Real-time Perfusion Echocardiography Research Articles

Evaluation of cardiac masses by real-time perfusion imaging echocardiography.

BackgroundDiagnosis of cardiac masses is still challenging by echocardiography and distinguishing tumors from thrombi has important therapeutical implications. We sought to determine the diagnostic value of real-time perfusion echocardiography (RTPE) for cardiac masses characterization.MethodsWe prospectively studied 86 patients, 23 with malignant tumors (MT), 26 with benign tumors (BT), 33 with thrombi and 6 with pseudotumors who underwent RTPE. Mass perfusion was analyzed qualitatively and blood flow volume (A), blood flow velocity (β), and microvascular blood flow (A x β) were determined by quantitative RTPE.ResultsLogistic regression models showed that the probability of having a tumor increased by 15.8 times with a peripheral qualitative perfusion pattern, and 34.5 times with a central perfusion pattern, in comparison with the absence of perfusion. Using quantitative RTPE analysis, thrombi group had parameters of blood flow lower than tumor group. A values for thrombi, MT, and BT were 0.1 dB (0.01-0.22), 2.78 dB (1–7) and 2.58 dB (1.44-5), respectively; p < 0.05, while A x β values were 0.0 dB/s−1 (0.01–0.14), 2.00 dB/s−1 (1–6), and 1.18 dB/s−1 (0.52–3), respectively; p < 0.05. At peak dipyridamole stress, MT had greater microvascular blood volume than BT [A = 4.18 dB (2.14-7.93) versus A = 2.04 dB (1.09-3.55); p < 0.05], but no difference in blood flow [Axβ = 2.46 dB/s−1 (1.42–4.59) versus Axβ = 1.55 dB/s [1] (0.51-4.08); p = NS]. An A value >3.28 dB at peak dipyridamole stress predicted MT (AUC = 0.75) and conferred 5.8-times higher chance of being MT rather than BT.ConclusionRTPE demonstrated that cardiac tumors have greater microvascular blood volume and regional blood flow when compared with thrombi. Dipyridamole stress was useful in differentiating MT from BT.

Prognostic Value of High-Dose Dipyridamole Stress Myocardial Contrast Perfusion Echocardiography

The addition of myocardial perfusion (MP) imaging during dipyridamole real-time contrast echocardiography improves the sensitivity to detect coronary artery disease, but its prognostic value to predict hard cardiac events in large numbers of patients with known or suspected coronary artery disease remains unknown. We studied 1252 patients with the use of dipyridamole real-time contrast echocardiography and followed them for a median of 25 months. The prognostic value of MP imaging regarding death and nonfatal myocardial infarction was determined and related to wall motion (WM), clinical risk factors, and rest ejection fraction by the use of Cox proportional-hazards models, C index, and risk reclassification analysis. A total of 59 hard events (4.7%) occurred during the follow-up (24 deaths, 35 myocardial infarctions). The 2-year event-free survival was 97.9% in patients with normal MP and WM, 91.9% with isolated reversible MP defects but normal WM, and 67.4% with both reversible MP and WM abnormalities (P<0.001). By multivariate analysis the independent predictors of events were age (hazard ratio 1.05, 95% confidence interval [CI], 1.02-1.08), sex (hazard ratio, 2.36; 95% CI, 1.32-4.23), reversible MP defects (hazard ratio, 3.88; 95% CI, 1.83-8.21), and reversible WM abnormalities with reversible MP defects (hazard ratio, 4.51; 95% CI, 2.25-9.07). Reversible MP defects added incremental predictive value and reclassification benefit over WM response and clinical factors (P=0.001). MP imaging using real-time perfusion echocardiography during dipyridamole real-time contrast echocardiography provides independent, incremental prognostic information regarding hard cardiac events in patients with known or suspected coronary artery disease. Patients with normal MP responses have better outcome than patients with normal WM; patients with both reversible WM and MP abnormalities have the worst outcome.

Rapid Detection of Coronary Artery Stenoses With Real-Time Perfusion Echocardiography During Regadenoson Stress

Real-time myocardial contrast echocardiography permits the detection of myocardial perfusion abnormalities during stress echocardiography, which may improve the accuracy of the test in detecting coronary artery stenoses. We hypothesized that this technique could be used after a bolus injection of the selective A2A receptor agonist regadenoson to rapidly and safely detect coronary artery stenoses. In 100 patients referred for quantitative coronary angiography, real-time myocardial contrast echocardiography was performed during a continuous intravenous infusion of 3% Definity at baseline and at 2-minute intervals for up to 6 minutes after a regadenoson bolus injection (400 μg). Myocardial perfusion was assessed by examination of myocardial contrast replenishment after brief high mechanical index impulses. A perfusion defect was defined as a delay (>2 seconds) in myocardial contrast replenishment in 2 contiguous segments. Wall motion was also analyzed. The overall sensitivity/specificity/accuracy for myocardial perfusion analysis in detecting a >50% diameter stenosis was 80%/74%/78%, whereas for wall motion analysis it was 60%/72%/66% (P<0.001 for differences in sensitivity). Sensitivity for myocardial perfusion analysis was highest on images obtained during the first 2 minutes after regadenoson bolus (P<0.001 compared with wall motion), whereas wall motion sensitivity was highest at the 4-to-6-minute period after the bolus. No significant side effects occurred after regadenoson bolus injection. Regadenoson real-time myocardial contrast echocardiography appears to be a feasible, safe, and rapid noninvasive method for the detection of significant coronary artery stenoses.

Real-time perfusion echocardiography during treadmill exercise and dobutamine stress testing

BackgroundReal-time perfusion (RTP) echocardiographic imaging with a continuous infusion of microbubbles has improved the sensitivity of dobutamine stress echocardiography (DSE) in detecting coronary artery disease (CAD). The impact of RTP...

Abstract 4705: Detection of Significant Left Anterior Descending Coronary Artery Disease in Pacemaker Dependent Patients Utilizing Real Time Perfusion Imaging During Dobutamine Stress Echocardiography

Non-invasive methods of detecting left anterior descending (LAD) coronary artery disease (CAD) in patients who are pacemaker dependent (PD) are limited because of right ventricular (RV)-pacing induced left ventricular wall thickening (WT) abnormalities involving the septum and apex. Real time perfusion echocardiography (RTPE) analyzes myocardial blood flow (MBF) changes with high resolution (&lt;2 mm) during intravenous (IV) infusions of ultrasound contrast, and can potentially identify whether significant LAD is present in PD patients during dobutamine stress (DS). 54 consecutive PD patients who were being evaluated for CAD using DS echocardiography with RTPE were identified. Dobutamine was infused to 30 u/kg/min, but had to be combined with incremental RV pacing to achieve 85% predicted maximum heart rate. Perfusion and WT in the septum and apex were assessed at rest and at peak DS. MBF in the LAD territory was considered abnormal if a &gt;4 second delay in contrast replenishment occurred during a continuous 3% Definity infusion at rest, or &gt;2 second delay at peak DS. Quantitative coronary angiography (QCA) was performed to assess for significant CAD (&gt;50% diameter stenosis considered significant). Outcomes were analyzed by examining coronary events (death, non-fatal myocardial infarction, or need for coronary revascularization) at a median follow-up of 20 months post DS. WT abnormalities in the septum and apex due to RV pacing were noted in 43 of the patients (80%), while the remaining patients exhibited normal WT. Of those with pacing-induced WT abnormalities, 25 (58%) had a MBF abnormality at peak stress, while 18 (42%) had normal myocardial contrast enhancement. Overall, the positive predictive value (PPV) of abnormal MBF by RTPE for the detection of LAD CAD in PD patients was 85%. Patients with a MBF abnormality in the LAD territory by RTPE had a coronary event rate of 17 % at follow up, while patients with normal MBF responses during DS had no events at follow up (negative predictive value 100%). RTPE is helpful in detecting CAD in the LAD territory of patients who are PD. A normal MBF response predicts an excellent cardiac outcome, irrespective of WT responses.

Detection of Coronary Artery Disease with a Continuous Infusion of Definity Ultrasound Contrast during Adenosine Stress Real Time Perfusion Echocardiography

Myocardial perfusion imaging during adenosine stress is an accurate method of detecting physiologically relevant coronary artery disease. Real time perfusion echocardiography (RTPE) was compared to nuclear scintigraphy (rest Thallium, stress Sestamibi) in 40 patients with intermediate to high pretest probability. RTPE was performed with a continuous infusion of intravenous microbubbles (Definity; Bristol Myers Squibb) and intermittent high mechanical index impulses, with visual examination of both the replenishment rate and plateau intensity of contrast. Of the 119 coronary artery territories compared, SPECT and RTPE were in agreement in 105 (88% agreement; kappa 0.67). In patients who went on to quantitative coronary arteriography (QCA), there were three who had normal appearing radionuclide SPECT during adenosine, but subendocardial perfusion defects with RTPE. In all three cases, QCA confirmed the presence of a >50% diameter stenosis in the abnormal territory. We conclude from this study that adenosine stress imaging with RTPE is an accurate method of detecting coronary artery disease. The higher resolution of RTPE may identify subendocardial defects that would otherwise have gone undetected with radionuclide imaging.