Complications After Dental Sedation: A Myotonic Mystery Case Report.

Myotonic dystrophy (dystrophia myotonica; DM) is an uncommon progressive hereditary muscle disorder that can present with variable severity at birth, in early childhood, or most commonly as an adult. Patients with DM, especially type 1 (DM1), are extremely sensitive to the respiratory depressant effects of sedative-hypnotics, anxiolytics, and opioid agonists. This case report describes a 37-year-old male patient with previously undiagnosed DM1 who received dental care under minimal sedation using intravenous midazolam. During the case, the patient experienced 2 brief episodes of hypoxemia, the second of which required emergency intubation after propofol and succinylcholine and resulted in extended hospital admission. A lipid emulsion (Liposyn II 20%) infusion was given approximately 2 hours after the last local anesthetic injection due to slight ST elevation and suspicion of local anesthetic toxicity (LAST). Months after treatment, the patient suffered a fall resulting in a fatal traumatic brain injury. Complications noted in this case report were primarily attributed to the unknown diagnosis of DM1, although additional precipitating factors were likely present. This report also provides a basic review of the literature and clinical guidelines for managing myotonic dystrophy patients for dental care with local anesthesia, sedation, or general anesthesia.

Myotonic dystrophy type 1 and high ventricular vulnerability at the electrophysiological evaluation: ICD yes or not?

A significant number of sudden death (SD) is observed in myotonic dystrophy (DM1) despite pacemaker implantation and some consider the ICD to be the preferential device in patients with conduction disease. According to the latest guidelines, prophylactic ICD implantation in patients with neuromuscular disorder should follow the same recommendations of non-ischemic dilated cardiomyopathy, being reasonable when pacing is needed. We here report a case of DM1 patient who underwent ICD implantation even in the absence of conduction disturbances on ECG and ventricular dysfunction/fibrosis at cardiac magnetic resonance. The occurrence of syncope, non-sustained ventricular tachycardias at 24-Holter ECG monitoring and a family history of SD resulted associated with ventricular fibrillation inducibility at electrophysiological study, favouring ICD implantation. On our advice, DM1 patient with this association of SD risk factors should be targeted for ICD implantation.

Diagnosis and management of adult hereditary cardio-neuromuscular disorders: A model for the multidisciplinary care of complex genetic disorders.

Genetic disorders that disrupt the structure and function of the cardiovascular system and the peripheral nervous system are common enough to be encountered in routine cardiovascular practice. Although often these patients are diagnosed in childhood and come to the cardiologist fully characterized, some patients with hereditary neuromuscular disease may not manifest until adulthood and will present initially to the adult cardiologist for an evaluation of an abnormal ECG, unexplained syncope, LV hypertrophy, and or a dilated cardiomyopathy of unknown cause. Cardiologists are often ill-equipped to manage these patients due to lack of training and exposure as well as the complete absence of practice guidelines to aid in the diagnosis and management of these disorders. Here, we review three key neuromuscular diseases that affect the cardiovascular system in adults (myotonic dystrophy type 1, Friedreich ataxia, and Emery-Dreifuss muscular dystrophy), with an emphasis on their clinical presentation, genetic and molecular pathogenesis, and recent important research on medical and interventional treatments. We also advocate the development of interdisciplinary cardio-neuromuscular clinics to optimize the care for these patients.

Risk of arrhythmias in myotonic dystrophy: trial design of the RAMYD study.

OBJECTIVE: Myotonic dystrophy type 1 (DM1) is the most frequent muscular dystrophy in adults. DM1 is a multisystem disorder also affecting the heart with an increased incidence of sudden death, which has been explained with the common impairment of the conduction system often requiring pacemaker implantation; however, the occurrence of sudden death despite pacemaker implantation and the observation of major ventricular arrhythmias generated the hypothesis that ventricular arrhythmias may play a causal role as well. The aim of the study was to assess the 2-year cumulative incidence and the value of noninvasive and invasive findings as predictive factors for sudden death, resuscitated cardiac arrest, ventricular fibrillation, sustained ventricular tachycardia and severe sinus dysfunction or high-degree atrioventricular block. METHODS/DESIGN: More than 500 DM1 patients will be evaluated at baseline with a clinical interview, 12-lead ECG, 24-h ECG and echocardiogram. Conventional and nonconventional indications to electrophysiological study, pacemaker, implantable cardioverter defibrillator or loop recorder implantation have been developed. In the case of an indication to electrophysiological study, pacemaker, implantable cardioverter defibrillator or loop recorder implant at baseline or at follow-up, the patient will be referred for the procedure. At the end of 2-year follow-up, all candidate prognostic factors will be tested for their association with the endpoints. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT00127582. CONCLUSION: The available evidence supports the hypothesis that both bradyarrhythmias and tachyarrhythmias may cause sudden death in DM1, but the course of cardiac disease in DM1 is still unclear. We expect that this large, prospective, multicenter study will provide evidence to improve diagnostic and therapeutic strategies in DM1.

Should we perform systematic electrophysiological study in Steinert's disease?

Myotonic dystrophy type 1 (Steinert's disease) is a multisystem disorder with autosomal dominant inheritance. This disease is associated with the presence of an abnormal expansion of a cytosine thymine-guanine (CTG) trinucleotide repeat on chromosome 19q13.3. Because of rhythmic complications, the place for systematic electrophysiological study (EPS) has to be discussed.

Trastornos de sueño en la distrofia miotónica tipo 1 / Sleep disorders in myotonic dystrophy type I

Evaluamos los trastornos de sueño en ocho pacientes con distrofia miotónica tipo 1 confirmada genéticamente, con edades comprendidas entre 38 y 58 años. Los pacientes fueron estudiados mediante polisomnografía y test de latencias múltiples de sueño. Encontramos excesiva somnolencia diurna en el 75% de los pacientes, no justificable por los eventos respiratorios durante el sueño. El modafinil mejoró este síntoma en todos ellos (AU)

We investigated the sleep disorders in eight patients with genetically confirmed myotonic dystrophy type 1, aged from 38 to 58 years. Patients were studied with nocturnal polysomnogram and multiple sleep latency tests. We found excessive daytime sleepiness in 75% of them, not accountable for respiratory events during sleep. Modafinil improved this symptom in all of them (AU)

[The electrotherapy of the arrhythmias in 3 cases of myotonic dystrophy (Steinert's disease)]. / Terapia elettrica delle aritmie in tre casi di distrofia miotonica (malattia di Steinert).

Myotonic dystrophy is a progressive multisystem disease with autosomal dominant inheritance. Cardiac involvement is an integral part of the disorder, the most prominent manifestations being various conduction defects and rhythm disturbances sometimes related to syncope or sudden cardiac death. We describe 3 cases admitted to our Centres. Two patients received a permanent pacemaker for atrioventricular block of different degree and in the third case an implantable cardioverter defibrillator with antibradycardia pacing was inserted for malignant ventricular tachyarrhythmias and advanced atrioventricular block during atrial flutter.

[The positive effect of mud applications in the treatment of myotonic dystrophy]. / Polozhitel'nyi éffekt griazevykh applikatsii pri lechenii miotonicheskoi distrofii.

A case communication. Positive effect in reducing myotonia after mud applications was achieved in a myotonic patient. Plausible therapeutical mechanisms of peloid action on the disease are described.

Dystrophia myotonica: a case report.

A case study is presented to demonstrate the importance of utilizing clinical and laboratory diagnosis to confirm dystrophic disease. A review of the signs and symptoms of myotonic dystrophy is discussed, and a chiropractic approach is outlined for management of this debilitating disease.

1H and 31P nuclear magnetic resonance spectroscopy of erythrocyte extracts in myotonic muscular dystrophy.

Extracts freshly prepared from erythrocytes of patients with myotonic muscular dystrophy, their unaffected siblings, and normal control subjects were examined with both 1H and 31P nuclear magnetic resonance spectroscopy. A moderate variability was found in the relative amounts of various nonphosphorylated compounds among patients and control subjects; however, no significant differences were found between the groups. As for the phosphorylated compounds, the sum of ADP + ATP was found significantly elevated in the myotonic muscular dystrophy patients.

[Endocrine aspects of Steinert's disease]. / Aspects endocriniens de la maladie de Steinert

The authors report a case of Steinert's disease in a woman and discuss the endocrine profile of this disease after giving an account of the criteria of diagnosis. Disorders of gonad function are mild in women, primary testicular atrophy is very frequent in man with reduction in 17-ketosteroids and testosterone. Thyroid function was normal but, in a few cases, a low fixation curve was found (our case) corrected by TSH stimulation. The frequency of cataract emphasizes the interest of this sign for detection. Diabetes, associated with hyperinsulinism, seemed more frequent than in a population without Steinert's disease. The pathogenesis of these endocrine disorders appears secondary and is ill explained if one considers it as a single disease. Better knowledge, no doubt linked to progress in biochemistry of normal and myopathic muscle, will help to explain the pathogenesis.