How Heart Disease Can Lead to Stroke
Stroke is closely associated with heart disease. If you have heart disease, you might be tempted to ignore it or postpone treatment if you don’t have very bothersome symptoms. But, if you have been diagnosed with heart disease, it is important that you do not ignore it. You should definitely be sure to go to all of your recommended medical appointments because heart disease can have major health consequences, one of the most severe of which is stroke.
Types of Heart Disease Associated With Stroke
How does heart disease cause stroke? There are different types of heart disease associated with stroke and they may cause stroke due to the close interaction between the heart and the blood flow to the brain.
Heart Rhythm Abnormalities (Arrhythmia)
A healthy heart beats regularly, making a steady heartbeat. Each heartbeat reliably pumps blood throughout your body about 60-100 times per minute.
There is a type of heart disease characterized by an irregular heartbeat. An irregular heartbeat is called an arrhythmia. When the heart pumps irregularly, this can lead to a series of events that may cause a stroke.
The most common type of arrhythmia is called atrial fibrillation. Atrial fibrillation is caused by abnormal electrical firing in the heart due to a malfunction of the heart’s natural pacemaker, which is located in a compartment of the heart called the right atrium.
Ventricular fibrillation is another of the commonly identified cardiac arrhythmias. Ventricular fibrillation is characterized by an erratic electrical firing of the heart.
Arrhythmias contribute to stroke because when the heart beats irregularly, blood does not flow as evenly as it should. Some of the blood may stagnate in place, instead of flowing efficiently. This stagnation of blood flow, which is called stasis, lasts for only milliseconds, but that is enough time for the blood to form clots.
The blood clots that are formed can travel from the heart to the carotid arteries or to the brain, interrupting circulation in the brain and causing ischemic strokes. The brain injury of ischemic strokes sometimes results in bleeding in the brain through a process called hemorrhagic transformation. Thus, hemorrhagic transformation of ischemic strokes can occur with strokes that are caused by heart disease.
Arrhythmias are typically discovered during a routine medical examination. When your doctor listens to your heart with a stethoscope, she is listening for the rhythm, and therefore she can detect whether your heart beats with a regular or irregular rhythm. Further testing with diagnostic tests such as electrocardiogram (EKG), echocardiogram, stress test or Holter monitor may be necessary to better identify the pattern and the cause of the rhythm problem.
Most arrhythmias are treatable with medication or surgery. If you have an arrhythmia, you might need to take a blood thinner to help prevent a stroke, even if you receive medical treatment for your irregular heartbeat. Treatment for the arrhythmia itself may not be completely effective. Surgery or medication for arrhythmia in conjunction with blood thinners has been found to be more effective at preventing strokes than treatment of arrhythmia without a blood thinner.
Heart failure and congestive heart failure are the terms commonly used to describe the heart when it is weak and not functioning efficiently. People who have heart failure or congestive heart failure are roughly 2-3 times more likely to experience a stroke than people who do not have heart failure.
Heart failure results in a number of symptoms, including fatigue, low energy, and shortness of breath. These symptoms are consequences of the heart’s inefficient blood delivery to the body due to the weakness of the heart muscle. Sometimes, people who have heart failure have a rapid heartbeat, which is the heart’s attempt to compensate for the weak pumping action of the heart muscle.
The explanation for the association between heart failure and stroke is complex and related to a number of factors. One of the ways that heart failure contributes to stroke is through the body’s physiologic response to the inadequate oxygen supply and compensatory work of the heart. The body attempts to compensate for these problems by releasing a number of hormones that make the blood more likely to clot, which causes strokes.
Another way that the body attempts to compensate for heart failure is by altering the blood pressure in ways that can lead to stroke. Heart failure may also lead to an irregular or erratic heart rate, which can cause the heart to form blood clots that can travel to the carotid arteries or to the brain, interrupting blood supply in the brain and causing a stroke. And yet another reason for the increased risk of stroke associated with heart failure is that the same biological processes that cause heart failure also cause disease of the blood vessels, which leads to blood clot formation and strokes.
Heart Valve Disease
Heart valves are small structures that are located in the chambers of the heart and in the blood vessels of the heart. These valves serve to maintain the proper direction of blood flow as it travels to the heart, within the heart, and out of the heart.
Defective heart valves can lead to a number of serious consequences. Blood may leak or ‘backflow’ in the wrong direction, resulting in blood clots due to stasis. Blood, cholesterol and other materials may stick and form small growths on the valves. These growths can break off and ultimately travel to the brain, blocking small blood vessels in the brain, interrupting blood flow and causing ischemic strokes. Heart valves may even become infected, sending debris and ‘sticky’ material that can block blood vessels of the brain.
Heart valve problems are typically recognized during a medical appointment when your doctor listens to your heart sounds with a stethoscope. Heart valve defects are characterized by distinctive, abnormal heart sounds. Further examination with diagnostic tests such as an echocardiogram can better identify the specific type of heart valve defect and help with constructing a plan for valve repair, which may include medication or surgery.
A heart attack, also called a myocardial infarction (death of heart muscle due to lack of blood supply), is usually a painful event characterized by severe shortness of breath and chest pressure. Depending on which part of the heart is damaged during a heart attack, the injury can result in malfunction of the damaged region.
If the heart attack injures one of the areas of the heart that controls heart rhythm, an arrhythmia can occur. If the heart attack damages heart muscle, then the weak heart muscle movement might result in heart failure. In a major heart attack, there may be a lack of adequate blood supply to the brain at the time of the heart attack. Thus, a person can experience a stroke at the same time as a heart attack.
The long-term stroke risk after a heart attack is one of the well-known adverse effects of this condition. This is why one of the important aspects of post-heart attack care includes addressing stroke prevention, which includes maintaining healthy cholesterol levels and blood pressure in the recommended range.
Heart Infections and Inflammation
Overall, heart infections and inflammatory disease of the heart are not that common. Heart infections increase the chances of having an ischemic stroke or a hemorrhagic stroke. Endocarditis is a type of inflammation or infection of the heart tissue. Endocarditis may be related to risk factors such as artificial heart valves. Valve disease such as rheumatic heart disease is another risk factor for infective endocarditis. Management of endocarditis requires very close care, and surgical intervention may be necessary.
Inborn Heart Defects
A number of inborn heart defects are associated with an increased chance of having a stroke. Inborn heart conditions are often referred to as congenital heart defects. There are a variety of congenital heart defects, including heart valve defects and malformations in the structure of the blood vessels in the heart. The most common congenital heart defect is an opening or a ‘hole’ in the septum, which is the structure that separates the compartments, called chambers, of the heart.
A patent foramen ovale (PFO) is a defect in the region of the septum that separates the right atria of the heart from the left atria of the heart. PFO had been considered a significant stroke risk factor for many years, but recently, research has suggested it may be less of a risk factor than previously thought. Currently, people who have a patent foramen ovale are not always advised to have a surgical repair.
Most congenital heart defects are detected during childhood. However, while congenital heart defects increase the chances of having a stroke at a young age, the overall chance of having a stroke at a young age is fairly low.
If you have a congenital heart defect, it is likely that your pediatrician detected it when you were a child or a young adult. It is important that you maintain visits with a cardiologist throughout your life until you are cleared regarding your congenital heart defect.
How Can You Know If You Have Heart Disease?
The signs of heart disease vary depending on the specific heart condition. Some heart conditions produce a sense of fatigue, while some produce palpitations, and yet others produce exhaustion in association with physical exertion. Heart disease may manifest with dizziness.
While some heart conditions do not cause any symptoms, particularly if they are mild or still in the early stage, your routine physicals are designed to help detect many illnesses, including heart disease. The best thing you can do to find out if you have heart disease is to be observant about any changes in your energy level and to make sure that you schedule your recommended physical examinations.
Heart disease is not uncommon, but that does not mean that you should not take it seriously. If you have any symptoms of heart disease, you should not delay getting medical attention. The medical care of heart disease has come a long way and the vast majority of heart problems can be well managed to prevent consequences such as stroke.
Making sure to get routine medical check-ups is the best way to ensure that health problems are detected early before they cause significant problems.
- Hauber AB, Obi EN, Price MA, Whalley D, Chang CL. Quantifying the relative importance to patients of avoiding symptoms and outcomes of heart failure. Curr Med Res Opin. 2017;33(11):2027-2038. doi:10.1080/03007995.2017.1355782