Abstract
Transseptal puncture is increasingly utilized in electrophysiology and interventional cardiology. With a wide range of therapeutic indications, incidence of iatrogenic atrial septal defect (iASD) is likely to increase. However, the clinical and hemodynamic significance of iatrogenic atrial septal defect is not clear. We report a case of an 88 year old woman with prior transcatheter aortic valve implantation and symptomatic severe degenerative mitral regurgitation. She developed persistent hypoxemia following MitraClip ® procedure, requiring closure of iASD resulting in immediate recovery of hemodynamics. In here, we discuss the hemodynamic changes following percutaneous mitral valve repair and review the evidence supporting the closure of iatrogenic atrial septal defects.
Highlights
- •
Usually iatrogenic atrial septal defects (iASD) are small and of no clinical significance
- •
Preprocedural severe pulmonary hypertension can lead to refractory hypoxemia from hemodynamically significant right to left shunting
- •
Post procedural imaging of these defects and assessment of size, magnitude and direction of the shunt is recommended
- •
Closure of iASD is beneficial in the presence of refractory hypoxemia
88 year old Caucasian female with past medical history of hypertension, paroxysmal atrial fibrillation (PAF) presented with decompensated congestive heart failure (New York Heart Association Class IV symptoms). Cardiac examination was remarkable for harsh ejection systolic murmur along the left sternal border and pan systolic murmur at the apex. Her vital signs were stable. Transesophageal echocardiogram (TEE) showed severe calcific aortic stenosis (AS) and severe degenerative mitral regurgitation (MR) with preserved left ventricular ejection fraction. Mitral valve appeared to be myxomatous with a flail and prolapsing P2 segment. Color Doppler showed eccentric jet anteriorly directed consistent with posterior leaflet pathology. Proximal isovelocity surface area (PISA), effective regurgitation orifice area (EROA) and regurgitant volume (RV) were consistent with severe MR. Estimated right ventricular systolic pressure (RVSP) was 90 mmHg (tricuspid regurgitation (TR) Vmax 4.5 m/s). Society of Thoracic Surgeons (STS) score was 8% (high risk) in addition to her frailty and elevated pulmonary pressures. She successfully underwent a transapical transcatheter aortic valve implantation (TAVI) with balloon expandable valve (Edwards Sapien #26 mm, Edwards Lifesciences Corporation, Irvine, CA). Four months later, MR continued to be severe with NYHA class III symptoms. Left and right heart catheterization showed elevated wedge pressure (25 mmHg) with prominent V wave and elevated pulmonary artery pressures (55/24 mmHg). RVSP continued to be elevated at 60 mmHg (TR Vmax 3.5 m/s). She successfully underwent transcatheter edge to edge mitral valve repair (MitraClip ® , Abbott Vascular, Santa Clara, CA) through right femoral transvenous transseptal approach with reduction to MR < 2 + and mean gradient of 4 mm gradient across the mitral valve. Per standard cath lab protocol, residual ASD size measured at the end of the procedure was 7 mm.
Despite successful clip delivery, patient could not be extubated in the operating room which is standard protocol in our institution. Limited 2D transthoracic echocardiogram (TTE) was performed after she was moved to the recovery room which revealed trace MR and no evidence of device embolization, pericardial effusion or great vessel injury. Further, arterial blood gas analysis demonstrated persistent hypoxemia (O2 saturation 85%) despite FiO2 100% and positive end expiratory pressure of 10 mmHg. She was brought back to the operating room after a brief stay in the recovery area and a TEE demonstrated the iatrogenic atrial septal defect demonstrating a bidirectional shunt with a predominant right to left component ( Fig. 1 ). Patient’s hemodynamics improved instantaneously with positioning the delivery sheath over a wire across the defect, confirming our clinical suspicion. We closed the defect with an 8 mm Atrial Septal Occluder device (Amplatzer™ Septal Occluder, St. Jude Medical, St Paul, MN) ( Fig. 2 ). Septal Occluder device was chosen as it has a higher waist to disc ratio than cribriform device, thereby reducing the risk for erosion given the posterior and superior location of the defect in the atrial septum. Typically, a sizing balloon is indicated in congenital septal defects to assess size, and also the compliance and stiffness of the defect. However in this instance, it was iatrogenic and hence we did not think balloon sizing would be necessary. She was extubated on the table in the operating room following successful defect closure. Follow up at 6 months showed that she was living independently with NYHA class I symptoms and improved quality of life by Kansas City Cardiomyopathy Questionnaire and her MR was trace with an RVSP of 40 mmHg.
