A 58-year-old male consulted our emergency department (ED) in May 2023 for new-onset severe dyspnea and ankle swelling. Patient history included previous aortic valve replacement (STJ 23 mechanical aortic valve) in 2004 for sub-valvular stenosis due to subaortic membrane.
ED transthoracic echocardiogram (TTE) showed a dilated left ventricle (LV) with severely depressed ejection fraction (EF: 25%), LV non-compaction (LVNC), aortic mechanic prosthesis with increased gradients (49/32 mmHg), no perivalvular leaks, dilated pulmonary artery.
Increased aortic gradients raised suspicion of aortic prosthetic thrombosis as the cause of acute pulmonary edema. However, urgent fluoroscopic investigation proved normal mobility of the hemidisks (Fig.1). Patient was admitted to cardiac intensive care unit.
TTE also showed increased LVOT gradients, suggesting a hyperdynamic condition. Lab tests ruled out hyperthyroidism, sepsis and anemia. RV stroke volume was measured: QpQs was 0.7. Careful search for intra/extra-cardiac shunts with TTE ruled out intra-cardiac shunts, but highlighted a patent ductus arteriosus (PDA). PDA represents a peculiar case in which, despite being a left to right shunt, echo-measured QpQs results <1 as pulmonary flow is measured in the RVOT, upstream of the shunt. CT ruled out pulmonary embolism and coronary artery disease and confirmed the presence of PDA and pulmonary artery dilation. Transesophageal echo confirmed the PDA (Fig.2) and highlighted coronary sinus dilation due to persistence of left superior vena cava (PLSVC). Right heart catheterization (RHC) showed a significant shunt (Qp/Qs 1,57) with increased pulmonary pressure (mPAP 33 mmHg) and pulmonary vascular resistance (PVR, 4,03 WU). Cardiac MRI confirmed LVNC with late gadolinium enhancement in the basal septum. LV function improved (EF 36%, Fig.3) after optimal unloading. Patient was discharged with optimal medical therapy for HFrEF (ARNI, SGLT2i, MRA, BB) and was referred to hub congenital heart disease Center (Regina Margherita Hospital, Torino) for percutaneous duct closure after balloon closure test. Percutaneous closure was successfully performed without any complications. RHC three months after closure showed normalization of PVR (0,9 WU) and pulmonary pressure (mPAP 19 mmHg). To our knowledge, this is the first reported case of subaortic membrane, LVNC, PDA and PLSVC. Patient was successfully treated with percutaneous PDA closure and is currently asymptomatic, class NYHA 1.
