Cardiac Tamponade Totalis: Unique Phenomenon of Biventricular Tamponade After LVAD Implant

Abstract

<h3>Introduction</h3> Cardiac tamponade results in obstructive shock due to cardiac chamber compression and impaired cardiac output. This commonly involves the RV due to its lower pressure. We report the first case of biventricular tamponade in a patient with a LVAD. <h3>Case Report</h3> A 30 yr old female (ht 4'7", wt 32 kg, BSA 1.13 m²) with inotrope dependent non-ischemic cardiomyopathy presented for heart transplant evaluation. Right heart catheterization on milrinone 0.375 mcg/kg/min was notable for RA 32 mmHg, PA 51/30 (37) mmHg, PCWP 34 mmHg, CI 1.2 L/min/m², PVR 1.8 Wood units. She was listed for cardiac transplant as her vessels were too small for percutaneous peripheral short term mechanical circulatory support. She decompensated needing VA-ECMO and then HeartWare LVAD implantation (speed 2300 RPM). 7 days post operatively, low flow alarms occurred with hypotension requiring escalating doses of ino-pressors. Echocardiography revealed a large circumferential pericardial effusion resulting in biventricular collapse (Figure A). Emergent surgical drainage was performed with 500 ml blood removal, resulting in re-expansion of both ventricles (Figure B). <h3>Summary</h3> To our knowledge this is the first report of biventricular cardiac tamponade, or as we have termed it, tamponade totalis. In the presence of a pericardial effusion, continuous LV unloading via a LVAD can cause the LV pressure to be lower than the pericardial pressure. Coupled with reduced RV preload from post-operative bleeding, this results in biventricular compression and tamponade. A combination of patient (size, anticoagulation, surgical approach) and pump (RPM) related factors likely lead to the development of tamponade totalis. Diagnosis of tamponade in a patient with a continuous flow LVAD is challenging due to similarities in presentation of right heart failure and atypical signs. Unique clues suggestive of tamponade in patients with a LVAD are respiratory variation of the pulsatilitiy index waveform and pulseless paradoxus. Imaging is key to diagnosis.