Hypertrophic Cardiomyopathy

Abstract

Hypertrophic cardiomyopathy (HCM) is a common genetic cardiomyopathy caused by mutations in genes which encode for the myofi lament protein components of the sarcomere or the z-disc [ 1 -4 ]. It has a prevalence of 1 in 500 in the general population and is a global disease affecting patients in all continents [ 5 ] and of both genders [ 6 ]. It is the leading cause of sudden death in young people, with an annual mortality rate of 1 % [ 7 ]. Since its fi rst description over 50 years ago, the pathophysiology of the disease is still incompletely understood [ 8 ]. The disease is associated with tremendous heterogeneity with regard to its presentation, phenotype, and prognosis. The diagnosis for HCM is usually made clinically after symptom onset or cardiac events, but may also be found after routine 12-lead electrocardiogram (ECG), heart murmur on cardiac exam, or in family screening of probands. ImagingClinical diagnosis is confi rmed through imaging using 2D echocardiography and/or cardiac MRI (CMR) or CT by identifying an increase in left ventricular (LV) wall thickness ≥15 mm (mean ~22 mm [normal ≤12 mm]) without a dilated LV chamber in absence of other cardiac or systemic disease processes (e.g., aortic stenosis, chronic hypertension) capable of producing the magnitude of hypertrophy [ 9 ]. In certain instances, such as patients with a family history of HCM, a maximal wall thickness ≥13 mm may be compatible with the diagnosis of HCM. LV hypertrophy is most commonly asymmetric, with the most common location of increased wall thickness occurring in the contiguous area of the basal anterior septum and anterior wall [ 10 ] (Fig. 16.1 ), although there is tremendous heterogeneity in phenotypic expression, even in those with a common genotype. In addition, in close to 25 % of HCM patients, segments of LV hypertrophy can be separated by myocardial regions of normal thickness, i.e., noncontiguous pattern of LV hypertrophy. Concentric pattern of LV hypertrophy occurs very rarely in HCM (~1 %) [ 11 , 12 ] (Fig. 16.2 ).

Alcohol Septal Ablation versus Septal Myectomy Treatment of Obstructive Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

“…Hypertrophic cardiomyopathy (HCM) is the most common inheritable heart disease characterized by left ventricular (LV) hypertrophy, diverse clinical presentation and hemodynamic abnormalities [ 1 ]. Left ventricular outflow tract obstruction (LVOTO) is a characteristic feature of many patients with HCM [ 2 ]. Significant LVOTO is associated not only with symptoms such as chest pain, dyspnea and fatigue, but also with increased risk for all-cause mortality, cardiovascular (CV) mortality, sudden cardiac death (SCD) and other CV complications [ 3 , 4 , 5 ].…”