cardiomyopathy Flashcards
classification
Classification Clinical classification
- Obstructive
a. Dilated: L and/or R ventricular enlargement, impaired systolic function of the left and/or right ventricle, CHF, arrhythmias, emboli. no abnormal loading conditions eg HT, valve diseases
b. restrictive: endomyocardial scarring or myocardial infiltration resulting in restriction to L and/or R ventricular filling
c. Hypertrophic: disproportionate L ventricular hypertrophy, typically involving septum more than free wall, with or without an intraventricular systolic pressure gradient; usually nondilated L ventricular cavity. disorganization of cardiac myocytes and myofibrils occur
Primary myocardial involvement
- idiopathic (dilated, restrictive, hypertrophic)
- familial (dilated, restrictive, hypertrophic)
- eosinophilic endomyocardial disease (restrictive)
- endomyocardial fibrosis (restrictive)
Secondary myocardial involvement
a. Infective (dilated)
- viral myocarditis
- bacterial myocarditis
- fungal myocarditis
- protozoal myocarditis
- metazoal myocarditis
- spirochetal
- rickettsial
b. Metabolic (dilated)
c. Familial storage disease (dilated, restrictive)
- glycogen storage disease
- mucopolysaccharidoses
- hemochromatosis
- Fabry‘s disease
d. Deficiency (dilated)
- electrolytes
- nutritional
e. Connective tissue disorders (dilated)
- systemic lupus erythematosus
- polyarteritis nodosa
- rheumatoid arthritis
- progressive systemic sclerosis
- dermatomyositis
f. Infiltrations and granulomas (restrictive, dilated)
- amyloidosis
- sarcoidosis
- malignancy
g. Neuromuscular (dilated)
- muscular dystrophy
- myotonic dystrophy
- Friedreich‘s ataxia (hypertrophic, dilated)
h. Sensitivity and toxic reactions (dilated)
- alcohol, radiation, drugs
i. Peripartum heart disease (dilated)
Obstructive Hypertrophic cardiomyopathy : pathogenesis
- Characterized by variable myocardial hypertrophy, involving the interventricular septum & disorganization of cardiac myocytes & myofibrils.
- hypertrophy, systolic anterior motion of the anterior mitral valve leaflet & rapid ventricular ejection causing dynamic left ventricular outflow tract obstruction
- May also due to familial, autosomal dominant & mutations in the genes encoding sarcometric proteins.
Obstructive Hypertrophic cardiomyopathy : clinical symptoms
- Usually asymptomatic or mild
- Chest pain, dyspnoea, syncope / presyncope (with exertion), cardiac arrhythmias & sudden death
- Fatigue, left ventricular emptying is impaired, compounded by outflow obstruction.
- Systolic good until progressive dilatation occur.
- Atrial fibrillation
- Double or triple apical precordial impulse, a rapidly rising carotid arterial pulse, and a 4th heart sound
- systolic murmur, harsh, diamond-shaped, after 1st heart sound. at lower L sternal border & apex
- Pansystolic murmur at mitral regurgitation
Obstructive Hypertrophic cardiomyopathy : investigation
- ECG - left ventricular hypertrophy, ST & T wave changes. Widespread, deep, broad Q waves suggest old MI. Many have both atrial and ventricular arrhythmias.
- Echocardiogram - asymmetric left ventricular hypertrophy, systolic anterior motion of the mitral valve, vigorously contracting ventricle, Septum with unusual ground-glass‖ appearance. LV cavity is small, vigorous posterior wall motion, reduced septal excursion
- Pedigree analysis - autosomal dominant inheritance
- Exercise test & ECG ambulatory recording
- CXR: mild to moderate increase in cardiac silhouette
- Radionuclide scintigraphy with thalium 201: reveal myocardial perfusion defects
Obstructive Hypertrophic cardiomyopathy : treatment
- Beta blockers, verapamil (to treat chest pain)
- disopyramide for obstruction, to reduce LV contractility and outflow pressure gradient
- amiodarone: reducing frequency of supraventricular & life-threatening ventricular arrhythmias
- verapamil and diltiazem - reduce stiffness of ventricle, reduce the elevated diastolic pressures, increase exercise tolerance, and reduce severity of outflow tract pressure gradients
- combination beta blockers and calcium antagonists used with caution
- dehydration avoided, diuretics used with caution
- AVOID vasodilators, nifedipine
- Resection of septal myocardium
- Implantable defibrillators
- strenuous activity should be prohibited
Obstructive Hypertrophic cardiomyopathy : complications
- Hyperthrophy in diff portion of L ventricle
- Ventricular septum thickness disproportionally increased
- Disproportion of apex or L vent free wall
- Disarrangement cardiac muscle cell
Obstructive Hypertrophic cardiomyopathy : prognosis
- improvement of symptoms with time
- LV systolic impairment, wall thinning, and chamber enlargement occurs over time
- predictors of sudden death include age less than 30 yrs, ventricular tachycardia on ambulatory monitoring, marked ventricular hypertrophy, syncope (esp in children), genetic mutations associated with an increased risk, and a family history of sudden death
Dilated cardiomyopathy : pathogenesis
- majority no cause is found - ‗idiopathic‘; familial inheritance is usually autosomal dominant; probably myocardial damage produced by toxic, metabolic, or infectious agents, & late sequel of acute viral myocarditis mediated through an immunologic mechanism
- So, L or R ventricular systolic function is impaired, progressive cardiac enlargement, remodeling process produce symptoms of CHF. mural thrombi may be present in the LV apex
- reversible form may be with alcohol abuse, pregnancy, selenium deficiency, hypophosphatemia, hypocalcemia, thyroid disease, cocaine use, and chronic uncontrolled tachycardia
dilated CMP : Clinical symptoms
Clinical symptoms
- Presentation of congestive heart failure
- Initial presentation is with sudden cardiac death.
- Syncope, dyspnea during slight physical extertion/rest, Suffocation and cardiac pain
- Borders of heart displaced to right, upwards and left
- Heart sounds at apex dulled, 2nd sound over pulmo trunk is accentuated, gallop rhythm, systolic murmur
- Pulse is small and fast
- Arterial pressure decreased (usually)
dilated cardiomyopathy : Investigation
Investigation
- Chest X-ray - enlargement of cardiac silhouette due to LV enlargement; lung fields: pulmonary venous HT and interstitial or alveolar edema
- ECG - diffuse non-specific ST segment & T wave changes. Sinus tachycardia, conduction abnormalities & arrhythmias. atrial fibrillation, ventricular arrhythmias, L atrial abnormality,
- Echocardiography and radionuclide ventriculography - LV dilatation, normal or minimally thickened or thinned walls, and systolic dysfunction (reduced ejection fraction)
- angiography: dilated, diffusely hypokinetic LV, some degree of mitral regurgitation
dilated cmp : treatment
Treatment
- salt restriction, ACEI, diuretics (not be used in isolation), and digitalis
- beta-adrenergic blocker prevent arrhythmias
- myocardial inflammation treated with immunosuppressive therapy
- alcohol should be avoided
- insertion of an implantable cardioverter-defibrillator in patients with malignant arrhythmias
- cardiac transplantation considered in ptts with advanced disease
Dilated CMP : complications
Complications
- Congestive heart failure.
- Sudden cardiac death.
- Ventricular tachy or bradyarrhytmia
restrictive CMP : pathogenesis
- restricted ventricular filling, resulting in symptoms & signs of heart failure.
- Dilatation of the atria & thrombus formation occur.
- associated with amyloidosis, Loeffler‘s endocarditis, endomyocardial fibrosis, hemochromatosis, glycogen deposition, sarcoidosis, Fabry‘s disease, the eosinophilias, and scleroderma
- The idiopathic form may be familial.
- due to abnormal diastolic function; ventricular walls excessively rigid and impede ventricular filling, transplanted heart; and in neoplastic infiltration and myocardial fibrosis
- myocardial fibrosis, hypertrophy, or infiltration
restrictive CMP : clinical symptoms
Clinical symptoms
- Dyspnoea, fatigue & embolic symptoms
- Restriction to ventricular filling - elevated venous pressures, hepatic enlargement, ascites & dependant oedema
- exercise intolerance
- enlarged, tender and pulsatile liver
- jugular venous pressure elevated or may rise with inspiration (Kussmaul‘s sign)
- heart sounds may be distant, S3 and S4 are common
- apex impulse easily palpable
- mitral regurgitation
- Friedreich‘s sign (high jugular venous pressure with diastolic collapse)
Restrictive CMP : investigation
Investigation
- Chest X-ray: show pulmonary venous congestion. The cardiac silhouette can be normal / show cardiomegaly & / atrial enlargement.
- Echocardiogram: symmetrical myocardial thickening & normal systolic ejection fraction, impaired ventricular filling.
- Endomyocardial biopsy permit specific diagnosis such as amyloidosis to be made.
- ECG: low voltage, nonspecific ST-T wave changes and various arrhythmias
- Xray: pericardial calcification is absent
- Doppler recordings: accentuated early diastolic filling
- cardiac catheterization: decreased cardiac output, elevation of R and L ventricular end-diastolic pressures, and a dip-and-plateau configuration of the diastolic portion of the ventricular pressure pulse. Helps distinct from constrictive pericarditis
