State-of-the-art paper: Therapeutic hypothermia in out of hospital cardiac arrest survivors.

Out of hospital cardiac arrest (OHCA) is associated with an extremely poor survival rate, with mortality in most cases being related to neurological injury. Among patients who experience return of spontaneous circulation (ROSC), therapeutic hypothermia (TH) is the only proven intervention shown to reduce mortality and improve neurological outcome. First described in 1958, the field of TH has rapidly evolved in recent years. While recent technological advances in TH will likely improve outcomes in OHCA survivors, several fundamental questions remain to be answered including the optimal speed of cooling, which patients benefit from an early invasive strategy, and whether technological advances will facilitate application of TH in the field. An increased awareness and understanding of TH strategies, devices, monitoring, techniques, and complications will allow for a more widespread adoption of this important treatment modality.

Effect of Hurricane Katrina on chronobiology at onset of acute myocardial infarction during the subsequent three years.

The onset of acute myocardial infarction (AMI) has been shown to occur in a nonrandom pattern, with peaks in midmorning and on weekdays (especially Monday). The incidence of AMI has been shown to increase locally after natural disasters, but the effect of catastrophic events on AMI biorhythms is largely unknown. To assess the differences in the chronobiology of AMI in residents of New Orleans before and after Hurricane Katrina, the onset of AMI in patients at Tulane University Health Sciences Center in the 6 years before and the 3 years after Hurricane Katrina was retrospectively examined. Compared to the pre-Katrina group, the post-Katrina cohort demonstrated significant decreases in the onset of AMI during mornings (p = 0.002), Mondays (p <0.0001), and weekdays (p <0.0001) and significant increases in onset during weekends (p <0.0001) and nights (p <0.0001). These changes persisted during all 3 years after the storm. In conclusion, the normal pattern of AMI onset was altered after Hurricane Katrina, and expected morning, weekday, and Monday peaks were eliminated.

Diagnosis of arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an infrequently diagnosed condition with a high incidence of sudden cardiac death. While the only option for cure is orthotopic cardiac transplantation, the use of an implantable cardiac defibrillator can be life saving. Accordingly, the prompt recognition of ARVC is crucial. Fortunately, a definitive diagnosis of ARVC can often be made by a combination of the clinical history and electrocardiogram alone, as illustrated by the present case. In our patient, who presented with multiple syncopal episodes and in whom ventricular tachycardia was observed shortly after her admission to the emergency department, a lengthy and expensive workup was initiated, which ultimately may have delayed implantation of an implantable cardiac defibrillator. Clinicians should be made aware of the clinical guidelines for dealing with this potentially dangerous condition so that appropriate therapy can be promptly initiated.

Induced hypothermia as a neuroprotectant in post-cardiac arrest.

Survivors of out-of-hospital cardiac arrest frequently suffer devastating effects from anoxic brain injury. Therapeutic hypothermia is the first therapy to show benefit in improving survival as well as limiting neurologic injury. We review the data supporting the use of therapeutic hypothermia in this patient population, the pathophysiologic basis of its neuroprotectant effects, the methods of hypothermic induction, and the clinical application.