These are both probably too broad a definition for diastolic heart failure, and this group of patients is more precisely described as having heart failure with normal systolic function. Echocardiography can be used to diagnose diastolic dysfunction but is a limited modality unless it is supplemented by stress imaging. MUGA imaging is an earlier mathematical attempt to distinguish systolic from diastolic heart failure.No single echocardiographic parameter can confirm a diagnosis of diastolic heart failure. Multiple echocardiographic parameters have been proposed as sufficiently sensitive and specific, including mitral inflow velocity patterns, pulmonary vein flow patterns, E/A reversal, tissue Doppler measurements, and M-mode echo measurements (i.e. of left atrial size). Algorithms have also been developed which combine multiple echocardiographic parameters to diagnose diastolic heart failure.There are four basic Echocardiographic patterns of diastolic heart failure, which are graded I to IV:
The mildest form is called an "abnormal relaxation pattern", or grade I diastolic dysfunction. On the mitral inflow Doppler echocardiogram, there is reversal of the normal E/A ratio. This pattern may develop normally with age in some patients, and many grade I patients will not have any clinical signs or symptoms of heart failure. Grade II diastolic dysfunction is called "pseudonormal filling dynamics". This is considered moderate diastolic dysfunction and is associated with elevated left atrial filling pressures. These patients more commonly have symptoms of heart failure, and many have left atrial enlargement due to the elevated pressures in the left heart.Grade III and IV diastolic dysfunction are called "restrictive filling dynamics".
While therapies for dyssynchrony, such as biventricular pacing provide benefits to HFrEF patients, no benefit is appreciable in HFpEF patients at this time. Systemic abnormalities
Patients with HFpEF, in addition to cardiac abnormalities, display changes in (endothelial) microvascular function, skeletal muscle metabolism and in fat distribution and character throughout the body. The importance of these changes is demonstrated in that stable, non-decompensated patients seem to benefit from exercise; specifically increased VO2 max and exercise tolerance. However, this benefit appears to be derived from changes in muscle and vasculature as opposed to directly on the heart, which displays minimal change in output following exercise training. Diagnosis
HFpEF is typically diagnosed with echocardiography. Techniques such as catheterization are invasive procedures and thus reserved for patients with co-morbid conditions or those who are suspected to have HFpEF but lack clear non-invasive findings. Catheterization does represent are more definitive diagnostic assessment as pressure and volume measurements are taken simultaneously and directly. In either technique, the heart is evaluated for left ventricular diastolic function. Important parameters include, rate of isovolumic relaxation, rate of ventricular filling, and stiffness.Frequently patients are subjected to stress echocardiography, which involves the above assessment of diastolic function during exercise. This is undertaken because perturbations in diastole are exaggerated during the increased demands of exercise. Exercise requires increased left ventricular filling and subsequent output. Typically the heart responds by increasing heart rate and relaxation time. However, in patients with HFpEF both responses are diminished due to increased ventricular stiffness.