Lecture 12: Cardiomyopathy Flashcards
Define cardiomyopathy.
- Morphologically and functionally abnormal myocardium.
- Excludes cardiac dysfunction caused by structural heart disease.
Structural HD: CAD, primary valve disease, and HTN
What are the 3 classifications of cardiomyopathy?
- Dilated
- Hypertrophic
- Restrictive
What part of the heart is primarily affected in cardiomyopathy?
LV function
What is the initial imaging modality for cardiomyopathy?
Echocardiography
What does systolic dysfunction eventually lead to?
- LV enlargement
- Higher stroke volume
- HF develops once this fails
What characterizes systolic dysfunction?
- Decreases in myocardial contractility
- Reduction in LVEF
- Heart will compensate by enlarging LV.
What characterizes diastolic dysfunction?
- Abnormal LV relaxation and filling
- Elevated filling pressures
- Does not always occur with systolic dysfunction.
- However, if there is systolic dysfunction, it will always occur.
What is myocarditis?
- Inflammatory, infiltrative process due to both infectious and non-infectious causes.
- Leads to myocardial dysfunction and dilated cardiomyopathy.
What are the two main mechanisms by which myocarditis occurs?
- Host-mediated: direct cytotoxic effect of the causative agent.
- Autoimmune-mediated: secondary immune response.
What occurs in the acute phase of myocarditis?
- First 2 weeks
- Myocyte death due to causative agent.
What occurs in the chronic phase of myocarditis?
- After 2 weeks
- Result of inappropriate, overactive immune response.
What are the primary viral causes of myocarditis?
- Adenovirus
- Coxsackie B virus
- CMV
What are the primary toxins that cause myocarditis?
- Alcohol
- Anthracyclines
- Cocaine
Who is myocarditis MC in?
20-50 y/o men
What typically precipitates infective myocarditis?
- Acute febrile illness/respiratory infection
Will develop a few days or weeks after.
What are the classic symptoms associated with infective myocarditis?
- SOB
- Pleural chest pain
- Fever/chills
- HF
- Arrhythmias
What PE findings are we looking for in infective myocarditis?
- Pericardial friction rub
- S3/S4
- Mitral/tri regur
- Volume overload
What are the important initial diagnostic tests to order for suspected infective myocarditis?
- EKG (PVCs)
- Cardiac Biomarkers (elevated troponins)
- CXR (non-specific)
- Echocardiogram
What labs are appropriate to order for suspected infective myocarditis?
- CRP
- ESR
- CBC (eosinophilia)
- Rheumatology workup
- Serum viral antibody titers
- BNP > 100
How is infective myocarditis concretely diagnosed?
Histologic evidence via endomyocardial biopsy.
Only do this if there is a high probability it will change management.
What is the primary treatment for myocarditis?
- Consult cardiology
- ACEi, BBs, Colchicine (pain)
What is the primary treatment for noninfectious myocarditis?
Monitoring until HF symptoms start occurring.
What is the #1 reason for heart transplant?
Dilated cardiomyopathy
What is dilated cardiomyopathy?
- LVEF < 40%
- No CAD or valvular disease
- Dilation and impaired contraction of one or both ventricles
Regurgitation may occur due to the stretch of mitral/aortic valves.
Who is dilated cardiomyopathy MC in?
Black patients
What is the primary cause of dilated cardiomyopathy?
Idiopathic
What are the two main diseases that can lead to DCM?
- Chagas disease (protozoan infection in central and south america)
- Lyme disease (conduction abnormality)
Trypanosoma cruzi
What are the 3 main bacterial causes of DCM?
- TB
- Meningococcal
- Pneumococcal
What is the main genetic inheritance of DCM?
Autosomal Dominant
When specifically does peripartum CM occur?
Late pregnancy or early postpartum.
Early treatment can resolve it within 2-3 months.
What is the DCM etiology mnemonic?
- Alcohol Abuse
- Beriberi (wet)
- Coxsackie B myocarditis
- Chronic cocaine use
- Chagas’ disease
- Doxorubicin toxicity
ABCCCD
A Bunch of stuff Can Cause Cardiac Disease
What EKG findings can be seen in DCM?
- Tachycardia
- Pulsus alternans
- LBBB
What symptom would prompt us to order a BNP or NT-proBNP for DCM?
Dyspnea
What characterizes restrictive cardiomyopathy?
- Nondilated ventricle with impaired filling
- Fibrosis or infiltration of the ventricular wall
- Diastolic dysfunction
- Biatrial enlargement
Most uncommon type.
What are the primary causes of restrictive cardiomyopathy?
- Infiltrative disorders (amyloidosis, sarcoidosis, fatty infiltration)
- Storage Disease (Hemochromatosis, Fabry’s)
- Radiation, chemo, carcinoid heart disease, hypereosinophilic syndrome
MCC is chemo in the US.
How do we treat restrictive cardiomyopathy?
- Treat underlying causes
- Diuretics (edema and congestion)
Most likely bc it backs up into the lungs since filling gets back up due to poor diastolic function.
What characterizes hypertrophic cardiomyopathy?
- LV hypertrophy
- Interventricular dysfunction most commonly involved as myocytes build up.
- NOT due to HTN or valvular issues.
- Diastolic dysfunction
How is HCM typically inherited?
Autosomal dominant
What valve is at risk in HCM?
Aortic valve, since it sits above the interventricular septum.
How does HCM typically present?
- Fatigue
- CP
- CHF
- Syncope
- SCA
- Carotid pulses bisferiens d/t mimicked AS
What murmur may occur in HCM?
- Mid-systolic, harsh, 3rd-4th intercostal that is louder with valsalva
- Quieter on squatting.
What is the usual EKG change seen in HCM?
LVH
What is the diagnostic modality of choice for HCM?
Echocardiogram
What medications are we advised to AVOID in HCM treatment?
- Diuretics
- Vasodilators
We do not want lowering of preload.
What medications are indicated for HCM?
- BBs
- Verapamil specifically
What procedures may help with HCM?
- Septal myectomy
- Alcohol septal ablation
What screening is recommended for any 1st degree relative with HCM?
- Annual echo until 20
- Q5years afterwards
What is the MCC of HF in the US?
Ischemic cardiomyopathy
What is the typical cause of ischemic cardiomyopathy?
CAD
What characterizes ischemic cardiomyopathy?
- Systolic dysfunction
- LV involvement primarily
- CHF (edema, dyspnea, JVD)
What should appear on echo for ischemic cardiomyopathy?
- Decreased LVEF
- Regional wall motion abnormality
What diagnostic study after an echo may help with ischemic cardiomyopathy?
Coronary angiography
How do we manage ischemic cardiomyopathy?
- Revascularization via PCI or CABG
- Nuclear viability study to check for sleeping myocardium
- CHF management
How do we prevent SCA?
- External wearable defibrillator (Lifevest)
- ICD
What characterizes arrhythmogenic RVCM?
- Ventricular arrhythmias
- RV dilation
- Causes sudden death in young adults in Europe primarily
How do we manage arrhythmogenic RVCM?
- Diuretics for systemic congestion
- Anitarrhythmics, ablation, or ICD for ventricular arrhythmias.
What is Left ventricular noncompaction cardiomyopathy?
- Congenital cardiomyopathy
- Altered myocardial wall
How do we treat Left ventricular noncompaction cardiomyopathy?
Heart transplant
What is takotsubo cardiomyopathy?
- Stress-induced/broken heart syndrome
- Causes ACS due to high catecholamine surge
MC in postmenopausal women.
How is takotsubo diagnosed?
LV apical ballooning
How is takotsubo’s treated?
BBs for a year
