A heart attack (myocardial infarction) occurs when blood flow to a part of the heart muscle is severely reduced or completely blocked. This blockage is typically caused by a blood clot forming over a ruptured plaque within a coronary artery. When the heart muscle does not receive necessary oxygen, the affected tissue sustains damage and eventually dies (infarction). The duration of symptoms is highly variable, but the short answer to whether a heart attack can last for hours is yes.
Understanding Symptom Duration and Variability
Heart attack symptoms can persist for a few minutes or continue for several hours, sometimes waxing and waning. Symptoms last as long as the underlying blockage remains and the heart muscle is deprived of oxygen. This sustained lack of blood supply defines the duration of the ischemic event.
Studies show the median time from symptom onset to treatment (ischemic time) is approximately 260 minutes, illustrating how often heart attacks last for hours before intervention. Symptoms that come and go may indicate unstable angina, but if they do not resolve with rest and return, they signal an ongoing myocardial infarction. Prolonged symptoms indicate continuous tissue damage and greater immediate danger.
Recognizing the Varying Warning Signs
The most common sensation is discomfort in the center or left side of the chest, often described as pressure, squeezing, or fullness. This discomfort may radiate outward to the arm, shoulder, neck, jaw, back, or upper abdomen. Other signs include a cold sweat, lightheadedness, or sudden dizziness.
Not everyone experiences these “classic” symptoms; many presentations are atypical, which can delay treatment. Women, the elderly, and individuals with diabetes often present with less obvious signs. Atypical symptoms include profound, unexplained fatigue, nausea or vomiting, and shortness of breath that can occur with or without any chest pain. For people with diabetes, nerve damage (autonomic neuropathy) can mask typical pain signals, resulting in a “silent heart attack.”
The Biological Impact of Prolonged Events
The duration of the heart attack directly relates to the extent of irreversible muscle damage, summarized as “Time is Muscle.” When blood flow is blocked for an extended period, heart muscle cells die (necrosis) and are permanently lost. The dead tissue cannot regenerate and is replaced by fibrotic scar tissue, which does not contract or conduct electrical signals effectively.
This irreversible damage compromises the heart’s pumping ability, increasing the long-term risk of serious complications. Significant muscle loss can lead to heart failure, where the heart cannot pump enough blood to meet the body’s needs. Damaged areas can also disrupt the heart’s electrical system, causing irregular, potentially life-threatening rhythms (arrhythmias). Minimizing the event’s duration is the primary goal to preserve functional heart muscle.
Immediate Steps: Time is Muscle
If any warning signs last for more than a few minutes, or if they disappear and return, immediate emergency medical attention is required. The most important first step is to call 911 or your local emergency number immediately. Calling emergency services ensures medical personnel can begin treatment upon arrival and safely transport the patient to a cardiac-equipped hospital.
While waiting for responders, the person should sit down, rest, and remain calm. If there are no known contraindications or allergies, the emergency dispatcher may advise chewing a full-strength aspirin (about 300 mg). Aspirin helps thin the blood and reduce the size of the clot, potentially limiting ongoing damage until professional help arrives.