Clinical Atlas of Cardiac and Aortic CT and MRI

Abstract

The term (nonischemic) cardiomyopathy comprises a heterogenous group of myocardial disorders that are not caused by hemodynamic disturbances such as hypertension, valve disease, obstructive coronary artery disease, or congenital heart disease and involves structural and/or functional myocardial abnormalities. The European Society of Cardiology Working Group defines cardiomyopathies according to cardiac phenotype, as follows: (1) hypertrophic cardiomyopathy (HCM); (2) dilated cardiomyopathy (DCM); (3) arrhythmogenic right ventricular cardiomyopathy (ARVC); (4) restrictive cardiomyopathy (RCM); and (5) unclassified (mainly left ventricular non-compaction and Takotsubo cardiomyopathy). Furthermore, each one of the above will be discriminated between familial and non-familial and by the disease subtype and/or gene involved (or idiopathic). This classification is summarized in Table 4.1. Cardiac magnetic resonance (CMR) has an important role in the diagnosis, classification, and risk stratification of patients with suspected or established cardiomyopathies and lacks the acoustic window limitations that can be observed with echocardiography in a number of patients. In particular, both the presence and extension of late gadolinium enhancement (LGE) are independent predictors of ventricular arrhythmia, systolic dysfunction, all-cause mortality, and sudden cardiac death. In parallel, cardiac computed tomography with late iodine enhancement offers an alternative to CMR among patients unsuitable or with contraindications for CMR, such as those with claustrophobia, non-compatible cardiac implants, obese, and end-stage renal failure. The main differences in late enhancement patterns are displayed in Fig. 4.1.