Cardiomyopathy

Question 1

Classification of cardiomyopathy (3)

Answer 1

1. Dilated = pump fail
   -ventricular dilatation (w/ wall thinning) and systolic dysfunction (can’t contract as well, one or both ventricles)
2. Hypertrophic (HCM)
   -ventricular hypertrophy
   -intraventricular septum may be disproportionately greater than free wall
3. Restrictive = can’t fill
   -rigid, poorly distensible myocardium
   -diminished compliance
   (d/t amyloidosis, hemochromatosis…)

Question 2

etiology of dilated CM (7)

Answer 2

-ischemic
-peripartum (rare, highest in Nigeria and Haiti; developed in the final month up to 6mo postpartum)
-drugs and toxins (alcohol, cocaine, doxorubicin & daunorubicin, trastuzumab)
-genetic (up to 50% have FH)
-idiopathic
-stress (Takotsubo CM - “broken heart syndrome”)
-viruses (parvovirus B19, adenovirus, CMV, HHV6, influenza, coxsackievirus, echovirus, HIV)

Question 3

Clinical features of dilated CM

Answer 3

-dyspnea and fatigue are MC
-palpitations
-chest pain in 1/3, usually atypical pain

Question 4

Px findings in pt w/ dilated CM

Answer 4

-elevated JVP
-cardiomegaly
-peripheral edema
-ascites

-reflects severity of LV dysfunction (ranges from asx to CHF)
-on auscultation - S4 in 100%, S3 in 75%

Question 5

EKG findings indicative of dilated CM

Answer 5

-50% show LVH
-ST & T wave abnormalities are freq
-P wave changes of L or R atrial abnormalities are common
-1st degree AV block
-arrhythmias (PACs and PVCs); afib in up to 20% (poorly tolerated)

Question 6

Dx tests to order for dilated CM

Answer 6

-CXR: dilated/enlarged heart
-EKG
-ECHO
-MRI
-Labs: BNP or NT-proBNP
-Cardiac catheterization to assess for an ischemic cause

Question 7

what echo findings may suggest dilated CM

Answer 7

-chamber enlargement w/ diminished ventricular contractility
-decreased EF w/ exercise

Question 8

medical tx for dilated CM (tons!)

Answer 8

-wt reduction if needed
-alcohol abstinence
-control of DM
-salt restriction
-all pts w/ decreased LVEF should be given ACE-I, ARBS, or ideally Entresto + selective B-blockers, spironolactone, and SGLT2 inhibitors
-antiarrhythmic agents (Amiodarone) if >10 premature beats/min, multiform premature beats, or nonSVT
-AC (NOACs >warfarin)
-Inotropic agents (if hypoperfusion): use in hosp for severe cases - IV dobutamine
-Defibrillation if symptomatic SVT that is refractory to meds (life vest, ICD)
-Surgery: coronary artery bypass may improve EF if ischemia is the cause; heart transplant if severe CHF and poor prognosis