Diagnosis and Treatment of Patent Foramen Ovale (PFO) in Patient Supported with Left Ventricular Assist Devices(LVAD)

Abstract

Early diagnosis and treatment of PFO in patients with LVAD have been challenging. LVAD unloads left ventricle and decreases left atrial pressure. Such hemodynamic change causes right to left shunting via PFO resulting in hypoxemia immediately or days after implantation of LVAD. Frequently the diagnosis was missed and treatment was delayed due to the lack of understanding of dynamic nature of PFO in LVAD patients. In this study we prospectively performed intraoperative transesophageal echocardiography (TEE) in all patients receivin LVAD (HeartMate) to determine the dynamic nature of PFO. Method: TEE was performed in our recent six consecutive patients receivin LVAD. The patients were all males, with an average age of 56. The etiologies for heart failure were ischemic cardiomyopathy in 4, acute myocardial infarction in and idiopathic cardiomyopathy in 1. A four-chamber view morphologic study and bubble contrast study were obtained in each patient before bypass and after LVAD was turned on. Oxygen saturation (O2 Sat) was recorded simultaneously as well. Bi-caval venous cannulation was used for bypass in each patient in preparation for possible PFO closure. Results: The four-chamber view reviewed that the atrial septum was bulgin towards right atrium before bypass and bulging towards left atrium after LVAD was turned on in all 6 patients. The bubble contrast study was negative for PFO in all 6 patients (0/6) before bypass and was positive for PFO in 3 out of 6 patients (3/6 after LVAD was turned on. O2 Sat was 100% in all 6 patients before bypass an was less than 90% in 2 out of 3 patients with positive PFO after LVAD was turne on. All three TEE documented PFO were confirmed grossly and surgically close during the same procedure. There were no operative death and no PFO closur related complications. Conclusions: The diagnosis of PFO by TEE in LVAD patients can be made reliably only when LVAD was turned on. Early closure of PFO in LVAD patients is important to avoid post LVAD implantation hypoxemia and its related complications. Routine bi-caval venous cannulation in LVAD implantation make closure of unexpected PFO easy.