sudden cardiac death


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Sudden Cardiac Death

 

Definition

Sudden cardiac death (SCD) is an unexpected death due to heart problems, which occurs within one hour from the start of any cardiac-related symptoms. SCD is sometimes called cardiac arrest.

Description

When the heart suddenly stops beating effectively and breathing ceases, a person is said to have experienced sudden cardiac death.
SCD is not the same as actual death. In actual death, the brain also dies. The important difference is that sudden cardiac death is potentially reversible. If it is reversed quickly enough, the brain will not die.
Sudden cardiac death is also not the same as a heart attack. A heart attack (myocardial infarction) is the result of a blockage in an artery which feeds the heart, so the heart becomes starved for oxygen. The part that has been starved is damaged beyond repair, but the heart can still beat effectively.

Causes and symptoms

Sudden cardiac death is usually caused by ventricular fibrillation (the lower chamber of the heart quivers instead of pumping in an organized rhythm). Ventricular fibrillation almost never returns to normal by itself, so the condition requires immediate intervention. Ventricular tachycardia can also lead to sudden cardiac death. The risk for SCD is higher for anyone with heart disease.
When the heart stops beating effectively and the brain is being deprived of oxygenated blood, a medical emergency exists.

Diagnosis

Diagnosis of sudden cardiac death is made when there is a sudden loss of consciousness, breathing stops, and there is no effective heart beat.

Treatment

When sudden cardiac death occurs, the first priority is to establish the flow of oxygenated blood to the brain. The next priority is to restore normal rhythm to the heart. Forcing air into the mouth will get oxygen into the lungs. Compressing the chest simulates a pumping heart and will get some blood flow to the lungs, brain, and coronary arteries. This method is called cardiopulmonary resuscitation (CPR). When trained help arrives, they will attempt to establish a normal heart beat by using a device called a defibrillator.
When If sudden cardiac death occurs outside the hospital setting, cardiopulmonary resuscitation (CPR) must begin within four to six minutes and advanced life support measures must begin within eight minutes, to avoid brain death. CPR requires no special medical skills and training is available for the ordinary person nationwide.

Key terms

Defibrillator — A device which delivers a controlled electric shock to the heart to return it to normal beating rhythm.
Ventricular fibrillation — When The lower chamber of the heart quivers instead of pumping in an organized way.
Ventricular tachycardia — A rapid heartbeat, usually over 100 beats per minute.

Prognosis

Sudden cardiac death is reversible in most people if treatment is begun quickly. However, of the people who are resuscitated, 40% will have another SCD within two years if they do not receive appropriate treatment for the underlying cause of the episode.

Prevention

When In order to prevent sudden cardiac death, underlying heart conditions must be addressed. Medications and implantable cardioverter-defibrillators may be used.

Resources

Organizations

American Heart Association. 7320 Greenville Ave. Dallas, TX 75231. (214) 373-6300. http://www.americanheart.org.

sudden cardiac death

Death within one hour of onset of witnessed cardiac symptoms, usually due to ventricular dysrhythmia in those younger than age 30 and to vascular changes in those older than 30. Electrical instability (e.g., long-QT syndrome) plays a major role and may be linked to sudden death in diabetes, obesity, epilepsy, alcohol, and idiopathic.

Incidence
80–120/105/year in developed countries.

Sudden cardiac death, aetiology in young patients
Atherosclerosis, cocaine abuse, congenital heart disease, coronary anomalies, coronary dissection, coronary embolism, coronary vasculitis, dilated cardiomyopathy, HOCM, myocardial bridging, myocardial fibrosis, myocarditis, right ventricular cardiomyopathy, sarcoidosis.

sudden cardiac death

Cardiology Death due to cardiac disease ≤ 1 hr after onset of Sx Public health A nontraumatic, nonviolent, unexpected event due to sudden cardiac arrest within 6 hrs of a previously witnessed usual state of normal health; SCD is the most common COD in the US–±400,000 deaths/yr, primarily of ♂ age 20-64; 75% are due to sustained ventricular arrhythmias Etiology Anomalous aortic origin–LCA or circumflex from right sinus of Valsalva–SOV; RCA from left SOV; CA origin from pulmonary artery, myocardial bridging, ostial stenosis, coronary arteritis or AV fistula, coronary artery dissection, embolism, hypoplasia, or spasm, idiopathic arterial calcification of infancy, fibromuscular dysplasia. See Sudden unexplained nocturnal death.
References in periodicals archive ?
There are some predictors of poor prognosis that has been identified such as young age at diagnosis, positive family history of sudden cardiac death, present of heart failure symptoms at New York Heart Association Class II and above, and others.[4]
Although rare, sudden cardiac death in athletes is a traumatic event that has a large impact on society, and therefore, increased access to automated external defibrillators as well as training in cardiopulmonary resuscitation at a community level are important means of reducing sudden cardiac death in athletes.
- Sudden cardiac deaths account for 30 to 50 percent of deaths in patients with heart failure
This may also shed light on etiology of sudden cardiac death in patients with known hyperthyroidism especially those of new onset without adequate correction of T4.
All of the deaths reported in the Neurology study met the widely accepted World Health Organization criteria for sudden cardiac death. Following a systemic evaluation of 352 consecutive sudden cardiac deaths reported to the San Francisco Medical Examiner between 2011 and 2013 including a full autopsy and detailed evaluation of the heart and cranial vault in 95 percent of cases (335) the researchers found that 5.4 percent of these deaths (18) should have been classified instead as a sudden neurological death.
In encouraging news for people who are able to quit smoking, however, the study found that former smokers had a similar risk of sudden cardiac death as people who had never smoked.
"By showing how calmodulin mutation could disrupt this and lead to sudden cardiac death, the Cardiff team have provided new clues for how to treat the condition in the future.
Proceeds from the tournament were used to fund two key things in the fight against sudden cardiac death in children, and one that keeps the memory of Josh alive.
In the study, funded by the NHLBI, 10,701 people who participated in sleep studies were followed for an average of 5.3 years for incidence of sudden cardiac death. In that time, 142 patients died of sudden cardiac death.
Sudden cardiac death occurs when a person's heart abruptly stops beating, and coronary artery disease - the clogging of arteries supplying the heart with blood - is the most common cause.
DENVER--Both second- and first-generation antipsychotic agents proved to be independently associated with greater than threefold increased risks of sudden cardiac death, according to results from a large, population-based study.
Now a new study, published in the January 14, 2013 JAMA Internal Medicine, suggests it also may double the likelihood of sudden cardiac death.