Reversed paradoxical splitting of the second heart sound: A unique case report

A 73-year-old female presented with split second heart sound (S2) and ejection systolic murmur. The S2 split only during expiration (paradoxical splitting) with a softer second component (pulmonary component), which was in reverse order compared to typical paradoxical splitting (termed reversed paradoxical splitting). Furthermore, the murmur increased during expiration and decreased during inspiration (reversed Rivero-Carvallo's sign). Transthoracic echocardiography revealed a mass adherent to the free wall of the right ventricular outflow tract. Open-heart surgery was performed, and the tumor was surgically resected. Histopathological examination confirmed the diagnosis of a capillary hemangioma. The patient's recovery was smooth and uneventful.

Splitting of the second heart sound (S2) sometimes provides significant clinical clues for cardiopulmonary disease. Paradoxical splitting of S2 typically features a softer pulmonary component (P2) followed by a clearer aortic component (A2) during expiration. We encountered a case of paradoxical splitting in which A2 preceded P2 (termed reversed paradoxical splitting) in a patient with right ventricular outflow tract obstruction due to cardiac hemangioma. Auscultation findings were definitive in this case.