Cardiomyopathy and Myocardial Disease - Mackinnon Flashcards
Give the 5 WHO classification categories of cardiomyopathy
- Dilated
- Hypertrophic
- Restrictive
- Arrhythmogenic RV dysplasia
- Unclassified
Describe the general features of dilated cardiomyopathy
- progressive cardiac dilation: enlarged (hypertrophic), flabby, heavy heart
- systolic dysfunction
- potential thrombus formation
- functional regurgitation (due to ventricular dilation)
List some potential etiologies of dilated myopathy
- ischemia
- valvular dysfunction
- hypertension
- familial factors (genetic)
- idiopathic
- inflammation (infectious and non-infectious)
- toxins
- abnormal metabolism
- nutrition
- neuromuscular dysfunction (ex: Duchenne MD)
List (3) genetic inheritance patterns seem in dilated cardiomyopathy and the gene product(s) generally affected
- Autosomal dominant mutations - affecting cytoskeletal proteins (alpha-cardiac actin, desmin, nuclear laminins A/C)
- X-linked inheritance - dystrophin
- Mitochondrial genome mutations - oxPhos and FA beta-oxidation dysfunction
Describe the mechanism and epidemiology of acute viral myocarditis
Coxsackie B or Echovirus
Unclear mechanism leading to myocyte death and fibrosis. May be immune-mediated, but reaction unaltered by immunosuppressive drugs
Usually affects young people, self-limited
Name two sources of iron overload seen in dilated cardiomyopathy
- hemochromatosis
- multiple transfusions
What is beriberi heart disease?
Thiamine deficiency that triggers a dilated cardiomyopathy. Related to alcohol consumption
Describe the effects of alcohol on the heart that contibute to dilated cardiomyopathy
- Direct toxic effects on the myocardium
- Indirect toxic effects due to thiamine definiency (beriberi)
What type of antibiotics feature dilated cardiomyopathy as an adverse effect?
anthracyclines
*dose-dependent*
When does peripartum cardiomyopathy occur?
What probable causes underlie this condition?
Late pregnancy or several week s post-partum
- pregnancy-associated hypertension
- volume overload
- nutritional deficiency
- metabolic derangement
- immunological reaction
- prolactin
What is functional regurgitation?
regurgitation that occurs due to excessive dilation of the atria
Describe some epidemiological factors associated with increased risk of idiopathic dilated cardiomyopathy
- Male gender
- black race
- hypertension
- chronic beta-agonist use
Describe some clinical presentation features of dilated cardiomyopathy
- Heart failure symptoms
- anginal chest pain
- emboli
- syncope
- sudden cardiac death
What etiology of dilated cardiomyopathy has an especially bad prognosis (<25% @ >5 years)?
Cardiomyopathy due to HIV infection
When might Warfarin be used for dilated cadriomyopathy?
Chronic or paroxysmal Afib, LV thrombus, or prior thrombotic event
What drug(s) might be indicated for dilated cardiomyopathy in patients intolerant to ACE inhibitors?
ARBs, hyralazine/nitrates
What might also be given in addition to an ACE inhibitor for dilated cardiomyopathy to reduce heart failure symptoms?
Beta-blocker
Persistent heart failure symptoms in dilated cardiomyopathy despite diuretics and ACE inhibitors might indicate use of what drug?
digoxin
What drug(s) are most commonly indicated for management of dilated cardiomyopathy?
ACE inhibitors (symptomatic heart failure or asymptomatic LV dysfunction) + diuretics (volume overload)