What Causes Heart Attacks?

Heart attacks (myocardial infarctions) are most often caused when the coronary arteries have a blockage that keeps them from supplying blood to the heart muscle. When cholesterol and fats build up on the inner lining of blood vessels (atherosclerosis), it causes narrowing of the blood vessel lumen. As blood supply to the heart muscle decreases, it can cause angina, chest pain due to inadequate blood flow to the heart.

Fat and cholesterol in blood vessels are called plaque. When the surface of the plaque ruptures, blood clots can form on its roughened surface. If they become large enough, they block blood flow to a portion of the heart. This is a heart attack. A heart attack differs from a cardiac arrest, which is a disruption in the electrical pathway through the heart. In the United States, in 2019, 370,000 people died from cardiac causes.¹

Heart Structure

The heart has two upper chambers, the atria, and two lower chambers, the ventricles. The left side of the heart pumps oxygenated blood to the body, and the right-side pumps deoxygenated blood to the lungs. When oxygenated blood returns from the lungs to the heart, it passes through the left atria and left ventricle and enters the aorta. The aorta is a large artery that branches to supply oxygenated blood throughout the body. The coronary arteries branch off the aorta to supply blood to the heart muscle.

Coronary arteries:

• Left main coronary artery: The left main coronary artery supplies blood to the left ventricle and left atrium.
  • Left anterior descending artery: supplies blood to the front of the heart.
  • Circumflex: supplies blood to the outer side and back of the heart.
• Right coronary artery: Supplies blood to the right ventricle, the right atrium, the sinoatrial (SA) node, and the atrioventricular (AV) node.

Risk Factors for Heart Attacks 

Coronary artery disease puts people at increased risk for heart attacks. However, it is possible to have a heart attack without coronary artery blockage. This is called myocardial infarction in the absence of obstructive coronary artery disease (MINOCA). About 5% to 15% of people with acute heart attacks do not have obstruction. MINOCA is more common in female patients.²

Physical Risk Factors

If you have a family history of early cardiovascular disease, it may increase your heart attack risk. Early is defined as before age 55 in men and 65 in women. Other medical conditions that can increase the risk of heart attacks include:

• High blood pressure
• High cholesterol or triglycerides
• Diabetes mellitus
• Obesity

Metabolic syndrome is diagnosed when three of the five markers for metabolic health fall outside of the optimal range. This increases your risk of heart disease.

Markers used to diagnose metabolic syndrome:

• A waist measurement of 35 inches or more for women and 40 inches or more for men
• Fasting glucose that exceeds 100 mg/dL
• HDL cholesterol is less than 40 mg/dL in men and less than 50 mg/dL in women
• Triglycerides above 150 mg/dL
• Blood pressure equal to or higher than 130/85 mmHg

Improving any of these health markers can reduce your risk for heart attacks. Other steps you can take to reduce your risk include:

• Consume a nutritious, whole, unprocessed diet high in antioxidants, vitamins, minerals, lean proteins, healthy fats, and whole, complex carbohydrates.
• Incorporate physical activity into your daily schedule, aiming for about 150 minutes weekly.
• Stop smoking. Smoking is a major risk factor for heart disease. The chemical in cigarette smoke increases the risk of developing plaque, damaging blood vessels, and increasing blood vessel spasms.

Mental and Emotional Risk Factors

Chronic stress stimulates the sympathetic nervous system and cortisol release. This fight-or-flight response is most active when your body is under physical or perceived stress. It causes an increase in heart rate and blood pressure. Research suggests that among patients with stable coronary artery disease, adding mental stress increases their risk of heart attacks when compared to people with coronary artery disease and no added stress.³

Anxiety can also increase your risk of heart disease. In a 2010 analysis of multiple studies that involved nearly 250,000 patients, researchers found that even after controlling for other variables, anxiety increased the risk of coronary artery disease by 26%.⁴

Preventing Heart Attacks 

The best way to prevent heart attacks is to improve the risk factors you have some control over. Make lifestyle changes to reduce your risk of heart attacks from unhealthy diets, physical inactivity, and smoking.

Lifestyle Changes

Consider making some of all of these changes to improve your metabolic health and reduce your risk of heart disease:

• Quit smoking: heart disease risk increases with every cigarette you smoke per day.
• Move every day. Whether you prefer structured exercise programs or walking the dog, increasing daily physical activity improves your heart’s health.
• Moderate your alcohol consumption. The link between alcohol use and heart health is unclear, but it increases with excessive alcohol consumption.
• Manage your stress.
• Choose a whole-food diet high in nutrients.
• Get outside to increase your vitamin D levels.
• Get 7 to 9 hours of restful sleep each night.

Monitoring Your Health

As you work to improve your metabolic health, it is important to schedule regular check-ups to monitor your progress. For convenience, consider making an appointment with an online doctor on call. They can evaluate your family history and heart disease risk factors to develop an action plan to reduce heart disease and provide an online diagnosis that helps you track your overall health.

For mental and emotional risk factors for heart disease, consider therapy or counseling to help you manage stress and anxiety. Access to telemedicine has made it much easier for people to proactively manage their health and prevent heart attacks.  

Treatment Options for Those at High-risk 

Suppose you are at high risk for heart disease. In that case, online medicine can increase your access to specialists, such as cardiologists, psychiatrists, and endocrinologists. These specialists have a deep understanding of their field and can write online prescriptions for any medications you need.

Disclaimer

While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.

References

1. Tsao CW, Aday AW, Almarzooq ZI, Alonso A, Beaton AZ, Bittencourt MS, Boehme AK, Buxton AE, Carson AP, Commodore-Mensah Y, Elkind MSV, Evenson KR, Eze-Nliam C, Ferguson JF, Generoso G, Ho JE, Kalani R, Khan SS, Kissela BM, Knutson KL, Levine DA, Lewis TT, Liu J, Loop MS, Ma J, Mussolino ME, Navaneethan SD, Perak AM, Poudel R, Rezk-Hanna M, Roth GA, Schroeder EB, Shah SH, Thacker EL, VanWagner LB, Virani SS, Voecks JH, Wang NY, Yaffe K, Martin SS. Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association. Circulation. 2022 Feb 22;145(8):e153-e639. doi: 10.1161/CIR.0000000000001052. Epub 2022 Jan 26. Erratum in: Circulation. 2022 Sep 6;146(10):e141. PMID: 35078371.
2. Talebi S, Jadhav P, Tamis-Holland JE. Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease (MINOCA): a Review of the Present and Preview of the Future. Curr Atheroscler Rep. 2021 Jul 6;23(9):49. doi: 10.1007/s11883-021-00945-0. PMID: 34226967; PMCID: PMC8257265.
3. Vaccarino V, Almuwaqqat Z, Kim JH, et al. Association of Mental Stress–Induced Myocardial Ischemia With Cardiovascular Events in Patients With Coronary Heart Disease. JAMA. 2021;326(18):1818–1828. doi:10.1001/jama.2021.17649
4. Celano CM, Daunis DJ, Lokko HN, Campbell KA, Huffman JC. Anxiety Disorders and Cardiovascular Disease. Curr Psychiatry Rep. 2016 Nov;18(11):101. doi: 10.1007/s11920-016-0739-5. PMID: 27671918; PMCID: PMC5149447.