Table 1.
Autopsy-based definitions of the subtypes of nonischemic heart disease (NIHD).
| Causes of nonischemic SCD | Definition of the subtype of NIHD based on autopsy |
|---|---|
| Hypertensive CM | LVH, increased heart weight, unspecific fibrosis, other organ changes related to hypertension (e.g. arterial medial hypertrophy, intimal fibrosis in renal arterioles). |
| CM related to obesity | LVH or both left and right ventricular wall hypertrophy, increased heart weight, dilation of ventricles and atria, excessive epicardial and myocardial fat, obesity. |
| Alcoholic CM or unspecified CM | Focal replacement fibrosis of the myocardium, increased heart weight and LVH. In later stages, signs of dilated cardiomyopathy, other organ changes related to excessive long-term alcohol consumption (e.g. liver cirrhosis and/or severe steatosis, pancreatic fibrosis). |
| Fibrotic CM | Diffuse, interstitial or patchy myocardial fibrosis without myocardial scarring, LVH, or other apparent cause for fibrosis. |
| DCM | Left ventricular dilation with inadequate degree of LVH, unspecific fibrosis and focal atrophy or hypertrophy of myocytes. In later stages, pale and flabby myocardium and dilation of ventricles and atria. |
| HCM | Concentric LVH with myocyte disarray and various degrees of interstitial fibrosis, often asymmetrical septal hypertrophy. |
| Myocarditis | Inflammatory infiltration of the myocardium with necrosis and/or degeneration of the adjacent myocytes. |
| Valvular heart disease | Aortic or mitral valve calcification |
| ARVC | Right ventricular dilation, right ventricular myocardial atrophy with fibro fatty replacement of myocytes. |
| Anomalous coronary arteries | Anomalies of origination, course or coronary termination. Anomalous collateral vessels, anomalies of intrinsic coronary arterial anatomy. |
| Structurally normal heart | Macroscopically and microscopically normal heart with or without long QT syndrome mutations |
ARVC: Arrhythmogenic right ventricular cardiomyopathy; CM: cardiomyopathy; DCM: dilated cardiomyopathy; HCM: hypertrophic cardiomyopathy, LVH: left ventricular hypertrophy.