Carbon Monoxide-Induced Cardiomyopathy: Epidemiology, Clinical Characteristics and Prognosis

Background: Previous reports demonstrated mechanisms of cardiac toxicity in acute carbon monoxide (CO) poisoning. Still, none established CO-induced cardiomyopathy (CMP) as a clinical entity. The aim of this study is to investigate CO-induced CMP in patients with acute CO poisoning in terms of its epidemiology, clinical characteristics, and prognosis. Methods and Results: A retrospective study was conducted on consecutive patients who were diagnosed with acute CO poisoning at the emergency department of Ajou University Hospital during the period of 62 month. Six hundred and twenty-six patients were diagnosed with acute CO poisoning. During the initial echocardiography, 19 patients were abnormal: (1) global hypokinesia/akinesia (n=7), (2) regional wall hypokinesia/akinesia [n=12; takotsubo type (n=6), reverse takotsubo type (n=2), non-specific type (n=4)]. The ejection fraction (EF) was 36.3±13.5% (from 15% to 55%) and less than 45% for 14 patients. In the follow-up echocardiography performed within 12 days after the initial performance, most patients were found to have cardiac wall motion abnormalities, and their EF had returned to normal (ie, EF ≥50%). Conclusions: CO-induced CMP was identified in 3.04% (n=19) of all patients (n=626). It might not be too critical in acute clinical courses of acute CO poisoning because the prognosis seems favorable. Considering the common factors between CO-induced CMP and takotsubo CMP, myocardial stunning subject to a catecholamine surge most likely plays a central role in the development of CO-induced CMP. (Circ J 2014; 78: 1437–1444)