Dilated Cardiomyopathy
Other Names
- Congestive Cardiomyopathy
- Dilated Cardiomyopathy (DCM)
- Congestive Cardiomyopathy
- Idiopathic Dilated Cardiomyopathy
- Nonischemic Dilated Cardiomyopathy
- Familial Dilated Cardiomyopathy
- Primary Dilated Cardiomyopathy
- Secondary Dilated Cardiomyopathy
- Dilated Cardiomyopathic Heart Disease
- Dilated Myocardiopathy
- Dilated Heart Muscle Disease
Background
- This page discussed Dilated Cardiomyopathy (DCM)
History
- Needs to be updated
Epidemiology
- Needs to be Updated
Introduction
General
- Dilated cardiomyopathy (DCM) is characterized by enlargement of one/both ventricles with reduced systolic function
- Common causes include genetic mutations, viral myocarditis, alcohol misuse, chemotherapy exposure, idiopathic
- Clinical presentation includes heart failure symptoms, exercise intolerance, arrhythmias, thromboembolism, sudden cardiac death
- Diagnosis is made with echocardiography demonstrating ventricular dilation and decreased ejection fraction
Definition
- Left or biventricular dilation with impaired systolic function that is not secondary to CAD, abnormal loading pressures (i.e., HTN, or underlying valvular disease) or congenital heart disease. Is the most common type of cardiomyopathy.
Etiology
- Genetics is the most common cause (~25-45% of cases)
- Mutations in genes that encode sarcomeres, and desmosomes, like:
- TTN gene: encodes intrasarcomeric protein titin
- MYH7 gene: encodes beta-myosin heavy chains
- LMNA gene: encodes protein structure w/in nuclear membranes
- Mutations in genes that encode sarcomeres, and desmosomes, like:
- Idiopathic
- Infectious/inflammatory
- Viral myocarditis is most common infectious cause
- Coxsackie B Virus
- HIV
- Adenovirus
- Influenza A & B
- Herpes
- Bacterial is far less common
- Viral myocarditis is most common infectious cause
- Infiltrative, Autoimmune and Neuromuscular
- Systemic Lupus Erythematosus
- Sarcoidosis
- Vasculitis
- Myotonic dystrophy
- Duchene muscular dystrophy
- Becker Muscular dystrophy
- Toxic
- Cocaine
- Alcohol
- Amphetamines
- Heavy Metals
- Drug induced
- Cardiotoxic drugs: Anthracyclines
- AZT
- Endocrine/Metabolic
- Thyroid disease
- Pheochromocytoma
- Acromegaly
- Thiamine, Selenium, Carnitine, calcium deficiency
- Sustained Tachy arrhythmias: Afib
- Peripartum cardiomyopathy
Pathophysiology
- Primary myocardial insult causes reduced intrinsic contractility. --> Compensatory increase in preload (Frank-Starling) via increasing end-diastolic volume (EDV). Initially, the sarcomeres stretch and increase the stroke volume. --> persistent increased EDV causes Eccentric hypertrophy (sarcomeres in serries). Typically starts in the left ventricle and left atrium. --> Progressive systolic dysfunction, caused by dilated and remodeled ventricles with decreased contractile efficiency, and increased wall stress (Laplace’s law).
Risk Factors
- Needs to be updated
Differential Diagnosis
- Hypertrophic Cardiomyopathy
- Restrictive Cardiomyopathy
- Ischemic Cardiomyopathy
Clinical Features
History
- Patients typically present with symptoms of Systolic Heart Failure:
- Dyspnea
- Fatigue
- Exercise intolerance
- Fluid retention
- Some may also present with heart arrhythmias like A-fib, thromboembolic events, and cardiogenic shock.
- The LMNA variant in particular can present with conduction abnormalities before overt systolic heart failure symptoms
Physical Exam: Physical Exam Cardiology
- Needs to be updated
Special Tests
- Needs to be updated
Evaluation
General
- Screening and detection in athletes is done during the pre-participation evaluations. It is imperative to get a thorough cardiovascular history, and do a good physical exam including a 12-lead ECG and Chest x-ray. History red flags to look out for exertional syncope, unexplained dyspnea or fatigue, and family history of DCM, SCD, or heart failure before age 50.
- If DCM is suspected, should get full workup.
- Typically the first imagig study obtained
- Often normal, especially in early or compensated dilated cardiomyopathy
- Potential findings include:
- Cardiomegaly
- Pulmonary vascular congestion
- Interstitial/ Alveolar pulmonary edem
- Pleural Effusion
- Cephalization of pulmonary blood flow
Echocardiogram
- First line for assessing LV dilation and heart functioning
Cardiac MRI
- Needs to be updated
Event Monitor
- Needs to be updated
Laboratory
- Consider the following:
- Brain Natriuretic Peptide (BNP)
- Troponin
- Thyroid Studies
- Viral PCR
- Irone Studies
- Complete blood count
- Complete metabolic panel
Genetic Testing
- Genetic Testing: Recommended for all patients with DCM, especially for those with familial disease or features suggestive of genetic etiology.
- Should consider family screening echos for first-degree relatives
Biopsy
- Endomyocardial biopsy: When myocarditis, infiltrative diseases are suspected etiologies.
Classification
- Needs to be updated
Management
General
- Treat underlying and reversible causes
- Needs to be updated
Guideline Directed Medical Therapy (GDMT)
- Follow the Guideline Directed Medical Therapy (GDMT) for heart failure
- ARNI or ACE inhibitor or ARB
- Sacubitril-Valsartan AKA Entresto, is the preferred ARNI
- Beta-blocker
- Carvedilol
- Metoprolol succinate
- Bisoprolol
- Mineralocorticoid receptor antagonist
- Spironolactone
- Eplerenone
- SGLT2 inhibitor
- Dapagliflozin
- Empagliflozin
Initiation of all 4 class of medications/ quadruple therapy within the first 3 months is proven to be the most effective.
Device Therapy
- ICD: For primary prevention or should be considered if LVEF remains ≤35% after ≥3 months of optimized GDMT.
- Cardiac Resynchronization Therapy (CRT)
Sports Participation and Return to Play
Participation
- Based on shared decision making. Genotype positive but phenotype negative, or people with the genetic disposition but without clinical disease, should be surveilled closely during play. Especially those in which phenotype conversion can be triggered by exercise, like in LMNA variant.
- Athletes with clinical disease should have extensive evaluation by specialist, be optimized on GDMT and have a shared decision making conversation/agreement, with the risks and benefits to playing being discussed in detail, before returning to play. Those with high risk features like LVEF <40%-45%, documented ventricular arrhythmia on holter or exercise stress test, high risk genotypes, unexplained syncope, late gadolinium, enhancement on CMR, warrant caution.
Return to Play
- Needs to be updated
Prognosis and Complications
Prognosis
- Needs to be updated
Complications
- Heart Failure
- Arrhythmia
- Thromboembolism
- Syncope
- Sudden cardiac death
See Also
References
1. Dilated Cardiomyopathy. Lancet. 2017. Weintraub RG, Semsarian C, Macdonald P.
2. Emerging Techniques for Risk Stratification in Nonischemic Dilated Cardiomyopathy: JACC Review Topic of the Week. Journal of the American College of Cardiology. 2020. Marrow BA, Cook SA, Prasad SK, McCann GP.
3. Dilated Cardiomyopathy: Causes, Mechanisms, and Current and Future Treatment Approaches. Lancet. 2023. Heymans S, Lakdawala NK, Tschöpe C, Klingel K.
4. Contemporary and Future Approaches To Precision Medicine in Inherited Cardiomyopathies: JACC Focus Seminar 3/5. Journal of the American College of Cardiology. 2021. Fatkin D, Calkins H, Elliott P, et al.
5. Implementing Guideline-Directed Medical Therapy for Heart Failure: JACC Focus Seminar 1/3. Journal of the American College of Cardiology. 2023. Patolia H, Khan MS, Fonarow GC, Butler J, Greene SJ.
6. 2024 ACC Expert Consensus Decision Pathway for Treatment of Heart Failure With Reduced Ejection Fraction: A Report of the American College of Cardiology Solution Set Oversight Committee. Journal of the American College of Cardiology. 2024. Maddox TM, Januzzi JL, Allen LA, et al.
7.2016 AHA/ACC Clinical Performance and Quality Measures for Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Performance Measures. Journal of the American College of Cardiology. 2017. Al-Khatib SM, Yancy CW, Solis P, et al.
8. Clinical Considerations for Competitive Sports Participation for Athletes With Cardiovascular Abnormalities: A Scientific Statement From the American Heart Association and American College of Cardiology. Circulation. 2025. Kim JH, Baggish AL, Levine BD, et al.
9.2024 HRS Expert Consensus Statement on Arrhythmias in the Athlete: Evaluation, Treatment, and Return to Play. Heart Rhythm. 2024. Lampert R, Chung EH, Ackerman MJ, et al.