Right atrial collapse in the absence of pericardial effusion.

Abstract

A 16-year-old male with severe pectus excavatum (PEx; Panel A) was referred to our institution due to progressive exertional dyspnea, palpitations, and chest wall discomfort. Transthoracic echocardiography performed at an outside institution reported minimal compression of the right heart chambers without haemodynamic disturbances. Considering the severity of the deformity and cardiopulmonary symptoms, surgical repair with intraoperative transesophageal echocardiography (TEE) surveillance was indicated. Intraoperative TEE showed severe extrinsic compression of the right atrium (RA) due to the depression of the anterior chest wall, with RA collapse starting in early diastole and extending into end-diastole (Panel B, Video 1). No pericardial effusion was noted. After PEx repair, TEE imaging noted no further evidence of RA collapse (Panel C). On postoperative Day 2, the patient was discharged without complications, and in subsequent 6 weeks follow up, he reported significant improvement in symptoms. Sustained RA collapse is a highly sensitive and specific marker for cardiac tamponade, usually indicating emergency situations in which intrapericardial pressure transiently exceeds intracardiac pressure. In early stages of cardiac tamponade, RA collapse is observed during end-diastole when the RA pressure is at its lowest. The phenomenon gradually extends throughout most of the diastole with the increase of intrapericardial pressure. In our unique case of a PEx patient, RA collapse occupying entire diastolic period was observed due to external compression in the absence of cardiac tamponade, and completely resolved with surgical repair. This finding supports the need for a comprehensive assessment of the right-sided chambers compression in symptomatic PEx patients.