Heart attack

The first hour can be a killer

Ed's delay is typical. Half of all people who have heart attacks wait two hours or longer before seeking treatment. And half die before reaching the hospital.

Of those who survive to deal with recovery, most of the permanent damage done to the heart occurs during the first hour. If you're having a heart attack, what you don't do could kill you.

Why is the first hour critical?

A heart attack is injury to heart muscle due to a loss of blood supply. An attack occurs when arteries supplying your heart with blood and oxygen become blocked.

A blood clot that forms in an artery narrowed by buildup of cholesterol and other fatty deposits usually causes the blockage. Without oxygen, cells are destroyed, causing pain or pressure, and heart function is impaired.

A heart attack is not a static, one-time event. It's a dynamic process that typically evolves over four to six hours. With each passing minute, more tissue is deprived of oxygen and deteriorates or dies.

Minutes matter

The main way to prevent progressive damage is to treat early with clot-dissolving medications. "Clot-busters" such as tissue plasminogen activator (tPA) and streptokinase dissolve the clot and restore blood flow. In a University of Washington study, 75 percent of people survived heart attacks with little or no heart damage when clot-dissolving therapy was started within 70 minutes of onset of symptoms.

Emergency angioplasty, a procedure available at large medical centers, also widens blocked arteries, letting blood flow more freely to your heart. As with use of clot-dissolving drugs, if angioplasty is delayed beyond two hours, benefits are substantially reduced.

In the initial minutes, a heart attack can also trigger ventricular fibrillation. This unstable heart rhythm produces an ineffective heartbeat, causing insufficient blood flow to vital organs. Without immediate treatment, ventricular fibrillation can lead to sudden death.

Be alert to symptoms

During a heart attack, many people waste precious minutes because they don't recognize symptoms or they deny them. Many people also delay calling for help because they're afraid to risk the embarrassment of a "false alarm."

A heart attack generally causes chest pain for more than 15 minutes. But a heart attack also can be "silent" and have no symptoms.

About half of heart attack victims have warning symptoms hours, days or weeks in advance. The earliest predictor of an attack may be recurrent chest pain that's triggered by exertion and relieved by rest.

The American Heart Association (AHA) lists these warning signs of a heart attack. Be aware that you may not have them all, and that symptoms may come and go.

• Uncomfortable pressure, fullness or squeezing pain in the center of your chest, lasting more than a few minutes.
• Pain spreading to your shoulders, neck or arms.
• Lightheadedness, fainting, sweating, nausea or shortness of breath.

Plan your response

In a heart attack emergency, you have to make crucial decisions under stress. Even if you ultimately make wise choices, you waste valuable minutes weighing your options. Whether you suspect a heart attack or think it's just indigestion, act immediately. Take these steps:

• Call 999 first--999 contacts the emergency medical services (EMS) system. In areas without 999, call the emergency medical response system. It's usually better to call these emergency numbers first. Calling your doctor may add unnecessary time.

  When you call, describe symptoms such as severe shortness of breath or chest pain. This ensures a priority dispatch of EMS responders trained in basic and advanced cardiac life support.

  Most EMS units carry portable defibrillators. Restoring normal heart rhythm by delivering electrical shocks to the heart is critical to early treatment and survival. Many police and fire rescue units also carry defibrillators and may respond before an ambulance.

• Begin CPR--If the person is unconscious, a 999 dispatcher may advise you to begin CPR (mouth-to-mouth breathing and chest compression). Even if you're not trained, a dispatcher can instruct you in CPR until help arrives.
• Decide on fastest method of transport--A dispatcher automatically notifies the closest well-equipped EMS unit. Ideally, EMS responders should reach you within four or five minutes. If you live in a rural or large metropolitan area, however, you may get someone to the hospital faster by driving. If you think you're having a heart attack, ask someone to drive you. Never drive yourself.
• Go to the nearest emergency cardiac care facility--Identify, in advance, the nearest center staffed 24 hours a day with physicians trained to provide emergency cardiac care.
• Chew aspirin--Aspirin inhibits blood clotting, which helps maintain blood flow through a narrowed artery. When taken during a heart attack, aspirin can decrease death rates by about 25 percent. Take a regular-strength aspirin and chew to speed absorption.

  Clot-dissolving drugs and angioplasty improve your chances of surviving a heart attack once treatment begins. But successful treatment begins early. Recognize symptoms and act quickly.