Ratio of right to left ventricular ejection: a pilot study using Doppler to detect interventricular dyssynchrony

Echo-Doppler measures of right ventricular systolic function are affected by reduced left ventricular systolic function

BACKGROUND

Objective right ventricular (RV) systolic function assessment is attained using a series of well-described and validated echo-Doppler measurements. However, how left ventricular (LV) systolic function influences these RV functional measurements has not been previously studied. Consequently, we conducted a retrospective proof-of-concept analysis to answer this important question.

METHODS

A total of 100 echocardiographic studies were included and patients were divided into two groups according to their LV ejection fraction (LVEF). The following RV variables were acquired including, tricuspid annular systolic plane excursion (TAPSE), velocity of the systolic motion (TA TDI s'), RV outflow tract velocity time integral (VTI), pulmonary vascular resistance (PVR), and the TAPSE to pulmonary artery systolic pressure (PASP) ratio.

RESULTS

Not only TAPSE, TA DI s', RVOT VTI, PVR, and TAPSE/PASP were all significantly different between patients with normal versus abnormal LVEF; but most importantly, RVOT VTI (p < .0001) was the best discriminatory variable in assessing normal versus abnormal LVEF followed by TAPSE (p = .0001). Using receiver operating characteristic curve analysis, an RVOT VTI value > 11 identified patients with a normal LVEF with a sensitivity of 90% and specificity of 76%.

CONCLUSION

Based on our results, reduced LVEF affects the RV, likely mediated by mechanisms of interventricular dependence. Therefore, RV analysis cannot be performed in isolation as it not only reflects intrinsic RV systolic function but also, is dependent on LV systolic function. In cases of reduced LVEF, additional measures of RV assessment should be used to provide better objective assessments.

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.

Right ventricular dyssynchrony and its improvements after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

PURPOSE

Whether pathologic alterations of right ventricle (RV) in chronic obstructive pulmonary disease (COPD) affect intra- and interventricular dyssynchrony due to changes in mechanical activation of the septum and RV is unclear. The aim of this study was to determine mechanical activation and its changes after pulmonary rehabilitation program (PRP) with speckle tracking echocardiography (STE) in COPD patients.

METHODS

After the exclusion of 15 patients due to poor echogenicity and 5 patients not tolerating PRP out of 69 consecutive COPD patients undergoing PRP, the remaining 49 patients and 41 healthy subjects were enrolled. The mechanical activations of both ventricles were evaluated at admission and after PRP with STE.

RESULTS

Chronic obstructive pulmonary disease patients had intra- and interventricular dyssynchrony compared to controls. The interventricular dyssynchrony assessed by time to peak longitudinal systolic strain (PLSS) difference between RV free wall and left ventricle (LV) lateral wall and intraventricular dyssynchrony assessed by RV peak systolic strain dyssynchrony (PSSD) index were improved after PRP. In all, 18 patients were hospitalized due to symptoms of right heart failure within 1 year. The time to PLSS difference between RV free wall and LV lateral wall and RV PSSD index were independent predictors of hospitalization. Receiver operating characteristics (ROC) analysis revealed that a time to PLSS difference between RV free wall and LV lateral wall >15 ms predicted hospitalization within 1 year with 77.8% sensitivity and 64.5% specificity.

CONCLUSIONS

Chronic obstructive pulmonary disease was associated with intra- and interventricular dyssynchrony. PRP had an important impact on the improvement of both intra-, and interventricular dyssynchrony, which might be used in predicting hospitalization within 1 year.

Risk of death and need for transplantation in chronic pulmonary hypertension

BACKGROUND

Echo-Doppler parameters that exemplify right ventricular (RV) outflow dynamics and measures of annular tissue Doppler imaging to assess left ventricular (LV) and RV diastolic function, known to be affected in chronic pulmonary hypertension (cPH), have never been studied to determine if they could be predictive of mortality or need for transplantation 1-year after follow-up.

METHODS

Numerous echo-Doppler parameters of RV and LV performance were recorded from 120 patients. This patient population was divided into 3 groups. Group I had no PH, group II had cPH but no documented death or need for either lung or heart transplantation, at 1-year follow-up after their initial echocardiogram whereas group III had cPH and patients had either died or required heart and/or lung transplantation during the same time period.

RESULTS

Analysis of variance was first used to identify which echo-Doppler variables were significant among the studied groups. A logistic regression analysis was then performed to identify predictive variables of the occurrence death and need for transplantation. Finally, a multiple regression analysis was used between groups II and III to identify which echo-Doppler variables were most useful in identifying severe cPH patients at risk of the prespecified events.

CONCLUSIONS

Even though older patients with worse RV fractional area change might be considered at risk of worse prognosis in patients with severe cPH, only a low mitral annular early diastolic velocity was useful in identifying which of those individuals were at highest risk of death or in need of transplantation.