Cardiomyopathies Flashcards
What is Cardiomyopathies (CMPs)?
- Diseases of the heart muscle
- Manifest with various structural and functional abnormalities
- Frequently genetic
Types of Cardiomyopathy?
- Dilated cardiomyopathy (DCM)
- Restrictive cardiomyopathy (RCM)
- Hypertrophic cardiomyopathy (HCM)
- Hypertrophic obstructive cardiomyopathy (HOCM)
What is Dilated cardiomyopathy (DCM)?
-Dilatation and impaired contraction of one or both ventricles
-Impaired systolic function
(Ejection Fraction (EF) <40%)
-Often develop heart failure
-Possibly conduction abnormalities, arrhythmias
-Prevalence 36 per 100,000
Causes of Dilated cardiomyopathy?
- Idiopathic (most common – often familial/gene mutations)
- Infections (i.e. viral myocarditis, Chagas disease)
- Toxins (drugs, meds, alcohol)
- Tachycardia induced CMP
- Stress (takotsubo) – sometimes considered “unclassified”
Factors of Infectious cardiomyopathy?
- Begins as infectious myocarditis, nflammation of the myocardium secondary to infection
- Viral – most common
- Bacterial (Lyme, Mycoplasma)
- Protozoan (Chagas Disease)
Clinical Manifestations of Dilated Cardiomyopathy that end up being infectious myocarditis?
- Fever, myalgias, muscle tenderness
- Heart palpitations/Arrhythmias
- Heart block
- Chest pain
- Pre-syncope, syncope
- Heart failure
- Clinical syndrome ranges from subclinical to fulminan
What is Chagas disease?
- Protozoan infection (Trypanosoma cruzi)
- Leading cause of DCM in Central and S. America.
- Acute myocarditis
- Cardiac enlargement
- Nonspecific EKG abnormalities
- Left ventricular apical aneurysms
Clinical manifestation of Chagas disease?
-Heart failure
-Arrhythmias & heart blocks (all types)
-Thromboembolism (right or left ventricular mural thrombi)
(Pulmonary Embolism,
Cerebrovascular accident) (CVA) = stroke
-Chest pain
Diagnosis of Chagas Disease?
- Serologic test that detects IgG antibiodies to T. cruzi
- CXR with cardiomegaly
- EKG with RBBB or LBBB and ST-T changes (non-specific)
- Echocardiography – cardiac structure and function abnormalities
- Cardiac MRI – detects myocardial fibrosis
Treatment of Chagas Disease?
- Antitrypanosomal drugs for acute disease & indeterminate disease (not useful in chronic condition)
- Standard treatment of heart failure
- Implantable cardiac pacer +/- defibrillator
Toxic Cardiomyopathy causes?
Alcohol (*most common toxic CMP)
Cocaine
Medications
What is Alcohol induced cardiomyopathy?
- Correlated to amount and duration of daily drinking
- Abstinence can lead to improved cardiac function if diagnosed early
Whats Tachycardia induced cardiomyopathy?
- Afib with RVR
- AVNRT
- Preexcitation syndromes
- Mechanism unclear
- Reduced myocardial contractility
- Abnormalities in myocardial architecture
- Decrease in calcium responsiveness
- Treatment of arrhythmia results in reversal of myocardial dysfunction
Stress-induced cardiomyopathy (takotsubo)?
- Precipitated by intense psychological stress induced (i.e. death of loved one) “broken heart syndrome.”
- Post-menopausal women
- Left ventricular apical ballooning
- ST elevation without CAD
Restrictive Cardiomyopathy?
- Non-dilated ventricles with impaired ventricular filling
- Hypertrophy is typically absent (normal wall thickness)
- Rigid ventricular walls resulting in diastolic dysfunction
- Systolic function usually remains normal
- Biatrial enlargement
Causes of Restrictive Cardiomyopathy?
- Familial
- Infiltrative (amyloidosis, sarcoidosis)
- Storage diseases (rare inherited disorders)
- Scleroderma
- Endomyocardial fibrosis
Hypertrophic cardiomyopathy (HCM)?
- Genetically determined heart muscle disease
- Interventricular septum typically more prominently involved than the LV free wall
- LV volume is normal or reduced, diastolic dysfunction is usually present
Hypertrophic obstructive cardiomyopathy (HOCM)
- Hypertrophy of the ventricular septum
- Significant left ventricular outflow tract (LVOT) obstruction
- Teenagers and young adults who collapse and lose consciousness during exercise
- Can cause sudden death (most common cause of sudden death in young people)
- Harsh crescendo-decrescendo systolic murmur
Common symptoms of Hypertrophic obstructive cardiomyopathy (HOCM)?
fatigue, dyspnea, chest pain, palpitations, presyncope or syncope
Manifestations of HCM?
- LV outflow obstruction (HOCM)
- Diastolic dysfunction
- Myocardial ischemia
- Mitral regurgitation
- Systolic dysfunction (end-stage)
- Heart failure
- Supraventricular and ventricular arrhythmias
- Sudden death
Management of Hypertrophic Cardiomyopathy?
- Stay hydrated
- Restrict intense physical exertion
- Medical therapy to treat chest pain and dyspnea
- Medical therapy to treat arrhythmias
- Invasive procedures to improve LV outflow tract (alcohol septal ablation or septal myectomy)
Arrhythmogenic right ventricular cardiomyopathy (ARVC)?
- Myocardium of right ventricle is replaced by fibrous and/or fibro-fatty tissue
- Genetically determined
- Ventricular arrhythmias (V-tach)
- Right ventricular function is abnormal with regional akinesis or dyskinesis
- Global right ventricular dilation and dysfunction in severe cases
- Sudden cardiac death in young adults
Symptoms of ARVC?
- May be silent
- Palpitations
- Syncope
- Atypical chest pain
- Dyspnea
Diagnosing for ARVC?
- Echocardiogram
- Cardiac MRI
- Genetic testing
- Endomyocardial biopsy
Treatment for ARVC?
- Implantable cardiac defibrillator (ICD)
- Antiarrhythmic drugs if not a candidate for ICD or as adjunct to ICD
- Patients should not participate in competitive sports
- Cardiac transplant if progressive and debilitating conditions after optimal use of other treatments
