Restrictive cardiomyopathy resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Steven Bellm, M.D. [2]

Restrictive cardiomyopathy resident survival guide Microchapters
Overview
Classification
Causes
Diagnosis
Treatment Overview Restrictive cardiomyopathy is defined as heart-muscle disease with impaired ventricular filling usually due to increased stiffness. The diastolic volume of either or both ventricles is normal or decreased,the systolic function usually remains normal and wall thickness may be normal or increased. The symptoms and signs may consist of right (jugular venous pressure, peripheral edema, and ascites) or left ventricular failure (breathlessness and evidence of pulmonary edema). Classification               Restrictive cardiomyopathy                                                                   Myocardial               Endomyocardial                                                                                                                                       Nininfiltrative   Infiltrative Storage Disease           Causes Common Causes Idiopathic cardiomyopathy Amyloisosis Sarcoidosis Endomyocardial fibrosis Radiation Toxic effects of anthracycline Complete Diagnostic Approach A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.               History and symptoms: ❑  Hints for etiology (history of pericarditis/ tuberculosis/ trauma DD:contrictive pericarditis or amyloidosis/ sarcoidosis)) ❑  Duration and onset of illness/ symptoms ❑  Severity and triggers of dyspnea/ orthopnea and fatigue/ weakness, presence of chest pain, exercise capacity, physical activity, sexual activity (NYHA?) ❑  Weight loss/weight gain (cachexia/ volume overload?) ❑  Palpitations/ (pre)syncope/ ventricular tachycardias/ cardiac arrest or fibrillation ❑  Symptoms of transient ischemic attack or thromboembolism (anticoagulation necessary?) ❑  Presence of peripheral edema, ascites or anasarca (volume overload?) ❑  Problems with breathing at night/ sleep ❑  Medical history ❑  Prior hospitalizations ❑  Medication ❑  Diet (restriction of sodium and fluid intake?)               Physical examination: ❑  Vital signs: ❑  Pulse (strength and regularity) ❑  Blood pressure ❑  Respiratory rate ❑  General appearance: ❑  BMI(weight loss/weight gain) ❑  Peripheral edema ❑  JVD may show severity of hemodynamic impairment, most prominent wave is the y descent/ jugular venous pulse doesn't fall during inspiration (Kussmaul's sign) ❑  Heart: ❑  S¹ sound is usually normal, and S² sound is split normally,S3 may be present, rarely S4 ❑  Regurgitant murmurs common ❑  Carotid and peripheral pulses may show evidence of a low output ❑  Apical impulse may be prominent ❑  Lungs: ❑  Rales? ❑  Pleural effusion? ❑  Abdomen: ❑  Hepatomegaly, pulsatile liver and/or ascites (volume overload) ❑  Extremities: ❑  Temperature of lower extremities               Laboratory findings: ❑  Complete blood count ❑  Chemistry: ❑  Troponin, BNP or NT-proBNP ❑  Serum electrolytes (including calcium and magnesium) ❑  Blood urea nitrogen ❑  Serum creatinine ❑  Glucose ❑  Fasting lipid profile ❑  Liver function tests ❑  Thyroid-stimulating hormone ❑  Consider Screening for hemochromatosis, HIV, rheumatologic diseases, amyloidosis, sarcoidosis               Imaging and additional tests: ❑  Noninvasive imaging and tests: ❑  ECG: ❑  Low voltage (especially in amyloidosis) ❑  Non-specific ST- and T-wave abnormalities ❑  Eventually Depolarization abnormalities: Such as bundle-branch or ventricular hypertrophy, or abnormalities of conduction, including atrioventricular block, atrial fibrillation, pseudoinfarction, ❑  Left-axis deviation ❑  Chest x-ray: Cardiac size (normal or cardiomegaly), atrial enlargement, pulmonary congestion, interstitial edema with Kerley B lines, pleural effusions? ❑  2D echocardiography with Doppler: ❑  Pattern of mitral-inflow velocity: increased early diastolic filling velocity (>1.0 m per second)/ decreased atrial filling velocity (<0.5 m per second)/ increased ratio of early diastolic filling to atrial filling (>2)/ decreased deceleration time (<150 msec)/ decreased isovolumic relaxation time (<70 msec) ❑  Pulmonary-vein or hepatic-vein flow: systolic forward flow is less than diastolic forward flow/ increased reversal of diastolic flow after atrial contraction with inspiration in the hepatic and pulmonary veins ❑  shortened deceleration time across the mitral and tricuspid valves, mitral and tricuspid regurgitation common ❑  Increased wall thickness, thickened cardiac valves, granular sparkling texture (in amyloidosis)::❑   ❑  Biatrial enlargement, a normal or small left ventricular size with generally preserved systolic left ventricular function, and abnormal diastolic function ❑  Cardiac magnetic resonance: ❑  Increasingly information in the identification or exclusion of various causes, Late gadolinium enhancement (LGE) for identification of myocardial fibrosis and characteristic patterns of certain diseases Invasive imaging and tests: ❑  Cardiac catheterization ❑  Deep and rapid early decline in ventricular pressure at the onset of diastole and rapid rise to a plateau in the diastole (dip and plateau/ square-root sign), LVEDP often >5 mm Hg greater than RVEDP ❑  Right atrial pressure is elevated, wave form is M- or W-shaped ❑  Respiratory variation of venous pressure is usually absent, y descent may become deeper ❑  Right ventricular systolic pressure may be elevated ❑  Endomyocardial biopsy ❑  For patients in whom the diagnosis is not clear by other methods of evaluation Treatment Symptomatic therapy Loop diuretics (low to medium dose): to relieve venous congestion in the pulmonary and systemic circulation, may cause signs of hypotension and hypoperfusion. Monitor systemic perfusion with physical examination, blood urea nitrogen and serum creatinine concentration Calcium channel blockers: may increase diastolic function Beta blockers: may have benefit by improving ventricular relaxation Angiotensin-converting enzyme (ACE) inhibitors and/or angiotensin II receptor blockers: may improve diastolic filling Digoxin: increases intracellular calcium and therefore should be used with caution Treat atrial fibrillation: atrial fibrillation with the removal of the atrial contribution to ventricular filling may worsen existing diastolic dysfunction, patients with atrial fibrillation should be anticoagulated Advanced conduction-system disease (i.e. advanced AV-block): Treat by the implantation of a pacemaker Malignant ventricular arrhythmias:May require treatment with an automatic implantable defibrillator or an antitachycardia device Cardiac transplantation should be performed in eligible patients with intractable heart failure References