P102: Hemodynamic Ramp Studies in Continuous Flow Ventricular Assist Device in Fontan Patients: A Case Series

Abstract

Purpose: There is limited experience in patients with single ventricle physiology using the Heartmate III (HM3). With a growing population of failing Fontan patients and long wait times for cardiac transplantation, the need for an appropriate strategy for durable mechanical support is increasing. Determination of the best strategies to optimize the HM3 device in Fontan circulation has not yet been elucidated. Methods: A retrospective case series of three patients with failing Fontan on VAD who underwent ramp studies by cardiac catheterization were reviewed with the intent of optimizing hemodynamics. Results: All patients had hypoplastic left heart syndrome, completed Fontan, and were on durable VAD. Patient 1 was a 19y male on a Heartware at 2640 rpm. Initial hemodynamics with a PCWP of 25 mmHg and Fontan pressure of 25 mmHg. Increase in RPM to 2900 bpm showed no change in Fontan pressure and decrease in PCWP to 20 mmHg. No change on adjustment back to 2700 RPM though improvement noted in tricuspid regurgitation in echocardiogram. Patient 2 was a 13y male on HM 3 at 5000 rpm with PCWP 15 mmHg and Fontan 19 mmHg. Tricuspid regurgitation on echocardiogram improved from moderate to mild and final VAD speed was 5200 RPM. Patient 3 was a 12y male on HM3 at 5100 rpm with PCWP of 15 mmHg and Fontan 18 mmHg. Increase up to 5500 RPM with no change in PCWP and Fontan at 17mmHg. Final speed at 5200 RPM with PCWP of 14mmHg and Fontan 17 mmHg. Conclusions: Significant hemodynamic changes on catheterization ramp study were not found. Increase in support from the VAD was made due to clinical indications and echocardiographic assessment of atrioventricular valve regurgitation. Hemodynamic data was useful in reassuring that changes made to the device were not detrimental to the patient. Further data on ramp studies and indications for changes in device speed will be useful in the care of these patients.