Internal Medicine Resident Houston, Texas, United States
Disclosure(s):
Babivigasan Gunasegaran, MD: No financial relationships to disclose
Background: Right ventricular myocardial infarction (RVMI) due to proximal right coronary artery (RCA) occlusion may result in severe cardiogenic shock. Early risk stratification using multiple tools, such as echocardiography, right heart catheterization, and the Pulmonary Artery Pulsatility Index (PAPI), can help to identify patients who may benefit from mechanical circulatory support.
Methods: We report the case of a 32-year-old male with a past medical history of alcohol, amphetamine, and benzodiazepine abuse who presented with cardiogenic shock secondary to inferior myocardial infarction. The patient was brought in by his roommate, who stated that he was driving the patient home and found the patient unresponsive and without a pulse. He called EMS and started CPR.
Upon arrival to the ED, electrocardiography revealed ST-segment elevations in leads II, III, and aVF, consistent with RVMI. Emergent coronary angiography identified a total occlusion in the proximal RCA, which was successfully treated with two drug-eluting stents, resulting in restored TIMI-3 flow.
Even with the use of vasopressors and inotropes, he continued to be hypotensive, and the decision was made for Impella placement. Despite revascularization, optimized pharmacologic therapy, and Impella support, the patient remained in refractory cardiogenic shock. Transthoracic echocardiography done the following day demonstrated severe biventricular dysfunction with a left ventricular ejection fraction of less than 20%. Invasive hemodynamic assessment showed a PAPI of 0.54, indicating severe right ventricular failure. Given the severely reduced PAPI and profound ventricular dysfunction, ECPELLA support was initiated to provide biventricular unloading and maintain systemic perfusion.
Outcome: Following the initiation of ECPELLA, the patient demonstrated rapid hemodynamic stabilization, with improvements in mean arterial pressure, a decrease in lactate from 3639 IUnits/L to 680 IUnits/L, and improved end-organ perfusion. His vasopressor and inotrope requirements progressively decreased with norepinephrine being stopped the day after ECPELLA initiation and dobutamine being stopped another day later. In total, the patient was on Impella alone for 3 days, followed by ECPELLA for 1 day.
A repeat transthoracic echocardiogram performed one day after ECMO was stopped demonstrated marked recovery of ventricular function, with improvement of left ventricular ejection fraction to 60-64% and significant recovery of right ventricular systolic function. By this point, the patient’s shock liver had completely resolved, he was able to be extubated, and the only remaining complication was acute renal failure for which he was started on hemodialysis.
Conclusion: This case demonstrates that early identification of patients with high-risk RVMI using PAPI and echocardiography can guide timely escalation to ECPELLA in cases of refractory cardiogenic shock. Prompt mechanical circulatory support can help facilitate patient recovery and may even be lifesaving in select patients with RVMI complicated by refractory shock.
