Abstract

Tachycardia with wide QRS complex on a cocaine dependent patient: not everything is what it seems

Author(s): Marcio Galindo Kiuchi, Gustavo Ramalho e Silva, Luis Marcelo Rodrigues Paz and Gladyston Luiz Lima Souto

Introduction: Ventricular arrhythmias related to cocaine may not respond to antiarrhythmic drugs and may need treatment with radiofrequency ablation. Case presentation: In this case we describe a 33-year-old man that presented to the emergency room complaining of chest discomfort and slight palpitations predominantly in the precordium, starting for 1 hour ago. The patient reports rare episodes of non tachycardic palpitations in the past, short-lived. He denied syncope or pre- syncope and did not show low output objective signs. After exams, he was diagnosed with sustained ventricular tachycardia confirmed by all used electrocardiographic criteria; the emergency medical team chose to use intravenous amiodarone, which reverted the arrhythmia. The patient was hospitalized, and continued intravenous amiodarone, sedation with benzodiazepines and 24-hour continuous monitoring electrocardiographic (Holter) were conducted. Amiodarone was suspended and was initiated oral diltiazem 80 mg in 8/8 hours. We requested a cardiac nuclear magnetic resonance image that showed normal perfusion and contractility, the absence of delayed enhancement, mild hypertrophy of the basal septum and lack of arrhythmogenic substrate. Electrophysiological study (EPS) was performed. Conclusion: During the EPS, the ECG at baseline was normal. The programmed electrical stimulation induced atrioventricular nodal reentrant tachycardia (AVNRT) with aberrant conduction. The ablation of the slow pathway was successful, and the patient did not present new tachycardia episodes.