Too fast, too furious

A woman in her 30s, a case of rheumatic mitral stenosis status post balloon mitral valvuloplasty 15 years prior, presented to urgent care with palpitations and dyspnoea for 1 week. She was noted to be in heart failure, with hypotension and tachycardia. Initial assessment with electrocardiography revealed a regular narrow complex tachycardia with 2:1 atrioventricular (AV) relationship, no clear isoelectric baseline and positive P waves in lead V1 consistent with an atrial flutter of left atrial origin with a rapid ventricular rate (~160/min) (figure 1A). Echocardiography demonstrated severe calcific mitral stenosis with pulmonary hypertension. With decompensated heart failure and adequate prior anticoagulation, the patient underwent direct current synchronised …