By Julian Booker, MD
Your wife finally convinces you to go see your doctor because the two months of worsening shortness of breath is not getting better and seems to be getting worse. The doctor walks into the room where you are quietly waiting and tells you that you have heart failure. Immediately you try to understand how and when you heart became weak, but much to your surprise, you are told that the heart muscle (myocardium) “strength” is fine. Well this doesn’t make any sense until you rush home and read diastolic heart failure – part 1. Now you understand a little better what you have, but how should you be treated?
Let us review those four major objectives outlined by the American Heart Association before going further:
- Excellent control of your blood pressure
- If you have atrial fibrillation or an abnormally fast heart rate, your heart rate should be controlled.
- Treat your symptoms of heart failure
- If you have significant coronary artery disease then blockages should that are contributing to your symptoms should be addressed.
We will spend the next few minutes going into greater detail for these items. Be on the lookout for very detailed posts for these conditions in the near future.
Blood pressure control
Your heart is like a muscular engine built around a connective tissue chassis. It is powerful and has almost unimaginable endurance. It responds to work and stress by getting stronger. High blood pressure is like lifting weights for your heart. On the surface, that seems like it should be a good thing. Unfortunately your heart doesn’t like lifting weights is prefers yoga. Lifting the heavy load of blood pressure does the same thing to your heart that it does to your biceps. The muscle gets bulky (left ventricular hypertrophy or LVH) and inflexible (impaired relaxation). If you recall from part 1 of this post, stiffening of the heart is what gets you into trouble. As a matter of fact, high blood pressure of hypertension is one of the, if not the leading cause of diastolic dysfunction.
The good thing is that all is not lost. There is solid evidence that improving ones blood pressure can lead to regression of LVH. Some medicines such as angiotensin II receptor blockers (ARBs), calcium channel blockers and angiotensin converting enzyme (ACE) inhibitors seem to lead to regression faster than other classes. Other classes such as diuretics and beta-blockers are also effective but to a lesser degree. There is no strong evidence that faster regression leads to improved outcomes.
The most important thing for you is to get your blood pressure under control. The Joint National Committee regularly updates their recommendations on how to best control blood pressure. There are extensive guidelines as to what medicines are most helpful in certain medical conditions such as diabetes and coronary artery disease. For those of you with diastolic heart failure, your medication regimen will be based largely on any other co-existing medical conditions. When it comes to diastolic heart failure, the journey is probably less important than the destination.
Heart rate control
We have already learned that the heart fills with blood during diastole. When the heart becomes stiff, it needs more time to fill. Diastole is indirectly related to heart rate so faster heart rates mean shorter filling times. This is why tachycardia, or an abnormally fast heart rate, is not well tolerated in this condition. This is magnified in conditions such as atrial fibrillation or atrial flutter. Usually, the atria and ventricles work in concert. The atria are essentially reservoirs that sit above the ventricles (the heart’s main pumping chambers). They intermittently pump blood into the ventricles to help the ventricles fill with as much blood as possible. This results in a more efficient diastole and happier ventricles. These conditions often result in tachycardia and more importantly; the coordinated squeeze is also lost. In the setting of diastolic heart failure, since ventricular filling is already compromised, this can have a profound effect. It becomes doubly important to have a reasonably slow heart rate to allow for optimal filling. The medicines used most commonly to slow your heart rate fall under the categories of beta-blocker and calcium channel blocker. Sometimes in atrial fibrillation or flutter we have to go a step further and take actions to return you to a normal heart rhythm.
Treat your symptoms of heart failure
Treatment for diastolic heart failure is primarily directed at treating the “congestion” of congestive heart failure. These symptoms are related to higher than normal pressures within your heart and lead to the classical symptoms including shortness of breath, edema and fatigue. Management of these symptoms relies heavily on diuretic use to help your body eliminate excess fluid. Limiting salt intake is of critical importance (please review Dr. Guichard’s discussion on salt in heart failure). Lowering an abnormally high blood pressure and treated other correctable causes such as aortic stenosis are also beneficial. Long-term exercise has been shown to improve diastolic function and improves the functional capacity of persons with abnormal diastolic function
Ischemia is bad
Coronary artery disease were the blockage cause a significantly decreased blood flow can lead to varying levels of ischemia in the myocardium. Ischemia is a shortage of blood flow that results in insufficient oxygen and nutrient transport to maintain normal metabolism. Relaxation of the myocardium is an energy driven process, meaning that it requires work to relax (kind of oxymoronic). Coronary blockages can thereby affect the heart ability to relax and should be aggressively treated.
Diastolic heart failure is a complex entity that is not always intuitive. A good low salt diet, blood pressure control and regular exercise will go a long way to controlling many of your symptoms. Your doctor will be able to help you determine what the likely cause of your diastolic disease and devise a treatment plan to combat it.