The pathophysiology of heart failure with preserved ejection fraction

Our studies demonstrate that patients with HfpEF have impaired myocardial energetics as indicated by the diminished in vivo myocardial PCr/ATP ratio. Data acquired during semi-supine cycling exercise indicates that patients with HfpEF had a dynamic impairment of LV active relaxation. In addition, ventricular-vascular coupling ratio was unchanged during exercise in HfpEF patients in contrast to healthy controls where the ratio fell substantially during exercise. In addition, we found patients with HfpEF with normal LA dimensions had increased LA contribution during exercise as compared to controls. Furthermore, we showed patients with HfpEF exhibited contractile inefficiency as well as systolic and diastolic dyssynchrony as measured by speckle tracking imaging (STI). And that the LV anterior wall appears to be the most delayed segment. We also demonstrated that HfpEF patients exhibited chronotropic incompetence during peak exercise testing and abnormal HR recovery following exercise compared to age-gender-matched healthy controls and hypertensive patients. In a separate study, we showed that changes in LV torsion, untwist and LV strain and strain rate in patients with HfpEF at rest were similar to changes found in normal aging.EThOS - Electronic Theses Online ServiceGBUnited Kingdo