A myocardial infarction (MI), commonly known as a heart attack, happens when blood flow to part of the heart is blocked, usually by plaque or a blood clot in a coronary artery. The blockage prevents oxygen and nutrients from reaching the heart muscle, which can damage the affected tissue.

When the heart muscle is damaged, its ability to pump blood efficiently is impaired. This can affect overall cardiovascular function and lead to symptoms such as chest pain, shortness of breath and fatigue—the hallmark signs of a heart attack. If left untreated, a myocardial infarction can have potentially serious complications, such as irregular heart rhythms (arrhythmias) and heart failure.

Understanding myocardial infarctions, recognizing the signs and seeking appropriate medical attention when necessary are key to maintaining overall cardiovascular health. Early detection and management of an MI—which may include medications, lifestyle changes or a procedure such as angioplasty—can minimize any damage to the heart and improve the outcome. Ignoring a heart attack can have long-term consequences that significantly impact the quality of life.

What Are the Types of Myocardial Infarctions?

Heart attacks are categorized based on their underlying cause, severity and impact on heart function. The main types include:

• ST-elevation myocardial infarction (STEMI) – A STEMI heart attack is caused by a complete blockage in a coronary artery, which can cause severe damage to the heart muscle and requires immediate treatment.
• Non-ST-elevation myocardial infarction (NSTEMI) – An NSTEMI heart attack results from a partial blockage in a coronary artery, which generally causes less severe damage than a STEMI heart attack but still warrants prompt medical attention.
• “Silent” myocardial infarction – Some heart attacks occur without causing any recognizable symptoms, such as chest pain, sweating or shortness of breath. Instead, the MI may be detected during a routine medical checkup or imaging test performed for an unrelated reason.
• Type 1 myocardial infarction – Usually, a type 1 heart attack is caused by atherosclerosis, which occurs when deposits of cholesterol, fat, calcium and other substances build up in the walls of the coronary arteries. In addition to narrowing the arteries and inhibiting blood flow, plaque can potentially burst, leading to the formation of a life-threatening blood clot.
• Type 2 myocardial infarction – Rather than a direct arterial blockage, a type 2 heart attack is caused by an imbalance between the heart's oxygen supply and demand, which may occur due to severe illness, low blood oxygen levels or anemia.
• Type 3 myocardial infarction – A type 3 heart attack occurs very suddenly and becomes fatal before a physician can confirm the MI with diagnostic testing.
• Type 4 and 5 myocardial infarctions – Some heart attacks are linked to medical procedures; for instance, type 4a can occur during percutaneous coronary intervention (PCI), type 4b can result from a stent thrombosis and type 5 can develop during coronary artery bypass grafting (CABG).

What Can Cause a Myocardial Infarction and What Are the Risk Factors?

In general, a heart attack occurs when blood flow to the heart muscle is disrupted. Potential causes include:

• Coronary artery blockage – Often associated with atherosclerosis, a coronary artery blockage occurs when blood flow to the heart muscle is obstructed by plaque buildup or a blood clot in the artery.
• Coronary artery dissection – A tear in the inner wall of a coronary artery can block blood flow to the heart, potentially leading to chest pain or a myocardial infarction.
• Coronary artery spasm – A sudden, temporary tightening of the muscles in the wall of a coronary artery can restrict blood flow to the heart. This may occur due to stress or drug use.
• Electrical issues in the heart – An arrhythmia, such as atrial fibrillation (Afib), can disrupt the heart’s normal rhythm, impairing its ability to pump blood efficiently and reducing blood flow to the heart and other organs.
• Embolism – A coronary artery can become blocked by a blood clot that develops in another part of the body, breaks free and travels through the bloodstream toward the heart.
• Inflammation – An inflammatory condition that affects blood vessels, such as endocarditis or vasculitis, can damage the arterial walls and cut off blood flow to the heart.

Certain factors can increase the risk of myocardial infarction. These include:

• Advanced age – Heart attack risk increases with age, especially in men older than 45 and women older than 55.
• Anxiety – Chronic stress can lead to a myocardial infarction by increasing blood pressure, triggering inflammation and contributing to plaque buildup and rupture in the arteries.
• Certain medical conditions – Diabetes, high blood pressure (hypertension) and high cholesterol can increase the strain on the heart and blood vessels.
• Family history – Genetics can predispose individuals to hypertension, high cholesterol and atherosclerosis; additionally, some relatives share lifestyle practices that can influence cardiovascular health.
• Obesity – Carrying excess body weight can contribute to the development of diabetes and hypertension, indirectly increasing the risk of myocardial infarction.
• Unhealthy lifestyle habits – Smoking, excessive alcohol consumption, poor diet and lack of physical activity all contribute to heart attack risk.

What Are the Warning Signs and Symptoms of a Myocardial Infarction?

Recognizing the early warning signs of a heart attack can save a life. Common symptoms include:

• Chest discomfort – Some patients experience a sensation of pressure, squeezing, fullness or pain in the center or left side of the chest, which typically lasts for more than a few minutes but may also come and go.
• Cold sweats – Moist, pale, clammy skin may develop suddenly, without physical exertion or high temperatures.
• Dizziness or lightheadedness – A heart attack may cause a feeling of faintness or a loss of balance.
• Fatigue – Unexplained or extreme tiredness often precedes a myocardial infarction, especially in women.
• Nausea or vomiting – MI can produce an unsettled or queasy feeling in the stomach, which is usually accompanied by an urge to vomit but may not lead to actual vomiting.
• Radiating pain – Heart attack pain often originates in the chest and spreads to the shoulders, arms, neck, jaw or back, predominantly affecting the left side of the body.
• Shortness of breath – A myocardial infarction can cause difficulty breathing with or without chest discomfort.

A suspected heart attack demands immediate medical attention. For severe chest pain, shortness of breath or any other symptoms that suggest a myocardial infarction, it is imperative to call 911 or go immediately to the nearest hospital emergency room. Fast action is the key to preventing or reducing damage to the heart and achieving the best possible outcome.

It is important to note that some heart attacks occur without causing any noticeable symptoms. These “silent” cardiac events—which are particularly common in older adults and individuals with diabetes—can still cause significant heart damage.

How Is a Myocardial Infarction Diagnosed?

Before confirming that a heart attack has occurred, a physician will need to rule out other conditions that can cause similar symptoms, such as:

• Anxiety – A panic attack can cause a rapid heartbeat and chest tightness, mimicking a myocardial infarction.
• Gastroesophageal reflux disease (GERD) – Acid reflux can produce chest discomfort that feels like a heart attack.
• Pulmonary embolism – A blood clot, typically originating in the legs, can travel to the lungs and block blood flow in a pulmonary artery, leading to heart attack-like symptoms such as chest pain and shortness of breath.

Typically, the physician will perform a clinical assessment and order diagnostic testing to evaluate the heart’s function and check for heart muscle damage. This may include a:

• Medical history and symptom review – The physician will ask the patient to describe their symptoms and discuss their risk factors, such as smoking, diabetes and a family history of cardiovascular disease.
• Physical examination – To gain valuable insights into the patient’s general health and cardiovascular condition, the physician will check their blood pressure, heart rate and other vital signs, evaluate the appearance of their skin and look for indications of heart strain and complications, such as fluid buildup.
• Electrocardiogram (EKG) – This quick and essential test can help the physician evaluate the electrical activity of the heart and detect abnormalities, such as changes in heart rhythm or signs of heart muscle damage.
• Blood test – To check for heart muscle damage or assess the severity of a heart attack, the physician may order blood work to evaluate the levels of certain cardiac biomarkers, such as troponin, which are released into the bloodstream when heart muscle cells are damaged.
• Echocardiogram – Using high-frequency sound waves, this ultrasound imaging test can help the physician visualize the heart’s structure and function, including areas of poor blood flow or damage, and identify heart wall abnormalities and complications, such as valve issues.
• Magnetic resonance imaging (MRI) scan – This noninvasive imaging test uses radio waves and a strong magnetic field to create detailed images of the heart and other tissues, which can help the physician assess heart muscle damage and blood flow.
• Computed tomography (CT) scan – This common imaging technique uses a series of X-rays to create cross-sectional views of the body’s internal structures, such as the heart and blood vessels, which can help the physician identify blockages and complications, such as aortic dissection.

How Is a Myocardial Infarction Treated?

Heart attack treatment may involve medication, lifestyle changes and/or procedural intervention. The aim is to restore blood flow to the heart, prevent further heart muscle damage and reduce the risk of future cardiac events. The choice of treatment can vary depending on the severity of the myocardial infarction and the patient’s overall health.

Several types of medication may be prescribed after a heart attack. These include:

• Antibiotics – If an underlying bacterial infection, such as endocarditis, is identified as a contributing factor to the heart attack, a course of antibiotics may be prescribed to treat the infection.
• Anticoagulants – Blood thinners, such as warfarin, may be prescribed to help prevent blood clot formation, especially in cases of Afib.
• Antiplatelet drugs – Medications, such as aspirin, may be used during or immediately after a heart attack to prevent naturally sticky platelets from clumping together and forming blood clots, which can help reduce the risk of further arterial blockage.
• Beta blockers – A class of medicines predominantly used to manage arrhythmias, beta blockers may also be prescribed post-heart attack to stabilize heart function.
• Statins – Widely used to manage cholesterol by lowering the level of low-density lipoprotein (LDL) cholesterol in the blood, statins may be prescribed after a heart attack as a long-term solution to help prevent plaque buildup in the arteries and reduce the risk of further cardiac events.

A healthy lifestyle is a key component of a plan to achieve and maintain optimal heart health, especially after a myocardial infarction. This typically encompasses:

• Dietary changes – To manage blood pressure and cholesterol levels, many experts recommend adopting a heart-healthy diet that is rich in fruits, vegetables, whole grains, lean proteins and healthy fats and low in sugar, salt and saturated fats.
• Physical activity – By engaging in at least 150 minutes of moderate aerobic exercise per week, a heart attack survivor can improve their blood circulation, strengthen their heart muscle and achieve and maintain a healthy body weight.
• Smoking cessation – Quitting tobacco immediately eliminates a significant risk factor for cardiovascular disease and can dramatically improve both general health and heart health.
• Stress reduction – By practicing relaxation techniques, such as mindfulness, deep breathing or yoga, it may be possible to manage stress and reduce its negative impact on the heart.

In some cases, procedural or surgical intervention may be considered after a heart attack. Options may include:

• CABG – In a severe case involving multiple arterial blockages, a surgeon may create new pathways for blood to flow around the blocked arteries.
• Coronary angioplasty and stenting – During or shortly after a heart attack, a surgeon may use a special balloon-like device to open the blocked artery and quickly restore circulation, and then place a stent to maintain proper blood flow.
• Catheter ablation – In a case of arrhythmia, such as Afib, a surgeon may use heat or extreme cold to destroy a small area of damaged heart tissue that is generating irregular electrical signals.
• Pacemaker placement – To address an bradyarrhythmia (slow heart rate), a surgeon may implant a small, battery-powered medical device in the chest or abdomen, which will produce electrical pulses to regulate abnormal heart rhythms and maintain a steady heartbeat.
• Valve repair or replacement – If a faulty valve is contributing to heart dysfunction, a surgeon may repair or replace the damaged valve.

Ongoing management, follow-up care and cardiac rehabilitation are essential to promote optimal recovery from a heart attack. Many patients benefit from participating in a structured program that includes education, counseling and monitored exercise. Support groups are also available to help patients and their families cope with the emotional and psychological aftereffects of a heart attack.

What Are the Possible Complications and Long-Term Effects of a Myocardial Infarction?

A heart attack can have significant short- and long-term effects on both the heart and overall health. The severity can vary based on the extent of heart muscle damage, how quickly treatment was administered and how effectively any risk factors are managed. Without proper care, a myocardial infarction can lead to several chronic health issues, including:

• Arrhythmias – Disruptions in the heart’s electrical signals can cause an irregular heartbeat, increasing the risk of stroke and sudden cardiac arrest.
• Cardiogenic shock – A severe complication of a myocardial infarction, cardiogenic shock occurs when the heart cannot pump enough blood to meet the body’s needs, often requiring emergency medical intervention.
• Fatigue and reduced physical capacity – Long-term damage to the heart can result in persistent tiredness and difficulty performing physical tasks, significantly impacting daily life.
• Heart failure – The damaged heart muscle may lose its ability to pump blood efficiently, leading to chronic symptoms such as shortness of breath, fatigue and swelling in the legs and feet.
• Pericarditis – After a heart attack, the sac surrounding the heart (pericardium) may become inflamed, leading to chest pain and additional discomfort.
• Recurrent heart attacks – Heart muscle damage increases susceptibility to arterial blockages and subsequent myocardial infarctions, especially if lifestyle changes and medications are not adhered to.
• Stroke and blood clots – Altered blood flow and damaged heart tissue can promote the formation of blood clots, which may travel to the brain, lungs or other vital organs and cause serious complications.

How Can Myocardial Infarctions Be Prevented?

Heart attacks can often be prevented by managing any controllable risk factors and staying vigilant about heart health. Key preventive measures include:

• Avoiding tobacco use
• Consuming a nutritious, heart-healthy diet
• Exercising regularly
• Limiting alcohol intake
• Managing stress
• Monitoring and managing medical conditions, such as diabetes

Life After a Myocardial Infarction

Usually, life after a heart attack involves physical, emotional and lifestyle adjustments. Many patients experience lingering fatigue, anxiety and/or fear about their health, but with proper care, recovery is possible.

Most patients are advised to adopt healthier habits, such as eating a heart-friendly diet, engaging in regular physical activity, quitting smoking and managing stress. Medications may be prescribed to manage blood pressure, lower cholesterol and/or prevent blood clots.

Cardiac rehabilitation programs are often recommended to help heart attack survivors rebuild their strength, improve their cardiovascular health and regain their confidence. Ongoing follow-up care can help ensure full recovery and prevent future cardiovascular issues. With the right support and dedication, most people can lead a fulfilling life after a myocardial infarction.

Benefit From World-Class Care at TGH

Tampa General Hospital is ranked among the Nation’s Best Hospitals for Heart and Vascular Care, and recognized as a High Performing Hospital for Heart Attack by U.S. News & World Report for 2024-25. Our Heart and Vascular Institute is an exceptional choice for patients with myocardial infarction, offering the benefits of specialized medical expertise, state-of-the-art facilities and patient-centered care. With a steadfast commitment to research and innovation, we ensure that our patients can access the latest diagnostic and treatment options, including advanced imaging techniques, minimally invasive procedures and comprehensive cardiac rehabilitation programs. By prioritizing education, we empower our patients to take an active role in their recovery and long-term heart health.

With a strong emphasis on both clinical excellence and compassionate care, TGH stands out as a leader in cardiac care. To request a consultation with a specialist on our team, please contact us at (800) 844-3900 or email us at heart-vascular@tgh.org.