Noninvasive Doppler-derived myocardial performance index: correlation with simultaneous measurements of cardiac
C Tei1, R A Nishimura, J B Seward
1Division of Cardiovascular Disease, Mayo Clinic, Rochester, Minnesota, USA.
Insights
A new noninvasive Doppler index effectively assesses overall cardiac function. This simple index correlates well with invasive measurements of left ventricular systolic and diastolic performance.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Assessing overall cardiac function noninvasively is crucial for patient management.
- Existing noninvasive methods may have limitations in reproducibility or scope.
- A simple, reproducible Doppler index for cardiac function assessment has been previously described.
Purpose of the Study:
- To correlate a novel noninvasive Doppler index with established invasive cardiac catheterization measures of left ventricular performance.
- To validate the utility of this Doppler index in patients with ischemic heart disease and dilated cardiomyopathy.
Main Methods:
- A prospective study involving 34 patients with ischemic heart disease or idiopathic dilated cardiomyopathy.
- Simultaneous cardiac catheterization and Doppler echocardiographic studies were performed.
- Invasive measurements included peak +dP/dt, peak -dP/dt, and tau; the Doppler index was calculated as (isovolumetric contraction time + isovolumetric relaxation time) / ejection time.
Main Results:
- Doppler measurements of isovolumetric contraction time strongly correlated with peak +dP/dt (r=0.842, p<0.0001).
- Doppler measurements of isovolumetric relaxation time correlated with peak -dP/dt (r=0.638, p<0.001).
- The overall Doppler index showed significant correlations with systolic peak +dP/dt (r=0.821, p<0.0001), diastolic peak -dP/dt (r=0.833, p<0.001), and tau (r=0.680, p<0.0001).
Conclusions:
- The noninvasive Doppler index demonstrates a strong correlation with invasive measurements of left ventricular systolic and diastolic function.
- This Doppler index is a promising tool for noninvasive assessment of overall cardiac function.
- Its simplicity and reproducibility make it a valuable addition to cardiac diagnostics.
Abstract:
A simple, reproducible, noninvasive Doppler index for the assessment of overall cardiac function has been described previously. The purpose of this study was to correlate the Doppler index with accepted indexes of cardiac catheterization of left ventricular performance. Thirty-four patients with ischemic heart disease or idiopathic dilated cardiomyopathy prospectively underwent a simultaneous cardiac catheterization and Doppler echocardiographic study. Invasive measurements of peak +dP/dt, peak -dP/dt, and tau were obtained from the high-fidelity left ventricular pressures. A Doppler index of myocardial performance was defined as the summation of isovolumetric contraction and relaxation time divided by ejection time. There was a correlation between Doppler measurement of isovolumetric contraction time and peak +dP/dt (r = 0.842; p < 0.0001) and Doppler measurement of isovolumetric relaxation time and peak -dP/dt (r = 0.638; p < 0.001). Left ventricular ejection time correlated with both peak +dP/dt (r = 0.539; p < 0.001) and peak -dP/dt (r = 0.582; p < 0.001). The Doppler index correlated with simultaneously recorded systolic peak +dP/dt (r = 0.821; p < 0.0001) and diastolic peak -dP/dt (r = 0.833; p < 0.001) and tau (r = 0.680; p < 0.0001). This study documents that a simple, easily recordable, noninvasive Doppler index of myocardial performance correlates with invasive measurement of left ventricular systolic and diastolic function and appears to be a promising noninvasive measurement of overall cardiac function.
