"The Heart Sound Quintet": A Case Report of Right-Sided Heart Failure Due to Free Pulmonary Regurgitation Long After Intracardiac Repair of Tetralogy of Fallot.

BACKGROUND Intracardiac repair of tetralogy of Fallot (TOF) is generally performed during childhood. However, the majority of patients develop the sequelae long after surgical repair, which results in significant right ventricular (RV) dilation, RV myocardial dysfunction, and, ultimately, in right-sided heart failure. CASE REPORT A 52-year-old man was referred to our institution for the evaluation of sudden-onset ventricular tachycardia. His medical history included RV outflow tract reconstruction at 5 years of age. Auscultation revealed a harsh diastolic regurgitant murmur, widely split first heart sound (S₁), and a single second heart sound (S₂), indicating a severely dilated RV due to severe pulmonary regurgitation (PR) and the presence of a non-functioning pulmonary valve. Moreover, the right-sided third heart sound (S₃) and fourth heart sound (S₄) were present, consistent with elevated RV filling pressure and the presence of a non-compliant RV. Eventually, the aforementioned "heart sound quintet" was confirmed using multimodal evaluation as right-sided heart failure with a concomitant severely dilated RV because of complete regression of the pulmonary valve and resultant free PR. CONCLUSIONS We encountered a case with a "heart sound quintet" that was composed of a widely split S₁, single S₂ with a harsh diastolic regurgitant murmur, and right-sided S₃ and S₄ The logical interpretation of the findings from physical examination will contribute to understanding the pathophysiology and aid clinical decision-making.