Abstract 19982: Patients With Heart Failure With Normal Ejection Fraction Develop Significant Diastolic Ventricular Interaction During Exercise

Introduction: Diastolic ventricular interaction (DVI) is the phenomenon in which raised diastolic pressure in the right ventricle impedes the filling of the left ventricle via the interventricular septum, and is associated with septal flattening at end diastole. In experimental models it develops during acute volume and /or pressure overload of the right ventricle, and is also seen at rest in some patients with systolic heart failure. Hypothesis: In many patients with HFnEF pulmonary artery pressure markedly rises on exercise, we therefore hypothesized that DVI may frequently develops during exercise. Methods: We studied 28 patients with HFnEF (all with peak VO2 Results: ‘Normalised radius of curvature’ (NRC) is the ratio of the measured radius of curvature and predicted radius of curvature (assuming the LV was circular). At rest NRC was similar in the three groups (p= 0.832) but there was a significant difference in the NRC at peak exercise and the change from rest to peak exercise of NRC between the three groups (p=0.001 and 0.008 respectively). On Bonferroni analysis significant differences were demonstrated between the HV and HFnEF subjects for the peak exercise NRC and for change (peak - resting NRC) between the healthy volunteers vs HFnEF and hypertensives vs HFnEF subjects. There was no difference in normalized septal radius of curvature during exercise between the healthy and hypertensive groups. Conclusion: Patients with HFnEF frequently demonstrate diastolic septal flattening on exercise, indicating the development of DVI and potentially contributing to impaired diastolic LV filling on exercise