Sudden cardiac death


Sudden cardiac death
Sudden cardiac death
Classification and external resources
ICD-10 I46.1
eMedicine article/151907
MeSH D016757

Sudden cardiac death is natural death from cardiac causes, heralded by abrupt loss of consciousness within one hour of the onset of acute symptoms.[1] Other forms of sudden death may be noncardiac in origin. Examples of this include respiratory arrest (such as due to airway obstruction, which may be seen in cases of choking or asphyxiation), toxicity or poisoning, anaphylaxis, or trauma.[2]

It is important to make a distinction between this term and the related term cardiac arrest, which refers to cessation of cardiac pump function which may be reversible. The phrase sudden cardiac death is a public health concept incorporating the features of natural, rapid, and unexpected. It does not specifically refer to the mechanism or cause of death.

Contents

Causes

The most common cause of sudden cardiac death in adults over the age of 30 is coronary artery atheroma. The most common finding at postmortem examination is chronic high-grade stenosis of at least one segment of a major coronary artery, the arteries which supply the heart muscle with its blood supply. A significant number of cases also have an identifiable thrombus (clot) in a major coronary artery which causes transmural occlusion of that vessel. Death in these cases is thought to result from a period of transient or prolonged ischaemia (lack of blood supply) in the myocardium (muscle of the heart wall) which induces an arrhythmia (a conduction disturbance), usually a ventricular arrhythmia, which terminates into ventricular fibrillation. As a consequence there may be no changes in the myocardium. The absence of the histological signs of acute necrosis and a healed infarct are a common finding. Chronic high-grade stenosis may have caused previous episodes of ischaemia and areas of focal fibrosis may be seen histologically in the myocardium. Ventricular arrhythmias may arise from a myocardium which has been previously scarred by episodes of ischaemia.

Left ventricular hypertrophy is the second leading cause of sudden cardiac death in the adult population. This is most commonly the result of longstanding raised high blood pressure which has caused secondary damage to the wall of the main pumping chamber of the heart, the left ventricle. Once again, hypertrophy is associated with cardiac arrhythmias.

The mechanism of death in a the majority of patients dying of sudden cardiac death is ventricular fibrillation and as a consequence there may be no prodromal symptoms associated with the death. These patients may be going about their daily business and suddenly collapse without the typical features of myocardial infarction such as chest pain and shortness of breath. There are a number of cases in which patients feel the effect of myocardial ischaemia. Myocardial ischaemia is associated with referred pain, classically to the front of the chest, the left arm and the jaw. Patients may feel generally unwell, with nausea, dizziness and vomiting. These symptoms may precede the death for any length of time between a few minutes and several hours.

Cardiac rapid response units and the use of portable defibrillators have contributed to the survival of many people who have collapsed with ventricular fibrillation. However, in cases of sudden cardiac death, the heart appears to be resistant to attempts of resuscitation. Early defibrillation in these cases rarely results in survival. The mechanism underlying this resistance is currently being investigated.

Much attention in the press has been focused on young athletes who die suddenly whilst training as a consequence of sudden cardiac death. Though these cases are rare compared to the hundreds who die each year of coronary artery atheroma and left ventricular hypertrophy, they attract much more attention due to the sensational nature of young, otherwise healthy persons suddenly and unexpectedly dying. A great deal of time and money is being spent on researching these cases and implementing schemes to screen young athletes to prevent their occurrence.

Although the most frequent cause of sudden cardiac death is coronary artery disease, other causes include:

See also

References

  1. ^ Myerburg, Robert J. "Cardiac Arrest and Sudden Cardiac Death" in Heart Disease: A Textbook of Cardiovascular Medicine, 7th edition. Philadelphia: WB Saunders, 2005.
  2. ^ http://poptop.hypermart.net/sudden.html

External links


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • sudden cardiac death — n death occurring within minutes or hours following onset of acute symptoms of cardiac arrest resulting esp. from an arrhythmia * * * unexpected natural death from cardiac causes, occurring rapidly after onset of acute symptoms in a patient with… …   Medical dictionary

  • Sudden Cardiac Death — Klassifikation nach ICD 10 I21 I22 Plötzlicher Tod bei Myokardinfarkt I44 I45 Plötzlicher Tod bei Erregungsleitungsst …   Deutsch Wikipedia

  • sudden cardiac death — noun death from cardiac malfunction, with abrupt loss of consciousness as a preliminary symptom. Abbrev.: SCD …   Australian English dictionary

  • Sudden adult death syndrome — can refer to: * sudden unexpected nocturnal death syndrome * sudden cardiac death …   Wikipedia

  • sudden adult death syndrome — sudden arrhythmia death syndrome, sudden arrhythmic death syndrome (SADS) any of various conditions in which sudden cardiac death results from an arrhythmia, usually tachycardia but occasionally severe bradycardia …   Medical dictionary

  • Sudden unexplained death syndrome — Sudden unexpected death syndrome (SUDS) or Sudden unexpected nocturnal death syndrome (SUNDS) is sudden unexpected death of adolescents and adults during sleep.Fact|date=September 2008 It is rarely observed in the Western world, and appears to… …   Wikipedia

  • Cardiac Risk in the Young — (CRY) humanitarian charitable organization helping to raise awareness of cardiac risk, Sudden Cardiac Death (SCD), Sudden Death Syndrome (SDS, SADS). Established in 1995 by Alison Cox and based in the United Kingdom.The organization promotes… …   Wikipedia

  • Sudden Death — may refer to: Sudden cardiac death Sudden death (sport) Sudden Death may refer to: 1958 NFL Championship Game, nicknamed Sudden Death for its dramatic ending Sudden Death (1977 film), starring Robert Conrad Sudden Death (1985 film), starring… …   Wikipedia

  • sudden death — n unexpected death that is instantaneous or occurs within minutes or hours from any cause other than violence <sudden death following coronary occlusion> esp SUDDEN CARDIAC DEATH …   Medical dictionary

  • Cardiac asthma — Classification and external resources ICD 10 I50.1 ICD 9 428.1 …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.