It is important that the medical profession plays a significant role in critically evaluating the use of diagnostic procedures and therapies as they are introduced and tested in the detection, management, or prevention of disease states. Rigorous and expert analysis of the available data documenting absolute and relative benefits and risks of those procedures and therapies can produce helpful guidelines that improve the effectiveness of care, optimize patient outcomes, and favorably affect the overall cost of care by focusing resources on the most effective strategies.

The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) have jointly engaged in the production of such guidelines in the area of cardiovascular disease since 1980. The ACC/AHA Task Force on Practice Guidelines, whose charge is to develop, update, or revise practice guidelines for important cardiovascular diseases and procedures, directs this effort. The Task Force is pleased to have this guideline developed in conjunction with the European Society of Cardiology (ESC). Writing committees are charged with the task of performing an assessment of the evidence and acting as an independent group of authors to develop or update written recommendations for clinical practice.

Experts in the subject under consideration have been selected from all 3 organizations to examine subject-specific data and write guidelines. The process includes additional representatives from other medical practitioner and specialty groups when appropriate. Writing committees are specifically charged to perform a formal literature review, weigh the strength of evidence for or against a particular treatment or procedure, and include estimates of expected health outcomes where data exist. Patient-specific modifiers, comorbidities, and issues of patient preference that might influence the choice of particular tests or therapies are considered as well as frequency of follow-up and cost effectiveness. When available, information from studies on cost will be considered; however, review …

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ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death

Background Empirical antiarrhythmic therapy has not reduced mortality among patients with coronary artery disease and asymptomatic ventricular arrhythmias. Previous studies have suggested that antiarrhythmic therapy guided by electrophysiologic testing might reduce the risk of sudden death. Methods We conducted a randomized, controlled trial to test the hypothesis that electrophysiologically guided antiarrhythmic therapy would reduce the risk of sudden death among patients with coronary artery disease, a left ventricular ejection fraction of 40 percent or less, and asymptomatic, unsustained ventricular tachycardia. Patients in whom sustained ventricular tachyarrhythmias were induced by programmed stimulation were randomly assigned to receive either antiarrhythmic therapy, including drugs and implantable defibrillators, as indicated by the results of electrophysiologic testing, or no antiarrhythmic therapy. Angiotensin-converting-enzyme inhibitors and beta-adrenergic-blocking agents were administered if the patients could tolerate them. Results A total of 704 patients with inducible, sustained ventricular tachyarrhythmias were randomly assigned to treatment groups. Five-year Kaplan-Meier estimates of the incidence of the primary end point of cardiac arrest or death from arrhythmia were 25 percent among those receiving electrophysiologically guided therapy and 32 percent among the patients assigned to no antiarrhythmic therapy (relative risk, 0.73; 95 percent confidence interval, 0.53 to 0.99), representing a reduction in risk of 27 percent). The five-year estimates of overall mortality were 42 percent and 48 percent, respectively (relative risk, 0.80; 95 percent confidence interval, 0.64 to 1.01). The risk of cardiac arrest or death from arrhythmia among the patients who received treatment with defibrillators was significantly lower than that among the patients discharged without receiving defibrillator treatment (relative risk, 0.24; 95 percent confidence interval, 0.13 to 0.45; P Conclusions Electrophysiologically guided antiarrhythmic therapy with implantable defibrillators, but not with antiarrhythmic drugs, reduces the risk of sudden death in high-risk patients with coronary disease.

A Randomized Study of the Prevention of Sudden Death in Patients with Coronary Artery Disease

The clinical management of acute myocardial infarction and crescendo angina as well as the prevention of sudden ischaemic death require accurate knowledge of the underlying arterial pathology. It is on just this aspect that until recently there has been disagreement particularly among pathologists. In brief, this controversy was concerned with whether coronary artery thrombi were or were not directly responsible for all three clinical pictures of acute ischaemia. Resolution of the controversy has been derived from coronary angiography in life in patients with acute infarction and crescendo angina and from detailed pathological studies. These latter studies differ from many carried out previously by the use of postmortem coronary angiography and histological reconstruction of the microanatomy of occlusive lesions.

https://heart.bmj.com/content/heartjnl/53/4/363.full.pdf

Plaque fissuring--the cause of acute myocardial infarction, sudden ischaemic death, and crescendo angina.

https://www.urgences-serveur.fr/IMG/pdf/TDRV_ESC.pdf

ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death)

Sudden cardiac death.

The subsequent course of 301 subjects with prehospital ventricular fibrillation detected by rescue units was analyzed. Defibrillation was successful in 199. Of these patients, 98 died before admission; of 101 who were hospitalized, 59 died in the hospital, and 42 were discharged alive. Initially rapid post-defibrillation heart rates and atrial fibrillation or sinus tachycardia were associated with good survival in contrast to slow rates and idioventricular or junctional rhythms. Among hospitalized patients ventricular fibrillation or ventricular tachycardia recurred in 57 per cent and in most within 24 hours. Acute myocardial infarction was diagnosed in 35 per cent, and ischemia alone (predominantly of the anterior wall) in 32 per cent. In 17 per cent no acute myocardial changes evolved. Congestive heart failure occurred in 63 per cent, cardiogenic shock in 25 per cent, and pulmonary complications in 42 per cent. Of the 42 who were discharged, 60 per cent returned to pre-arrest status; 28 per cen...

https://www.nejm.org/doi/pdf/10.1056/NEJM197408152910701?listPDF=true

Prehospital ventricular defibrillation. Prognosis and follow-up course.

In order to better understand the problem of prehospital sudden cardiac death (SCD) two groups of individuals were studied. One group was monitored by rescue squads during attempted rescue. These subjects were defibrillated from prehospital ventricular fibrillation (VF) and hospitalized if they survived or autopsied if they could not be resuscitated. The second group were SCDs which were witnessed and described by observers. Detailed past histories of both groups were collected, and either clinical or autopsy diagnoses were obtained. On the day of death or VF, one quarter reported new symptoms (primarily chest pain and dyspnea) preceding collapse by more than 30 minutes, one quarter reported symptoms lasting from 1 to 30 minutes, and one half collapsed instantaneously or within 1 minute of acute symptoms. A history of old myocardial infarction (MI) was present in 41% and of angina pectoris in 54%, and 27% reported new or changing symptoms within four weeks. In defibrillated survivors, "would-be SCDs," ele...

Pathophysiologic Observations in Prehospital Ventricular Fibrillation and Sudden Cardiac Death

The military anti-shock trouser in civilian pre-hospital emergency care.

By means of a telemetry-medical command system, a program based on cooperation between in-hospital physicians and mobile paramedical rescue crews, 146 consecutive victims were monitored remotely by telemetered electrocardiogram over a 24-month period. Of those successfully monitored, ventricular fibrillation or standstill was found in 15% while bradyrhythmias were found in 6%. Response time by rescue vehicle was four minutes or less in 80% of the cases. This mobile emergency care system offers advantages over new and special physician-staffed systems in that it has very fast response times, uses highly trained paramedics, possesses immediate availability, entails lower costs, permits higher utilization by applying to a greater variety of emergency conditions, and commands general community acceptance. Defibrillation of a victim outside the hospital was monitored by radio.

https://jamanetwork.com/journals/JAMA/articlepdf/357109/jama_214_2_009.pdf

Telemetry-medical command in coronary and other mobile emergency care systems.

Complications of prehospital use of the military anti-shock trouser (MAST) in treating hypotensive and hypovolemic patients have been few and minor. Undesirable consequences — compromised respiratory excursion or autonomic disturbances such as emesis, urination or defecation — were rare. Forty-seven (88.7%) of 53 patients with conditions classed as potentially lethal or severe survived. Close communications between prehospital and emergency department personnel can assure accurate transmission of circumstances of MAST application and result in optimal responses and improved inhospital patient care. Both "false positives" (supposed initial hypotension or hypovolemia) and "false negatives" (seeming stability in the face of major anatomic derangements) require a carefully structured operational sequence. Further evaluation of the device, particularly in cardiovascular/cardiopulmonary cases, is in progress.

https://www.annemergmed.com/article/S0361-1124(76)80216-X/pdf

Jim C. Hirschman

Papers

Prehospital ventricular defibrillation. Prognosis and follow-up course.

Pathophysiologic Observations in Prehospital Ventricular Fibrillation and Sudden Cardiac Death

The military anti-shock trouser in civilian pre-hospital emergency care.

Telemetry-medical command in coronary and other mobile emergency care systems.

Prehospital use of the military anti-shock trouser (MAST).