Cardiac arrest is a medical emergency where the heart ceases to pump and blood does not circulate through the body. If the patient does not receive immediate treatment, brain death can occur in four to six minutes. Many cases of cardiac arrest are treatable, although the patient will need additional care after she is stable. Treatment involves cardiopulmonary resuscitation to support the patient's circulatory system, followed by defibrillation, or application of an electrical impulse to restart the heart, if the heart enters a shockable rhythm.
Patients usually develop this condition because of an underlying disease, although it can also be the result of sudden trauma or electrical shock. The patient may report chest pain and discomfort, and when the heart stops beating the patient will rapidly slip into unconsciousness because the circulatory system no longer carries oxygen. Patients in cardiac arrest have no palpable pulse and do not breathe.
Immediate treatment involves chest compressions to pump the heart, forcing blood to circulate. In addition, the patient needs rescue breathing, where a care provider will force air into the lungs to promote oxygenation. A doctor can evaluate the patient to determine if defibrillation would be an effective treatment. A carefully placed electrical impulse can shock the heart into a normal rhythm, and it will start beating again. Usually the patient needs additional supportive care like supplementary oxygen and fluids to aid with recovery.
This condition can onset very suddenly, sometimes with no obvious warning. Because cardiac arrest can lead to clinical death within minutes, first aid is critical. Bystanders should call emergency services for assistance, but must also prepare to render medical aid themselves, because it is unlikely trained medical professionals will be able to reach the patient in time unless they happen to be among the bystanders. Basic first aid training includes cardiopulmonary resuscitation, and some facilities have automated defibrillator devices first aid providers can use; the device will assess the heart rhythm and tell the operator when a shock is indicated.
Preventative care to limit the chance of heart trouble can include a diet and exercise plan to promote cardiac health, along with treatment for underlying heart conditions. Patients with unstable heart rhythms may need to take medications or use an implanted device to manage their heart rhythm. Older adults and others at increased risk of cardiac arrest may be able to take additional steps to control their health and keep their hearts as healthy as possible.