Relationship Between Tei Index and PEP-Derived Myocardial Performance Index in Sinus Rhythm

Feasibility study on evaluating right ventricular diastolic function by new Tei'-Index

Objective

Doppler-derived myocardial performance index (Tei) has been used in the evaluation of right ventricular (RV) function. However, the usage in isolated diastolic dysfunction is limited.We sought to find a new Tei'-index that is more appropriate for evaluating isolated diastolic dysfunction (IDD) based on the symmetry of cardiac structure and function.

Methods

21 patients with impaired RV relaxation were compared to 44 control subjects. Tei and Tei' including their components, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), the ejection time (ET), and RV rapid filling time (RFT) were measured from RV outflow and tricuspid inflow Doppler velocity profiles.

Results

Tei-index have no change between IDD group and control subjects (0.21 ± 0.08 vs 0.23 ± 0.07 P[bond, double bond]NS). The Tei'-index was significantly shortened in IDD group(0.24 ± 0.09 vs 0.32 ± 0.12,p＜0.05).The decrease in Tei'-index was due to the prolongation of both IRT and RFT, and in the abbreviation of ICT. Tei'-index cutoff value of ≥0.31 identified impaired RV relaxation with a sensitivity of 50 % and specificity of 86 %.We also find that the Tei'-index correlated well with doppler measures of diastolic parameters like E/A, E/e', DT, which suggests its potential use as a noninvasive indicator of the right ventricular (RV) relaxation in patients with heart failure of different causes.

Conclusion

New Tei's index is highly effective and specific in the evaluation of early diastolic dysfunction of right ventricle, and can be used as an indicator for the detection of IDD in clinic.

Physical Activity Engagement Worsens Health Outcomes and Limits Exercise Capacity in Growth-restricted Mice

INTRODUCTION

A total of 161 million children a year are growth restricted, leading to a 47% increased risk of chronic disease in adulthood. Physical activity (PA) reduces the risk of mortality from chronic disease. The purpose of the present investigation was to determine the effect of a PA intervention (wheel running) on cardiac and skeletal muscle capacities in gestational (GUN) and postnatal (PUN) growth-restricted mice as compared with nonrestricted controls (CON).

METHODS

A low-protein cross-fostering FVB mouse model was used to induce growth restriction during gestation and the first 21 d of postnatal life. Mouse pups were recovered on a healthy diet until mature and provided wheel access for 3 wk. At completion of the PA intervention, mice underwent maximal exercise testing on a treadmill, echocardiography, and skeletal muscle histology.

RESULTS

After the PA intervention, CON mice had a 45% improvement in maximal exercise capacity (P = 0.0390) because of cardiac and skeletal muscle adaptations, but GUN and PUN mice did not. Alarmingly, PUN female mice exposed to wheels had 11.45% lower left ventricular volume (P = 0.0540) and 18% lower left ventricle area (P = 0.0585), with blood flow velocities indicative of cardiac fibrosis (GUN had elevated isovolumetric contraction time P = 0.0374; GUN females and PUN males had longer isovolumetric relaxation time P = 0.0703). PUN male mice had mixed skeletal muscle responses with an oxidative shift in the diaphragm (P = 0.0162) but a glycolytic shift in the extensor digitorum longus (P = 0.0647). PUN female mice had a glycolytic shift in the soleus after wheel running.

CONCLUSIONS

Unexpectedly, growth-restricted mice were nonresponders to a PA intervention and displayed negative cardiac outcomes.

The evaluation of diastolic function and myocardial performance index during pregnancy: A tissue Doppler echocardiography study

BACKGROUND

The pregnancy process is characterized by several changes in the cardiovascular system, especially in left ventricle (LV) systolic and diastolic function. Tissue Doppler imaging (TDI) is a useful tool to evaluate global LV function. This study investigated changes in LV functions using TDI in third-trimester pregnant women.

METHODS

A total of 86 consecutive third-trimester healthy pregnant women and 40 age-matched nonpregnant healthy women (control group) were enrolled in this cross-sectional study. LV diameter, standard Doppler and tissue Doppler parameters, and myocardial performance index (MPI) were measured for all patients.

RESULTS

There was no significant difference in baseline characteristics between the pregnant and control groups. However, the cardiac chamber diameter was larger, the Am velocity was higher, and the E velocity, Em velocity, and E/A ratio were lower in the pregnant group. In addition, the MPI was significantly higher in the pregnant group compared to the control group (0.57 ± 0.11 vs 0.42 ± 0.02, P < .001). Correlation analysis showed that gestational week was positively correlated with the MPI (r = .407, P = .003).

CONCLUSIONS

Detailed assessment of cardiac function is important during pregnancy. We demonstrated that pregnancy was associated with a significantly increased MPI, as well as structural and functional changes.

R-Wave Modified Tissue Doppler Imaging Myocardial Performance Index for the Assessment of Cardiac Function in Children with Congestive Heart Failure: A Feasibility Study

Background

The aim of this study was to evaluate the feasibility of an R-wave modified tissue Doppler imaging (TDI) myocardial performance index (MPI), or MPI TDI-R, for the assessment of cardiac function in children with congestive heart failure (CHF).

Material/Methods

Forty children with CHF and 40 normal children were evaluated using the modified pediatric Ross heart failure grading system. TDI recorded the spectrum of diastolic function at the mitral valve annulus to measure the MPI. Twelve-lead electrocardiogram (ECG) measured the R-wave in the QRS complex, resulting in the modified MPI TDI-R. Correlation between the MPI TDI-R, other echocardiographic indices, and the Ross heart failure grades were analyzed, with reproducibility analysis.

Results

Compared with normal children, the MPI TDI and MPI TDI-R were significantly increased in the pediatric CHF group (P<0.01). The MPI TDI-R was significantly correlated with other indices of cardiac function and Ross grading for CHF in children (r=0.769). The MPI TDI-R showed good correlation with the findings of the MPI TDI, calculated by traditional methods. Receiver-operating characteristic (ROC) curve analysis showed that the MPI TDI-R had a sensitivity of 67.5%, and a specificity of 97.5%. The reproducibility of the MPI TDI-R was confirmed to be superior when compared with the non-modified MPI TDI.

Conclusions

This feasibility study showed that the modified MPI TDI-R, formed by combining the MPI TDI with synchronous surface ECG measurements, was simple to perform, reproducible, and provided a specific index for the assessment of cardiac function in children with CHF.