P 023: Idiopathic left fascicular ventricular tachycardia in pregnancy

Abstract

Ventricular tachycardia (VT) can occasionally cause complications in pregnancy. In structurally normal heart, VT that arises in the left ventricle is uncommon and is termed as idiopathic left fascicular VT (ILVT). We report a case of 32-year-old lady, gravida 4 para 3 who presented to us at 34 weeks of pregnancy with symptomatic stable cardiac arrythmia with heart rate of 160 beats per minute. Electrocardiogram showed wide complex tachycardia with positive initial R wave at aVR and capture beats suggestive of ILVT. Echocardiogram was normal. She received IV verapamil 25 mg in total which failed to revert to sinus rhythm and hence, she underwent emergency Caesarean section followed by synchronized cardioversion urgently in operation theatre. Post cardioversion ECG showed sinus rhythm with memory T waves at chest leads. She was scheduled radiofrequency ablation later. This case highlights the importance of attaining the diagnosis of ILVT with distinctive ECG changes. Left ventricular outflow tract (LVOT) VT morphology depends on the site of origin, with either LBBB or early precordial transition in leads V1 to V2 or RBBB pattern in V1 with broad monophasic R in the precordial leads. In addition, there will be an R:S amplitude ratio of 30% or more or an R:QRS duration ratio of 50% in leads V1–2 with other features like capture beats and fusion beats. ILVT responds well with verapamil and can be cured with cardiac ablation, with success rates of more than 90%. ILVT though difficult to diagnose, it has distinctive ECG features which can lead to its diagnosis for appropriate treatment to be given accordingly. ILVT in pregnant patients generally has a good prognosis.