Thus, ECHO has been chosen as an ideal means to detect excessive wall thickening of cardiac muscle in HCM.For children with HCM, treatment strategies aim to reduce disease symptoms and lower the risk of sudden death. Due to the heterogeneity of the disease, treatment is usually modified according to individuals needs. β-blockers improve left ventricular filling and relaxation and thereby improve symptoms. In some children, β–blockers (e.g., propranolol) were shown effective to reduce the risk of sudden death. Further, calcium channel blockers (verapamil) and antiarrhythmic drugs may be used as an adjunct therapy to β-blockers in symptomatic children. Nonetheless, further testing is needed to determine their definitive benefits. Other animals
Cats
Feline hypertrophic cardiomyopathy (HCM) is the most common heart disease in domestic cats; the disease process and genetics are believed to be similar to the disease in humans. In Maine Coon cats, HCM has been confirmed as an autosomal dominant inherited trait. Numerous cat breeds have HCM as a problem in the breed. The first genetic mutation (in cardiac myosin binding protein C) responsible for feline HCM was discovered in 2005 in Maine Coon cats. A test for this mutation (A31P) is available. About one-third of Maine Coon cats tested for the mutation are either heterozygous or homozygous for the mutation, although many of the cats that are heterozygous have no overt evidence of the disease on an echocardiogram (low penetrance). Some Maine Coon cats with clinical evidence of hypertrophic cardiomyopathy test negative for this mutation, strongly suggesting that another cause exists in the breed.
In about 60 to 70% of the cases, cardiac MRI shows thickening of more than 15 mm of the lower part of the ventricular septum. T1-weighted imaging may identify scarring of cardiac tissues while T2-weighted imaging may identify oedema and inflammation of cardiac tissue which is associated with acute clinical signs of chest pain and fainting episodes.Pulsus bisferiens may occasional be found during examination. Variants
Depending on whether the distortion of normal heart anatomy causes an obstruction of the outflow of blood from the left ventricle of the heart, HCM can be classified as obstructive or non-obstructive. The obstructive variant of HCM is hypertrophic obstructive cardiomyopathy (HOCM), also historically known as idiopathic hypertrophic subaortic stenosis(IHSS) or asymmetric septal hypertrophy (ASH). The diagnosis of left ventricular outflow tract obstruction is usually made by echocardiographic assessment and is defined as a peak left ventricular outflow tract gradient of ≥ 30 mmHg.Another, non-obstructive variant of HCM is apical hypertrophic cardiomyopathy (AHC), also called Yamaguchi syndrome. It was first described in individuals of Japanese descent. Cardiac catheterization
Upon cardiac catheterization, catheters can be placed in the left ventricle and the ascending aorta, to measure the pressure difference between these structures. In normal individuals, during ventricular systole, the pressure in the ascending aorta and the left ventricle will equalize, and the aortic valve is open. In individuals with aortic stenosis or with HCM with an outflow tract gradient, there will be a pressure gradient (difference) between the left ventricle and the aorta, with the left ventricular pressure higher than the aortic pressure.