Diastolic
heart failure occurs when the heart does not
completely relax before it fills up with blood between heartbeats. This can
result in blood that backs up into the lungs and the rest of the body. Experts
know less about the treatment of diastolic heart failure than systolic heart
failure for two reasons:
- It is hard to define diastolic heart failure
precisely.
- Few clinical trials have found clearly effective
strategies for treating diastolic heart failure.
The most common cause of diastolic heart failure is left
ventricular hypertrophy caused by ongoing high blood pressure (hypertension).
In this condition, the heart muscle thickens in response to higher-than-normal
blood pressure in the arteries. This results in a smaller filling chamber in
the heart and therefore a diminished ability of the heart to fill with blood.
The heart also may not relax properly, which also affects how well the left
ventricle fills.
The best therapy for diastolic heart failure
caused by left ventricular hypertrophy is to treat the high blood pressure.
Your doctor will usually prescribe drug treatment for diastolic heart failure
itself only after treatment of its underlying cause is not effective in
relieving symptoms.
Since no standard drug combinations exist for
diastolic heart failure, your doctor will use your symptoms as a guide in
choosing your drugs. Beta-blockers, calcium channel blockers, diuretics,
angiotensin-converting enzyme (ACE) inhibitors, and angiotensin II receptor
blockers (ARBs) all have some ability to decrease symptoms in some
people.
Beta-blockers and calcium channel blockers. One of the main causes of diastolic dysfunction is that the
heart does not have enough time to relax and fill before pumping blood out to
the rest of your body. Beta-blockers and certain calcium channel blockers
decrease your heart rate and allow more time for your heart to fill before
pumping out blood with each beat. Another benefit of these medicines is that
they also effectively reduce your blood pressure. This change can both slow and
reverse the tendency of your heart muscle to thicken.
Diuretics. Just as in people with systolic heart failure,
diuretics can improve symptoms in people with diastolic heart failure by
removing excess fluid from the body. There is a delicate balance between too
little removal of fluid and thus incomplete relief of symptoms and too much
removal of fluid, which can lead to an increased heart rate and heart function
that is worse.
ACE inhibitors and ARBs. ACE
inhibitors and ARBs (angiotensin II receptor blockers) can improve symptoms in
people with diastolic heart failure. This may be because these agents can lower
the blood pressure and because of direct effects these medicines have on the
heart muscle, both of which can lead to less thickening of the heart muscle and
improved diastolic function.