Strain echocardiography tracks dobutamine-induced decrease in regional myocardial perfusion in nonocclusive coronary
Gabriel Yip1, Bijoy Khandheria, Marek Belohlavek
1Division of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Insights
Strain echocardiography parameters, including systolic strain rate (sSR) and time to regional lengthening (T(RL)), accurately predict changes in regional myocardial perfusion (RMBF) during dobutamine stress. These novel quantitative strain parameters show promise for improving ischemia detection in stress echocardiography.
Area of Science:
- Cardiology
- Echocardiography
- Myocardial Perfusion Imaging
Background:
- Strain echocardiography assesses regional myocardial mechanical activity.
- Ischemia impairs systolic strain rate (sSR) and prolongs time to regional lengthening (T(RL)).
- Dobutamine stress echocardiography is a key tool for diagnosing myocardial ischemia.
Purpose of the Study:
- To evaluate if strain echocardiography parameters correlate with regional myocardial perfusion (RMBF) changes during dobutamine stress.
- To assess the diagnostic accuracy of sSR and T(RL) for detecting ischemia.
Main Methods:
- A closed-chest pig model with induced coronary stenosis was used (n=14).
- Regional myocardial blood flow (RMBF) was measured using colored microspheres.
- Strain parameters (sSR, T(RL)) and hemodynamics were assessed at baseline and during dobutamine infusion, with and without stenosis.
Main Results:
- Peak sSR demonstrated a strong correlation with RMBF (r=0.70).
- Dobutamine increased RMBF and sSR while decreasing T(RL) in normal segments; this was blunted with stenosis.
- sSR achieved 81% sensitivity and 91% specificity for predicting reduced RMBF, while T(RL) showed 65% sensitivity and 91% specificity.
Conclusions:
- Novel strain parameters accurately predict regional myocardial perfusion changes during dobutamine stress.
- Quantitative strain echocardiography may enhance current ischemia detection methods.
- These findings suggest improved accuracy and reproducibility for stress echocardiography.
Objectives:
This study was designed to determine whether strain echocardiography parameters reflect changes in regional myocardial perfusion during dobutamine stress.
Background:
Strain echocardiography depicts regional myocardial mechanical activity. Ischemia has been shown to reduce systolic strain rate (sSR) and prolong the time to regional lengthening (T(RL)). In an experimental model, we tested whether sSR and T(RL) tracked dobutamine-induced changes in regional myocardial perfusion (regional myocardial blood flow [RMBF]), as measured by colored microspheres.
Methods:
We used a closed-chest pig model of nonocclusive coronary stenosis (n = 14) created by inflating an angioplasty balloon in the proximal left anterior descending artery. Invasive hemodynamics, RMBF, and strain parameters were measured at baseline and peak dobutamine stimulation before and during the coronary stenosis. We compared segments with reduced RMBF versus those with preserved RMBF at peak dobutamine stimulation.
Results:
Peak sSR correlated with RMBF (r = 0.70). In the absence of coronary stenosis, dobutamine stimulation caused a significant increase in RMBF and sSR and a decrease in T(RL). This response was blunted during coronary stenosis. Using the "best cutoff" method, the sensitivity and specificity for prediction of reduced RMBF (ischemia) was 81% and 91% for sSR and 65% and 91% for T(RL), respectively. These changes occurred in the absence of any change in global systolic and diastolic function (dP/dT(max), dP/dT(min), and tau).
Conclusions:
Novel strain parameters that depict regional myocardial mechanics are able to predict changes in RMBF during dobutamine stress. Quantitative strain parameters may complement current echocardiographic techniques for ischemia detection and potentially improve the accuracy and reproducibility of stress echocardiography.
Related Concept Videos
01:20Imaging Studies for Cardiovascular System II:Types of Echocardiography
Types of Echocardiography
Transthoracic Echocardiography (TTE)
TTE is the most common type of echocardiogram which involves placing a transducer on the patient's chest, emitting sound waves to create heart images. TTE is invaluable for evaluating the heart's size, structure, and motion, making it particularly useful for diagnosing...
01:30Acute Coronary Syndrome III: Diagnostic Studies