The Tei Index: Methodology and Disease State Values

Abstract

Systolic and diastolic ventricular dysfunction frequently coexist. Both are important determinants of prognosis; consequently, a clinical measurement that assesses both systolic and diastolic function may be more useful than one that addresses only one aspect of ventricular function. Recently, a Doppler-derived index (referred to as the Tei index, or myocardial performance index) that combines systolic and diastolic time intervals has been developed to assess global cardiac function. 1 In this brief review we will discuss the measurement and utility of the Tei index.The Tei index, which may be used to assess either left or right ventricular function, is equal to the sum of the isovolumic contraction time (ICT) and isovolumic relaxation time (IRT) divided by ejection time (ET). As originally described by Tei, 1 the time intervals used to calculate the index are measured using pulsed-wave Doppler velocity spectra of ventricular inflow and outflow. Mitral or tricuspid flow velocity spectra are obtained by positioning the pulsed-wave Doppler sample volume at the tips of the mitral or tricuspid valve leaflets in the apical four-chamber view. Left ventricular outflow velocity spectra may be obtained from either the apical five-chamber or the long-axis view, by positioning the pulsed-wave Doppler sample volume at the level of the aorAddress for correspondence and reprint requests: tic annulus. Right ventricular outflow velocity spectra are obtained from the parasternal short-axis view, with the pulsed-wave Doppler sample volume positioned at the pulmonic annulus. Calculation of the Tei index ( Fig. 1) involves measuring the time interval a, extending from the cessation of mitral or tricuspid inflow to its subsequent onset, and ejection time b, which is the duration of the left or right Figure 1. Schema of Doppler flow velocity spectra representing the time intervals used for calculation of the Tei index. Interval 'a' extends from the cessation to the onset of mitral or tricuspid inflow. It includes the isovolumic contraction time, ejection time, and isovolumic relaxation time. Interval 'b' is the duration of left or right ventricular outflow (ejection time). The Tei index is equal to (a − b)/b. ET, ejection time; ICT, isovolumic contraction time; IRT, isovolumic relaxation time.

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“…Short-axis M-mode echocardiography was performed and the following measurements were obtained as an average of at least three cardiac cycles: Left ventricular internal diameter at diastole and systole (LVIDd and LVIDs, respectively), posterior wall thickness at diastole and systole (PWTd and PWTs, respectively), interventricular septal thickness at diastole and systole (IVSd and IVSs, respectively), and fractional shortening (%FS) was calculated using the equation, FS = [(LVIDd−LVIDs)/LVIDd] X 100. Tei index was determined from left ventricular inflow and outflow Doppler recordings as previously described [28].…”

Comparison of the Tei index with invasive measurements of right ventricular function

“…However, accurate echocardiographic evaluation of right ventricular function remains difficult and challenging by its complex structural geometry and contraction pattern [1]. The Doppler echocardiographically derived myocardial performance index, also referred to as the Tei index, is easily obtainable and has been clinically useful in assessing global ventricular function in both, left and right ventricles, and adults and children [2][3][4]. The index combines systolic and diastolic time intervals and is independent of heart rate and ventricular geometry [3,5,6].…”

Effect of cilnidipine on left ventricular function in hypertensive patients as assessed by tissue Doppler Tei index

“…However, the inability to measure the interval between the end and onset of mitral inflow and the ejection time simultaneously is a limitation of conventional Tei index. 15,16 Tissue Doppler imaging (TDI) is a new ultrasound technique that selectively calculates and displays online myocardial velocity information derived from the Doppler shifts created by cardiac motion. 17 Studies that use Tei index derived from TDI demonstrated that TDI Tei index correlated with conventional Tei index very well.…”