From the Guidelines
Hypertrophic cardiomyopathy (HCM) and heart failure (HF) are distinct cardiac conditions, with HCM being a specific disease characterized by abnormal thickening of the heart muscle, and HF being a clinical syndrome representing the end stage of various heart diseases. The main difference between the two conditions lies in their underlying pathophysiology and clinical presentation. HCM is often due to genetic mutations in sarcomere proteins, leading to thickening of the heart muscle, particularly the left ventricle, which can cause stiffening of the heart walls, obstruction of blood flow, and impaired filling 1. On the other hand, HF is a broader clinical syndrome characterized by symptoms like shortness of breath, fatigue, and fluid retention, resulting from the heart's inability to pump enough blood to meet the body's needs.
Some key features of HCM include:
- Abnormal thickening of the heart muscle, particularly the left ventricle
- Often due to genetic mutations in sarcomere proteins
- Can lead to stiffening of the heart walls, obstruction of blood flow, and impaired filling
- May progress to heart failure with extensive myocardial scarring and systolic dysfunction 1
In contrast, HF can result from various underlying conditions, including:
- Coronary artery disease
- Valve disorders
- Other types of cardiomyopathy
- Advanced hypertrophic cardiomyopathy
It is essential to note that HCM can eventually lead to HF, particularly in cases where there is extensive myocardial scarring and systolic dysfunction 1. However, HF can also result from many other conditions, making it a more broadly defined clinical syndrome. The natural history of HCM can be altered by various therapeutic interventions, including implantable cardioverter-defibrillators (ICDs), drugs to control heart failure symptoms, surgical septal myectomy or alcohol septal ablation, and heart transplantation 1.
The clinical distinction between HCM and HF is crucial, as it guides treatment decisions and prognosis. The management of HCM focuses on controlling symptoms, preventing sudden cardiac death, and addressing underlying structural abnormalities, whereas the management of HF focuses on improving cardiac function, reducing symptoms, and slowing disease progression. Overall, while HCM and HF are related but distinct conditions, understanding their differences is essential for providing optimal patient care.
From the Research
Definition and Characteristics
- Hypertrophic cardiomyopathy (HCM) is a complex heterogeneous cardiovascular disorder characterized by hypertrophied and disorganized myocytes with varying degrees of interstitial fibrosis 2.
- HCM is the most common cause of sudden unexpected death in childhood and has significantly higher sudden death mortality in the 8- to 16-year age range than in the 17- to 30-year age range 3.
Comparison with Heart Failure
- Heart failure (HF) is not directly defined in the provided studies, but it is mentioned as a potential complication of HCM, particularly in patients with severe generalized hypertrophy 3.
- Calcium-channel blockers, which are sometimes used to treat HF, can increase the risk of HF-associated death in HCM patients with severe generalized hypertrophy and should be avoided in such patients 3.
Treatment and Management
- The current management strategies for HCM include genetic and familial screening, symptom control, and prevention of sudden cardiac death in those at high risk 2.
- Beta-blocker therapy with lipophilic beta-blockers has been shown to significantly reduce the risk of sudden death in HCM patients 3.
- Verapamil, a calcium channel blocker, may be used as a second-line therapy for HCM, but its use should be cautious and monitored due to potential deleterious effects 4.
Risk Assessment and Stratification
- Risk stratification models, such as the HCM Risk-SCD calculator, have been proposed to assess the risk of sudden cardiac death in HCM patients 5.
- Apical hypertrophic cardiomyopathy (ApHCM) represents a complex subset of patients, whose risk of sudden cardiac death seems not negligible, and may require additional predictors of rhythmic risk 6.