Danon Disease Treatment & Management

Updated: Feb 09, 2016
  • Author: Keith K Vaux, MD; Chief Editor: Maria Descartes, MD  more...
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Treatment

Medical Care

Patients with Danon disease require frequent follow-up, with particular attention to the potential for atrial or ventricular arrhythmias and congestive heart failure (CHF). As is recommended in patients with hypertrophic cardiomyopathy (HCM), a ventricular septal thickness more than 30 mm is considered a risk factor for a life-threatening event, particularly in this group of patients who often have a poor prognosis for survival beyond their teenage years. [32]

An implantable cardioverter-defibrillator (ICD) may be indicated. However, in Maron’s study, all 7 patients had ICDs and 5 had lethal arrhythmias that did not convert with ICD therapy. [15] However, not all of those patients died from the arrhythmia. In addition, 4 of those 7 actually died of CHF. CHF must be treated according to the hemodynamic cause for the symptoms. For example, patients with HCM have a relatively restrictive physiology with diastolic dysfunction and should be treated accordingly (ie, improving ventricular filling, improved heart rate control, sinus rhythm maintenance, improved diastolic relaxation); whereas, those with a dilated form of cardiomyopathy tend to have a systolic dysfunction problem that may require different treatment (ie, improved afterload reduction and increased contractility).

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Surgical Care

Several surgical interventions should be considered in patients with Danon disease. The proper timing of any of these interventions is not known; however, the risk of sudden death in teenage male patients appears to be substantial. This risk may influence decisions about the timing of surgical interventions.

  • Implantable loop recorder (ILR)

  • This device is implanted under the skin to record any arrhythmias that may happen when cardiovascular symptoms occur.

    • The usual indication is an assessment of severe symptoms that occur too infrequently to be recorded by using conventional, external event recorders.

    • The battery in one device (Reveal Plus; Medtronic, Minneapolis, MN) lasts for 14 months. It can be automatically activated when the programmed parameters of the device are satisfied. It can also be activated when the patient has symptoms. An activator that the patient carries is placed over the device, and a button is pushed to activate the ILR.

  • ICD placement

    • After Danon disease and severe hypertrophic changes of the heart are diagnosed, placement of an ICD should be considered. For patients who have the dilated form of cardiomyopathy, ICDs may be indicated because of the degree of their dysfunction and their history of arrhythmias.

    • Recommendations from the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) trial apply to these patients. [33]

    • Furthermore, if the degree of CHF has progressed to New York Heart Association class III or IV with maximal medical therapy (eg, beta-blockers, afterload reduction, spironolactone, diuretics), placement of a biventricular pacing system, usually a biventricular ICD, should be considered. [34]

  • Cardiac transplantation

  • Several reports mention patients with Danon disease who underwent cardiac transplantation. [20, 14, 11, 24, 15]

    • Cardiac transplant should be considered as long-term treatment because the life expectancy is short. [19] Consideration of cardiac transplantation is necessary because of the limited life expectancy of teenaged male patients, who have a high incidence of sudden death. Maron et al even recommend consideration of early transplant. [15]

    • In addition, female patients may need a cardiac transplant because they are not expected to live past their fifth decade.

    • Cardiac transplantation is a reasonable treatment for Danon disease despite the presence of muscular problems because the neurologic disability or problems are mild.

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Consultations

Because of the severe nature of this disease and the short life expectancy in male patients, extensive counseling and education with the patient and family is important. When an ICD or cardiac transplantation is contemplated, psychiatric counseling may be needed. Dealing with these issues may be particularly challenging if the patient has clinically significant mental retardation.

Consultation with a neurologist is recommended to assess the degree of skeletal myopathy and cognitive deficiencies.

Genetic consultation regarding molecular testing and genetic counseling is important.

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Diet

For the most part, no dietary restrictions are necessary for Danon disease. However, when the patient has symptoms of CHF, sodium restriction may be beneficial. Caffeine can potentially aggravate any underlying tachyarrhythmia.

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Activity

Competitive athletic activity should be restricted for individuals with Danon disease and cardiomyopathy as recommended in the 36th Bethesda Conference: Eligibility Recommendations for Competitive Athletes With Cardiovascular Abnormalities. [35] Exceptions include activities classified as I-A, which include low-intensity sports with low static and low dynamic components, such as billiards, bowling, or golf.

As for noncompetitive activity, leisurely activities (eg, using an exercise bike or treadmill, playing doubles tennis, cycling at low intensity) are permitted in patients with HCM. The premise is that patients engaging in low-intensity activities are more apt than others to respond to the onset of warning symptoms. [36]

From a neurologic standpoint, male patients with Danon disease may exercise the skeletal muscles. However, they should avoid excessive fatigue, which could cause muscle injury. [37]

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