179 ICD or not ICD? A difficult choice for a young patient presenting with palpitations in emergency department

A fit-and-well 52-year-old worker, with negative familiar story, was admitted to Emergency Department (ED) with haemodynamically unstable but well bore broad complex tachycardia of 180 b.p.m. (Figure 1). Twenty years before the patient had heart-surgery to repair atrial septal venous sinus defect with patch. The defect determined anomalous pulmonary venous return in right atrium with left to right shunt and moderate pulmonary hypertension. The surgery, 20 years before, was complicated by a single event of supraventricular tachycardia pharmacology resolved. Next follow-up was normal although at transthoracic echocardiography severe right ventricular (RV) dilation was reported. In the ED the patient had palpitation but not chest pain or dyspnoea. General clinical examination was normal but he was hypertensive (170/137 mmHg) and with heart rate of 180 b.p.m. Valsalva manoeuver was performed and adenosine (6 mg–12 mg–12 mg) was administered without benefit. Eventually, the patient was cardioverted to sinus rhythm with a single 100 J shock. His baseline ECG (Figure 2) showed sinus rhythm, normal axis, as well as right bundle branch block and T-wave inversion in leads V1–V4 and a waves with a small spike upward in lead V1 which represent characteristic epsilon waves.

Successively patient was admitted to Cardiology Department where transthoracic echocardiography showed severe RV dilation and moderate hypokinesia with a tricuspid annular plane excursion of 15 mm, TAV 9.6 cm/s, fractional area change of 29%. The right atrium was moderate dilated (volume 70 ml, indexed volume 35.53 ml/m²). Left chambers were normal. No shunts were observed. An electrophysiology study with isoprenaline infusion was performed but no arrhythmias were induced. Cardiac magnetic resonance imaging (MRI) was normal save for global RV dilatation, increased RV end diastolic volume (156 ml/m²), and global RV systolic dysfunction (reduction of RV ejection fraction 31%). Arrhythmogenic cardiomyopathy was excluded as patient’s background suggested RV dilation was due the overload caused by the history of left–right shunt. Blood tests and personal history negative initially exclude myocarditis and cardiac MRI confirmed the absence of oedema. An accurate ECG analysis excluded Brugada syndrome. Following discussion between electrophysiologists, clinical cardiologists, and the patient who first need to be informed, trans-venous ICD was implanted.

179 Figure 1

ECG in ED.               Figure 2 Baseline ECG.                 Figure 3 Cardiac MRI.

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