Abstract 13203: Unexpected Cause of Rare Type of Wide QRS Tachycardia
A 45 year old male with no previous cardiac disease and unremarkable familial history was admitted due to recurrent hour-lasting episodes of chest pain that was caused by wide QRS tachycardia that required DC cardioversion. Primary investigation noticed slight asymmetric hypomimia and moderate peripheral muscle weakness resulting in non-debilitating walking abnormalities. Clinical blood, thyroid and coagulogic profiles were normal. Biochemistry panel revealed hyperlipidemia and modestly elevated creatine kinase. Troponin test was negative. ECG displayed sinus rhythm, PQ 200 ms, QRS 120 ms and rare ventricular premature beats. Echocardiography revealed asymmetric non-obstructive hypertrophy of ventricular septum (up to 16 mm in basal segment) with preserved LVEF, no wall motion abnormalities and slightly enlarged LA. Cardiac MRI demonstrated large areas of subendocardial late gadolinium enhancement in septal, inferior and lateral walls of LV suspicious for ischemic lesions. Coronary angiography revealed intact arteries. Electrophysiologic study showed delayed conduction in His-Purkinje system (HPS; HV 70 ms). Right ventricle pacing induced bundle-branch reentrant VT with a rate of 250 BPM and LBBB morphology. Considering structural heart disease and HPS involvement decision to retain from radiofrequency ablation of RBB or LBB and to implant 2-chamber ICD was made. Brain MRI prior to implantation showed multiple vascular lesions in white matter and glyotic lesions in grey matter of temporal lobes. Patient discharged on Bisoprolol 7.5 mg OD and referred to neurological center where diagnosis of myotonic dystrophy (MD) was made by electromyography. Genetic test confirmed multiple CTG repeats in DMPK gene. A 10-month follow-up was remarkable for 4 appropriate shocks and multiple long-lasting and mostly asymptomatic AFib episodes revealed by ICD telemetry. Considering hypertrophic cardiomyopathy and glyotic grey matter lesions anticoagulant therapy by rivaroxaban 20 mg OD was initiated.
Cardiac disease is frequent in MD, but commonly affects patients with prominent neuromuscular symptoms. Progressive HPS defect and AFib are more prevalent than VT. Brain involvement is common, but almost exclusively white matter lesions are described.
Author Disclosures: N. Mironov: None. N. Mironova: None. S. Sokolov: None. O. Stukalova: None. M. Saidova: None. Y. Mareev: None. N. Shlevkov: None. S. Golitsyn: None.
- © 2014 by American Heart Association, Inc.