| What is cardiomyopathy? | Disease of heart muscle, 5-10% of heart failure, divided into ischemic and non-ischemic cardiomyoapthy.
They are heterogenous diseases of mycardium, associated with mechanical / electrical dysfunction with inappropriate ventriuclar hypertrophy or dilation due to a cause (frequently genetic) |
| What are the classificationns of cardiomyopathy? | Dilated, restrictive and hypertrophic
Dilated and hypertrophic differ by size of LV wall, restrictive has increased wall thickness with prominent atrial enlargement
We can also classify them as primary or secondary to other systemic illness. Genetic, acquired or mixed |
| How is general presentation of cardiomyopathy? | exertional intolerance, breathlessness, fatigue, inadequate cardiac serving during exercise.
congestiven heart failure, |
| Compare between types of cardiomyopathy in terms of EF, LV thickness, valve regurg, first symptom, arrhythmias and atrial size. | . |
| What are etiologies of cardiomyopathy? | Recognized in hypertrophic cardiomyopathy.
Heritable (30% of dilated cardiomyopathy), usually inherited auto recessive/ X-linked.
Age dependent with incomplete penetrance. |
| How is the evaluation of cardiomyopathy? | Clinically (Hx & PE for disorders cardiac and others, family hx, alcohol, drugs, ability to perform activities, volume status, orthostatic BP, BMI)
Labs (ECG, CXR, TTR, MRI for inflammation/fibrosis, chemistry, hematology)
Evaluation of specific dx sus:
Titers for infection, viral, HIV, Chaga's/ toxoplasmosis, catheterization and angiography (angina), serology (rheumato), endocardial biopsy, sleep-disorders breathing |
| What is dilated cardiomyopathy? | Enlarged LV with decreased systolic function (decreased LV EF)
Systolic failure more marked than diastolic
Causes: inflammatory myocarditis (infective (viral, parastic, bacterial (diphtheria), fungal...) and non-infective (granulamtous disease, giant cell myocarditis, eosinophilic myocarditis, polymyositis, transplant rejection), toxic (alcohol, catecholamine, chemo, IFN, drugs, metals, exposure), metabolic (electrolyte disturb, nutritional def, endocrino (DM, pheo..), obesity, hemochromatosis) and inherited) |
| What are inherited metabolic pathway defects causing cardiomyopathy? | Familial (skeletal/cardiac myopathy, DMD, mitochonrial myopathy (Kearns-sayres), hemochromatosis, arrhythmogenic ventricular dysplasia)
Overlap with nondilated cardiomyopathy (amyloidosis, hemochromatosis, hypertrophic cardiomyopathy) |
| What are miscellaneous causes of cardiomyopathy? | Arrhythmogenic RV dysplasia (may also affect LV)
LV non compaction, peripartum cardiomyopathy, tachycardia cardiomyopathy (supraventricular, ventricular complex premature)
LBBB (cause of dilated cardiomyopathy) |
| What is myocarditis? | Inflammation of heart, from multiple causes most commonly infective cause through direct invasion, production of cardio-toxic substances, chronic inflammation w/ or w/out present infection.
There are coxsackie / adenovirus receptors on the heart, viral infection can replicate and cause myocardial injury. |
| How is evaluation of myocarditis done? | ECG, TTE, serum troponin and CK, MRI (for dx, sees edema and gadolinium enhancement), endomyocardial biopsy (not indicated unless ventricular tachyarrhythmia suggesting sarcoidosis/ giant cell myocarditis |
| How is dx of myocarditis? | 3 levels of dx, subclinical acute myocarditis (viral syndrome with no cardiac symptoms and one of elevated biomarkers, ECG finding of acute injury, reduced LV EF, abnormal imaging)
Acute myocarditis (above criteria w/ cardiac symptoms (SoB/ chest pain) suggestive of pericarditis / myocarditis.)
Definite dx when histo evidence of inflammation is seen doesn't need any labs/ images, so MRI considered useful |
| What is tx of myocarditis? | No recommended therapy during any stage of viral myocarditis |
| What is peripartum cardiomyopathy (PPCM)? | Developed during the last trimester, risk factors include increased maternal age, increased parity, twin pregnancy, malnutrition, tocolytic therapy use, toxemia |
| What is toxic cardiomyopathy? | Alcohol cause is most common cause of chronic dilated cardiomyopathy, 5-6 drinks daily for 5-10 years/ frequent binge-drinking.
marked improvement seen when 3-6 months of abstinence
Chemotherapy also can cause toxic cardiomyopathy (anthracyclines, trastuzumab, cyclophosphamide) |
| What are metabolic causes of cardiomyopathy? | Hyperthyroid, hypothyroid (can exacerbate heart failure)
Pheochromocytoma |
| What nutritional deficiencies cause cardiomyopathy? | Beriberi due to thiamine deficiency, Chronic heart failure due to chronic Ca deficiency (hypopara or intestinal issue), hypophosphatemia, hemochromatosis (causes restrictive myopathy and dilated) |
| What is familial cardiomyopathy? | Most recognizable with extra-cardiac myopathy, both duchenne and beckers (milder) are X-linked.
LV noncompaction, multiple trabeculations in LV distal to papillary muscles are dx criteria |
| What is takotsubo cardiomyopathy? | Apical ballooning syndrome (stress-induced cardiomyopathy) occurs in older women after emotional/ physical distress.
From intense sympathetic activation with heterogeneity of myocardial autonomic innervation diffuse microvascular spasm and catecholamine toxicity.
On ECG: ST elevation, deep T wave, patho Q wave before hospitalization, prolonged QT, prolonged PR |
| What is idiopathic dilated cardiomyopathy? | Dx of exclusion, 2/3 of dilated cardiomyopathy are idiopathic, but may be unrecognized genetic disease. |
| What is restrictive cardiomyopathy? | Abnormal diastolic function, mildly decreased contractility and EF (>30%).
Both atria enlarged, EDP elevated in both ventricles, preserved CO until late stages of disease.
Exercise intolerance usually first symptom, more right sided symptoms usually, differential usually includes constrictive pericardial disease, right sided heart failure |
| What are causes of restrictive cardiomyopathy? | Infiltrative (between myocytes, amyloidosis (primary, familial or senile), inherited metabolic defects)
Storage (within myocytes, hemochromatosis, inherited metabolic defects (Fabry's, glycogen storage disease II, III))
Fibrotic (radiation, scleroderma)
Endomyocardial (fibrotic disease (hypereosinophil, tropical), carcinoid, radiation, drugs)
Overlap with other cardiomyopathy (hypertrophic, minimally dilated)
Sarcoidosis
Idiopathic |
| What is hypertrophic cardiomyopathy? | • Hypertrophic cardiomyopathy is defined as left ventricular
hypertro-phy that develops in the absence of causative hemodynamic
factors, such as
• Hypertension
• Aortic valve disease
• Systemic infiltrative
• Storage diseases
• The terminology is now hypertrophic cardiomyopathy with or without
obstruction |
| What are the features of hypertrophic cardiomyopathy? | • It is the leading cause of sudden death in the young and is an important cause of heart failure
• Echocardiographic screening of families revealed an autosomal dominant pattern of inheritance.
• Initial genetic studies using linkage analysis in large families identified disease-causing mutations in sarcomeric genes
• Hypertrophic cardiomyopathy is characterized by age-dependent and incomplete penetrance
• The interventricular septum is the typical location of maximal hypertrophy
• Left ventricular out flow tract obstruction represents the most common focus of diagnosis and intervention
• Obstruction is present in 30% of patients at rest and can be provoked by exercise in another 30%.
• Systolic obstruction is initiated by drag forces, which push an ante-riorly displaced and enlarged anterior mitral leaflet into contact with the hypertrophied ventricular septum
• In order to maintain stroke volume across outflow tract obstruction, the ventricle generates higher pressures, leading to higher wall stress and myocardial oxygen demand |
| How is dx of hypertrophic cardiomyopathy? | • Cardiac imaging is central to diagnosis due to the insensitivity of
examination and ECG and the need to exclude other causes for
hypertrophy
• Rigorous athletic training (athlete's heart) may cause intermediate
degrees of physiologic hypertrophy difficult to differentiate for mild
hypertrophic cardiomyopathy
• Its regress with cessation of training
• Mild ventricular dilation
• Normal diastolic function |
| How is tx of hypertrophic cardiomyopathy? | • Treatment of symptoms
• first-line agents that reduce the severity of obstruction by slowing heart rate,
enhancing diastolic filling, and decreasing contractility.
• Surgical myectomy
• Alcohol septal ablation
• Management of sudden cardiac death and stroke
• Implantable cardioverter-defibrillator |
