Cardiac arrest occurs when the heart stops beating. The patient stops breathing, loses consciousness and then loses pulse and blood pressure.

Tissues and organs of the body don't get oxygen and cells begin to die. Brain death occurs within four to six minutes after the heart stops beating.

The most common cause of cardiac arrest is coronary artery disease. The arteries feeding the heart may be narrowed by fatty deposits. Some patients have heart muscle scarring from prior heart attacks. Normally, electrical impulses keep the heart beating in an orderly fashion. In people with heart disease or heart muscle damage, the electrical impulses may become rapid (ventricular tachycardia) or chaotic (ventricular fibrillation). Eventually, the heart may stop beating (cardiac arrest).

Early Resuscitation

When the heart stops, it needs an electric shock (defibrillation) to get started again. Emergency medical services (EMS) should be alerted immediately to get help to the scene as soon as possible. After the EMS system has been activated, witnesses can buy time for the patient with cardiopulmonary resuscitation (CPR). CPR has two components: (1) chest compressions to pump blood from the heart to the tissues of the body and (2) rescue breathing (mouth-to-mouth) to provide some oxygen to the lungs. The goal of CPR is to provide some oxygenated blood to the brain, heart and other vital organs until EMS responders arrive. The rescue technique is most effective when trained EMS personnel arrive within 8 to 12 minutes of the cardiac arrest.

The ResQ Valve

Researchers at Froedtert and The Medical College of Wisconsin have developed a device that improves survival in patients who receive CPR after cardiac arrest. It's called the ResQ Valve.

The ResQ Valve fits over the airway and can be placed on a face mask of an endotracheal tube. It acts like a one-way valve during chest compressions. As the rescuer pushes down on the chest, the valve remains open, allowing the air in the lungs to escape. On the upstroke of the compression (when the chest returns to its normal position), the valve closes, preventing air from going back into the lungs. This creates suction or a negative pressure in the chest. The process pulls more blood from the stomach and legs back to the heart. Then, with the next chest compression, there is more blood to pump out from the heart to the vital organs.

Research shows the ResQ Valve doubles blood pressure during CPR and improves survival rates. Investigators are now hoping to determine if use of the ResQ Valve will improve neurologic outcomes and higher discharge rates after rescue treatment for cardiac arrest.

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