Presence Of Myocardial Perfusion Abnormalities Research Articles

Determinants of left ventricular mechanical dyssynchrony in patients submitted to myocardial perfusion imaging: A cardiac CZT study

BackgroundAn interaction between coronary anatomy, myocardial perfusion, and left ventricular (LV) functional parameters in the development of mechanical LV dyssynchrony (LVD) has been suggested. This study examined the correlates of LVD in a large sample size of patients with known or suspected coronary artery disease (CAD) using cadmium-zinc-telluride camera. MethodsSix-hundred and fifty-seven consecutive patients who underwent myocardial perfusion imaging (MPI) and coronary angiography were included. Coronary stenosis >70% was considered significant. LV perfusion and functional parameters were computed from MPI images. The presence of significant LVD was evaluated by phase standard deviation and histogram bandwidth. Results415/657 (63%) patients had significant CAD. LVD was present in 247 (38%) patients and was associated with the presence of a higher CAD burden (P < .001), more impaired measures of LV perfusion (P < .001), contractile function (P < .001), and larger LV volumes (P < .001). By multivariate analysis, the LV end-systolic volume index (P < .001) and ischemic burden (P < .001) were the strongest predictors of LVD independent of CAD extent and LV systolic dysfunction. ConclusionsLVD is frequent in patients undergoing MPI for suspected or known CAD. Its presence is independent of CAD burden and LV systolic dysfunction, but is dependent on the presence of myocardial perfusion abnormalities and LV end-systolic volume.

CONCORDANCE OF ELECTROPHYSIOLOGICAL AND PERFUSION ABNORMALITIES IN THE LEFT VENTRICULAR MYOCARDIUM IN POST INFARCTION ANEURYSMS WITH VENTRICULAR TACHYCARDIA

Актуальность. Наличие желудочковой тахикардии у больных с постинфарктной аневризмой левого желудочка (ЛЖ) предполагает нарушения миокардиальной перфузии.

Lack of association between epicardial fat volume and extent of coronary artery calcification, severity of coronary artery disease, or presence of myocardial perfusion abnormalities in a diverse, symptomatic patient population: results from the CORE320 multicenter study.

Epicardial fat may play a role in the pathogenesis of coronary artery disease (CAD). We explored the relationship of epicardial fat volume (EFV) with the presence and severity of CAD or myocardial perfusion abnormalities in a diverse, symptomatic patient population. Patients (n=380) with known or suspected CAD who underwent 320-detector row computed tomographic angiography, nuclear stress perfusion imaging, and clinically driven invasive coronary angiography for the CORE320 international study were included. EFV was defined as adipose tissue within the pericardial borders as assessed by computed tomography using semiautomatic software. We used linear and logistic regression models to assess the relationship of EFV with coronary calcium score, stenosis severity by quantitative coronary angiography, and myocardial perfusion abnormalities by single photon emission computed tomography (SPECT). Median EFV among patients (median age, 62.6 years) was 102 cm(3) (interquartile range: 53). A coronary calcium score of ≥1 was present in 83% of patients. Fifty-nine percent of patients had ≥1 coronary artery stenosis of ≥50% by quantitative coronary angiography, and 49% had abnormal myocardial perfusion results by SPECT. There were no significant associations between EFV and coronary artery calcium scanning, presence severity of ≥50% stenosis by quantitative coronary angiography, or abnormal myocardial perfusion by SPECT. In a diverse population of symptomatic patients referred for invasive coronary angiography, we did not find associations of EFV with the presence and severity of CAD or with myocardial perfusion abnormalities. The clinical significance of quantifying EFV remains uncertain but may relate to the pathophysiology of acute coronary events rather than the presence of atherosclerotic disease.

Discordance Between the Morphological and Physiological Information of 64-Slice MSCT Coronary Angiography and Myocardial Perfusion Imaging in Patients With Intermediate to High Probability of Coronary Artery Disease

The aim of this study was to determine the relationship between the morphological and physiological information of coronary CT angiography (CCTA) and stress myocardial perfusion imaging (S-MPI) from the standpoint of risk stratification of patients with intermediate to high probability of coronary artery disease (CAD). In total, 51 patients underwent both CCTA and S-MPI as sequential examinations. In each patient, the severity of coronary plaque and stenosis (>50%) and the presence of myocardial perfusion abnormalities were assessed and the prognostic information from the CCTA and S-MPI results was compared. In 30 patients with normal S-MPI, 3 (10%) had only completely normal coronaries and another 3 (10%) had non-obstructive CAD as observed on CCTA. The remaining 24 patients (80%) with normal S-MPI and all 21 patients with abnormal S-MPI study had obstructive CAD. High-risk CAD (defined as obstructive left main trunk (LMT) lesion or 3-vessel disease) was seen in 10 (33%) of 30 patients with normal S-MPI, although it was less frequent than in the 14 (67%) of 21 patients with abnormal S-MPI. A normal S-MPI result can reflect a wide range of coronary atherosclerosis types and severities and, to some extent, involves severe coronary atherosclerosis such as LMT lesion and 3-vessel disease in patients with an intermediate to high probability of CAD.

Relation between exercise-induced ventricular arrhythmias and myocardial perfusion abnormalities in patients with intermediate pretest probability of coronary artery disease.

The significance of exercise-induced ventricular arrhythmias (VAs) is largely dependent on the clinical characteristics of the studied population. The relation between exercise-induced VAs and myocardial perfusion abnormalities has not yet been evaluated in a homogeneous patient population with intermediate probability of coronary artery disease (CAD). We studied 302 patients (mean age 54+/-9 years, 152 men and 150 women) with intermediate pretest probability of CAD (range=0.25-0.80, mean=0.43+/-0.20) by upright bicycle exercise stress test in conjunction with technetium-99m single-photon emission tomography (SPET) imaging. Exercise-induced VAs (frequent or complex premature ventricular contractions or ventricular tachycardia) occurred in 65 patients (22%). No significant difference was found between patients with and patient without VAs regarding the pretest probability of CAD (0.45+/-0.21 vs 0.43+/-0.20). Patients with exercise-induced VAs had a higher prevalence of perfusion abnormalities (52% vs 26%, P=0.002) and ischaemic electrocardiographic changes (31% vs 16%, P<0.05) compared to patients without VAs. A higher prevalence of perfusion abnormalities in patients with VAs was observed in both men (67% vs 35%, P<0.01) and women (38% vs 16%, P<0.05). However, the positive predictive value of exercise-induced VAs for the presence of myocardial perfusion abnormalities was higher in men than in women (67% vs 38%, P<0.05). The presence of abnormal myocardial perfusion was the only independent predictor of exercise-induced VAs (OR 2.2; 95% CI, 1.2-4.2) by multivariate analysis of clinical and stress test variables. It is concluded that in patients with intermediate pretest probability of CAD, exercise-induced VAs are predictive of a higher prevalence of myocardial perfusion abnormalities in both men and women. However, the positive predictive value of exercise-induced VAs for perfusion abnormalities is higher in men. Because of the underestimation of ischaemia by electrocardiographic changes, exercise-induced VAs should be interpreted as a marker of a higher probability of CAD.

Myocardial contrast echocardiography in human beings: Correlation of resting perfusion defects to sestamibi single photon emission computed tomography

The presence of myocardial perfusion abnormalities is generally accepted to suggest underlying coronary artery disease. In previous animal studies, myocardial contrast echocardiography (MCE) has been shown to be useful in delineating areas at risk after coronary occlusions. We sought to compare the presence or absence, size, and location of perfusion defects detected in human beings by MCE and sestamibi single photon emission computed tomography (SPECT). Regional wall motion was qualitatively assessed in the parasternal and apical views of a resting two-dimensional echocardiogram. Coronary angiography was performed in all patients and myocardial contrast echocardiography performed with 2 ml of intracoronary sonicated meglumine (Nycomed). A cine loop of the digitized contrast echocardiograms was used to analyze perfusion defects. Gated SPECT resting images in standard views were obtained after technetium 99m sestamibi (20 mCl) was administered. Visually perceived perfusion defects were established at 30% of maximal counts at end diastole. Perfusion defects by both techniques were planimetered, assigned to one of three perfusion artery territories, and expressed as a percentage of the perfusion territory studied. Comparison was made by linear regression analysis. Forty-one patients were studied. Perfusion defects were observed in 12 (29%) patients by MCE, 19 (46%) patients by SPECT, and 11 (27%) patients by both techniques. No perfusion defects were detected by MCE in 29 (70%) patients, by SPECT in 22 (53%) patients, or by either technique in 21 (51%) patients. The two techniques agreed in 78% of the patients. In 67 matching orthogonal views suitable for comparison between the two techniques, an 82% concordance for the presence or absence of defects was observed. The location of the defects matched in 86% of the cases. A significant correlation ( p < 0.001; r = 0.62) between these techniques was observed in assessing the size of perfusion defects. In conclusion, our results suggest that MCE and sestamibi SPECT are comparable techniques for detecting severely underperfused myocardium in human beings.