Unexpected sudden cardiac arrest due to ventricular fibrillation in a 7-year-old boy with Duchenne muscular dystrophy.

Efficacy of Multi-exon Skipping Treatment in Duchenne Muscular Dystrophy Dog Model Neonates

Holter electrocardiogram should be systematic in Duchenne muscular dystrophy

To Compress or Not to Compress; That Is the Question

The recommendations for electrical therapies described in this section are designed to improve survival from SCA and life-threatening arrhythmias. Whenever defibrillation is attempted, rescuers must coordinate high-quality CPR with defibrillation to minimize interruptions in chest compressions and to ensure immediate resumption of chest compressions after shock delivery. The high first-shock efficacy of newer biphasic defibrillators led to the recommendation of single shocks plus immediate CPR instead of 3-shock sequences that were recommended prior to 2005 to treat VF. Further data are needed to refine recommendations for energy levels for defibrillation and cardioversion using biphasic waveforms.

Sir William Osler reportedly once said, “Varicose veins are the result of an improper selection of grandparents.” Indeed, our family history strongly influences many aspects of our cardiovascular system, with the magnitude of effect ranging from very strong for autosomal dominant genetic disorders to more subtle in the setting of complex multigenic diseases like coronary atherosclerosis and hypertension. Accordingly, the standard evaluation of any new patient who presents to a physician includes assessment of their family history. Unfortunately, the family history may sometimes be discounted as noncontributory without detailed review. This can be exacerbated by busy office schedules with declining amounts of time available for comprehensive evaluations. A few minutes saved might seem to justify the lack of focus on an aspect of history that is sometimes deemed not to be particularly useful. However, a thorough assessment of family history also may provide the key diagnostic information to determine the cause of an illness, to determine who else is at risk of disease within the family, to add useful prognostic information, and to help for family planning and reproductive decisions. A family history of sudden death should prompt consideration of a wide range of heritable cardiovascular conditions, including many monogenic disorders (Table). However, the terms used by the lay public to describe sudden death may not adequately explain the cause of death on initial consideration. For instance, the phrase “heart attack” may be used to describe sudden death of any etiology. Further questioning may help one to discern whether there was a history of heart failure, cardiomyopathy, coronary artery disease (or its risk factors), aortic aneurysm, or features of syndromic disorders that are associated with sudden death. View this table: Table. Monogenic Disorders Associated With Sudden Death A 40-year-old man presents to a physician for evaluation of palpitations. These occur briefly about once per …

What Can We Learn From Clinical Trials of Exon Skipping for DMD?

External Defibrillation: The Need for Uniformity in Analyzing and Reporting Results

A manifesting female carrier of Duchenne muscular dystrophy: Importance of genetics for the dystrophinopathies.

Behavior patterns in Duchenne muscular dystrophy: Report on the Parent Project Muscular Dystrophy behavior workshop 8–9 of December 2006, Philadelphia, USA

30-Year-Old Man With Outside-of-Hospital Cardiac Arrest

AHA/ACCF Scientific Statement on the Evaluation of Syncope

A 20-year-old asymptomatic man was diagnosed with hypertrophic cardiomyopathy (HCM) after routine physical examination during which a systolic heart murmur was detected.Echocardiography showed massive left ventricular (LV) hypertrophy with ventricular septal thickness of 36 mm extending into the anterolateral wall (30 mm); outflow obstruction was absent.Ambulatory (Holter) ECG showed 3 isolated premature ventricular contractions, and blood pressure response to exercise was normal.Echocardiographic examinations in parents and siblings were negative for HCM.Although 2 centers advised against an implantable cardioverter-defibrillator (ICD) based on the presence of only 1 risk factor for sudden death (ie, extreme hypertrophy), a prophylactic device was recommended by a third cardiac consultant.After an uneventful 16-month period during which the ICD neither detected nor treated arrhythmias, an unprovoked episode of ventricular fibrillation triggered a defibrillation shock that immediately restored sinus rhythm (Figure 1).

M YOGLOBINURIA is an uncommon complication of a simple anesthetic. Cardiac arrest with or without the appearances of Malignant Hyperthermia (MH) is an even more dramatic complication. It has been suggested that Duchenne's and Becker's muscular dystrophies (two of a group of diseases classified as dys- trophoinopathies) predispose patients to developing these complications when an inhalational anesthetic has been administered. In this edition of the Journal, Obata, Yasumi, Suzuki, Nakajima, and Sato implicate one of our newer inhalation agents, sevoflurane as a causative agent of rhabdomyolysis following the administration of an anesthetic to a child with Duchenne's muscular dystrophy (DMD). In this case report, they describe the occurrence of acute rhabdomyolysis in a patient who received sevoflurane during strabismus repair. No muscle relaxants were given, and it is unlikely that the other agents used, hydrocortisone, diclofenac, or nitrous oxide, contributed to this complication. Although rhabdomyolysis in patients with DMD has been associated with halothane, isoflurane, and enflu- rane, it has not been described in association with the administration of sevoflurane. Rhabdomyolysis, with or without cardiac arrest can occur with inhalation anesthetics in patients with DMD, even if succinylcholine is avoided. Halothane and isoflurane alone have been implicated, as well as many other agents in multiple circumstances unrelat- ed to anesthesia. Rubiano, Chang, Carroll, Sonobolian, and Larson reported the occurrence of myglobinuria in a five year old boy who had a 12 min anesthetic with halothane, and the child was subse- quently demonstrated to have DMD. 1 Chalkiadis and Branch reported acute rhabdomyolysis and cardiac arrest in a child with known Becker's muscular dystro- phy who had a 35 min isoflurane anesthetic. 2 Sethna and Rockoff reported cardiac arrest with asystole in a five year old child with probable DMD after ten min- utes of halothane anesthesia: in this instance, the patient appeared to have malignant hyperthermia. 3 On the basis of this case and others they quoted from the Children's Hospital in Boston, it was recommend that patients with DMD should be treated as though they were susceptible to MH and, therefore, agents which could initiate MH should be avoided. Although Malignant Hyperthermia can occur in the presence of one of the dystrophoinopathies, the hypermetabolism that occurs may be unrelated to MH and it represents a different genetic entity. Gronert et al. described two two-year old boys who underwent muscle biopsy that established the histopathological diagnosis of Becker dystrophy in one, and Duchenne dystrophy in the other. Concomitant contracture test- ing with caffeine or halothane was normal for malig- nant hyperthermia (MH). They suggested that acute hypermetabolism or acute rhabdomyolysis during anesthesia, in patients with these disorders, is related to the X- linked myopathy and its associated muscle deterioration, rather than to the autosomal dominant MH. 4 The wide variation in timing and severity of reactions reflect an unpredictability of response for any one individual. In a recent editorial in Paediatric Anaesthesia, Morris provided a balanced view of issues related to anesthetic techniques for patients with DMD. He clearly identifies the reasons succinylcholine is now contraindicated for use in patients with DMD. Although some authors have cautioned against the use of volatile agents, he did not recommend that their use be limited in DMD. He stated that, there is no strong evidence to confirm that these agents are contraindi- cated. 5 There are no large prospective trials of use of inhalation agents in patients with DMD - most of the evidence substantiating complications is based on case reports and muscle analysis of individual patients. Some anesthesiologists have taken a stronger stand in relation to the use of inhalation agents. In 1983, Rosenberg and Heiman-Patterson recommended can-

Cardiac arrest is a common and treatable cause of death and disability. Each year ≈424 000 people experience emergency medical services (EMS)-assessed out-of-hospital cardiac arrest (OHCA) in the United States.1 The actual burden of OHCA is likely significantly higher because a substantial number go unassessed. In a prospective analysis of deaths in a US county, 5.6% of annual mortality was attributable to cardiac arrest.2 Many patients who suffer OHCA do not receive prompt cardiopulmonary resuscitation (CPR). Among those who receive CPR, a large number do not survive because of an inability to restore spontaneous circulation, or anoxic cerebral injury even after restoration of circulation. Nevertheless, when timely interventions are provided, a small proportion of patients (10.4% of all EMS-treated OHCA) recover to resume normal lives. The key therapeutic interventions that make the difference between life and death, metaphorically characterized as the 5 links in a chain of survival by the American Heart Association, include: (1) immediate recognition of cardiac arrest and activation of the EMS, (2) early CPR with emphasis on chest compression, (3) rapid defibrillation, (4) effective advanced life support, and (5) integrated postcardiac arrest care.3 Resuscitation science has undergone major advances since the origins of modern CPR >50 years ago.4 The field continues to be dynamic with emergence of new therapies such as therapeutic hypothermia5 and improvements in systems of care. However, many questions remain on issues such as optimum compression rate, efficacy of chest compression only CPR (CCCPR), dispatcher-assisted CPR, and benefits of postresuscitation measures such as hypothermia. A critical challenge also lies in the translation of resuscitation science into practice. To improve outcomes, each of the links in the chain of survival needs to be executed promptly and effectively. There remain several lacunae, which need to be overcome to develop an …

Part 6: Defibrillation