Cardiac rehabilitation after heart transplantation in a patient with Becker's muscular dystrophy: a case report

Management of Cardiac Involvement in Becker Muscular Dystrophy: A Case Report

Becker muscular dystrophy (BMD) is an X-linked recessive neuromuscular disorder caused by a mutation in the dystrophin gene. Cardiac involvement is a frequent finding in BMD, and manifestations may vary from asymptomatic cardiac involvement to developing symptoms of heart failure and severe cardiomyopathy. We presented the case of a 32-year-old wheelchair-dependent BMD patient who came to our cardiology clinic with a two-month history of heart palpitations, rest and nocturnal dyspnea, fatigue, and generalized muscular weakness. Upon evaluation, a 24-hour Holter rhythm showed complex ventricular arrhythmia and 300 polymorphic ventricular extrasystoles with episodes of ventricular bigeminy, while echocardiography revealed a dilated left ventricle with severe systolic dysfunction (left ventricular ejection fraction (LVEF) 23%) and impaired global contractility. An implantable cardioverter defibrillator (ICD) was implanted, and guideline direct medical therapy (GDMT), sacubitril/valsartan, bisoprolol, furosemide, spironolactone, and dapagliflozin were initiated. The patient was discharged five days later, in an improved clinical condition, without dyspnea. A follow-up appointment two weeks after discharge was recommended in order to evaluate the patient's symptoms and the effectiveness of GDMT and a follow-up echocardiography at least three months after discharge to evaluate the heart's systolic and diastolic function.

Is Cardiac Transplantation Still a Contraindication in Patients with Muscular Dystrophy-Related End-Stage Dilated Cardiomyopathy? A Systematic Review

Inherited muscular diseases (MDs) are genetic degenerative disorders typically caused by mutations in a single gene that affect striated muscle and result in progressive weakness and wasting in affected individuals. Cardiac muscle can also be involved with some variability that depends on the genetic basis of the MD (Muscular Dystrophy) phenotype. Heart involvement can manifest with two main clinical pictures: left ventricular systolic dysfunction with evolution towards dilated cardiomyopathy and refractory heart failure, or the presence of conduction system defects and serious life-threatening ventricular arrhythmias. The two pictures can coexist. In these cases, heart transplantation (HTx) is considered the most appropriate option in patients who are not responders to the optimized standard therapeutic protocols. However, cardiac transplant is still considered a relative contraindication in patients with inherited muscle disorders and end-stage cardiomyopathies. High operative risk related to muscle impairment and potential graft involvement secondary to the underlying myopathy have been the two main reasons implicated in the generalized reluctance to consider cardiac transplant as a viable option. We report an overview of cardiac involvement in MDs and its possible association with the underlying molecular defect, as well as a systematic review of HTx outcomes in patients with MD-related end-stage dilated cardiomyopathy, published so far in the literature.

Electrocardiographic Changes in Jordanian Patients With Becker Muscular Dystrophy

Background and aim Becker muscular dystrophy (BMD) is an X-linked disease caused by an in-frame mutation in the dystrophin gene, which is considered an allelic disorder to the most severe form of dystrophinopahies, Duchenne muscular dystrophy, which leads to skeletal and cardiac muscle involvement and results in dilated cardiomyopathy (DCM). The aim of this study is to present our ECG data and the significance of this data in the early detection of DCM in these patients. Methods This is a retrospective study. All patients known to the clinical Genetic Clinic and Queen Alia Heart Center in Jordan with a diagnosis of Becker muscular dystrophy from the year 2011-2022 are offered cardiac evaluation according to the guidelines, which included clinical assessment, electrocardiograph, and 2-D echocardiograph (echo) at the time of diagnosis and every five years thereafter once the initial assessment was normal. All the records were retrieved and analyzed. Results Fifty-three patients of all ages with genetically confirmed BMD were identified. Twelve had no record as they didn't attend any cardiac evaluation. Forty-one were under regular clinical follow-up. Two were excluded as they died, and another four had no recorded data in our center. Ultimately, 35 patients were included and studied. The mean age was 30.5 years ± 22.1, ranging from two to seventy-seven years of age. Twenty-seven (77%) had abnormal ECG. High voltage R wave in V2 and V1 was the most common finding, followed by repolarisation abnormalities and Q wave (43%, 17%, 13%, and 11% respectively). Incomplete right bundle branch block in 4% as well as R/S ratio >1.2. U wave abnormalities in 3% and sinus tachycardia were found in only one patient. Conclusion Cardiac surveillance for patients with Becker muscular dystrophy is mandatory after the age of 16. Q wave and repolarisation changes should be taken seriously as early signs of dilated cardiomyopathy, even if the echo is normal.

Early cardiac rehabilitation after heart transplantation in a patient with limb-girdle muscular dystrophy: A case report

RATIONALE

Cardiac rehabilitation (CR) after heart transplantation (HT) decreases the mortality rate and increases exercise capacity of patients. Dilated cardiomyopathy develops in most patients with muscular dystrophy (MD), leading to advanced heart failure, necessitating the use of left ventricular assist devices or HT. As the clinical outcomes of left ventricular assist devices and HT in patients with myopathy differ from those in patients without myopathy, CR adapted to patients with MD should be considered.

PATIENT CONCERNS

A 39-year-old man with limb-girdle muscular dystrophy developed dilated cardiomyopathy and underwent HT.

DIAGNOSIS

The patient was diagnosed as having limb-girdle muscular dystrophy in 1997.

INTERVENTION

Early CR was performed based on the patient's physical condition and ability.

OUTCOMES

With chest physiology, aerobic, and resistance exercises, the patient was able to walk using a walker 28 days after HT. This is important because his lower-extremity strength and walking ability were, to some extent, maintained after surgery.

LESSONS

Since an increasing number of patients with MD are undergoing HT, specific CR programs for these patients should be discussed.

Cardiomyopathy in becker muscular dystrophy: Overview

Becker muscular dystrophy (BMD) is an X-linked recessive disorder involving mutations of the dystrophin gene. Cardiac involvement in BMD has been described and cardiomyopathy represents the number one cause of death in these patients. In this paper, the pathophysiology, clinical evaluations and management of cardiomyopathy in patients with BMD will be discussed.

A case of Becker muscular dystrophy with early manifestation of cardiomyopathy

An 18-year-old boy was admitted with chest discomfort, nausea, and dyspnea at rest. At the age of 3 years, he underwent muscle biopsy and dystrophin gene analysis owing to an enlarged calf muscle and elevated serum kinase level (6,378 U/L) without overt weakness; based on the results, Becker muscular dystrophy (BMD) was diagnosed. The dystrophin gene showed deletion of exons 45 to 49. He remained ambulant and could step upstairs without significant difficulties. A chest roentgenogram showed cardiomegaly (cardiothoracic ratio, 54%), and his electrocardiogram (ECG) showed abnormal ST-T wave, biatrial enlargement, and left ventricular hypertrophy. The 2-dimensional and M-mode ECGs showed a severely dilated left ventricular cavity with diffuse hypokinesis. The systolic indices were reduced, including fractional shortening (9%) and ejection fraction (19%). Despite receiving intensive medical treatment, he died from congestive heart failure 5 months after the initial cardiac symptoms. We report a case of BMD with early-onset dilated cardiomyopathy associated with deletion of exons 45 to 49. Early cardiomyopathy can occur in BMD patients with certain genotypes; therefore, careful follow-up is required even in patients with mild phenotypes of BMD.

Cardiac involvement in Becker muscular dystrophy

The present review gives an overview of the clinical and subclinical manifestations of cardiac involvement (CI) in Becker muscular dystrophy (BMD), its pathophysiological background, diagnostic possibilities and therapeutic options for CI in BMD patients and carriers. CI may be subclinical or symptomatic. Up to 100% of patients develop subclinical CI. The onset of symptomatic CI is usually in the third decade of life, rarely in the first decade. One-third of patients develop dilative cardiomyopathy with concomitant heart failure. In BMD patients, CI manifests as electrocardiographic abnormalities, hypertrophic cardiomyopathy, dilation of the cardiac cavities with preserved systolic function, dilative cardiomyopathy or cardiac arrest. There is no correlation between CI and the severity of myopathy. CI is more prominent in patients than carriers. As soon as the diagnosis of BMD is established, a comprehensive cardiac examination should be performed. Because CI in BMD is progressive and adequate therapy is available, cardiac investigations need to be regularly repeated. If CI in BMD is recognized early, appropriate therapy may be applied early, resulting in a more favourable outcome.

Primary myopathies and the heart

Myopathies are frequently not confined to the skeletal muscles but also involve other organs or tissues. One of the most frequently affected organ in addition to the skeletal muscle is the heart (cardiac involvement, CI). CI manifests as impulse generation or conduction defects, focal or diffuse myocardial thickening, dilation of the cardiac cavities, relaxation abnormality, hypertrophic, dilated, restrictive cardiomyopathy, apical form of hypertrophic cardiomyopathy, noncompaction, Takotsubo phenomenon, secondary valve insufficiency, intra-cardiac thrombus formation, or heart failure with systolic or diastolic dysfunction. CI occurs in dystrophinopathies, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy, limb girdle muscular dystrophies, laminopathies, congenital muscular dystrophies, myotonic dystrophies, congenital myopathies, metabolic myopathies, desminopathies, myofibrillar myopathy, Barth syndrome, McLeod syndrome, Senger's syndrome, and Bethlem myopathy. Patients with myopathy should be cardiologically investigated as soon as their neurological diagnosis is established, since supportive cardiac therapy is available, which markedly influences prognosis and outcome of CI in these patients.

Cardiac involvement over 10 years in myotonic and Becker muscular dystrophy and mitochondrial disorder

BACKGROUND

Little is known about the long-term development and outcome of cardiac involvement (CI) in patients with myotonic dystrophy type 1 (MD), Becker muscular dystrophy (BMD), and mitochondrial myopathy (MMP).

OBJECTIVE

To assess the progression of "definite", "possible" or "absent" CI, based on the history, clinical examination, electrocardiography, 24-h ambulatory electrocardiography, and transthoracic echocardiography, over 10 years in MD, BMD, and MMP patients.

METHODS

Included were 13 MD patients, aged 29-60 years, 5 BMD patients, aged 23-68 years, and 9 MMP patients, aged 24-73 years. Main outcome measures were the muscular disability score, the CI-classification, and the sum of abnormality score.

RESULTS

Since seven patients (2 MD, 2 BMD, 3 MMP) died during the observational period and 2 MMP patients refused the 10 year-follow-up, 11 MD, 3 BMD, and 4 MMP patients were actually investigated. At baseline/10 year later CI was "definite" in 12/11, 4/3, 6/4, "possible" in 1/0, 1/0, 3/0, and "absent" in 0/0, 0/0, 1/0 of the MD, BMD and MMP patients respectively. The most frequently abnormal investigations at baseline and follow-up were the history, electrocardiography, and the echocardiography. The mean number of abnormalities per MD, BMD, MMP patient at baseline/10y later was 4.5/5.1, 5.6/7.3, and 4.1/3.5 respectively. Cardiac medication required 25% of the MMP, 27% of the MD, and 100% of the BMD patients.

CONCLUSION

CI becomes "definite" in all patients with MD, BMD, and MMP, but progresses markedly only in BMD patients within 10 years. MD, BMD, or MMP patients should be cardiologically investigated as soon as the neurological diagnosis is established and treated if CI becomes symptomatic, or in case of severe ECG or echocardiographic abnormalities.