We report the first case of witnessed
sudden death of an
Emery-Dreifuss muscular dystrophy (EDMD) patient with a properly functioning
implantable cardioverter-defibrillator (ICD). This 38-yr-old woman with normal left ventricular function had a history of recurrent
syncope and
nonsustained ventricular tachycardia, for which a single-chamber ventricular ICD was implanted. She later collapsed suddenly and unexpectedly while at home, with witnesses present, and was found cyanotic with pulseless electrical activity by the emergency squad. This event took place in the setting of previously documented hypercapnic ventilatory insufficiency, for which she had refused the use of respiratory muscle
aids to normalize alveolar ventilation. Subsequent interrogation of the ICD demonstrated normal function, with no evidence of
ventricular tachycardia or
ventricular fibrillation. In the hospital, her myocardial function was found to be normal by echocardiography. Further workup revealed that the patient had severe
anoxic encephalopathy. She was eventually made "do not resuscitate," and she died on the sixth day of hospitalization. An autopsy was performed, and no obvious cause for the
sudden death could be established. Review of the clinical presentation, with all the data available, suggests acute
respiratory failure as the likely primary cause of this patient's
sudden death, which then secondarily led to the observed pulseless electrical activity of the heart. The use of respiratory muscle
aids--in particular, noninvasive
mechanical ventilation to prevent chronic
hypercapnia and
cor pulmonale--is crucial for EDMD patients with symptomatic ventilatory insufficiency, for whom sudden deaths may not necessarily be of primarily cardiac origin.