Your heart and lungs work together as a team to oxygenate your body. So it only makes sense that a disease like chronic obstructive pulmonary disease (COPD) that affects the lungs might also, over time, affect the heart too.
In order to understand how a lung disease might affect the heart, it's important to have a good understanding of lung and heart anatomy. For this reason you may want to read how chronic bronchitis affects the lungs and how the heart and lungs work together.
As a refresher, here are two interesting facts:
Your heart is a muscle: Like other muscles of your body, when overworked it becomes enlarged (hypertrophic). When this happens to your biceps it may be a sign of good health. However, when this happens to your heart it's not so good, and means your heart is working too hard.
You have two hearts: You have a right heart that is small and generates only a slight pressure to pump blood through healthy lungs, and a left heart that is large and generates a strong pressure to pump blood through the rest of your body.
That noted, here is how COPD may affect your heart.
1. Poor Ventilation: As COPD progresses, loss of lung tissue and obstructed airways creates poorly ventilated areas inside your lungs, or areas that receive little or no oxygen. Studies show that supplemental oxygen does not appear to solve this because oxygen simply cannot get to these poorly ventilated areas.
2. Pulmonary Vasoconstriction: In the areas of poor ventilation, your body is tricked into thinking it can fix the problem by constricting pulmonary blood vessels, making the blood move faster in order to collect more oxygen.
3. Pulmonary Hypertension: Vasoconstriction causes the right heart to pump harder and faster in order to do its job, raising the blood pressure inside the lungs.
4. Cor Pulmonale: After years of working hard to pump blood through diseased lungs, the right heart increases in size, a condition known as cor pulmonale. When this occurs, it is generally considered the end stages of COPD. Learn more about cor pulmonale.
5. Right heart failure: Cor pulmonale makes the right heart a weaker pump, and over time it may simply become tired and poop out, causing blood to pool inside it.
6. Left heart failure: Since the right heart pumps blood through the lungs and to the left heart, right heart failure may lead to left heart failure. The heart is now unable to keep up with the demands of the body. Learn more about congested heart failure.
7. Peripheral edema: When your left heart is unable to effectively pump blood through your entire body, blood may pool in your legs, feet and ankles. This is an early sign of heart failure. If this happens, you should seek medical attention. This may also be a sign of chronic (meaning it's always there) heart failure.
8. Pulmonary edema: With a weak pump, and constricted pulmonary vessels, pulmonary blood pressure may increase so much that blood (fluid) seeps into lung tissue. This fluid is called pulmonary edema, and may make breathing difficult. This is a sign of acute (meaning it's happening now) heart failure. You must seek immediate medical attention (call 911).
9. Dyspnea/ Orthopnea: Dyspnea is an ancient Greek term often used to describe shortness of breath, difficulty breathing, or air hunger. Orthopnea is another Greek term meaning your breathing is so difficult you have to sit up to breathe. Again, you must seek immediate medical attention (call 911).
10. Atrial Fibrillation: This is the most common abnormal heartbeat (arrhythmia) that may result from the heart being overworked. This basically means that your heart fibrillates, causing a slow, rapid, or irregular heartbeat. It can be acute or chronic, although it can be treated either way. It may present with chest pain or dyspnea, or it may present with no symptoms at all. This heart arrhythmia increases your risk of heart failure and stroke. Learn more about Atrial Fibrillation.
Bottom line: So you can clearly see how sick lungs may lead to a sick heart. These are all things that could happen if you have COPD, but it doesn't mean they will happen. COPD progression can be slowed by stopping smoking and working with your physician to make necessary lifestyle changes. So you can live an active life wth COPD.
Robert Naeije and Joan A. Barbera, "Pulmonary Hypertension Associated with COPD," Critical Care, Nov. 3, 2001, 5 (6), pages 286-289
Adil Shujaat, Ruth Minkin and Edward Eden, "Chronic Hypertention and Cor Pulmonale in COPD," Sept. 2007, 2 (3), pages 273-282
"What is Atrial Fibrillation," nhlbi.nih.gov, http://www.nhlbi.nih.gov/health/health-topics/topics/af/, accessed 6/17/14