You have an older relative who calls, and they are short of breath. They have a wet cough. You take them to the emergency room and the doctors and staff do a lot of tests. You think that they must have pneumonia, because they can't breathe and are coughing. The doctor says that your relative will be hospitalized. The doctors talk about pneumonia but then later on they say, no, it is congestive heart failure. It is not a heart attack. You wonder why a heart problem shows up in the lungs.
Heart failure, or congestive heart failure, is a confusing name for an illness. Heart failure is uncommon among the young but becomes more and more common as people age. Understanding heart failure starts by remembering that the heart is a pump. Heart failure means the heart is not pumping right. What happens when a pump is failing?
"Something backs up," reply my patients. "Something floods."
Exactly! And where is the flooding? This depends on what part of the heart pump is not working. The heart has four chambers. The right side of the heart pumps blood in to the lungs, to pick up oxygen. The oxygenated blood goes to the left heart. The left side of the heart pumps blood to everything else: heart, brain, body, kidneys, organs, skin and so forth. Then the blood returns through veins to the right heart to pick up oxygen again.
With right sided heart failure, the blood backs up into the body. With left sided heart failure the blood backs up in to the lungs. Both can occur, so that the whole system is sluggish.
What causes heart failure? The two most common causes are coronary artery disease and hypertension. Coronary artery disease is partially blocked arteries that are supposed to take oxygen and nutrition to the heart. If the arteries are partially blocked, the heart muscle cannot get enough oxygen or nutrition and can't pump well. If the artery is fully blocked, that part of the heart muscle can die: that is a heart attack, or myocardial infarction. Hypertension is high blood pressure. If the heart pump is always pumping against high pressure, what does it do? The wall of the heart thickens, the muscle getting thicker. We think bigger muscles are better, but they aren't always. When the wall of the left heart thickens too much, the amount of blood that the heart can pump with each beat drops. Normally, the left heart pumps 55-70% of the blood into the body with each beat. In heart failure, the amount drops. If the left heart can only pump 20%, this is clearly bad. Some mild heart changes are normal with aging: as people reach their 70s and 80s, there is usually some right sided mild heart pump failure. This is not usually a problem. There are other more rare causes of heart failure and it can happen to someone young.
What are the symptoms of heart failure? If the right heart, that pumps to the lungs, is not pumping well, blood backs up in the body. Usually in the legs, because over time gravity and the pooling of blood cause swelling. The swelling can be enormous and frightening. If the left heart backs up, the lungs have too much fluid. The body tries to cope with this and there is often fluid backed up in the legs as well.
How do we prevent heart failure? Stay as healthy as possible, avoid coronary artery disease, and have your blood pressure checked yearly. I see people who boast that they have not seen a doctor for twenty years. If they have had high blood pressure for 15 of those years, the damage may already be done to their heart. We all know the recommendations for avoiding coronary artery disease and heart attacks: don't smoke or stop smoking, exercise, eat a diet high in whole grains and vegetables and low in fat and sweets, drink small amounts or no alcohol, avoid being overweight, and drugs like cocaine and methamphetamines can have bad heart effects as well.
"But doctor, I've lived a healthy life and now you say my blood pressure is high?" Yes, the high blood pressure experts say that 90% of people in the United States will develop high blood pressure. Sometimes not until age 90, but most people will! With exercise, not smoking, a healthy diet and so forth, you can delay this as long as possible: but when your doctor tells you your blood pressure is high, take your medicine. Then you delay heart failure!
How do medicines for heart failure work? There are many medicines that can help with heart failure. Diuretics, such as HCTZ and lasix, remove extra fluid through the kidneys and both lower blood pressure and the amount of fluid backing up the system. Beta blockers, like atenolol and propranolol, help the heart to pump more strongly and lower blood pressure. Calcium channel blockers, like diltiazem, also work on the heart muscle and lower blood pressure. If the cause is coronary artery disease, nitrates help to keep the arteries open and aspirin helps keep clots from forming.
If I have heart failure, what else can I do besides take medicine? Again, stop smoking and so forth. Eating salt can make heart failure worse, because the salt tends to keep the kidneys from removing fluid. If your doctor recommends a low salt diet, avoiding the potato chips and most canned soups and using less salt will all help. When someone's heart failure is getting out of control, their weight increases as fluid backs up: so get a good scale, know your goal weight and contact your doctor if you have a sudden weight gain, 4-5 pounds within a couple of days. The other big symptom is shortness of breath and a wet cough, if fluid is backing up in the lungs. Know when to ask for help.
This appeared in The Peninsula Daily News Healthy Living section, June, 2010.
For Science Quest 2012.