EP169: What Causes Heart Attack?

Welcome to my podcast. I am Doctor Warrick Bishop, and I want to help you to live as well as possible for as long as possible. I’m a practising cardiologist, best-selling author, keynote speaker, and the creator of The Healthy Heart Network. I have over 20 years as a specialist cardiologist and a private practice of over 10,000 patients. Episode Summary Introduction Dr. Warrick Bishop is a practicing cardiologist and author dedicated to educating patients about heart health, believing that informed patients receive better care. In this episode, he provides a detailed explanation of how heart attacks occur, emphasizing the critical importance of understanding this process given that heart attacks account for 9 million deaths annually worldwide and affect people of all ages, including approximately 20% of victims under age 65. Key Takeaways: Heart attacks result from myocardial ischemia (lack of blood flow to heart muscle) or myocardial infarction (death of heart tissue), caused by arterial blockages that prevent adequate blood supply. Plaque buildup in arteries begins with localized wear and tear on the arterial lining (endothelium), which triggers the body's repair process and brings cholesterol into the damaged area. LDL (low-density lipoprotein or "bad cholesterol") deposits cholesterol into the arterial tissue, triggering an inflammatory response where white blood cells called macrophages move in to clear excess cholesterol. Macrophages can become overwhelmed by excess cholesterol, swell up, and rupture, releasing destructive enzymes that cause scarring and create a foundation for calcium deposits and plaque formation. Fatty plaques develop a thin fibrous cap and can rupture inward into the artery, causing plaque contents to mix with blood and trigger dangerous clot formation. Approximately 40% or more of heart attacks occur on plaques that were not limiting blood flow prior to rupture, meaning patients can feel completely healthy right up until the artery closes off. The silent nature of plaque development makes cardiovascular maintenance and understanding personal risk factors critically important for prevention. A sudden clot blocking an artery can cause the heart muscle to become irritable and flip into a dangerous electrical rhythm that can be fatal.