24% (6.10 to 4.64 cc). After prolonged correction of calcium, QTc normalized (474 ms). CRT-D therapy has multiple indications in hypocalcemia-induced DCM, including improvement of LV size and function and prevention of fatal arrhythmias related to QTc prolongation.