Key Points:
- “Heart Disease” is a term that refers to a lot of different conditions.
- Think of heart disease when you have chest discomfort or difficulty breathing, especially if you have chronic medical conditions. Take these symptoms seriously.
- Chronic conditions including high blood pressure, diabetes, smoking, and obesity raise the risk of all types of heart disease.
- If you have a history of a family member developing heart disease early in life, specifically younger than age 50, that could suggest you have a genetic predisposition to early heart disease as well.
Heart disease gets a lot of attention – and it should. It remains the number one cause of death and disability in the United States, and accounts for approximately $363 billion dollars annually in health care costs and lost productivity. Despite this, most people don’t understand what the term “heart disease” represents. Over my 20+ year career, I have consistently noticed that my patients don’t really have a full appreciation of the different types of heart diseases, and what they can do to prevent it. During February we will discuss topics that relate to understanding, treating, and preventing heart disease – this one focuses on the major categories.
Coronary Artery Disease
Coronary artery disease (CAD) refers to the effects of gradual cholesterol build up in the heart arteries. This disease process starts much earlier in life than most people understand. We know from autopsy studies on soldiers in the mid 20th century that this phenomenon begins as early as late teens. Gradually over time, this cholesterol in the arteries accumulates to form plaques which are like small cholesterol “pimples” in the artery walls. When these grow big enough to limit blood flow (usually to at least a 70% blockage) they can cause a symptom known as angina. This is usually described as a pressure or tightness in the chest that comes on with physical activity or emotional stress and is relieved with rest or a medicine called nitroglycerine. This process tends to occur gradually, over many years, and usually becomes evident in the age range of 50-70s.
The more concerning effect of this disease occurs when these plaques rupture and this can happen at any time over their development. In fact, early plaques causing less than 40% of a blockage tend to be more likely to break. When this occurs, our bodies try to heal the rupture, but unfortunately this leads to a blood clot forming in the artery. This causes complete blockage of blood flow to the heart muscle – known as a “heart attack”. When the heart muscle lacks blood flow, and therefore oxygen, it starts to die. A serious risk, present in the first 48 hours after a heart attack, is the development of a life-threatening heart rhythm. Therefore, urgent treatment of heart attacks is extremely critical. Sadly, too many people try to wait it out, because they may not be sure the symptoms are coming from their heart. The symptoms will feel like angina as described earlier, but they are not relieved with rest, and they do NOT have to be severe. I have seen many people with very mild symptoms have significant seized heart attacks.
The two conditions that raise the risk of CAD developing are diabetes and smoking, especially when these two are combined. High blood pressure, high cholesterol, and obesity are also main contributors. Genetics can also play a significant role in the development of CAD earlier in life than it otherwise should. Delaying treatment can have serious consequences – in 50% of people who die suddenly from heart disease, it was their first symptom. Therefore, it is critical to take these symptoms seriously, especially if you have risk factors.
Heart Failure
The heart’s primary function is to contract in a coordinated fashion, pumping blood without oxygen to the lungs, and then delivering oxygen-rich blood to all the body’s other organs. When it loses its ability to do this effectively, we call that “heart failure”. Heart failure can cause a wide range of symptoms, some of which may seem vague. The classic description is difficulty breathing during exertion, often accompanied by swelling in the legs. But it can be more subtle, and include fatigue, difficulty sleeping, dizziness, and even early fullness while eating.
There are two main variants of heart failure. The first is when the heart becomes weak. This is known as “systolic” heart failure. The most common cause is, as discussed above, CAD. Specifically, a heart attack not treated quickly can lead to heart damage, which then impairs the heart’s ability to contract completely. Increasingly, other types of conditions can lead to overall heart weakness. Diabetes and obesity, especially when combined, can cause gradual reduction in heart squeezing function. Viruses have been implicated for many years as a potential cause, yet these can be difficult to diagnose. There are also many metabolic and genetic conditions that can lead to heart failure. Pregnancy is a well-recognized although uncommon cause of heart weakness.
The second, and now more common cause of heart failure, is when the heart muscle becomes stiff. This is known as “diastolic” heart failure. For the heart to pump, it must squeeze, but it then also must relax. This relaxing (or diastolic) phase is critical to determining the heart’s performance. Conditions that lead to increased stiffness of the heart muscle can have a dramatic effect on this relaxing phase. The most common condition in this space is high blood pressure, or hypertension. Think of it like working out at the gym. If you place your muscles against resistance repeatedly, they become thicker. This is great for your biceps! But not so great for your heart. In patients who develop diastolic heart failure, the squeezing function is often normal, however the heart stiffness reduces the amount of blood that fills the heart. Therefore, the result is the same – less blood pumped out to the body.
Heart Rhythm Abnormalities
Also known as “arrhythmias”, this is a group of conditions that are related to the heart beating “out of rhythm”. Arrhythmias are not all the same. Some are a mere annoyance, while others can be life threatening. And they can come from a range of genetic, structural, or metabolic conditions. Not surprisingly, the same risk factors for CAD and heart failure increase the risk for arrhythmias. The simplest way to categorize them is either problems with the way the heartbeat originates (either too fast, too slow, or too erratic), or problems with the way the electricity spreads over the heart (disorders of conduction). Despite the difference in the underlying cause, they tend to present with the same range of symptoms. The most common is palpitations, or the sense of an erratic heartbeat. Lightheadedness or dizziness is also common. The fortunate thing about arrythmias is that they are easy to define if the symptoms occur while someone is being monitored. So, a careful history, exam, and heart monitoring can usually get the bottom of things.
Heart disease is very common in the western world. And the risk factors that lead to heart disease are, in general, becoming more common and more severe in the population. Therefore, it is important for everyone to understand the basics, and be mindful for potential symptoms, because early intervention can make a dramatic difference in your outcome. In future articles will review risk factors, testing options, and treatment approaches to minimize your risk. It can be done, and the earlier start the better!
This article is not meant to be construed as medical advice, rather published for informational purposes only. Everyone’s health situation is different. As always, it is critical to discuss your symptoms, conditions, treatments, and medications with a licensed health care provider to ensure that any use is safe and effective in addressing your medical status and condition.