Diastolic dysfunction of the left ventricular occurs when the left ventricle becomes stiff. This can happen for a variety of reasons, but often doesn't affect systolic pump function (contraction), rather, it makes it more difficult for the heart to fill with blood and relax during diastole.
Importance of Diastolic Function
The heart is designed to be a supple, elastic muscle. This allows for the heart to relax fully with a recoil-mechanism (like a rubber-band) to suck blood into and out of the ventricle to allow for improved blood flow. As the heart stiffens, blood can get backed up and not pulled into the ventricle, which can sometimes result in shortness of breath and a rise in pressure in the left ventricle, creating more work for the left atrium (which is not a very muscular structure).
Diastolic dysfunction can worsen overall prognosis, depending on how severe it is, so it is important to get treated by a cardiologist.
Currently, echocardiography is the key measure of diastolic function. Some data can be extracted from a nuclear stress test and cardiac MRI, but usually echocardiography is the way it is diagnosed.
The exact mechanisms haven't been fully worked out, but the following can all cause a stiff heart:
The mainstays of therapy, currently, are intensive blood pressure control and intensive heart rate control.
This can often be achieved through regular physical activity, sometimes in combination with medicines. Usually, the use of an ACE-inhibitor or angiotensin receptor blocker to control blood pressure works best as it allows for heart remodeling, which may make the heart less stiff. Heart remodeling refers to the changes in size, shape, and function of the heart after injury to the ventricles.
Regular physical activity of up to 30 minutes a day (after checking with your doctor) is one of the best ways to reduce diastolic dysfunction – and in many patients exercise can serve as a cure for this condition.
Diastolic Heart Failure
Long-standing and worsening diastolic function can often lead to heart failure. This condition is known as diastolic heart failure (DHF) or "heart failure with normal ejection fraction" (HFNEF). In such patients, diastolic dysfunction is the underlying cause of the congestive failure and causes the symptoms and signs of heart failure, normal or near normal left ventricular (LV) ejection fraction (EF), and evidence of diastolic dysfunction (e.g. abnormal left ventricular filling and elevated filling pressures). Up to 50 percent of patients with diastolic heart failure have a normal or near normal left ventricular ejection fraction.