Early Identification and Implementation RVAD-MCS in Acute RV Shock
Presenter
Ahmed Noor, University of Kentucky College of Medicine - Lexington, Lexington, KY
Ahmed Noor, Jad Ballout and Benjamin Stoner, MD, University of Kentucky College of Medicine - Lexington, Lexington, KY
Title
- Early Identification and Implementation RVAD-MCS in Acute RV Shock
Introduction
We describe a 67 year old female who developed acute RV dysfunction after inferior STEMI. Right ventricular dysfunction was recognized early and proceeded with Right Ventricular Assist Device (RVAD) cannulation preventing irreversible organ dysfunction and successful bridge to recovery. Early recognition and MCS implementation in isolated acute RV shock is key as this post MI subgroup may portend a more favorable prognosis.
Clinical Case
A 67 year old female with a medical history diabetes mellitus and hypertension who presented to the hospital with chest pain and syncope. She was found to have inferior STEMI, complete heart block and underwent successful percutaneous coronary intervention. Shortly thereafter, she required increased doses of catecholaminergic medication and high levels of ventilatory support. Transthoracic echocardiography demonstrated moderate mitral regurgitation, normal LV systolic function and dilated and dysfunctional RV. There was no evidence of ventricular septal defect. The patient was taken to the catheterization lab where the following hemodynamics were obtained: RA 18 mmHg, PA 48/27 mmHg, PCWP 19 mmHg, cardiac output 3.26 L/min, cardiac index 1.9 L/min/m2. We then proceeded with insertion of Protek-Duo RVAD from a right internal jugular approach. Immediate post insertion hemodynamics demonstrated a mild increase in PCWP to 20 mmHg. The central venous pressure reduced to 16 mmHg. The patient was managed in our CCU for the next several days. After 2 days the temporary pacing wire was removed. Preload was optimized with intermittent diuresis. On day 5 the central venous pressure was 13 mmHg. A weaning trial was pursued by reducing the RPMs and subsequent flow being ~2L/min for 6 hours. Post-trial mixed venous oxygen saturation was 62%. Successful decannulation was performed and no recurrence of shock or congestion for the remainder of hospital admission.
Discussion
Acute right ventricular dysfunction is a recognized complication after myocardial infarction. In the revascularization era, RV dysfunction is most often reversible after resolution of stunning. The cardiac output reduction is mild as LV function is preserved in most cases. Prolonged low output will lead to tissue anoxia and multi-organ dysfunction. Herein lies the role of RV-MCS. When identified early, increasing LV preload via RVAD provides tissue perfusion while giving time for the RV to recover. After the development of shock and hypoxemia, our patient was recognized to be developing RV failure. We quickly cannulated with Protek-Duo RVAD as a bridge to recovery. The device additional benefit includes an addition of an oxygenator thus creating a veno-venous ECMO circuit. If VQ mismatching did not improve this may have been pursued. RVAD-MCS should be considered first line when assessing post MI RV failure.