Definition of dilated cardiomyopathy
Epidemiology and prognosis of dilated cardiomyopathy
Diagnosing dilated cardiomyopathy
Clinical presentation
The significance of imaging
Endomyocardial biopsy
Excluding other causes of left ventricular dilatation
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Patients with history of myocardial infarction (MI) or revascularization (coronary artery bypass grafting [CABG] or percutaneous coronary intervention [PCI])
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Patients with 75% stenosis of the left main or proximal left anterior descending artery (LAD)
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Patients with 75% stenosis of two or more epicardial vessels
Etiology of dilated cardiomyopathy
Disease or agent | Comments |
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Infections | |
Viral | Adenovirus, HIV, Coxsackie, Cytomegalovirus, Varicella, Epstein–Barr viruses |
Bacterial | Streptococci, Diphtheria, Typhoid fever, Mycobacteria, Brucellosis |
Fungal | Histoplasmosis, cryptococcosis |
Parasitic | Toxoplasmosis, trypanosomiasis, schistosomiasis, trichinosis |
Spirochetal | Leptospirosis, syphilis, Lyme disease |
Toxic | |
Ethanol (alcoholic cardiomyopathy) | Biventricular dysfunction and dilatation, absence of other causes → abstinence; often good response after withdrawal |
Cocaine | Long-term use, direct toxicity for the myocardium |
Methamphetamine | Fourfold increased risk of developing cardiomyopathy → in the case of abstinence, recovery is possible |
Deposition | |
Amyloidosis | Starts with restrictive cardiomyopathy, can progress to severe systolic dysfunction → amyloid identification and treatment thereafter |
Iron | Hemochromatosis |
Neuromuscular | |
Duchenne muscular dystrophy; Becker muscular dystrophy | X‑linked; CK elevation; family screening |
Drugs | |
Chemotherapeutic Agents | Anthracyclines (early and late events), cyclophosphamide, trastuzumab |
Psychiatric drugs | For example, lithium, clozapine, risperidone, tricyclic antidepressants → stop therapy; in the case of recovery, re-initiation can be discussed |
Autoimmune/Inflammatory | |
Giant cell myocarditis | Multinucleated giant cell; AV block, VT |
Inflammatory DCM | Non-infectious myocarditis, in biopsy |
Lupus erythematosus, Polymyositis, Wegner’s granulomatosis, Churg–Strauss syndrome, rheumatoid arthritis, dermatomyositis | Development of DCM possible but rather scarce; biopsy → treatment depends on underlying cause |
Myocarditis | Any inflammatory disease of the myocardium, biopsy, causes vary |
Sarcoidosis | Granulomatous inflammation, abnormal systolic and diastolic function, DCM is possible; high risk for arrhythmias → corticosteroids, immunosuppressive therapy (azathioprine), ICD |
Endocrinologic | |
Hypo- and hyperthyroidism | – |
Cushing disease/Addison disease | – |
Pheochromocytoma | – |
Acromegaly | – |
Diabetes mellitus | – |
Other | |
Peripartum cardiomyopathy | Last month before birth or in the first few months thereafter, predisposing factors: hypertension, Black race, age >30 years, multiparity, pre-eclampsia, smoking, family history and diabetes → with unstable hemodynamics urgent delivery |
Tachycardia-induced cardiomyopathy | Caused by increased ventricular rate; arrhythmias; RV pacing → rhythm or frequency control, catheter ablation; CRT (D) |
Electrolyte/renal | Hypocalcemia, hypophosphatemia, uremia |
Nutritional deficiencies | Thiamine, selenium, carnitine, niacin |
Inflammation
Drugs, cardiotoxins, and chemotherapeutic agents
Peripartum cardiomyopathy
Genetics of DCM
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Identification of etiology
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Risk assessment (e.g., recommended implantation of an implantable cardioverter-defibrillator [ICD] in certain gene variants)
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Predictive testing of relatives
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Advice on family planning.
Protein function | Gene (protein) | Presentation | Estimated prevalence in DCM (%) |
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Sarcomere | ACTC 1 (α-Cardiac actin) | HCM, NCCM, HCM | <1 |
MYH7 (β-Myosin heavy chain) | DCM, NCCM, HCM, myopathies | 4–10 | |
TNNT2 (Cardiac troponin) | DCM, NCCM, HCM | 2–3 | |
TPM1 (Tropomyosin) | DCM, NCCM, HCM | 0.5–1.0 | |
MYBPC3 (Myosin-binding protein C) | DCM, NCCM, HCM | 2 | |
Cytoskeleton | TTN (Titin) | DCM, NCCM, PPCM | 12–25 |
Nuclear envelope | LMNA (Lamin A/C) | DCM +/− non-compaction phenotype, NCCM | 4–6a |
Nucleus | RBM20 (RNA-binding protein) | DCM | 2–5 |
Ion channel | SCN5A (Sodium Channel, type 5) | Brugada, LQT3, AF, SSS, DCM | 2 |