Doppler-derived myocardial performance index in patients with impaired left ventricular relaxation and preserved
José Maria G Fernandes1, Ivan Romero Rivera, Benício de Oliveira Romão
1Cardiology Division, Federal University of Alagoas, Federal University of Sao Paulo, Sao Paulo, Brazil.
Background:
The Doppler-derived myocardial performance index (MPI) has been used in the evaluation of left ventricular (LV) function in several diseases. In patients with isolated diastolic dysfunction, the diagnostic utility of this index remains unclear. The aim of this study was to determine the diagnostic utility of MPI in patients with systemic hypertension, impaired LV relaxation, and normal ejection fraction.
Methods:
Thirty hypertensive patients with impaired LV relaxation were compared to 30 control subjects. MPI and its components, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and the ejection time (ET), were measured from LV outflow and mitral inflow Doppler velocity profiles.
Results:
MPI was higher in patients than in control subjects (0.45 +/- 0.13 vs 0.37 +/- 0.07 P < 0.0029). The increase in MPI was due to the prolongation of IRT without significant change of ICT and ET. MPI cutoff value of > or =0.40 identified impaired LV relaxation with a sensitivity of 63% and specificity of 70% while an IRT >94 ms had a sensitivity of 67% and specificity of 80%. Multivariate analysis identified relative wall thickness, mitral early filling wave velocity (E), and systolic myocardial velocity (Sm) as independent predictors of MPI in patients with hypertension.
Conclusions:
MPI was increase in patients with hypertension, diastolic dysfunction, and normal ejection fraction but was not superior to IRT to detect impaired LV relaxation.
Insights
Myocardial performance index (MPI) increased in hypertensive patients with diastolic dysfunction, but isovolumetric relaxation time (IRT) better detects impaired left ventricular relaxation.
Area of Science:
- Cardiology
- Echocardiography
- Diastology
Background:
- Myocardial performance index (MPI) is used to assess left ventricular (LV) function.
- Its diagnostic utility in isolated diastolic dysfunction is unclear.
- Systemic hypertension can lead to diastolic dysfunction.
Purpose of the Study:
- To determine the diagnostic utility of MPI in patients with systemic hypertension, impaired LV relaxation, and normal ejection fraction.
- To compare MPI with isovolumetric relaxation time (IRT) in detecting diastolic dysfunction.
Main Methods:
- Doppler echocardiography was used to measure MPI and its components (IRT, ICT, ET).
- Thirty hypertensive patients with impaired LV relaxation were compared to 30 controls.
- Measurements were taken from LV outflow and mitral inflow Doppler velocity profiles.
Main Results:
- MPI was significantly higher in hypertensive patients (0.45 ± 0.13) than in controls (0.37 ± 0.07).
- The increase in MPI was due to prolonged IRT.
- An MPI cutoff of ≥0.40 had 63% sensitivity and 70% specificity; an IRT cutoff of >94 ms had 67% sensitivity and 80% specificity.
Conclusions:
- MPI is elevated in hypertensive patients with diastolic dysfunction and normal ejection fraction.
- MPI is not superior to IRT in detecting impaired LV relaxation.
- Relative wall thickness, mitral E wave, and systolic myocardial velocity predict MPI in hypertensive patients.