Sudden Cardiac Arrest

Sudden cardiac arrest is most often caused by heart disease. Those who suffer sudden cardiac arrest may or may not have diagnosed heart disease. Types of heart disease most often associated with sudden death include:

• Coronary artery disease
• Ventricular fibrillation
• Congestive heart failure
• Heart valve problems
• Cardiomyopathy

Symptoms of sudden cardiac arrest are not subtle:

• The heart simply stops beating.
• Loss of consciousness is almost immediate.
• There is no pulse.
• There are no signs of breathing.

Risk factors for sudden cardiac arrest are the same as for coronary artery disease. In some cases, sudden cardiac arrest can occur spontaneously without any known risk factors associated with its onset. Young athletes are also at higher risk for sudden cardiac death.

Sudden cardiac arrest is, unfortunately, often diagnosed on autopsy. However, sudden cardiac arrest may be preventable by diagnosing and treating underlying heart-related conditions that can lead to such deaths.

The majority of people whose heart stops beating unexpectedly have ventricular fibrillation, a type of arrhythmia that causes an extremely erratic heart rate. The definitive treatment for this is cardiopulmonary resuscitation (CPR) and defibrillation, using electricity to shock the heart back into a regular rhythm. Unless treatment occurs within four to six minutes, there is a high risk of death or permanent brain damage.

If the patient survives, tests will be done to determine the cause of the heart stoppage, so that preventative measures can be taken. These tests may include:

• Electrocardiogram (EKG or ECG)
• Echocardiogram
• Cardiac catheterization
• Electrophysiology (EP) study, to help pinpoint the arrhythmia

Survivors of sudden cardiac arrest are often candidates for implantable cardiac defibrillators (ICDs). Similar to a pacemaker, ICDs monitor the heart constantly, but only initiate an electrical signal when a prespecified, dangerous rhythmic abnormality is detected.