Refractory atrioventricular nodal re-entrant tachycardia: A rare manifestation of acute massive pulmonary embolism

With a wide array of manifestations ranging from mild dyspnea to fatal cardiogenic shock, acute pulmonary embolism (PE) remains an enigmatic clinical entity. Vivid electrocardiography (ECG) patterns portrayed in different clinical instances of acute PE have always remained an interesting, yet debatable subject since the classic S1Q3T3 pattern on ECG secondary to PE was first described in 1935. Atrial fibrillation, atrial flutter and atrial tachycardia are commonly described supraventricular tachycardias in association with PE; however, there is scant description of PE in the literature presenting as atrioventricular nodal re-entrant tachycardia (AVNRT). The present report describes the clinical course of an elderly woman presenting with refractory typical AVNRT who was subsequently found to have bilateral multilobar acute PE. To the authors’ knowledge, the present report is the first to describe a case involving acute PE presenting as hemodynamically unstable AVNRT requiring cardioversion.