Background: Unexplained cardiac arrests in deceased patients are often attributed to their underlying disease. However, it is well known that autopsies can reveal pathologies that were not noticed before death.

Case Summary: Multiple micro-scars (MMS) found in the myocardium of 3 patients who died of unexplained cardiac arrest were presented in our clinicopathology conference. Upon review of the clinical record, patients with MMS before their death had arrhythmia i.e., atrial fibrillation, non-sustained ventricular tachycardia including newly onset. Interestingly, MMS were found in the left ventricle, junction of pulmonary vein and left atrium, right ventricle and right atrium. All 3 patients had a history of COVID-19 booster vaccination, and one of the 3 patients had a history of COVID-19 infection.

Discussion: For patients with unexplained cardiac arrest complicated with arrhythmia, cardiac MMS is given as the differential background disease

JACC Case Reports Interim Editors-in-Chief 

Gilbert H. L. Tang, MD, MSc, MBA

CME Editor 

Kenneth A. Ellenbogen, MD

Author

Gbemiga G. Sofowora, MBChB

 Important Dates

Date of Release: March 5, 2025 

Term of Approval/Date of CME/MOC Expiration: March 4, 2026