Extent Of Myocardial Perfusion Defects Research Articles

Effect of Beta-Blocker Consumption on the Severity and Extension of Perfusion Defects in Dipyridamole Myocardial Perfusion Single-Photon Emission Computed Tomography.

Background Regarding the less-known effects of beta-blocker consumption on the diagnostic value of the myocardial perfusion scan with dipyridamole stress in coronary artery disease (CAD), we aimed to compare the findings of the scans done on the beta-blocker consumption course and after discontinuation of this medications. Materials and Methods Thirty patients with probably CAD and abnormal myocardial perfusion scans (presence of reversible defect), who had been treated with beta-blockers for at least 3 months, were studied. Dipyridamole stress phase of myocardial perfusion single-photon emission computed tomography (SPECT) was performed two times with an interval of about 1 week, once after discontinuation of all antianginal and anti-ischemic medications, statins, and beta-blockers for 72 hours prior to the study, and again after discontinuation of all these medications except for beta-blockers. Imaging was done with the same protocol, radiopharmaceutical dose, and imaging parameters. Summed stress score (SSS), summed stress rest, and summed difference scores (SDS), total perfusion deficit (TPD), severity, and extension of myocardial perfusion defects in three coronary artery territories were analyzed, using quantitative perfusion SPECT software. Results Most variables such as SSS, SDS, TPD, severity, and extension of defects showed a significant difference between the two conditions including beta-blocker consumption and after discontinuing beta-blocker consumption before stress imaging ( p < 0.05). Moreover, in patients on treatment with metoprolol, all studied factors including SSS, SDS, TPD, severity, and extension of perfusion defects were significantly reduced when patients consumed beta-blockers before SPECT evaluation ( p < 0.05). Conclusion Beta-blocker consumption can lead to a decrease in the severity and extent of myocardial perfusion defects and therefore probably a decrease in the sensitivity of myocardial scans. Discontinuation of beta-blocker prior to the dipyridamole myocardial perfusion scan can improve diagnostic accuracy.

QRS Fragmentation in Preserved Ejection Fraction Heart Failure: Functional Insights, Pathological Correlates, and Prognosis.

Background Fragmented QRS (fQRS) morphology as a surrogate marker of the possible presence of myocardial scarring has been shown to confer a higher risk in patients with reduced ejection fraction heart failure. We aimed to investigate the pathophysiological correlates and prognostic implications of fQRS in patients with heart failure with preserved ejection fraction (HFpEF). Methods and Results We consecutively studied 960 patients with HFpEF (76.4±12.7 years, men: 37.2%). fQRS was assessed using a body surface ECG during hospitalization. QRS morphology was available and classified into 3 categories among 960 subjects with HFpEF as non-fQRS, inferior fQRS, and anterior/lateral fQRS groups. Despite comparable clinical features in most baseline demographics among the 3 fQRS categories, anterior/lateral fQRS showed significantly higher B-type natriuretic peptide/troponin levels (both P<0.001), with both the inferior and anterior/lateral fQRS HFpEF groups demonstrating a higher degree of unfavorable cardiac remodeling, greater extent of myocardial perfusion defect, and slower coronary flow phenomenon (all P<0.05). Patients with anterior/lateral fQRS HFpEF exhibited significantly altered cardiac structure/function and more impaired diastolic indices (all P<0.05). During a median of 657 days follow-up, the presence of anterior/lateral fQRS conferred a doubled HF re-admission risk (adjusted hazard ratio 1.90, P<0.001), with both inferior and anterior/lateral fQRS having a higher risk of cardiovascular and all-cause death (all P<0.05) by using Cox regression models. Conclusions The presence of fQRS in HFpEF was associated with more extensive myocardial perfusion defects and worsened mechanics, which possibly denotes a more severe involvement of cardiac damage. Early recognition in such patients with HFpEF likely benefits from targeted therapeutic interventions.

The Role of Myocardial Perfusion Imaging in Patients with Diabetes Mellitus

Abstract Diabetes mellitus is a complex pathology with increasing incidence, associated with an increased risk of coronary heart disease. Myocardial perfusion imaging (MPI) is an important diagnostic tool for the evaluation of coronary artery disease (CAD), with a high prognostic value. Objective. The aim of this study was to evaluate the role of stress-rest MPI in the assessment of patients with DM and suspected or confirmed CAD. Method. We performed a retrospective analysis of 128 patients who underwent stress-rest MPI in our department, all of them with coronary angiography (CA) available. All patients underwent stress rest myocardial perfusion SPECT using a 1-day or 2-day protocol. The radiopharmaceuticals used were 99m-Tc-MIBI or tetrofosmin. The study was performed with a gated protocol SPECT, synchronous with the ECG, using a dual-head gamma camera. Patients were divided in 4 subgroups based on the presence of DM and of significant CA changes. Results. In the group of patients with significant coronary disease on CA and previously diagnosed DM, number of perfusion defects on the stress-rest MPI were higher and also the presence of systolic disfunction and the severity of defects. Our results support the idea that the severity and extent of myocardial perfusion defects are greater in diabetic patients than in non-diabetic patients. Conclusions. We can consider myocardial perfusion SPECT with 99mTc-labeled agents as a feasible method for the diagnosis and evaluation of CAD and for the management of diabetic patients.

Myocardial perfusion defect assessed by single-photon emission computed tomography and frontal QRS-T angle in patients with prior anterior myocardial infarction.

The frontal QRS-T angle is one of the markers of ventricular repolarization. We sought to assess the effects of myocardial perfusion defect on QRS-T angle in patients with prior anterior myocardial infarction (MI). Seventy-one patients with prior anterior MI and 71 age- and sex-matched control subjects having no myocardial perfusion defect were selected. Frontal QRS-T angle was defined as the absolute value of the difference between the frontal plane QRS axis and T-wave axis. The extent of myocardial perfusion defect was determined using myocardial perfusion single-photon emission computed tomography (SPECT). The extent of myocardial perfusion defect of patients with prior anterior MI was 21.8 ± 13.7%. Frontal QRS-T angle was significantly larger in patients with prior anterior MI than control subjects (82° ± 49° vs 30° ± 26°, p < 0.001). Prevalence of abnormal frontal QRS-T angle defined as more than 90° was significantly higher in patients with prior anterior MI than control subjects (42% vs 4%, p < 0.001). Multivariate linear regression analysis showed that age (β=0.18, p = 0.02) and myocardial perfusion defect (β = 0.46, p = 0.02) were independent determinants of frontal QRS-T angle. Our results suggest that the extent of myocardial perfusion defect is an independent determinant of frontal QRS-T angle in patients with prior anterior MI.

Impact of data-driven cardiac respiratory motion correction on the extent and severity of myocardial perfusion defects with free-breathing CZT SPECT

We previously reported the clinical feasibility and positive impact on image characteristics of a data-driven cardiac respiratory motion (RM) correction method (REGAT) applicable to CZT SPECT myocardial perfusion imaging (MPI). Here, we evaluate its impact on the extent and severity of myocardial perfusion defects (MPD). We included 25 patients having a 1-day 99mTc-Tetrofosmin stress/rest MPI acquired with multi-pinhole CZT SPECT. Acquisitions were processed with REGAT to generate mean RM gated SPECT. These were summed either after (R-SPECT) or without realignment (NR-SPECT). We noted the maximal cardiac RM shift in the 3 axes of the left ventricle (LV). Both visual and semi-quantitative analyses of myocardial tracer uptake were realized. Studies were classified as having an impact on the extent/severity of MPD with REGAT if ≥1 segment presented a severity score changing by ≥1 level between NR-SPECT and R-SPECT. An impact on the extent of MPD was considered present if at least 1 segment shifted from normal (score = 0) to abnormal (score different from 0) or inversely. Cardiac RM was >10 mm in 55% of studies. With visual and semi-quantitative analyses, an impact on the extent/severity MPD was observed in 14% of all studies (7/49) and 60% of studies with cardiac RM >15 mm. An impact on the extent of MPD was observed in 5 of the 7 upper listed studies. All studies presenting an impact on MPD had RM in the anterior to inferior LV axis >10 mm. A substantial number of MPI studies presented significant cardiac RM. Cardiac RM compensation showed a frequent impact on the extent/severity of MPD.

Left ventricular systolic synchrony assessed by phase analysis of gated myocardial perfusion imaging in patients with old myocardial infarction

To assess the left ventricular (LV) systolic synchrony by phase analysis of gated myocardial perfusion imaging (GMPI) with SPECT/CT in patients with old myocardial infarction (OMI) and further to identify independent predictors for LV dyssynchrony. Seventy-six OMI patients and seventy-four healthy volunteers (control group) underwent resting GMPI from October 2010 to September 2013 in our hospital were included in this study. The left ventricular systolic synchrony parameters including phase histogram bandwidth (BW) and phase standard deviation (SD) were obtained by Cedars-Sinai quantitative gated SPECT (QGS) phase analysis technique, and LV cardiac function was also measured. The extent of myocardial perfusion defect was analyzed by the Quantitative Perfusion SPECT (QPS) software. The value of BW and SD were compared between OMI and the control groups, between LVEF ≤ 35% and LVEF > 35% groups in OMI patients. Dyssynchrony was defined when the BW exceeded the abnormality threshold derived from a normal control group (threshold = x ± 2s for normal BW). (1) The BW ((91.3 ± 58.6)° vs. (37.2 ± 11.7)°) and SD ((27.3 ± 20.8)° vs. (11.8 ± 5.4)°) were significantly higher and the LVEF was significantly lower in OMI group than in the normal control group (all P < 0.01). In addition, BW ((136.0 ± 52.9)° vs. (51.0 ± 24.0)°) and SD ((38.7 ± 21.3)° vs. (17.1 ± 14.0)°) were significantly higher in patients with LVEF ≤ 35% than in patients with LVEF > 35% (all P < 0.001). (2) Dyssynchrony (BW > 60.6°) prevalence was 57.9% (44/76) in OMI patients. Compared with the synchrony group, LVEF was significantly lower, while the left ventricular end-diastolic volume, end-systolic volume, summed motion score, summed thickening score and extent were significantly higher in dyssynchrony group (all P < 0.001). (3) Additionally, dyssynchrony prevalence was significantly higher in patients with LVEF ≤ 35% compared with patients with LVEF > 35% (91.7% (33/36) vs. 27.5% (11/40), P < 0.001). (4) Pearson correlation analysis showed that LVEF was negatively correlated with BW (r = -0.807, P < 0.001). (5) Multivariate logistic regression analysis revealed that the extent of myocardial perfusion defect was an independent predictor for dyssynchrony in OMI patients (OR = 1.076, 95% CI: 1.015-1.141, P = 0.015). GMPI phase analysis can reliably reflect left ventricular systolic synchrony. The left ventricular systolic dyssynchrony in OMI patients is significantly increased. Left ventricular dyssynchrony is closely related to LVEF. The extent of myocardial perfusion defect (Extent) is an independent predictor for left ventricular systolic dyssynchrony in OMI patients.

All-systolic non-ECG-gated stress perfusion CMR: improved visualization of subendocardial defects compared to conventional ECG-gated imaging

Background The effects of ischemia are first realized in the subendocardium and progress transmurally. Hence, detection of the transmural extent of myocardial perfusion (MP) defects has important diagnostic/prognostic implications. Systolic MP imaging using ECG-gated methods has been shown to provide improved visualization of subendocardial defects [1]. We developed an innovative non-ECGgated perfusion CMR technique capable of imaging all slices at the same systolic phase, and hypothesized that it improves visualization of the transmural extent of MP defects compared to the conventional method in CMR studies of CAD patients.

POSTCONDITIONING EFFECTS OF ORAL NICORANDIL TREATMENT ON PATIENTS WITH ACUTE ANTERIOR MYOCARDIAL INFARCTION

ObjectivesIn recent years, the development of thrombolysis and percutaneous coronary intervention (PCI) have positive impacts on outcome of the patients with acute myocardial infarction (AMI), but the reperfusion injury followed...

POSTCONDITIONING EFFECTS OF ORAL NICORANDIL TREATMENT ON PATIENTS WITH ACUTE ANTERIOR MYOCARDIAL INFARCTION

ObjectivesIn recent years, the development of thrombolysis and percutaneous coronary intervention (PCI) have positive impacts on outcome of the patients with acute myocardial infarction (AMI), but the reperfusion injury followed...

Assessment of Cardiac Computed TomographyMyocardial Perfusion Imaging

Cardiac computed tomography (CT) has evolved rapidly over the last decade into a reliable imaging modality for the non-invasive assessment of coronary artery disease. With the advancement in multi-detector CT technology, there has developed an increasing body of evidence that suggests that the role of cardiac CT can be extended to include functional assessment of the myocardium not only at rest but also during stress. Simultaneous anatomical and functional assessment approaches will have a number of advantages such as evaluation of the transmural extent of myocardial perfusion defects (including small subendocardial perfusion defects), reduced risk associated with multiple sources of radiation, and short image acquisition time. Although initial results hold some promise, CT myocardial perfusion imaging is a modality in the early stages of development and further work and studies are required to define, validate, and optimize this technique. This review will provide an overview of this novel perfusion imaging method, its underlying principles, evolution, limitations and future directions.

Significant Association of Female Gender with Lower Degree of Pathological 99mTc-sestamibi Scintigraphy Results as well as Higher Cardiac-Related Deaths Free Survival in Elderly Patients

The aim of the present study was to assess the impact of female gender on the extent of myocardial perfusion defects as revealed by (99m)Tc-sestamibi myocardial perfusion scintigraphy (MPS) and on emerging cardiac events (CE) in patients aged ≥ 70 years. 86 patients aged ≥ 70 years with known or suspected CAD undergoing MPS (74.4 ± 3.2 years; women: n = 46; 53.5%) were included in this study. Semiquantitative analysis of MPS was performed and summed stress (SSS), summed difference (SDS), and summed rest scores (SRS) were calculated. Emerging CE comprised myocardial revascularization and -infarction and cardiac-related death. Multivariate regression analysis was performed to assess the independent prognostic impact of several patient related variables on MPS results. Kaplan-Meier- and log rank analyses were calculated for assessment of CE free survival as related to gender. Normal SSS (87.0% vs. 27.5%; p < 0.0001), SDS (80.4% vs. 27.5%; p < 0.0001), and SRS (97.8% vs. 82.5%; p = 0.023) were significantly more often found in women, whereas incidence of mildly and severely impaired SSS (6.5% vs. 35%; p = 0.001 and 2.2% vs. 25%; p = 0.002, respectively) and SDS (15.2% vs. 52.5%; p < 0.0001 and 2.2% vs. 17.5%; p = 0.023, respectively) were significantly higher in men. Multivariate logistic regression analysis revealed female gender as an independent predictor of normal SSS (odds ratio/OR: 17.6) and SDS (OR: 53.3). Female gender was associated with a significant higher cardiac-death free survival compared to male patients (p = 0.031). Female gender is independently associated with a significantly lower degree of pathological MPS results and a higher cardiac-death free survival in elderly patients.

Vascular dysfunction measured by fingertip thermal monitoring is associated with the extent of myocardial perfusion defect

Previous studies have shown that vascular dysfunction measured by digital thermal monitoring (DTM) during an arm-cuff reactive hyperemia procedure correlates with the severity of coronary artery disease measured by coronary artery calcium in asymptomatic patients. Current study investigates the correlation between DTM and abnormal myocardial perfusion imaging (MPI). About 116 consecutive patients with chest discomfort, age 57 +/- 10 years, underwent MPI, DTM and Framingham Risk Score (FRS) assessment. Fingertip temperature rebound (TR), DTM index of vascular reactivity, was assessed after a 2-minute arm-cuff reactive hyperemia test. The extent of myocardial perfusion defect was measured by summed stress score (SSS). TR decreased from SSS < 4 (1.61 +/- 0.15) to 4 < or = SSS < or = 8 (0.5 +/- 0.22) to 9 < or = SSS < or = 13 (0.26 +/- 0.15) to SSS > 13 (-0.37 +/- 0.19) (P = .0001). After adjusting for cardiac risk factors, the odds ratio of the lowest versus two upper tertiles of TR was 3.93 for SSS > or = 4 and 9.65 for SSS > or = 8 compared to SSS < 4. TR correlated well with SSS (r = -0.88, P = .0001). Addition of TR to FRS increased the area under the ROC curve to predict abnormal MPI, SSS > or = 4, from 0.65 to 0.84 (P < .05). Vascular dysfunction measured by DTM is associated with the extent of myocardial perfusion defect independent of age, gender, and cardiac risk factors.

2008 Quality and Outcomes Abstracts

HomeCirculationVol. 117, No. 212008 Quality and Outcomes Abstracts Free AccessAbstractPDF/EPUBAboutView PDFSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessAbstractPDF/EPUB2008 Quality and Outcomes Abstracts Originally published27 May 2008https://doi.org/10.1161/CIRCULATIONAHA.108.189902Circulation. 2008;117:e409–e468 Previous Back to top Next FiguresReferencesRelatedDetailsCited By Ahmadi N, Usman N, Shim J, Nuguri V, Vasinrapee P, Hajsadeghi F, Wang Z, Foster G, Nasir K, Hecht H, Naghavi M and Budoff M (2009) Vascular dysfunction measured by fingertip thermal monitoring is associated with the extent of myocardial perfusion defect, Journal of Nuclear Cardiology, 10.1007/s12350-008-9044-y, 16:3, Online publication date: 1-Jun-2009. May 27, 2008Vol 117, Issue 21 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.108.189902 Originally publishedMay 27, 2008 PDF download Advertisement

P11 Displaying the extent of myocardial perfusion defects using 4D-MSPECT

P11 Displaying the extent of myocardial perfusion defects using 4D-MSPECT

Acute rest perfusion imaging in high risk unstable angina: association with troponin T and clinical endpoints.

Troponin T (TnT) and rest perfusion imaging (RPI) have been reported to be important diagnostic tools for risk stratification in patients with chest pain. We investigated the association between two methods in 60 patients presenting with typical chest pain at rest within the last 6 h before admission. All patients underwent Tc-99m gated SPECT imaging and serial TnT measurements and were followed for occurrence of adverse cardiac events up to 30 days. Perfusion defect was detected in 42 patients and elevated TnT was observed in 23 patients. All of the patients with an elevated TnT have also perfusion defect in RPI. Half of the patients with normal TnT level (51%) presented a perfusion defect detected by RPI (p = NS). The patients with elevated TnT levels had more perfusion defect numbers than those with normal TnT levels (8.2 +/- 2.9 vs. 5.3 +/- 2.2; p = 0.0007). Cardiac events occurred in 38 patients (14 MI, 24 revascularisation). In predicting cardiac events, RPI and TnT had sensitivities (97 vs. 58%; p < 0.001), specificities (77 vs. 95%, p = NS), positive predictive values (PPV) (88 vs. 96%; p = NS) and negative predictive values (NPV) (94% vs. 57%; p = NS), respectively. In predicting MI, the two tests had sensitivities (93 vs. 93%; p = NS), specificities (37 vs. 78%; p < 0.001), PPVs (31 vs. 57%; p = NS) and NPVs (94 vs. 97%; p = NS), respectively. These results suggest that in patients with rest angina (1) TnT elevation is associated with the extent of myocardial perfusion defect; (2) both tests are valuable, while positive RPI is more sensitive in predicting all cardiac events irrespective of TnT; both positive TnT and positive RPI predict a high probability to have MI; (3) both negative test results predict a very low probability to have cardiac event, including MI.

Sustained reduction of exercise perfusion defect extent and severity with isosorbide mononitrate (Imdur) as demonstrated by means of technetium 99m sestamibi

The impact of long-acting nitrates on the extent and severity of stress-induced myocardial ischemia is not well described, especially after long-term treatment. Forty patients with chronic stable angina and reversible ischemia on an exercise stress myocardial perfusion single photon emission computed tomography (ex-SPECT) were prospectively studied in a 6-week period. At baseline, rest thallium-201/exercise stress technetium 99m sestamibi SPECT was performed, followed by treatment with extended-release isosorbide 5-mononitrate (5-ISMN, Imdur). Follow-up ex-SPECT was performed 5 days and 6 weeks after the initiation of therapy with extended-release 5-ISMN. The exercise treadmill testing (ETT) protocol and exercise duration of the follow-up studies were the same as that of the baseline ETT. Defect extent and severity were analyzed both by means of an automated quantitative method, with CEqual software, and visually, with a 20-segment scoring system (which was also used to derive a summed stress score [SSS]). In the 6-week study period, significant reductions occurred in both the extent and the severity of exercise-induced ischemia by means of quantitative SPECT (13.8% [P<.0003] and 12.7% [P<.0003], respectively). There was no significant change in these variables between stages 2 (day 5) and 3 (6 weeks), indicating no development of tolerance to the nitrate effect. Similar reductions were noted by means of the visual analysis (SSS reduction of 13.0% [P<.002]) in the entire study period. Patients with chronic-stable-angina treated with a long-acting nitrate demonstrate improvement in myocardial perfusion defect extent and severity in an extended period by means of both visual and quantitative analysis of sequential exercise testing to the same rate-pressure product end point.

Relation between evolutionary ST segment and T-wave direction and electrocardiographic prediction of mycardial infarct size and left ventricular function among patients with anterior wall q-wave acute myocardial infarction who received reperfusion therapy

In the prethrombolytic era it was found that infarct size and left ventricular ejection fraction could be predicted using the Selvester QRS score. We evaluated whether infarct size and left ventricular ejection fraction could be predicted by the predischarge QRS score in patients who had received reperfusion therapy and whether considering the configuration of the ST segments and T waves would increase the accuracy of these predictions. We evaluated 51 patients with first anterior wall myocardial infarction who had received reperfusion therapy and predischarge resting technetium-99m-sestamibi scan. The electrocardiograms recorded on the same day of the scan were analyzed for the QRS score and were divided into 3 groups: A, isoelectric ST and negative T waves; B, ST elevation (> or =0.1 mV) and negative T waves; and C, ST elevation (> or =0.1 mV) and positive T waves. Groups A, B, and C included 12, 23, and 16 patients, respectively. The myocardial perfusion defect extent increased from groups A to C (median 21%, 37%, and 43.5% in groups A, B, and C, respectively; p = 0.023). Similarly, left ventricular ejection fraction decreased (44%, 38%, and 34%, respectively; p = 0.042) from groups A to C. Overall, the correlation between the QRS score and the myocardial perfusion defect extent (rho 0.249; p = 0.08) and ejection fraction (rho -0.229; p = 0.11) was poor. A statistically significant correlation between myocardial perfusion defect size and QRS score was found only in group A (rho 0.599, p = 0.04). Among patients with anterior myocardial infarction who received reperfusion therapy, the predischarge QRS score was predictive of infarct size only in those in whom ST elevation resolved completely. In patients with residual ST elevation there was no correlation between QRS score and infarct size.

The predischarge electrocardiographic pattern in anterior acute myocardial infarction: Relation between evolutionary ST segment and T-wave configuration and prediction of myocardial infarct size and left ventricular systolic function by the QRS selvester score

Left ventricular systolic function, determined mainly by final infarct size, has a major influence on prognosis after acute myocardial infarction (MI). It was found that infarct size and left ventricular ejection fraction can be predicted using the Selvester QRS-score in patients not receiving reperfusion therapy. We assessed whether the predischarge QRS-score can be used for estimating infarct size and left ventricular ejection fraction in 51 patients with a first anterior MI who had received reperfusion therapy and whether considering the configuration of the ST-segments and T-waves will increase the accuracy of these predictions. All patients had received reperfusion therapy and had predischarge resting 99mTc-sestamibi scan. We determined the Selvester QRS score using the electrocardiograms performed on the same day of the scan. In addition, we divided the patients into 3 groups: A: isoelectric ST and negative T-waves (n = 12); B: ST elevation (> or =0.1 mV) and negative T-waves (n = 23); and C: ST elevation (> or =0.1 mV) and positive T-waves (n = 16). The myocardial perfusion defect extent increased from group A to C (28.5+/-16.4%, 39.4+/-14.8%, and 45.3+/-15.8% in groups A, B, and C. respectively; P = .022). Similarly, the left ventricular ejection fraction decreased (41.7+/-11.6%, 38.4+/-8.1%, and 32.0+/-9.7%, respectively; P = .042) from group A to C. Overall, the correlation between the QRS-score and the myocardial perfusion defect extent (Rho = 0.249; P = .08), and ejection fraction (Rho = -0.229; P = .11) was not good. A statistically significant correlation between the myocardial perfusion defect size and the QRS-score was found only in group A (Rho = 0.599, P = .04). In patients with a first anterior myocardial infarction who underwent reperfusion therapy, the predischarge QRS-score is predictive of infarct size only in those in whom ST elevation resolved completely. In patients with residual ST elevation the Selvester QRS-score is inaccurate in predicting infarct size and left ventricular ejection fraction upon discharge.

Myocardial Perfusion Abnormalities by Intravenous Administration of the Contrast Agent NC100100 in an Experimental Model of Coronary Artery Thrombosis and Reperfusion.

The aim of this study was to evaluate a second-generation echo contrast agent (NC100100) for the study of myocardial perfusion. In eight anesthetized open-chest dogs, this agent was injected intravenously under baseline conditions, during acute coronary thrombosis, and after reperfusion, using both fundamental (FI) and harmonic (HI) imaging, both continuous and intermittent imaging, and both ultrasound (US) and integrated backscatter (IBS) imaging. Contrast injections did not modify the hemodynamic parameters. With all imaging modalities, myocardial contrast enhancement (MCE) was higher with intermittent than with continuous imaging (134 vs 82 gray level/pixel using FI, P = 0.02; 62 vs 32 acoustic units using US HI, P = 0.02; and 52 vs 12 dB using IBS, P = 0.05). MCE equally increased using either US or IBS imaging. The accuracy of MCE in detecting perfusion defects during coronary occlusion and myocardial reperfusion after thrombolysis was very good (sensitivity and specificity = 93% and 95% and 89% and 93%, respectively). The extent of myocardial perfusion defects by echo contrast showed a closer correlation with microspheres using HI (r = 0.82) than FI (r = 0.53). Thus, the intravenous administration of NC100100 during intermittent HI allows myocardial perfusion abnormalities to be accurately detected during acute myocardial infarction.

Effect of Ultrasound Transducer Depth Setting in Identifying the Presence and Spatial Extent of Myocardial Perfusion Defects During Rest and Dobutamine Stress With Intermittent Harmonic Imaging

Effect of Ultrasound Transducer Depth Setting in Identifying the Presence and Spatial Extent of Myocardial Perfusion Defects During Rest and Dobutamine Stress With Intermittent Harmonic Imaging