Cardiology #1 (Cardiomyopathies) Flashcards
What is the MC type of cardiomyopathy?
Dilated cardiomyopathy
What is dilated cardiomyopathy?
Systolic dysfunction, leading to a dilated, weak heart
-Reduced strength of ventricular contraction, leading to dilation of left ventricle
Risk factors for dilated cardiomyopathy
Men
Age 20-60 years old
Etiologies of dilated cardiomyopathy
- Idiopathic: MC
- Genetic abnormalities
- Excessive alcohol consumption, ETOH abuse
- Infection: Viral MC (Enteroviruses such as Coxsackievirus B)
- Cocaine use
- Doxorubicin use
- Vitamin B1 (thiamine) deficiency
Symptoms of dilated cardiomyopathy
- MC presentation is dyspnea
- S3 gallop
- Pulmonary crackles/rales
- Increased JVP
-Symptoms of left ventricular heart failure
Diagnostic study of choice for dilated cardiomyopathy
Echo: left ventricular dilation, decreased ejection fraction
What does a chest radiograph show for dilated cardiomyopathy?
-Cardiomegaly and pulmonary congestion
What is the treatment for dilated cardiomyopathy?
Standard systolic heart failure treatment
- Abstinence from alcohol
- ACE inhibitor
- BB (Metoprolol, Carvedilol)
- ARBs
- Spironolactone
- Symptom control with diuretics, Digoxin
- Automated implantable cardioverter/defibrillator if EF < 35-30%
What is stress (Takotsubo) Cardiomyopathy?
Transient regional systolic dysfunction of the left ventricle that can mimic an MI but is associated with absence of obstructive coronary artery disease or evidence of plaque rupture
Risk factors for stress cardiomyopathy
- Postmenopausal women exposed to physical or emotional stress
- Death of a loved one, catastrophic medical diagnosis, etc
Pathophysiology of stress cardiomyopathy
Catecholamine surge during physical or emotional stress
Symptoms of Takotsubo Cardiomyopathy
- Retrosternal chest pain similar to MI
- Dyspnea
- Syncope
Diagnostics for stress cardiomyopathy
- Cardiac enzymes: often positive (mimics MI)
- ECG: ST elevations (especially in anterior leads)
- Echo: Apical left ventricular ballooning
- Coronary angiography: absence of plaque rupture or obstructive coronary disease. “Patent coronary arteries with hypocontractility of left ventricular apex”
Again, what should you be looking for if a patient is having symptoms mimicking an MI, and you are doing an angiography?
Stress cardiomyopathy: patent coronary arteries and left ventricular apex hypocontractility
Because the initial presentation of stress cardiomyopathy presents similar to ACS/MI, patients are treated as ACS with 5 things. Name them.
Aspirin Nitroglycerin BB Heparin Coronary angiography to rule out coronary artery disease
Short-term management for stress cardiomyopathy
- Transient condition: conservative and supportive care is mainstay (BB, ACEi for 3-6 months with serial imaging to assess for improvement)
- Anticoagulation if EF < 30%
What is restrictive cardiomyopathy?
- Diastolic dysfunction in a non-dilated ventricle, which impedes ventricular filling (decreased compliance)
- LV is small or normal, with mildly reduced function
Etiologies of restrictive cardiomyopathy
- Infiltrative disease: amyloidosis (MC), sarcoidosis, hematochromatosis, scleroderma
- Radiation, chemotherapy
- Diabetes
- Endomyocardial fibrosis
Symptoms of restrictive cardiomyopathy
- Right sided heart failure: decreased exercise tolerance, peripheral edema, JVD, hepatomegaly, ascites, GI symptoms, pulmonary HTN
- S3 may be heard
- Kussmaul’s Sign: increased in JVP with inspiration
What is Kussmaul’s Sign
Increased in JVP with inspiration
Diagnostics for restrictive cardiomyopathy
- CXR: mildly to moderately enlarged cardiac silhouette
- Echocardiogram: diagnostic of choice (non-dilated ventricles with normal thickness, diastolic dysfunction, marked dilation of both atria).
- Endomyocardial biopsy: definitive diagnosis
If restrictive cardiomyopathy is associated with amyloidosis, what will be seen on an echocardiogram and what will be seen on a biopsy?
Echocardiogram: bright speckled myocardium
Biopsy: apple-green birefringence with congo-red staining
Treatment for restrictive cardiomyopathy
- No specific treatment
- Treat the underlying disorder: glucocorticoids for sarcoidosis, etc.
- Gentle diuresis for symptoms, vasodilators
What is hypertrophic cardiomyopathy?
Autosomal dominant genetic disorder of inappropriate LV and/or RV hypertrophy with diastolic dysfunction
The obstruction of hypertrophic cardiomyopathy worsens with…
- Increased contractility (exercise, Digoxin, beta agonists)
- Decreased LV volume (dehydration, Valsalva maneuver)
Symptoms of hypertrophic cardiomyopathy
- Dyspnea (MC symptom)
- Fatigue, angina, syncope, dizziness, arrhythmias
- Sudden cardiac death, especially in adolescents during time of extreme exertion due to V fib
What is the murmur like in a patient with hypertrophic cardiomyopathy?
- Harsh systolic murmur heard best at the LSB
- Increased murmur intensity with decreased venous return (Valsalva, standing)
- Decreased murmur intensity with increased venous return (squatting, supine, leg raise)
- May have loud S4, S3, or pulsus biferens
Diagnostics for hypertrophic cardiomyopathy
- CXR often normal
- ECG: LVH, nonspecific ST and T wave changes
- Echo: asymmetric ventricular wall thickness (especially septal) 15 mm or greater, small LV chamber size
What is the treatment for hypertrophic cardiomyopathy?
- BB are first line management (Alternatives are CCB and Disopyramide)
- Myomectomy if refractory and young
- Alcohol septal ablation of septum
What should patients with hypertrophic cardiomyopathy avoid?
- Dehydration
- Extreme exertion
- Exercise
- Digoxin
- Nitrates
- Diuretics
