Abstract 10173: Chronic Pulmonary Hypertension Causes Significant Interventricular Spatiotemporal Dyssynchrony of Diastolic Flows
Background: Color M-mode (CMM) has been useful in characterizing left ventricular (LV) relaxation by analyzing flow propagation across the mitral inflow during diastole. In a similar fashion, interrogation of the tricuspid inflow has provided information regarding right ventricular (RV) filling dynamics and pressure gradients. The spatiotemporal resolution of CMM offers a unique opportunity to study the effect of chronic pulmonary hypertension (cPH) on biventricular diastolic function.
Methods: CMM were obtained from apical 4-chamber views across both mitral and tricuspid valves to measure propagation velocity as well as time to onset of both early and late LV and RV diastolic flows, respectively. Data was collected from 15 individuals with normal pulmonary artery systolic pressures in Group I (mean age 50 ± 13 years and 31 ± 6 mmHg) and from 20 patients with cPH in Group II (mean age 53 ± 16 years and 89 ± 24 mmHg).
Results: Group II patients had a delayed onset of early diastolic RV flow signals (525 ± 47 ms vs. 482 ± 48 ms; p< 0.01) with an earlier occurrence of late diastolic LV flow signals (723 ± 170 ms vs. 844 ± 146 ms; p< 0.04) than Group I patients. Most importantly, Group II patients had a significant difference between onset of RV to LV CMM early diastolic flows (Figure 1A) as well as lower propagation velocities in both RV and LV than Group I patients (Figure 1B).
Conclusions: This study is the first to our knowledge to describe how cPH not only appears to disrupt RV and LV diastolic signal distribution but also their temporal occurrence as well as reducing the propagation velocities of early diastolic signals in both ventricles. Taken together, these results seem to imply that cPH causes significant interventricular diastolic dyssynchrony and further studies are now needed to correlate these findings with regards to symptoms and patient clinical outcomes.
- © 2010 by American Heart Association, Inc.