February is American Heart Month, and February 7th is designated as “National Wear Red Day” to draw attention to heart disease, the leading cause of death in the United States. In 2019, cardiovascular disease claimed the lives of 874,613 Americans. Heart disease was responsible for 659,000 of these deaths, accounting for one in every four deaths in the U.S. or one death every 36 seconds.
What Causes Heart Disease?
In simplest terms, the heart is a pump that delivers oxygen and nutrients to the body. It has two upper chambers called atria and two lower chambers called ventricles. The left side of the heart pumps oxygenated blood to the body, while the right side pumps blood to the lungs for re-oxygenation.
The SA node, specialized cells in the right atrium, set a rhythmic pace for contraction at a resting rate of 60 to 80 beats per minute (heart rate varies based on demand). The electrical impulse spreads from the SA node across the atria and into the AV node, which is located at the junction of the right atria and ventricle. From there, the electrical impulse spreads throughout the ventricles. A delay at the AV node allows the atria to contract. This is followed by ventricular contraction.
Cardiovascular disease is an umbrella term that encompasses heart attacks (coronary artery disease), strokes (cerebrovascular disease), blood vessel disease, and aortic aneurysms. Heart disease can be from a heart attack, arrhythmia, high blood pressure, valve disease, congenital heart disease, or heart failure.
An arrhythmia is a problem with the electrical conduction in the heart. It causes a change in the heartbeat. Damage to the electrical fibers in the heart can cause abnormal heart rhythms to develop or even heart block, where the electrical impulse does not always pass from the atria to the ventricles correctly.
Tachycardia is a condition in which the heart beats too quickly. Bradycardia occurs when the heart rate is too slow. Some people may feel a pounding or fluttering in their chest when experiencing an arrhythmia.
Blood Vessel Disease
Damage to the blood vessels that supply heart cells with oxygen and nutrients can cause heart muscle damage. Risk factors for heart disease such as high blood pressure, high cholesterol, diabetes, and smoking cause damage to blood vessels, increasing the risk of having a heart attack.
Heart failure describes an inability of the heart to adequately pump blood. The heart is damaged and weak. Heart failure is most commonly caused by cardiomyopathy, which is an abnormality of the heart muscle. Dilated cardiomyopathy is the most common type of cardiomyopathy. The heart muscle in the left ventricle is stretched and thinned, reducing its ability to pump blood.
Heart failure can also be caused by heart attacks, coronary artery disease, high blood pressure, congenital heart disease, valve diseases, and heart infections.
If the heart cannot adequately pump blood, excess fluid accumulates in the lungs, abdomen, and lower extremities.
Aneurysms are bulges in the walls of blood vessels. Hardening of the arteries is a risk factor for aneurysms. If the bulging, thinned blood vessel wall bursts, internal bleeding can be life-threatening.
Symptoms of Heart Disease
When people think of a heart attack, they imagine crushing chest pain, shortness of breath, sweating, and pain in the left arm, shoulder, or jaw. While these are the classic signs associated with heart attacks, about one in five heart attacks are silent. Damage to heart muscle occurs without the person being aware of it.
Symptoms of heart disease can include:
- chest pain or discomfort
- shortness of breath
Women are frequently misdiagnosed because heart attacks tend to affect women differently. Women are more likely to experience:
- pain in the arm, neck, shoulder, or back
- nausea or vomiting
- shortness of breath
Chest pain is a symptom found in other less serious medical conditions, but chest pain should always be taken seriously since heart disease is common and can be dangerous.
Who is at increased risk for heart disease?
Risk factors can be divided into modifiable, those factors you have at least some control over, and unmodifiable.
Modifiable Risk Factors
There are several risk factors for heart disease that are secondary to lifestyle choices. Taking steps to improve your overall health could decrease your risk of heart disease.
These risk factors include:
- Overweight and obesity
- Sedentary lifestyle
- Excessive alcohol consumption
- Unmanaged stress
- Unhealthy diet
Unmodifiable Risk Factors
There are also uncontrollable risk factors for heart disease. It is important to be aware of your risk and treat any treatable medical conditions that may increase your risk of heart disease.
These risk factors include:
- Age: increased age increases the risk of heart disease
- Sex: Men have a higher risk of heart disease (24.4% in men, 22.3% in women)
- Heredity: A family history of heart disease can increase the risk
- Race: The risk for heart disease varies by race: White (23.7%), Black (23.5%), Asian American or Pacific Islander (21.4%), Hispanic (20.3%), American Indian or Alaska Native (18.3)
Medical Conditions that are Risk Factors
Some medical conditions are associated with blood vessel damage and increase the risk of heart disease.
These medical conditions include:
- High blood pressure
- High cholesterol
- Type 2 diabetes
It is important to understand your risk of heart disease. Several important measurements can help determine the risk, including:
- Blood pressure
- Smoking pack years
- Waist circumference
- Body mass index (BMI)
- Total cholesterol, LDL cholesterol (bad cholesterol), and HDL cholesterol (good cholesterol)
How is Heart Disease Diagnosed?
The way heart disease is diagnosed will depend on the symptoms and the type of heart disease. After a thorough medical history and physical exam, the following tests may be used to diagnose heart disease:
- Electrocardiogram (ECG): Records the electrical activity in the heart
- Chest x-ray: An image of the heart and lungs
- Echocardiogram: An ultrasound that uses sound waves to understand the structure of the heart
- Cardiac catheterization: An invasive test used to measure pressures in the heart and look at blood flow. It can be used to diagnose and treat heart disease
- Stress tests: Uses physical activity or medications to make the heart work harder and checks heart function with increased activity
- Heart CT or MRI: Imaging techniques used to construct an image of the heart and other structures
How Is Heart Disease Treated?
There are a wide range of treatment options available for heart disease. Factors such as the cause of heart disease, symptoms, age, and other medical conditions may determine the most appropriate treatment. Potential treatments include:
- Medications: Medications can control heart rate, support muscle contraction, improve symptoms from heart failure and decrease the risk of blood clots
- Surgeries: Bypass grafts can bypass blood vessel blockages and restore blood flow
- Defibrillators: Defibrillators can be implanted to control heart rate
- Ventricular assist devices (VADs): VADs can assist a weakened heart with pumping
- Transplants: When a heart is severely and irreversibly damaged, a heart transplant may be needed
How Can You Decrease Your Risk for Heart Disease?
Several strategies have been proven to decrease the risk of heart disease and help people live longer, healthier lives. These strategies include:
- Engaging in regular physical activity
- Choosing a healthy diet
- Maintaining a healthy weight
- Avoiding smoking and vaping
- Getting good quality sleep