Abstract 27: Pathological Findings Of Ventricular Fibrillation In Pts Without Coronary Heart Disease
To clarify histological characteristics in pts (pts) with out-of-hospital cardiac arrest , autopsies were immediately performed in 224 pts. We studied the cause of their sudden death investigating the incidence and the role of following pathological findings in 125 pts with sudden cardiac death (SCD). There were 95 men and 30 women aged from 16 to 93 years old (mean age : 60.3 ± 14.8 years old). Evaluated pathological findings were 1) myofiber break-up (MFB), 2) contraction band necrosis (CBN), 3) contraction band (CB), 4) hypereosinophilic myofiber (HEM). MFB and CBN are known to indicated hypercontracted myofibers due to ventricular fibrillation (VF) associated with acute myocardial infarction (AMI). The latter two findings were not considered to indicate severe myocardial damage as defined by MFB and CBN. Postmortem autopsies revealed AMI in 24 pts, old myocardial infarction (OMI) in 24 pts but coronary heart disease (CHD) was not observed in 77 pts including 2 pts with hypertrophic cardiomyopathy. Cardiac rupture was observed in 16 out of 24 pts with AMI. MFB was not observed in pts with AMI but it was observed in 2 pts with OMI and 28 pts without CHD. CBN was observed in 4 pts with AMI, 13 pts without CHD but not in pts with OMI. CB and HEM were observed diffusely in both ventricles except subendocardium in all 77 pts without CHD and 24 pts with OMI but in only 7 pts with AMI in whom cardiac rupture was not observed. Ischemic event to induce VF could not be confirmed in pts without CHD and in pts with OMI in this study.Therefore, CB and HEM were considered to be the pathological evidence of VF not related to CHD.
Conclusions: Cardiac rupture was the major reason of sudden death in pts with AMI rather than VF. In pts without CHD, the mechanism of SCD was considered to be VF. Nonischemic SCD was more frequently than SCD related to AMI in Japan.