How Do You Die From Muscular Dystrophy?
Cardiac Failure
Patients with muscular dystrophy (MD) are at risk of developing dilated cardiomyopathy (DCM).1 Dilated cardiomyopathy means the heat muscles are stretched and thinner, then the inside chamber enlarges. This usually starts in the left ventricle (ventricle that pumps blood to the whole body). Then the right ventricle and atria also becomes dilated. The heart muscle becomes weaker, and cannot pump blood properly. This causes arrhythmias, valve problems, blood clots and heart failure which can eventually lead to death. Some patients with muscular dystrophy can develop hypertrophic cardiomyopathy (HCM).
A study done in Sweden on patients with Duchenne muscular dystrophy (DMD) revealed that 40% of patients died due to cardiac failure. A study done in The University of Texas Southwestern Medical Center on 43 DMD patients revealed that all 43 of them had cardiomyopathy at the baseline evaluation. 8 patients died during the study, the reason for death in 6 of them were cardiac causes.
One study done on patients with Becker muscular dystrophy (BMD) shows 20% of patients had cardiac involvement. In another study 33% had DCM with or without heart failure, 22% had ECG changes and 15% died due to heart failure.
Respiratory Failure
Respiratory failure is another cause of death in most types of muscular dystrophy.2 Most patients with muscular dystrophy die of cardio-respiratory failure. There are few causes for respiratory failure in muscular dystrophy patients.
Muscular dystrophy patients have problems in swallowing and have gastroesophageal reflux. This can lead to aspiration and cause pneumonia. If pneumonia is not diagnosed in the initial stages it can develop into respiratory failure. Recurrent aspirations can damage the lung tissue and cause dead spaces, which are areas in the lung where gas exchange does not occur. This reduces the functioning lung volume and cause hypoxemia (reduced O2 levels) and hypercarbia (elevated CO2 levels) due to reduced gas exchange. This can also lead to respiratory failure.
Muscular dystrophy affects all skeletal muscles in the body, in some types it affects certain muscles groups more or it starts off from a certain muscle group and gradually progress into other muscle groups. Even the respiratory muscles are affected by muscular dystrophy. Respiratory muscles contract and relax during inspiration and expiration.
When the respiratory muscles are weak this does not occur, this causes restrictive pulmonary function and it leads to respiratory failure. If scoliosis is present which is seen in most muscular dystrophy’s the restrictive pulmonary function worsens.
A study done in Sweden on patients with Duchenne muscular dystrophy revealed that 35% of patients died due to cardiac failure. A study done in The University of Texas Southwestern Medical Center on 43 DMD patients revealed that all 43 of them had restrictive lung disease and some were on ventilator support at the baseline evaluation. 8 patients died during the study, the reason for death in 2 of them were respiratory failure.
BMD patients also get restrictive pulmonary function but the severity is less than DMD.
Multi Organ Failure
Some muscular dystrophy patients die of multi organ failure which can initiate with cardio-respiratory failure.
Summary
Most common cause for death in patients with muscular dystrophy (MD) is heart failure/cardiac arrest. Muscular dystrophy patients are at risk of developing dilated cardiomyopathy (DCM). This causes arrhythmias, valve problems, blood clots and heart failure which can eventually lead to death. Some patients with muscular dystrophy can develop hypertrophic cardiomyopathy (HCM). A study done in Sweden on patients with Duchenne muscular dystrophy (DMD) revealed that 40% of patients died due to cardiac failure. Respiratory failure is another cause of death in most types of muscular dystrophy. Respiratory failure can occur from acute pneumonia due to aspiration, restrictive pulmonary function due to respiratory muscle weakness. A study done in Sweden on patients with Duchenne muscular dystrophy revealed that 35% of patients died due to cardiac failure. Some muscular dystrophy patients die of multi organ failure which can initiate with cardio-respiratory failure.
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