
Patient Background: A 36-year-old man with well-controlled first-grade essential hypertension presented for a routine cardiovascular evaluation. He had a known heart murmur since childhood and had previously been told he might have a ventricular septal defect. Physical examination was unremarkable.
Assessment and Diagnosis: Initial ECG showed sinus rhythm (62 bpm), poor R-wave progression in leads V1–V4, and T wave inversions. Transthoracic echocardiography (TTE) revealed atypical cardiac positioning with suboptimal image acquisition. Atrial septal defect was suspected. Cardiac magnetic resonance (CMR) imaging delineated complete left-sided pericardial agenesis—demonstrating the heart displaced laterally and posteriorly into the left hemithorax, lung interposition between the great vessels, and absence of the left-sided pericardium. A patent foramen ovale (PFO) without significant right-to-left shunting was also identified.
Suggested Treatment Plan and Patient Education: No treatment was advised for the pericardial defect given the patient’s asymptomatic status. However, the potential risk of paradoxical embolism through the PFO was discussed, and closure of the defect was considered. Patient education focused on recognizing signs of cryptogenic stroke and understanding the clinical implications of the PFO.
Follow-up: Annual echocardiographic follow-up was recommended. At 6 months, the patient remained asymptomatic.
- Why was CMR essential in diagnosing pericardial agenesis in this asymptomatic patient? Answer CMR delineated heart displacement, lung interposition, and absence of pericardium—details not discernible on suboptimal TTE—making it essential for confirming the diagnosis.
- What is the management for asymptomatic pericardial agenesis with a PFO? Answer Asymptomatic pericardial agenesis requires no treatment. However, the PFO may increase stroke risk, and closure may be considered to prevent paradoxical embolism.

