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Question 1

What is cardiomyopathy?

Answer 1

A heterogenous group of diseases that affect the myocardium, leading to cardiac dysfunction, arrhythmias, heart failure, and sudden cardiac death.

Question 2

What are the classifications of cardiomyopathies?

Answer 2

Primary cardiomyopathy and Secondary cardiomyopathy.

Primary cardiomyopathy can be genetic, acquired, or mixed, while secondary cardiomyopathy develops due to another health condition.

Question 3

Name the types of primary cardiomyopathies.

Answer 3

• Dilated cardiomyopathy (DCM)
• Restrictive cardiomyopathy (RCM)
• Arrhythmogenic right ventricular cardiomyopathy (ARVC)
• Hypertrophic cardiomyopathy (HCM)

Question 4

What characterizes dilated cardiomyopathy (DCM)?

Answer 4

Thinness of heart muscle, left ventricular dilatation, and impairment of systolic function.

Question 5

What is the most common cause of dilated cardiomyopathy?

Answer 5

Most cases are familial and follow an autosomal dominant inheritance pattern.

Question 6

List clinical features of dilated cardiomyopathy (DCM).

Answer 6

• Decrease exercise capacity
• Fatigue
• Dyspnea
• Paroxysmal nocturnal dyspnea
• Abdominal bloating

Question 7

What defines restrictive cardiomyopathy (RCM)?

Answer 7

Heart muscle becomes rigid and unable to relax and fill with blood, with reduced diastolic but no alteration of systolic function.

Question 8

What are the clinical features of restrictive cardiomyopathy (RCM)?

Answer 8

• Fatigue
• Exercise intolerance
• Dyspnea
• Syncope
• Palpitation

Question 9

What characterizes arrhythmogenic right ventricular cardiomyopathy (ARVC)?

Answer 9

Progressive replacement of myocardium with adipose and fibrous tissue, disrupting normal electrical signals in the heart.

Question 10

What is hypertrophic cardiomyopathy (HCM)?

Answer 10

A genetic heart condition characterized by thickened heart muscle, with a prevalence of 1:200-1:500 in the world population.

Question 11

What are the types of hypertrophic cardiomyopathy (HCM)?

Answer 11

• Obstructive (HOCM)
• Non-obstructive HCM

Question 12

What causes left ventricular outflow tract (LVOT) obstruction in HCM?

Answer 12

Left ventricular hypertrophy and abnormalities of the mitral valve causing a narrowing of the outflow track from the left ventricle to the aorta.

Question 13

List symptoms of hypertrophic cardiomyopathy (HCM).

Answer 13

• Arrhythmia
• Chest pain
• Fatigue
• Fluttering or pounding feeling in the chest
• Heart murmur
• Dizziness
• Fainting
• Shortness of breath
• Swelling in feet, ankles, legs, belly, or neck

Question 14

True or False: Patients with HCM are at risk for sudden cardiac death.

Answer 14

True

Question 15

What is the most common cause of sudden cardiac death in people under age 35?

Answer 15

Hypertrophic cardiomyopathy (HCM)

Question 16

What is the molecular genetic basis of HCM?

Answer 16

HCM is caused by more than 1,400 mutations in 11 or more genes encoding proteins of the cardiac sarcomere.

Question 17

What is the first identified mutation for familial HCM?

Answer 17

Mutation in the MYH7 gene (p.Arg403Glu mutation).

Question 18

What does the MYH7 gene encode?

Answer 18

β-Myosin heavy chain, found in cardiac muscle and type I skeletal muscle fibers.

Question 19

What is the function of MyBP-C3 in HCM?

Answer 19

Regulates contraction/relaxation and cross-bridge formation between myosin heads and actin.

Question 20

Fill in the blank: HCM is characterized by mis-array of _______.

Answer 20

myocytes

Question 21

What are the common complications of hypertrophic cardiomyopathy (HCM)?

Answer 21

• Arrhythmias
• Heart failure
• Sudden cardiac death