Temporal differences in ejection between right and left ventricles in chronic pulmonary hypertension: a pulsed Doppler study

The Variation in the Diastolic Period with Interventricular Septal Displacement and Its Relation to the Right Ventricular Function in Pulmonary Hypertension: A Preliminary Cardiac Magnetic Resonance Study

Background: Pulmonary hypertension (PH) is known to alter the biventricular shape and temporal phases of the cardiac cycle. The presence of interventricular septal (IVS) displacement has been associated with the severity of PH. There has been limited cardiac magnetic resonance (CMR) data regarding the temporal parameters of the cardiac cycle in PH. This study aimed to quantify the temporal changes in the cardiac cycle derived from CMR in PH patients with and without IVS displacement and sought to understand the mechanism of cardiac dysfunction in the cardiac cycle. Methods: Patients with PH who had CMR and right heart catheterization (RHC) examinations were included retrospectively. Patients were divided into an IVS non-displacement (IVSND) group and an IVS displacement (IVSD) group according to IVS morphology, as observed on short-axis cine CMR images. Additionally, age-matched healthy volunteers were included as the health control (HC). Temporal parameters, IVS displacement, ventricular volume and functional parameters were obtained by CMR, and pulmonary hemodynamics were obtained by RHC. The risk stratification of the PH patients was also graded according to the guidelines. Results: A total of 70 subjects were included, consisting of 33 IVSD patients, 15 IVSND patients, and 22 HC patients. In the IVSND group, only the right ventricle ejection fraction (RVEF) was decreased in the ventricular function, and no temporal change in the cardiac cycle was found. A prolonged isovolumetric relaxation time (IRT) and shortened filling time (FT) in both ventricles, along with biventricular dysfunction, were detected in the IVSD group (p < 0.001). The IRT of the right ventricle (IRTRV) and FT of the right ventricle (FTRV) in the PH patients were associated with pulmonary vascular resistance, right cardiac index, and IVS curvature, and the IRTRV was also associated with the RVEF in a multivariate regression analysis. A total of 90% of the PH patients in the IVSD group were stratified into intermediate- and high-risk categories, and they showed a prolonged IRTRV and a shortened FTRV. The IRTRV was also the predictor of the major cardiovascular events. Conclusions: The temporal changes in the cardiac cycle were related to IVS displacement and mainly impacted the diastolic period of the two ventricles in the PH patients. The IRT and FT changes may provide useful pathophysiological information on the progression of PH.

Tricuspid Annular Systolic Velocity to Left Ventricular Outflow Velocity Time Integral Ratio: Proof of Concept Utility Analysis

Background

The tricuspid annular plane systolic excursion (TAPSE) / pulmonary artery systolic pressure (PASP) ratio has been a useful marker of right ventricular (RV)-pulmonary artery coupling. However, given the intricate functional and mechanical interdependence of the right and left ventricles, we believe this ratio would be less useful when assessing reduced left ventricular (LV) systolic function. Instead, we proposed using the tricuspid annular tissue Doppler imaging systolic velocity to LV outflow tract velocity time integral ratio (TA TDI s’ / LVOT VTI r) for this purpose.

 

Methods

For this proof-of-concept study, a retrospective analysis was conducted on 60 patients with complete echocardiographic studies while in sinus rhythm. The population was divided as follows; Group 1 included 20 individuals with normal left ventricular ejection fraction (LVEF) as well as normal RV and PASP. Group 2 was composed of 20 patients known to have been evaluated or treated for pulmonary hypertension, while group 3 was comprised of 20 patients treated for heart failure (HF). 

Results

TAPSE/PASP ratios were no different from any of the studied groups. However, the proposed TA TDI s' /LVOT VTI r was statistically different among all three groups (Group 1: 0.6 ± 0.1*; Group 2: 0.5 ± 0.1°; and Group 3: 0.8 ± 0.3^#; p < 0.001).

Conclusions

Based on these results, there is now a need for additional prospective studies to explore the overall utility of using this TA TDI s' / LVOT VTI r in day-to-day routine assessments not only for diagnostic purposes but also to determine how this ratio correlates with symptoms and changes with therapy.

Left Ventricular Diastolic Function Assessment of a Heterogeneous Cohort of Pulmonary Arterial Hypertension Patients

BACKGROUND

Pulmonary arterial hypertension (PAH) is known to trigger right ventricular (RV) remodeling that might compromise left ventricular (LV) filling due to inter-ventricular interdependence. In this study, we aimed to examine standard echocardiographic measurements of LV diastolic function in PAH patients.

METHODS

In this retrospective study, we identified clinical as well as complete echocardiographic data from 128 chronic PAH patients to fully assess LV diastolic dysfunction (LVDD) using standard recommended Doppler guidelines. Accordingly, patients were divided into three groups: LVDD 0, LVDD 1 and LVDD 2.

RESULTS

The mean age of the studied population was 57 ± 14 years with a mean pulmonary artery systolic pressure (PASP) of 55 ± 21 mm Hg. A total of 36% of the study patients had normal LV diastolic function. However, 64% had LVDD with LVDD stage 1 being the most common (48%). In terms of echocardiographic data, significant differences were found among the three LVDD groups in regards to PASP, LV end systolic and diastolic volumes, tricuspid annular plane systolic excursion, right ventricular fractional area change as well as many other tissue Doppler imaging parameters. Finally, just age and PASP were predictors of abnormal LV diastolic function (P < 0.05).

CONCLUSIONS

Impaired relaxation is a common abnormality in PAH patients. Additional studies are warranted to determine whether LVDD alters prognosis or is related to changes in the symptomatic profile of this group of patients.