Sudden cardiac death: Prevalence,pathogenesis, and prevention

Sudden cardiac death (SCD), also known as sudden arrest, is a major health problem worldwide. It is usually defined as an unexpected death from a cardiac cause occurring within a short time in a person with or without preexisting heart disease. The pathogenesis of SCD is complex and multifaceted. A dynamic triggering factor usually interacts with an underlying heart disease, either genetically determined or acquired, and the final outcome is the development of lethal tachyarrhythmias or, less frequently, bradycardia. It has increasingly been highlighted that a reliable clinical and diagnostic approach might be effective to unmask the most important genetic and environmental factors, allowing the construction of a rational personalized medicine framework that can be applied in both the preclinical and clinical settings of SCD. The aim of the present article is to provide a concise overview of prevalence, pathogenesis, clinical presentation, and diagnostic approach to this challenging disorder.     

Sudden cardiac death: prevalence, pathogenesis, and prevention

Sudden cardiac death (SCD), also known as sudden arrest, is a major health problem worldwide. It is usually defined as an unexpected death from a cardiac cause occurring within a short time in a person with or without preexisting heart disease. The pathogenesis of SCD is complex and multifaceted. A dynamic triggering factor usually interacts with an underlying heart disease, either genetically determined or acquired, and the final outcome is the development of lethal tachyarrhythmias or, less frequently, bradycardia. It has increasingly been highlighted that a reliable clinical and diagnostic approach might be effective to unmask the most important genetic and environmental factors, allowing the construction of a rational personalized medicine framework that can be applied in both the preclinical and clinical settings of SCD. The aim of the present article is to provide a concise overview of prevalence, pathogenesis, clinical presentation, and diagnostic approach to this challenging disorder.     

Sudden unexpected death in epilepsy: impact, mechanisms, and prevention

Patients with refractory epilepsy face an elevated risk of sudden death, with rates as high as 1% per year. This phenomenon, known as sudden unexpected death in epilepsy (SUDEP), is believed to be a seizure-related occurrence, but the exact underlying mechanisms are uncertain. Both pulmonary and cardiac pathophysiologies have been proposed. The cardiac mechanism of greatest interest is the precipitation of arrhythmias by seizure discharges via the autonomic nervous system. SUDEP prevention has centered on effective seizure control, and epilepsy surgery has reduced SUDEP incidence in a number of studies. Additional prophylaxis methods are needed, however, for the large number of patients with treatment-refractory epilepsy. Future research should aim to clarify whether the association between seizures and autonomic dysfunction and cardiac arrhythmias extends to a demonstrable cardiac mechanism for SUDEP.     

Pressure ulcers: etiology and prevention

Pressure ulcers are a major health care problem that nurses can directly impact by identifying contributing factors and taking measures to determine patients at risk. Prevention of pressure ulcers is based on an understanding of their origin. The purpose of this article is to review the etiology of pressure ulceration and to explore recent advances toward prevention of this clinically significant problem.     

Sudden cardiac death

Sudden cardiac death (SCD) due to ventricular tachyarrhythmias is a leading cause of death in the United States. Various etiologies, including ischemic and nonischemic cardiomyopathies, hypertrophic cardiomyopathy, valvular or congenital heart diseases and other less common disorders, may result in SCD. Beta blockers are the only class of medications that have been shown to be beneficial in the primary prevention of SCD. However, recently, aldosterone antagonism early after myocardial infarction has also been shown to significantly reduce the risk of SCD. Multiple trials have elaborated on the potential benefits of implantable cardioverter defibrillators (ICD) in appropriately selected patients. However, there is still some controversy regarding the optimum period for ICD implantation, and its cost-effectiveness. An evidence-based approach to primary and secondary prevention of SCD is presented. Management of out-of-hospital cardiac arrest is briefly discussed.     

Sudden cardiac death

Sudden cardiac death (SCD) due to ventricular tachyarrhythmias is a leading cause of death in the United States. This phenomenon is associated with coronary artery disease, valvular heart disease, nonischemic cardiomyopathies, congenital heart disease, primary electrical abnormalities, autonomic nervous system abnormalities, and other less common disorders. Evaluation and management of patients at risk for SCD (primary prevention) and of patients who have survived at least 1 episode of SCD (secondary prevention) have evolved in recent years because clinical trials have shown consistent benefit from implantation of cardioverter-defibrillators in appropriately selected patients. An evidence-based approach to primary and secondary prevention of SCD is presented.     

Sudden death.

The alert physician can identify and probably alter the risk of sudden death for certain patients (see Table 5). It appears preferable to study the patient who has already been identified as having coronary artery disease because of clinical symptoms such as R/O MI, which has been shown to have a high risk for subsequent sudden death. In addition, the physician must be sensitive to the middle-aged man with multiple coronary artery disease risk factors who suddenly decides to have a routine check or develops nonspecific complaints. Once identified, patients can be educated to minimize delay time in seeking medical help with crescendo or prolonged angina. Ambulatory ECG monitoring for detection and characterization of ventricular arrhythmias, and exercise stress testing to detect severe ST depression, can facilitate an estimation of the patient's prognosis. A therapeutic plan, including attack on the patient's coronary artery disease risk factors, patient education, and specific medical or surgical therapies may alter the risk of sudden death. Once an infarction has occurred, rapid transport to a coronary care unit or monitoring facility, and administration of intramuscular lidocaine by medical or paramedical personnel when feasible, appear to lessen out-of-hospital mortality.     

Sudden unexpected death

Sudden unexpected death is a major public health problem. Many cases could be prevented if they were anticipated through means of a better awareness among the medical community, new therapies based on early genetic screening, or corrected by countershock. The authors have stated that they do not have a significant financial interest or other relationship with any product manufacture or provider of services discussed in this article. The authors do not discuss the use of off-label products, which includes unlabeled, unapproved, or investigative products or devices.