Diastolic Heart Failure - Project description
Background and objective
The heart functions like a mechanical pump, such as a bellows, for example. Blood is pumped from the left ventricle of the heart into the aorta when the myocardium contracts. This phase is known as systole. Afterwards the myocardium relaxes; during this phase the main chambers fill with blood again. This phase is called diastole. Until a few years ago, it was assumed that dysfunctions (failure) occurred primarily in the systolic phase, we know in the meantime that at least as many people, particularly women in the higher age ranges, suffer from diastolic dysfunction, i.e. a problem with filling the heart.
Interim results
Within the Heart Failure Competence Network we have carried out two studies on diastolic heart failure. In a large, nationwide collaborative project in Germany within the Heart Failure Competence Network, we examined nearly 2,000 patients with cardiovascular risk factors (hypertension, diabetes mellitus, hyperlipidemia) or known coronary artery disease with regard to their cardiac function. This study revealed that diastolic dysfunction increased significantly with age (Fig. 1).
In patients 80 years of age or older, the prevalence of diastolic dysfunction was over 90%.
An analysis of the severity revealed that the majority of the patients suffered from a mild form of diastolic dysfunction. The proportion of patients with more severe diastolic dysfunction was only approximately 5 percent. However, it is not yet clear what predictive value these findings have for individual patients. Thus the collected data will not only be useful in improving the diagnosis of diastolic dysfunction but will also help in the future to detect heart disease in the early stages and facilitate timely intervention to prevent complications. For this purpose, all of the patients will be monitored for a period of at least 5 years after the study.
As part of a small but very complex study we researched the changes in the pressure/volume ratio in the myocardium using a special cardiac catheter examination.
This revealed that the hearts of the patients with diastolic heart failure (in red, Figure 2) are not able to pump more blood to the organs at a higher heart rate. As we were able to prove, this is due to impaired and incomplete relaxation of the myocardium.