Related Experiment Videos
An integrated measure of left ventricular diastolic function based on relative rates of mitral E and A wave
1Cardiology Section, Jerry L. Pettis VA Medical Center and Loma Linda University, CA, USA. ramdaspai@pol.net
Insights
The T(e)/T(a) ratio, a measure of mitral wave transit times, effectively assesses global left ventricular (LV) diastolic function. This ratio correlates with LV relaxation, stiffness, and filling pressures, offering valuable insights into diastolic performance.
Area of Science:
- Cardiology
- Echocardiography
- Diastology
Background:
- Mitral E wave propagation time (T(e)) slows with abnormal left ventricular (LV) relaxation.
- Mitral A wave propagation time (T(a)) shortens with elevated LV end-diastolic stiffness.
- The T(e)/T(a) ratio may integrate global LV diastolic function assessment.
Purpose of the Study:
- To investigate the T(e)/T(a) ratio as an integrated measure of global LV diastolic function.
- To correlate the T(e)/T(a) ratio with invasive hemodynamic parameters of LV diastolic function.
Main Methods:
- Doppler echocardiography was used to measure the T(e)/T(a) ratio in 94 subjects.
- Subjects included normal individuals, patients with LV hypertrophy, and patients undergoing left heart catheterization.
- Correlation analysis was performed with invasive parameters like Tau, peak negative dP/dt, and LV stiffness.
Main Results:
- The T(e)/T(a) ratio was significantly higher in patients with secondary LV hypertrophy and hypertrophic cardiomyopathy compared to normal subjects.
- The T(e)/T(a) ratio showed significant correlations with Tau (r=0.76), LV stiffness (r=0.57), and filling pressures (r=0.58, P<.0007).
- Stepwise multiple regression identified Tau and LV stiffness as sole determinants of the T(e)/T(a) ratio (R=0.82).
Conclusions:
- The T(e)/T(a) ratio is closely related to LV relaxation and late diastolic stiffness.
- This ratio provides valuable insights into LV diastolic performance and filling pressures.
- The T(e)/T(a) ratio serves as an effective integrated measure of global LV diastolic function.
Background And Objectives:
The mitral E wave propagation inside the left ventricle is slowed in patients with abnormal left ventricular (LV) relaxation with a prolongation of its transit time to the LV outflow tract (T(e)). On the contrary, the mitral A wave propagation is faster in those with elevated LV end-diastolic stiffness, resulting in a shortening of its transit time (T(a)). We hypothesized that the T(e)/T(a) ratio may serve an integrated measure of global LV diastolic function.
Methods And Results:
The T(e)/T(a) ratio was measured with Doppler echocardiography in 94 subjects: 25 normal subjects, 38 patients with LV hypertrophy (18 with secondary LV hypertrophy and 20 with hypertrophic cardiomyopathy), and 31 patients undergoing left heart catheterization for clinical indications. The T(e)/T(a) ratio was 1. 98 +/- 0.61 in the normal subjects, 3.32 +/- 0.93 in patients with secondary LV hypertrophy (P <.0001 vs normal), and 3.18 +/- 1.36 in patients with hypertrophic cardiomyopathy (P =.0003 vs normal). In the invasive group the T(e)/T(a) ratio (range 0.56 to 3.60) correlated significantly with Tau (r = 0.76, P <.0001), peak negative dP/dt (r = -0.46, P =.01), the LV late diastolic stiffness index (r = 0.57, P =.0013), LV pre-A wave pressure (r = 0.46, P =. 0096), LV end-diastolic pressure (r = 0.58, P =.0007), and the amount of LV pressure rise with atrial systole (r = 0.52, P =.0032) but not with the heart rate. Tau and LV stiffness were its sole determinants by stepwise multiple regression (R = 0.82).
Conclusions:
The ratio of mitral E and A wave transit times inside the LV (T(e)/T(a) ratio) is closely related to LV relaxation, its late diastolic stiffness, and filling pressures and gives valuable insights into LV diastolic performance.