Cardiomyopathies

Question 1

types of cardiomyopathies

Answer 1

• hypertrophic

- dilated

Question 2

symptoms of HCM

Answer 2

• tachypnea
• pallor
• syncope

Question 3

aetiology of HCM

Answer 3

• familial (mutations in the sarcomeric protein genes; usually autosomal dominant; age-related penetrance)
• sporadic (inaccurate family history; incomplete penetrance)
• genetic (can be pre-existing in the family or is de novo)

Question 4

interrelated abnormalities in HCM

Answer 4

• left ventricular outflow tract (LVOT) obstruction
• diastolic dysfunction
• mitral regurgitation
• myocardial ischaemia
• arrhythmias

Question 5

what is happening to the heart when there is HCM?

Answer 5

• the LV has hypertrophied more than the RV and thus, there is asymmetry
• the septum would thicken as well
• the contractions would obstruct the outflow tract due to the asymmettical septum
• when blood moves out into the artery, the coronaries cannot receive blood because of the obstruction
• this causes the diastolic dysfunction

Question 6

what are patients with HCM at risk of?

Answer 6

• developing a lethal arrhythmia

- lowered ejection fraction

Question 7

definition of HCM

Answer 7

• unexplained LV wall thickness >15mm
• septal/posterior wall thickness ratio >1.3 in normotensive patients
• septal/posterior wall thickness ratio >1.5 in hypertensive patients

Question 8

definition of HCM in children

Answer 8

wall thickness >2 standard deviations above the mean for age, sex and body size

Question 9

what is DCM?

Answer 9

• poorly contracting dilated left ventricle

- normal or reduced ventricular wall thickness

Question 10

causes of DCM

Answer 10

• idiopathic
• alcohol
• genetic: single-gene
• coronary artery disease
• infections (Coxsackie virus, adenovirus, parvovirus)
• nutritional deficiency
• cardiotoxins (anthracyclins)
• puerperium
• metals (Co, Pb, Hg, As)
• autoimmune and systemic disorders
• pheochromocytoma

Question 11

histopathologic features of DCM

Answer 11

• globular-shaped heart
• ventricular chamber dilatation
• diffuse endocardial thickening
• atrial enlargement
• focal myocyte death
• interstitial fibrosis

Question 12

what is arrhythmogenic right ventricular cardiomyopathy

Answer 12

• cause of ventricular arrhythmias in young patients
• can manifest as sudden death
• inherited in an autosomal dominant pattern
• point mutations in genes coding for desmosomal proteins are main causes for developing the disease