Sudden cardiac death (SCD) is the result of the loss of heart function known as sudden cardiac arrest. This can develop from the electrical interruption in the heart that affects the pumping action. It commonly occurs in individuals in their mid-30s and mid-40s while men are more prone to this condition than the women. This account for the largest cause of death in the Unites States and is estimated that around 325,000 deaths occur annually. The sudden cardiac arrest is not a heart attack which is the blockage of the coronary arteries that interrupts the receiving of oxygen-rich blood and as the result, the heart muscle becomes damaged.
Causes
In most cases, this occurs as the result of abnormal heart rhythms known as arrhythmias, the problem with the heart’s electrical system. The common cause of arrhythmia is a condition called ventricle fibrillation which is the erratic electrical impulses from the heart’s lower chamber (ventricle). When this happens, the heart is unable to pump and death can occur within minutes. The other causes of sudden cardiac arrest can include coronary heart disease, enlarged heart (cardiomyopathy), congenital heart disease and heart attack. The risk factors associated with developing cardiac arrest includes high blood pressure, diabetes, obesity, excessive alcohol consumption and family history of coronary heart disease.
Symptoms
In over half the cases, the cardiac arrest often occurs before the onset of symptoms. However, the symptoms can include no breathing, loss of consciousness, no pulse and sudden collapse. Death can occur in the affected individual if emergency treatment cannot be availed. Time is critical and death or brain damage can occur in the affected individual within a period of four to six minutes. The emergency action includes performing CPR and treating with defibrillator or compressions of the chest can increase the chance of survival.
Diagnosis
In case the affected individual survives the cardiac arrest, various diagnostic tests will be conducted to investigate the cause and to prevent the future onset of cardiac arrest. An ECG (electrocardiogram) can identify the abnormal electrical activity of the heart and blood test can assess the level of certain substances such as potassium, magnesium and other chemicals that can interfere with the heart’s function. The imaging tests include a chest x-ray to examine the shape of the heart and the blood vessels, an echocardiogram to assess the extent of damage to the heart or valvular abnormalities and nuclear scan can evaluate the blood flow to the heart.
Treatment
Immediate action is required for survival of individuals suffering from cardiac arrest. It is estimated that the survival rate can be as high as 90% if emergency action is immediately initiated and tends to decrease by 10% each minute. The initiation of CPR can ensure that the blood and oxygen are circulating in the body until emergency help arrives. The defibrillation is used to restart the heart by delivering electric shock using paddles. When the heart is restarted, most cases require hospitalization for the treatment. Once the patient reaches the hospital, they will be administered medications to stabilize the heart rhythm. In order to prevent the future cardiac arrest, the options include anti-arrhythmic medications, implantable cardioverter-defibrillator (ICD), coronary bypass surgery or coronary angioplasty.
References
http://my.clevelandclinic.org/services/heart/disorders/arrhythmia/sudden-cardiac-death
