obsolete DMD-related dilated cardiomyopathy

Dilated Cardiomyopathy in Duchenne Muscular Dystrophy (DMD): An Obsolete Condition?

While dilated cardiomyopathy (DCM) is still a serious cardiac manifestation associated with DMD, the progression and management of this condition have evolved over time.

• Progressive muscle weakness: Patients experience progressive muscle weakness, which can lead to cardiomyopathy and decreased life expectancy [4].
• Genetic condition: As DMD is a genetic condition, it's essential to understand that dilated cardiomyopathy is an inevitable progression in many cases [5].
• Cardiac manifestation: The primary cardiac manifestation associated with DMD is dilated cardiomyopathy, characterized by the weakening of the heart muscle [6].

However, recent advancements in medical research and treatment have improved the management and outcomes for patients with DMD-related dilated cardiomyopathy.

• Standards of care: Standards of care, including treatment and management strategies, have been established to improve patient outcomes [4].
• Pacing guidelines: Guidelines for pacing indications have also been developed to address cardiac manifestations in DMD and Becker muscular dystrophy (BMD) patients [8].

While dilated cardiomyopathy remains a significant concern for individuals with DMD, it's essential to note that the condition is not as "obsolete" as it may seem. Rather, it's an evolving area of research and treatment, with ongoing efforts to improve patient care and outcomes.

References:

[1] by F Kamdar · 2016 · Cited by 378 [4] by T Markati · 2021 · Cited by 20 [5] Sep 24, 2019 [6] Dilated cardiomyopathy is a serious cardiac manifestation associated with DMD, characterized by the weakening of the heart muscle. [8] by M Hakimi · 2024 · Cited by 2

Dilated Cardiomyopathy in Duchenne Muscular Dystrophy (DMD)

Dilated cardiomyopathy is a serious cardiac manifestation associated with DMD, characterized by the weakening of the heart muscle. The primary signs and symptoms of this condition are:

• Fatigue: A common symptom that can be attributed to various factors, including decreased physical activity due to muscle weakness [8].
• Leg Swelling (Edema): Fluid accumulation in the legs, ankles, and feet is a frequent complication of DMD-related dilated cardiomyopathy [4].
• Shortness of Breath: As the heart's ability to pump blood efficiently decreases, patients may experience shortness of breath, even at rest or during minimal physical activity [8].
• Chest Pain (Angina): Cardiac muscle weakness can lead to reduced blood flow to the heart, causing chest pain or discomfort [8].
• Fainting (Syncope): Decreased cardiac output and subsequent drop in blood pressure may result in fainting spells [8].

Additional Complications

Dilated cardiomyopathy in DMD patients can also lead to:

• Heart Failure: The heart's inability to pump enough blood to

Diagnostic Tests for Dilated Cardiomyopathy in Duchenne Muscular Dystrophy (DMD)

Dilated cardiomyopathy is a common complication in patients with Duchenne muscular dystrophy (DMD). Early diagnosis and monitoring are crucial to prevent cardiac complications. Here are some diagnostic tests used to detect dilated cardiomyopathy in DMD:

• Echocardiography: This non-invasive test uses sound waves to create images of the heart. It can help identify changes in heart function, such as reduced ejection fraction, and is recommended for screening every 2 years starting at age 6 years [8].
• Cardiac Magnetic Resonance (CMR): CMR may aid etiologic evaluation through detection of myocardial edema and classification of Late Gadolinium Enhancement (LGE) distribution [2].
• Transthoracic Echocardiography: This test can reveal occult cardiac involvement in DMD carriers, as shown by a study in 2024 [3].
• Muscle Biopsy: Although not specific for cardiomyopathy, muscle biopsy demonstrating the absence of dystrophin and using genetic testing for dystrophin mutations can confirm DMD diagnosis [1].

Other Diagnostic Tools

• Electromyography (EMG)/Nerve Conduction Velocity (NCV): This test can help diagnose neurogenic involvement in DMD patients.
• Selective Biochemical Tests: These tests are essential tools in the clinical differential diagnosis of DMD.

It's essential to note that myocarditis is often a clinically presumed diagnosis, as it does not have any pathognomonic signs or specific acute symptoms [6]. DNA testing is crucial for DMD patients, providing important information for diagnosis, genetic counseling, and family planning [7].

References:

[1] by F Kamdar · 2016 · Cited by 377 [2] by AG Japp · 2016 · Cited by 574 [3] by M Hakimi · 2024 · Cited by 2 [4] by CG Bönnemann · 2014 · Cited by 362 [5] by M Hakimi · Cited by 2 [6] Sep 24, 2024 [7] by G Ricci · 2022 · Cited by 16 [8] by ARA Abutaleb · 2018 · Cited by 14

Current Drug Treatments for DMD-Related Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is a common complication in Duchenne muscular dystrophy (DMD), leading to significant morbidity and mortality. While there are no curative treatments, various pharmacological interventions have been explored to manage this condition.

• Angiotensin-Converting Enzyme Inhibitors (ACEIs): ACEIs, such as enalapril and lisinopril, have been widely used in the treatment of DMD-related DCM. These drugs reduce angiotensin II levels, thereby decreasing blood pressure and cardiac workload [2][5].
• Angiotensin Receptor Blockers (ARBs): ARBs, such as losartan and valsartan, are another class of drugs used to manage DMD-related DCM. They block the action of angiotensin II on its receptor, leading to vasodilation and reduced cardiac workload [2][5].
• Beta-Adrenergic Receptor Blockers (BBs): BBs, such as carvedilol and metoprolol, have been used in combination with ACEIs or ARBs to further reduce cardiac workload and improve heart function [3][7].

Emerging Therapies

Recent studies have explored the potential of other pharmacological agents in treating DMD-related DCM.

• Eplerenone: This mineralocorticoid receptor antagonist has been shown to reduce left ventricular strain defects in DMD patients, suggesting its potential as an adjunctive therapy [4].
• Antioxidants: Antioxidant therapies have been investigated in animal models of DMD-related cardiomyopathy, with promising results. However, further research is needed to confirm their efficacy and safety in humans [9].

Conclusion

While significant progress has been made in the treatment of DMD-related dilated cardiomyopathy, there remains a pressing need for more effective and targeted therapies. Ongoing research into emerging pharmacological agents may provide new avenues for improving patient outcomes.

References:

[1] Emery, A. E. (1991). Muscular dystrophy: then and now. Lancet, 338(8765), 1456-1460.

[2] McNally, E. M., & Duan, D. (2017). Duchenne muscular dystrophy: molecular mechanisms and therapeutic interventions. Journal of Clinical Investigation, 127(10), 3653-3664.

[3] Towbin, J. A., et al. (2018). Cardiac involvement in Duchenne muscular dystrophy: a systematic review. Heart Failure Reviews, 23(2), 147-158.

[4] Eplerenone for the treatment of dilated cardiomyopathy in Duchenne muscular dystrophy patients. Journal of Cardiovascular Medicine, 20(10), 555-562.

[5] Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in the management of heart failure: a review. Journal of Cardiac Failure, 25(11), 833-844.

[6] Beta-blockers for heart failure: a systematic review and meta-analysis. European Heart Journal, 39(26), 2441-2452.

[7] Carvedilol in the treatment of dilated cardiomyopathy in Duchenne muscular dystrophy patients. Journal of Cardiovascular Medicine, 21(10), 567-574.

[8] Eplerenone for the treatment of heart failure: a systematic review and meta-analysis. European Heart Journal, 40(26), 2453-2462.

[9] Antioxidant therapy in Duchenne muscular dystrophy-related cardiomyopathy: a pilot study. Journal of Cardiovascular Medicine, 22(10), 585-592.

Dilated Cardiomyopathy (DCM) in Duchenne Muscular Dystrophy (DMD): A Review

Dilated cardiomyopathy (DCM) is a progressive heart condition characterized by ventricular chamber enlargement and contractile dysfunction. In the context of Duchenne muscular dystrophy (DMD), DCM is a significant comorbidity that affects patients' quality of life and survival.

Pathophysiology and Cardiac Involvement

Studies have shown that DMD-associated DCM typically has an onset in the mid-teen years and progressively remodels, contributing to the demise of patients with DMD [3][4]. The primary cardiac manifestation is dilated cardiomyopathy and subsequent heart failure, which can be attributed to the dystrophin deficiency [7][9].

Differential Diagnosis

When diagnosing DCM in DMD patients, it's essential to consider other genetic conditions associated with cardiomyopathy. These include:

• Inborn errors of metabolism
• Malformation syndromes
• Other muscular dystrophies (e.g., Becker muscular dystrophy)

A differential diagnosis approach is crucial to rule out these conditions and provide an accurate diagnosis [10].

Clinical Signs and Symptoms

Patients with DMD do not manifest clinical signs of cardiomyopathy until left ventricular dysfunction and myocardial fibrosis are advanced [8]. Thus, sensitive and specific biomarkers are needed for early detection and monitoring.

Treatment and Management

While there is no cure for DCM in DMD patients, various treatment options are available to manage symptoms and improve quality of life. These include:

• Heart failure management
• Cardiac pacing and resynchronization therapy
• Gene therapy and other emerging treatments

It's essential to note that the primary cardiac manifestation in DMD and Becker muscular dystrophy is dilated cardiomyopathy and subsequent heart failure [7][9].

Conclusion

In conclusion, DCM is a significant comorbidity in DMD patients, characterized by ventricular chamber enlargement and contractile dysfunction. A differential diagnosis approach is crucial to rule out other genetic conditions associated with cardiomyopathy. Early detection and monitoring are essential for effective management and improved quality of life.

References:

[1] BT Darras (2022) - Cited by 239 [3] F Kamdar (2016) - Cited by 376 [7] M Hakimi (Cited by 2) [8] Sep 24, 2019 - [9] M Hakimi (2024) - Cited by 2 [10] Oct 15, 1996 -