Related Experiment Videos
Contrast echocardiographic estimation of regional myocardial blood flow after acute coronary occlusion
Insights
Contrast echocardiography quantifies myocardial perfusion during acute coronary occlusion. This method accurately measures blood flow changes in ischemic heart tissue, aiding in risk assessment.
Area of Science:
- Cardiovascular Imaging
- Myocardial Perfusion Assessment
- Echocardiography
Background:
- Acute coronary occlusion leads to myocardial ischemia.
- Assessing residual myocardial perfusion is critical for risk stratification.
- Current methods for quantifying perfusion in ischemic regions have limitations.
Purpose of the Study:
- To determine if contrast echocardiography parameters quantitatively measure residual myocardial perfusion.
- To evaluate if serial contrast injections reflect changes in blood flow to acutely ischemic tissue.
- To correlate echocardiographic findings with radioactive microsphere blood flow measurements.
Main Methods:
- Supra-aortic hydrogen peroxide contrast echocardiography in 12 dogs.
- Acute circumflex coronary occlusion was induced.
- Contrast enhancement was assessed qualitatively (scoring) and quantitatively (computer algorithm).
- Comparison with radioactive microsphere blood flow measurements in myocardial segments.
Main Results:
- Qualitative contrast scoring showed a systematic relationship with normalized segmental blood flow (p < .01).
- Quantitative analysis demonstrated strong correlation with blood flow (r = .78, p < .01; r = .83, p < .001 in ischemic regions).
- Changes in contrast enhancement correlated significantly with changes in blood flow between serial observations (r = .88, p < .001; r = 0.70, p < .01).
Conclusions:
- Contrast echocardiography provides quantitative information on residual myocardial blood flow in ischemic regions.
- This technique can track dynamic changes in myocardial blood flow in vivo.
- Contrast echocardiography is a valuable tool for assessing myocardial perfusion during acute coronary occlusion.
Abstract:
Contrast echocardiography can predict pathologic area at risk during acute coronary occlusion. In this study we evaluated (1) whether the intensity and timing of contrast appearance in ischemic regions can provide a quantitative measure of residual myocardial perfusion, and (2) whether changes in these parameters observed after serial injections reflect changes in blood flow to acutely ischemic tissue. Supra-aortic hydrogen peroxide contrast echocardiography was performed in 12 consecutive dogs at 1, 20, and 120 min after acute circumflex coronary occlusion. Contrast enhancement was determined qualitatively with a segmental four-point scoring system based on the appearance time and peak perceived intensity of contrast enhancement and quantitatively with a computer algorithm designed to reflect these parameters. Comparison was made in each segment to concomitant radioactive microsphere blood flow. Qualitative scoring related systematically to normalized segmental blood flow (3+ = 93%; 2+ = 61%; 1+ = 32%; 0 = 18%; p less than .01 for each vs adjacent value), as did quantitative analysis including all segments (r = .78; p less than .01) and isolated to the ischemic region (flow = 1.13 intensity change +6.8%; r = .83, p less than .001). Changes in microsphere flow in ischemic regions between sequential observations were correlated with changes in qualitative score (r = .88, p less than .001) and results of quantitative analysis (r = 0.70, p less than .01). The amount of contrast enhancement can provide quantitative information about residual myocardial blood flow in ischemic regions and can also be used to track changing patterns of flow in vivo after acute coronary occlusion.