Abstract Body (Do not enter title and authors here): Background:
Ventricular stunning refers to a transient mechanical dysfunction of the myocardium, typically manifesting in response to ischemic insults, reperfusion injury, inflammatory states, or neurohormonal overload. Here, we present an unusual case of ventricular stunning precipitated by direct current electrical cardioversion (DEC).

Case Report:
A 73-year-old man with a history of heart failure with reduced ejection fraction, paroxysmal atrial fibrillation (AF), coronary artery disease, and chronic kidney disease was admitted to a Veterans Affairs hospital for heart failure exacerbation. His hospitalization was complicated by recurrent episodes of symptomatic AF with ventricular rates in the 120-150’s. This was initially managed with intravenous amiodarone and eventually DEC. He continued to experience symptomatic episodes of AF. Later in the hospitalization a repeat DEC with a single 200 joule shock was performed with restoration of sinus rhythm. Several hours afterwards he was found to be unresponsive and hypotensive. Cool extremities and rising serum lactate raised suspicion for cardiogenic shock resulting in transfer to the intensive care unit where vasopressor and inotropic support were initiated. Echocardiogram revealed a precipitous decrease in left ventricular ejection fraction from 25% to 5%. Serum troponin concentrations were unchanged from prior and ECGs demonstrated rate-controlled AF.

Clinical Decision Making:
This case highlights an episode of unexpected decrease in cardiac output following an otherwise routine repeat DEC for recurrent AF requiring escalation to mechanical circulatory support. His decompensation worsened, necessitating transfer to the local university center for placement of catheter-based miniaturized ventricular assist device (Impella 5’5). Over the subsequent days, with supportive care, his left ventricular ejection fraction recovered to baseline, and mechanical and inotropic support were withdrawn.

Conclusion:
Ventricular stunning, leading to cardiogenic shock, is a rare and incompletely understood complication of DEC. It warrants consideration when monitoring patients after cardioversion. Implementing vigilant observation protocols post-DEC to detect ventricular stunning and predisposing risk factors could significantly enhance clinical management strategies.