Nonspecific Cardiomyopathy: A Common Cause of Death with a Need for Standardization of Terminology.
Julia Shields, Ling Li, David R Fowler, Yang Zhang, Allen P Burke. University of Maryland, Baltimore; Maryland Office of the Chief Medical Examiner, Baltimore; University of Maryland School of Medicine, Baltimore
Background: The terminology and classification of sudden cardiac deaths in patients with cardiomegaly as the primary cause of death have not been clarified.
Design: A retrospective review of autopsy records from a single calendar year at a state-wide medical examiner's office was performed. Cases of sudden cardiac deaths were retained for study. Causes of death and cardiac findings were tabulated, and cases with potential noncardiac causes, such as drug and alcohol related deaths, were excluded. Cases with coronary atherosclerotic disease (≥1 vessel with ≥75% luminal area narrowing) were excluded. Cardiomegaly was determined based on body height and weight; mild cardiomegaly was defined as <50 grams above the 95% upper limit; moderate: 50-99 grams; marked: 100-200 grams; and massive: >200 grams above the limit, respectively. The incidence, demographics and terminology applied for these deaths was analyzed.
Results: Among 484 sudden cardiac deaths, 241 deaths (50%) had severe atherosclerosis, 41 arrhythmia/ sudden adult death syndrome (8%), 15 valvular disease (3%), 19 inflammatory or specific cardiomyopathy (4%) and 5 miscellaneous causes (1%). 161 deaths were due to nonspecific cardiomyopathy (NSC) (33%). Hypertrophic cardiomyopathy was excluded based on the lack of septal asymmetry and myofiber disarray. Of NSC cases, the mean age was 46 ± 12 years; there were 104 males and 57 females; 45% were African American. A history of hypertension was present in 66 cases (47%). The mean body mass index (BMI) was 33.5 ± 10.6. The mean heart weight was 572 ± 150g. Twelve percent of decedents had a remote history of alcohol abuse. Twenty-seven percent of the nonspecific cardiomyopathy deaths were witnessed and 1.2% were exertion related deaths. The autopsy reports listed a variety of terms, including left ventricular hypertrophy, arrhythmia associated with cardiomegaly, dilated cardiomegaly, hypertensive cardiovascular disease, and nonischemic cardiomyopathy.
Conclusions: Approximately one third of sudden cardiac deaths are secondary to nonspecific cardiomyopathy; however, a uniform nomenclature for the causes of death in these cases is lacking. The term nonspecific cardiomyopathy is recommended for use in such cases, with risk factors such as hypertension, obesity and alcoholism listed as contributing factors.
Monday, February 28, 2011 1:30 PM
Platform Session: Section G, Monday Afternoon