The diagnosis and treatment of hypertrophic cardiomyopathy

Abstract

Background: Hypertrophic cardiomyopathy (HCM) is the most common hereditary disease of the heart.

Methods: In this article, we summarize the current state of the diagnosis and treatment of HCM on the basis of a selective review of recent publications with relevance to clinical practice.

Results: Several hundred mutations in more than 27 genes, most of which encode sarcomeric structures, are associated with the HCM phenotype. Thus, HCM can be thought of as a sarcomeric disease, with myocardial fiber disarray as its histological hallmark. There are two types of HCM, a more common, obstructive type (HOCM, 70%) and a less common, non-obstructive type (HNCM; in all cases of HCM, testing should be performed to detect outflow obstruction at rest and/or on provocation, and to thereby determine whether HOCM or HNCM is present. The symptoms of HCM include dyspnea, angina pectoris, palpitations, dizziness, and occasionally syncope. Because sudden cardiac death is the most serious complication of HCM, particularly in young and asymptomatic patients, it follows that correct diagnosis, followed by risk stratification of patients with regard to the need for prophylactic implantation of an implantable cardiac defibrillator (ICD), can be of life-saving importance. The pharmacotherapy of symptomatic HNCM consists of the treatment of heart failure with a normal ejection fraction (HFNEF). In HOCM, the patient's symptoms and the obstructive gradient are the guide to treatment with beta-blockers or verapamil. For patients with drug-resistant disease, surgical myectomy and percutaneous septal ablation are now standard treatments.

Conclusion: A near-normal life expectancy and a highly satisfactory quality of life are now realistic treatment goals for patients with HCM.

Figure 1

Patient with extreme left ventricular wall hypertrophy. Such pronounced hypertrophy is rather rarely encountered

Figure 2

Clear septal fibrosis in a patient with hypertrophic cardiomyopathy verified using cardiac MRI (delayed enhancement)

Figure 3

Documentation of an aortic and a ventricular pressure curve with evidence of postextrasystolic potentiation (Brockenbrough sign)

Figure 4

LV angiogram of a patient with HCM

Figure 5

Documentation of an aortic and a ventricular pressure curve after performing alcohol ablation with no evidence of a significant pressure gradient following the intervention

Figure 6

Echocardiogram of a patient (a) before and (c) after septal myectomy. Echocardiogram (b) before and (d) after septal alcohol ablation