CARDIAC ARREST

cardiac arrest is the sudden, unexpected loss of heart function, breathing and consciousness. Sudden cardiac arrest usually results from an electrical disturbance in your heart that disrupts its pumping action, stopping blood flow to the rest of your body.

Sudden cardiac arrest is different from a heart attack, which occurs when blood flow to a portion of the heart is blocked. However, a heart attack can sometimes trigger an electrical disturbance that leads to sudden cardiac arrest.

Sudden cardiac arrest is a medical emergency. If not treated immediately, it causes sudden cardiac death. With fast, appropriate medical care, survival is possible. Administering cardiopulmonary resuscitation (CPR) — or even just compressions to the chest — can improve the chances of survival until emergency personnel arrive.

SYMPTOMS

cardiac arrest symptoms are immediate and drastic.

• Sudden collapse
• No pulse
• No breathing
• Loss of consciousness

Sometimes other signs and symptoms precede sudden cardiac arrest. These may include fatigue, fainting, blackouts, dizziness, chest pain, shortness of breath, weakness, palpitations or vomiting. But sudden cardiac arrest often occurs with no warning.

TREATMENTS

CPR

Immediate cardiopulmonary resuscitation (CPR) is critical to treating sudden cardiac arrest. By maintaining a flow of oxygen-rich blood to the body's vital organs, CPR can provide a vital link until more advanced emergency care is available.

To perform CPR:

• Is the person conscious or unconscious?
• If the person appears unconscious, tap or shake his or her shoulder and ask loudly, "Are you OK?"
• If the person doesn't respond and two people are available, have one person call 911 or the local emergency number and one begin CPR.
• If you're alone and have immediate access to a telephone, call 911 or the local emergency number before beginning CPR — unless you think the person has become unresponsive because of suffocation (such as from drowning); in this special case, begin CPR for one minute and then call 911 or emergency medical help.
• If you're alone and rescuing a child, perform CPR for two minutes before calling 911 or emergency help or using an AED.
• If an AED is immediately available, deliver one shock if advised by the device, then begin CPR.
• Start chest compressions by putting the heel of one hand in the center of the person's chest and covering the first hand with the other hand. Keeping your elbows straight, use your upper body weight to push down hard and fast on the person's chest at a rate of about 100 compressions a minute. For a child, you may need to use only one hand.
• If you haven't been trained in CPR, continue chest compressions until emergency medical help arrives.
• If you have been trained in CPR, after every 30 compressions, gently tilt the head back and lift the chin up to open the airway. Quickly check for normal breathing, taking no more than 10 seconds. If the person isn't breathing, give two rescue breaths, making sure the chest rises after a breath. Pinch the nostrils shut and give the first rescue breath — lasting one second — and watch to see if the chest rises. If it does rise, give the second breath. If the chest doesn't rise, repeat the head-tilt, chin-lift maneuver and then give the second breath.
• If a child has not begun moving after five cycles (about two minutes) and an AED is available, apply it and follow the prompts. Administer one shock if so advised, then resume CPR — starting with chest compressions — for two more minutes before administering a second shock. If you're not trained to use an AED, a 911 or emergency medical help operator may be able to guide you in its use.
• Continue CPR or chest compressions until the person recovers consciousness and is breathing normally or until emergency medical personnel take over.

Defibrillation

Advanced care for ventricular fibrillation, a type of arrhythmia that can cause sudden cardiac arrest, typically includes delivery of an electrical shock through the chest wall to the heart. The procedure, called defibrillation, momentarily stops the heart and the chaotic rhythm. This often allows the normal heart rhythm to resume.

Treatments may include:

• Drugs. Doctors use various anti-arrhythmic drugs for emergency or long-term treatment of arrhythmias or potential arrhythmia complications. A class of medications called beta blockers is commonly used in people at risk of sudden cardiac arrest. Other possible drugs include angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers or a drug called amiodarone (Cordarone).

• As with any medication, anti-arrhythmic drugs may have potential side effects. For example, an anti-arrhythmic drug may cause your particular arrhythmia to occur more frequently — or even cause a new arrhythmia to appear that's as bad as or worse than your pre-existing condition.
• Implantable cardioverter-defibrillator (ICD). After your condition stabilizes, your doctor is likely to recommend implantation of an ICD. An ICD is a battery-powered unit that's implanted near your left collarbone. One or more electrode-tipped wires from the ICD run through veins to your heart.
• The ICD constantly monitors your heart rhythm. If it detects a rhythm that's too slow, it paces your heart as a pacemaker would. If it detects a dangerous heart rhythm change, it sends out low- or high-energy shocks to reset your heart to a normal rhythm. An ICD may be more effective than preventive drug treatment at reducing your chance of having a fatal arrhythmia.
• Coronary angioplasty. This procedure opens blocked coronary arteries, letting blood flow more freely to your heart, which may reduce your risk of serious arrhythmia. Doctors insert a long, thin tube (catheter) that's passed through an artery, usually in your leg, to a blocked artery in your heart. This catheter is equipped with a special balloon tip that briefly inflates to open up a blocked coronary artery. At the same time, a metal mesh stent may be inserted into the artery to keep it open long term, restoring blood flow to your heart. Coronary angioplasty may be done at the same time as a coronary catheterization (angiogram), a procedure that doctors do first to locate narrowed arteries to the heart.
• Coronary bypass surgery. Another procedure to improve blood flow is coronary bypass surgery. Bypass surgery involves sewing veins or arteries in place at a site beyond a blocked or narrowed coronary artery (bypassing the narrowed section), restoring blood flow to your heart. This may improve the blood supply to your heart and reduce the frequency of racing heartbeats.
• Radiofrequency catheter ablation. This procedure may be used to block a single abnormal electrical pathway. In this procedure, one or more catheters are threaded through your blood vessels to your inner heart. They're positioned along electrical pathways identified by your doctor as causing your arrhythmia. Electrodes at the catheter tips are heated with radiofrequency energy. This destroys (ablates) a small spot of heart tissue and creates an electrical block along the pathway that's causing your arrhythmia. Usually this stops your arrhythmia.
• Corrective heart surgery. If you have a congenital heart deformity, a faulty valve or diseased heart muscle tissue due to cardiomyopathy, surgery to correct the abnormality may improve your heart rate and blood flow, reducing your risk of fatal arrhythmias.
• Heart transplantation. Some people with severe heart failure who've experienced cardiac arrest may be eligible for a heart transplant. But given the lack of donor hearts, availability is limited.

PREVENTION

There's no sure way to know your risk of sudden cardiac arrest, so reducing your risk is the best strategy. Steps to take include regular checkups, screening for heart disease and living a heart-healthy lifestyle with the following approaches:

• Don't smoke, and use alcohol in moderation (no more than one to two drinks a day).
• Eat a nutritious, balanced diet.
• Stay physically active.
• If you know you have heart disease or conditions that make you more vulnerable to an unhealthy heart, your doctor may recommend that you take appropriate steps to improve your health, such as taking medications for high cholesterol or carefully managing diabetes.

• In some people with a known high risk of sudden cardiac arrest — such as those with a heart condition — doctors may recommend anti-arrhythmic drugs or an implantable cardioverter-defibrillator (ICD) as primary prevention.
• If you have a high risk of sudden cardiac arrest, you may also wish to consider purchasing an automated external defibrillator (AED) for home use. Before purchasing one, discuss the decision with your doctor. AEDs can be expensive and aren't always covered by health insurance.
• If you live with someone who is vulnerable to sudden cardiac arrest, it's important that you be trained in CPR. The American Red Cross and other organizations offer courses in CPR and defibrillator use to the public. Being trained will help not only your loved one but also those in your community. The more people who know how to respond to a cardiac emergency, the more the survival rate for sudden cardiac arrest can be improved.