Cardiac arrest, heart attack, heart failure, stroke. The four horseman of the apocalypse? In fact, these are four very different expressions of cardiovascular disease that, although familiar, are a source of confusion for non-medical people.
The heart is a muscular pump. Each contraction of that pump, or heartbeat, is coordinated by the heart’s electrical, or conduction, system. When working properly, the electrical mechanism ensures an appropriate number of heartbeats each minute. The muscle that forms the walls of the heart normally squeezes forcefully with each beat and ejects the blood it contains with enough velocity to reach all the vital organs and extremities.
Because the heart works continuously (generating more than 100,000 beats each day), it requires a separate blood and oxygen supply. This is provided by the coronary arteries, a network of small blood vessels lying over the surface of the heart.
Cardiac arrest: A cardiac arrest occurs when coordinated contraction of the heart stops. Death will ensue in minutes. Most instances of cardiac arrest occur because the electrical stimulation has become chaotic and the contraction of the muscle is ineffective and not coordinated. This is known as ventricular fibrillation. It may account for more than a quarter-million deaths each year in the United States.
Heart attack: A sudden obstruction within the coronary arteries, or network of special blood vessels that provide oxygen to the heart muscle, leads to permanent damage to a portion of the heart’s muscle and loss of contraction in that portion. This is termed a heart attack.
Most individuals experience chest pain or discomfort that persists. Some individuals unfortunately die of ventricular fibrillation before they reach medical assistance. Once a heart attack victim reaches a hospital, they are very likely to survive, and most return to all of their previous activities.
Heart failure: Heart failure is a condition of the body’s circulation in which fluid is retained or insufficient blood is supplied to vital organs and the extremities. When fluid retention occurs in the lungs, breathing is compromised and severe respiratory symptoms may develop. In other cases, fatigue or ankle swelling may be the only symptoms. Most cases of heart failure respond well to medication and can be controlled for years.
Stroke: This results from sudden damage to brain tissue because of bleeding and blood accumulation or sudden obstruction of blood vessels to the brain. The physical deficit that develops depends on the part of the brain affected. Most commonly, weakness and/or numbness on one side of the body occurs. Individuals experiencing a stroke may or may not have heart disease.
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Dr. David Cooke is associate director of cardiology at Advocate Lutheran General Hospital in Park Ridge and immediate past president of the Midwest affiliate of the American Heart Association.
