Cardiomyopathy

Definition:
"A myocardial disorder in which the heart muscle is structurally and functionally abnormal in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to explain the observed myocardial abnormality"

즉,
- 심장근육의 병.
- 허혈, 판만, 고혈압에 의한 질환이 아님. (predominantly idiopathic/ genetic/toxin)

Three main types:
1. Hypertrophic cardiomyopathy
2. Dilated cardiomyopathy
3. Restrictive cardiomyopathy

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Hypertrophic cardiomyopathy
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Def:
genetic disorder characterized by
left ventricular hypertrophy (LVH)
without identifiable cause

-most common cause of sudden cardiac death in young people

Classification:
classifed into 1. obstructive and 2. non obstructive
based on left ventricular outflow tract obstruction. (as seen on echo)

Dx:
Hx of unexplained syncope
Family Hx of sudden death

Rx:
All pt should refrain from high-intensity competitive sports.

Pt at risk of sudden cardiac death:
(i.e. ventricular tachy on Holter monitoring, prior cardiac arrest)
-> ICD (implantable cardiverter defibrillator) placement


Asymptomatic pt:
-> no treatment

Symptomatic pt:

-pt with systolic dysfunction / end-stage heart failure:
--> standard heart failure therapy ( B blocker, ACEI/ARB, digoxin, +- diuretic(cautiously) )

-pt with preserved systolic function:
in obstructive type:
--> B blocker, disopyramide, surgery
in non-obstructive type
--> B blocker, verapamil (don't use disopyramide)