Left Ventricular Perfusion Research Articles

Whole Left Ventricular Coverage Versus Conventional 3-Slice Myocardial Perfusion Magnetic Resonance Imaging for the Detection of Suspected Coronary Artery Disease

Sliding-window conjugate-gradient highly constrained back-projection reconstruction (SW-CG-HYPR) allows whole left ventricular coverage, improved temporal and spatial resolution, and signal-to-noise ratio compared to the conventional 3-slice saturation recovery turbo-fast low-angle shot (SR-Turbo-FLASH) sequence. We prospectively compared the diagnostic value of whole leftventricular coverage myocardial perfusion magnetic resonance imaging (MRI) and conventional 3-slice technique in patients with suspected coronary artery disease (CAD). Thirty consecutive patients with suspected CAD who were scheduled for coronary angiography underwent myocardial perfusion MRI with both SW-CG-HYPR and SR-Turbo-FLASH in random order at 3.0 T. Perfusion defects were interpreted visually by two blinded observers and were correlated to x-ray angiographic stenoses ≥50%. Receiver-operating characteristic curve analysis was used to compare the diagnostic performance of the two imaging techniques. The image quality score of SW-CG-HYPR was significantly higher than that of SR-Turbo-FLASH (3.4 ± 0.6 vs 3.0 ± 0.7, respectively; p < 0.05). In the per-patient analysis, SW-CG-HYPR provided a higher sensitivity (94% vs 89%), specificity (83% vs 75%), and diagnostic accuracy (90% vs 83%) for the detection of CAD than SR-Turbo-FLASH. In the per-vessel analysis, the diagnostic performance of SW-CG-HYPR was significantly greater than that of SR-Turbo-FLASH for the overall detection of CAD (area under receiver-operating characteristic curve: 0.96 ± 0.02 vs 0.90 ± 0.03, respectively; p < 0.05). Whole left ventricular coverage myocardial perfusion MRI has higher diagnostic accuracy compared to conventional 3-slice technique for the detection of suspected CAD.

Tips and tricks for using extracorporeal life support devices in the intensive cardiac care unit

In patients with severe cardiac dysfunction refractory to conventional therapies, extracorporeal membrane oxygenation used in veno-arterious modality can provide temporary circulatory assistance (extracorporeal life support, ECLS). Since it is an invasive and complex technique, its use is potentially burdened by severe complications, thus requiring careful nursing and medical care during intensive cardiac care unit stay. The use of ECLS requires specific skills such as knowledge of protective mechanical invasive ventilation, specific echocardiographic evaluation, accurate monitoring of hemodynamics and laboratory tests. A patient on ECLS is at high risk of thrombotic and hemorrhagic complications that could be fatal, hence specific pro- and anti-hemostatic therapy is needed. Moreover, the knowledge of some peculiar aspects of ECLS system and management can help doctors to avoid several complications such as limb ischemia, left ventricular overload and regional perfusion discrepancy. In conclusion, careful management by adequately trained personnel is required.

Simultaneous dual-isotope 123I/99mTc acquisition using CZT-based cameras: Toward a one-stop-shop SPECT in heart failure patients

The CZT-cameras (DNM 530c and DSPECT) have only recently been introduced, and the impact of the increased energy resolution remains unknown. This paper summarizes the evidence on the assessment of: (i) the left ventricular function, (ii) the 123I/99mTc mismatch, and (iii) the heart-to-mediastinum ratio (HMR) of 123I-metaiodobenzylguanidine (MIBG) uptake under dual-isotope conditions (99mTc and 123I) using cadmium-zinc-telluride (CZT) technology. The diagnostic accuracy of CZT cameras for myocardial sympathetic innervation imaging, left ventricular function and perfusion assessment using perfusion-gated SPECT have only been established in a few studies, under single-isotope conditions. Limited evidence is available regarding simultaneous dual-isotope acquisition using CZT-cameras. However, recently reported data have shown that CZT cameras allow, in dual-isotope (123I and 99mTc) acquisitions and under routine conditions: (i) a simultaneous and accurate segmental study of myocardial innervation and perfusion (match and mismatch), (ii) the ventricular function assessment (EDV, ESV and LVEF), and (iii) the determination of the late HMR of cardiac 123I-MIBG uptake in patients with heart failure. However, this latter should be performed using transaxial reconstructed images and a linear correction based on phantom data acquisitions. ConclusionWith an increased energy resolution, the CZT cameras should become the one-stop shop SPECT for simultaneous dual-isotope 123I/99mTc acquisitions in heart failure patients, permitting to perform LV function, myocardial perfusion and innervation.

Association between left ventricular perfusion defects and myocardial deformation indexes in heart transplantation recipients

The aim of the study was to analyze possible correlations between strain echocardiography (STE) and PET myocardial perfusion in a population of heart transplantation (HTx) recipients showing preserved left ventricular (LV) ejection fraction. By STE, LV global longitudinal strain (LV GLS) was lower in HTx. PET showed no transient or chronic ischemia in 83 of 115 HTx (73%). Fixed perfusion defects were observed in 17% of HTx and reversible ischemia in 10%. Significant coronary stenosis was observed only in 10 cases. GLS was independently associated with age at HTx and fixed perfusion defects (HR 0.41; P<.001). Such relationships underline STE ability to early identify HTx pts with subclinical myocardial dysfunction during long-term follow-up.

Cardiovascular magnetic resonance imaging for the assessment of ischemic heart disease

AbstractCardiovascular magnetic resonance imaging (CMR) offers a broader assessment of cardiac structure and function than any other single imaging modality. In patients with known or suspected ischemic heart disease (IHD), a comprehensive CMR protocol provides an assessment of left ventricular function, myocardial perfusion, edema, and viability in a single sitting. There are applications for this technology in both the acute and chronic IHD settings. CMR is also a valuable tool in the assessment of patients presenting with chest pain, raised troponin levels, and unobstructed coronaries.Answer questions and earn CME: https://wileyhealthlearning.com/Activity2/5430068/Activity.aspx

Left bundle branch block: from cardiac mechanics to clinical and diagnostic challenges.

Left bundle branch block (LBBB) results in an altered pattern of left ventricular (LV) activation and subsequent contraction, causing remarkable changes in LV mechanics, perfusion and workload and ultimately leading to pathologic cardiac remodelling. Clinical and diagnostic notions about the LBBB phenomenon had evolved from just an electrocardiographic pattern to a critically important finding affecting diagnostic and clinical management of many patients and adversely influencing their outcomes. Recent advances in imaging techniques significantly improved the assessment of patients with LBBB and provided additional insights into pathophysiological mechanisms of LV remodelling. In the current review we summarized currently available data on the LBBB epidemiology, diagnosis, its impact on clinical management and prognosis, and the role and place of various imaging modalities in assessing cardiac mechanics and perfusion abnormalities, as well as their potential implications for diagnostic and treatment strategies.

NEUROTROPIC MYOCARDIAL SCINTIGRAPHY IN THE EVALUATION OF SUDDEN CARDIAC DEATH PROGNOSIS IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

Objective . To explore the features of cardiac sympathetic activity impairments using neurotropic scintigraphy and singlephoton emission tomography (SPECT) in patients with hypertrophic cardiomyopathy (HCM), including the context of the risk of sudden cardiac death (SCD). Material and methods. 36 patients with HCM, II–IV NYHA CHF grade, underwent cardiac neurotropic scintigraphy and SPECT with 123I-MIBG. 30 patients also underwent cardiac perfusion SPECT with 99mTc-MIBI, standard quantitative parameters of global and local left ventricular sympathetic activity and perfusion impairments were obtained. After 5 years of follow-up, the analysis of the dependence of the frequency of SCD in patients with HCM on the values of the above parameters was performed. Results. All parameters of perfusion and neurotropic myocardial SPECT were significantly different in patients with HCM compared with the control group (p 4) in the main group was detected in 32% of cases, while it had a diffuse character and had no connection with certain coronary artery regions. The volume of regional innervation defects (SMSe) in HCM patients significantly exceeded the total volume of perfusion defects (SSS, p 14 predicted the occurrence of SCD with sensitivity of 87.5% and specificity of 57.1%. The risk of five-year mortality from SCD was significantly higher when SMSe >14 (p=0.024). Conclusion. Neurotropic SPECT in patients with HCM is able to identify a group of patients at high risk of sudden cardiac death.

The natural history of takotsubo syndrome: a two-year follow-up study with myocardial sympathetic and perfusion G-SPECT imaging.

To investigate changes in sympathetic activity, perfusion, and left ventricular (LV) functionality in takotsubo cardiomyopathy (TTC) patients from onset (T0) to post-onset conditions at 1month (T1), 1-2 years (T2, T3). Twenty-two patients (70 ± 11 years) underwent serial gated single photon emission tomography (G-SPECT) studies with 123I-mIBG and 99mTc-Sestamibi. Statistics were performed using ANOVA/Sheffé post-hoc, correlation test, and receiver operating characteristic (ROC) curve analysis (p < 0.05). Patients presented at T0 with LV ballooning and reduced early-late mIBG uptake (95%, 100%), left ventricular ejection fraction (LVEF)G-SPECT (86%) and perfusion (77 %). Adrenergic dysfunction was greater in apex, it overlaps with contractile impairment, and both were more severe than perfusion defect. During follow-up, LVEFG-SPECT, contractility, and perfusion were normal, while 82% and 90% of patients at T1 and 50% at T2 and T3 continued to show a reduced apical early-late mIBG distribution. These patients presented at T0-T1 with greater impairment of adrenergic function, contractility, and perfusion. A relationship was present within innervation and both perfusion and contractile parameters at T0 and T1, and between the extent of adrenergic defect at T3 and both the defect extent and age at T0 (cut-off point 42.5%, 72 years). Outcome for TTC is not limited to a reversible contractile and perfusion abnormalities, but it includes residual adrenergic dysfunction, depending on the level of adrenergic impairment and age of patients at onset. The number of patients, as well as degree of perfusion abnormalities were found to be higher than those previously reported possibly depending on the time-interval between hospital admission and perfusion scan.

Abstract 13304: Prevalence, Perfusion-Based Markers, and Exercise Manifestations of Right Ventricular Dysfunction Among 2,051 Consecutive Patients Undergoing Exercise Myocardial Perfusion Imaging

Introduction: Right (RV) and left ventricular (LV) performance are linked via common coronary supply: Impact of altered LV perfusion on the RV, and independent influence of RV dysfunction (RV dys ) on effort tolerance are unknown. Methods: The population comprised pts undergoing myocardial perfusion imaging (MPI) and echocardiography (echo) within 1 month (5.5±7.9 days): RV dys was defined via standard echo criteria (TAPSE &lt; 1.6 cm, RV S’ &lt; 10mm/s). MPI was the reference for LV ischemia; effort tolerance was assessed via exercise treadmill testing (ETT) at time of MPI. Results: 2051 pts (64±12 yo, 59%M) were studied; 6% had RV dys on echo. Pts with RV dys had lower LVEF (53±14 vs. 62±9%), larger LV size (55±23 vs. 48±16 ml/m 2 ) and higher PA systolic pressure (34±12 vs 30±7 mmHg; all p&lt;0.01). On MPI, summed stress score was 3 fold higher among pts with RV dys (6.9±8.5 v. 2.7±6.1, p&lt;0.001). LV inferior (0.7±1.7 v. 0.2±1.0, p=0.007) and lateral ischemic defects (1.2±2.6 v. 0.2±1.1, p&lt;0.001) were larger in pts with RV dys (both p&lt;0.01); but anterior defects did not differ (p=NS): Inducible inferior and lateral perfusion defects increased likelihood for RV dys (both p&lt;0.001) independent of LV function and PA pressure. Pts with RV dys had lesser heart rate (α 56±26 vs. 69±24 bpm) and blood pressure augmentation (α 28±31 vs. 41±27mmHg, both p&lt;0.001) during ETT, paralleling lower effort duration (6.7±2.8 vs. 7.9±2.9 min, p&lt;0.001): Effort duration decreased in relation to both LV and RV dys , as evidenced by stepwise decrements among pts with normal biventricular function, isolated LV or RV dys and pts with biventricular dysfunction [ Figure ]: Impaired effort tolerance was independently associated with RV dys (regression coefficient 0.73 [CI 0.14-1.31], p=0.02) and LV dys (0.71 [0.27-1.16], p=0.002), even after controlling for age and β blocker use. Conclusions: LV ischemia in inferior and lateral walls confers increased likelihood for RV dys . RV dys impairs exercise tolerance independent of LV dys .

Right Ventricular Dysfunction Impairs Effort Tolerance Independent of Left Ventricular Function Among Patients Undergoing Exercise Stress Myocardial Perfusion Imaging.

Right ventricular (RV) and left ventricular (LV) function are closely linked due to a variety of factors, including common coronary blood supply. Altered LV perfusion holds the potential to affect the RV, but links between LV ischemia and RV performance, and independent impact of RV dysfunction on effort tolerance, are unknown. The population comprised 2051 patients who underwent exercise stress myocardial perfusion imaging and echo (5.5±7.9 days), among whom 6% had echo-evidenced RV dysfunction. Global summed stress scores were ≈3-fold higher among patients with RV dysfunction, attributable to increments in inducible and fixed LV perfusion defects (all P≤0.001). Regional inferior and lateral wall ischemia was greater among patients with RV dysfunction (both P<0.01), without difference in corresponding anterior defects (P=0.13). In multivariable analysis, inducible inferior and lateral wall perfusion defects increased the likelihood of RV dysfunction (both P<0.05) independent of LV function, fixed perfusion defects, and pulmonary artery pressure. Patients with RV dysfunction demonstrated lesser effort tolerance whether measured by exercise duration (6.7±2.8 versus 7.9±2.9 minutes; P<0.001) or peak treadmill stage (2.6±0.9 versus 3.1±1.0; P<0.001), paralleling results among patients with LV dysfunction (7.0±2.9 versus 8.0±2.9; P<0.001|2.7±1.0 versus 3.1±1.0; P<0.001 respectively). Exercise time decreased stepwise in relation to both RV and LV dysfunction (P<0.001) and was associated with each parameter independent of age or medication regimen. Among patients with known or suspected coronary artery disease, regional LV ischemia involving the inferior and lateral walls confers increased likelihood of RV dysfunction. RV dysfunction impairs exercise tolerance independent of LV dysfunction.

Assessment of endothelial damage and cardiac injury in a mouse model mimicking thrombotic thrombocytopenic purpura

Background Cardiac alterations represent a major cause of mortality in patients with thrombotic thrombocytopenic purpura (TTP). Endothelial injury remains poorly defined, but seems to be a key initiating event leading to the formation of platelet-rich thrombi in TTP patients. Objectives To assess the changes in endothelial function and the induced cardiac damage in a mouse model of TTP. Patients/methods We used an animal model in which TTP-like symptoms are triggered by injection of 2000 units kg-1 of recombinant von Willebrand factor in ADAMTS-13 knockout mice. Results These mice developed TTP-like symptoms, i.e. severe thrombocytopenia, schistocytosis, and anemia. On day 2, magnetic resonance imaging demonstrated a decrease in left ventricular perfusion associated with alteration of left ventricular ejection fraction, fractional shortening, and cardiac output, suggesting early systolic dysfunction. This was associated with decrease in endothelium-mediated relaxation responses to acetylcholine in mesenteric and coronary arteries, demonstrating severe early endothelial dysfunction. In parallel, we showed decreased cardiac expression of endothelial nitric oxide (NO) synthase and increased expression of antioxidant enzymes, suggesting alteration of the NO pathway. At this time, cardiac immunohistochemistry revealed an increase in the expression of VCAM-1 and E-selectin. Conclusion This study provides evidence that the heart is a sensitive target organ in TTP, and shows, for the first time, strong mesenteric and coronary endothelial dysfunction in an induced-TTP model. The mechanisms incriminated are the occurrence of a pro-oxidant state, and proadhesive and proinflammatory phenotypes. This previously largely unrecognized vascular dysfunction may represent an important contributor to the systemic organ failure occurring in TTP.

Diagnosis of prostate cancer using anti-PSMA aptamer A10-3.2-oriented lipid nanobubbles.

In this study, the lipid targeted nanobubble carrying the A10-3.2 aptamer against prostate specific membrane antigen was fabricated, and its effect in the ultrasound imaging of prostate cancer was investigated. Materials including 2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phosphatidic acid, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine, 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol, carboxyl-modified 1,2-distearoyl-sn-glycero-3-phosphoethanolamine, and polyethyleneglycol-2000 were for mechanical oscillation, and nanobubbles were obtained through the centrifugal flotation method. After mice were injected with nanobubbles, abdominal color Doppler blood flow imaging significantly improved. Through left ventricular perfusion with normal saline to empty the circulating nanobubbles, nanobubbles still existed in tumor tissue sections, which demonstrated that nanobubbles could enter tissue spaces via the permeability and retention effect. Fluorinated A10-3.2 aptamers obtained by chemical synthesis had good specificity for PSMA-positive cells, and were linked with carboxyl-modified 1,2-distearoyl-sn-glycero-3-phosphoethanolamine lipid molecules from the outer shell of nanobubbles via amide reaction to construct targeted nanobubbles. Gel electrophoresis and immunofluorescence confirmed that targeted nanobubbles were fabricated successfully. Next, targeted nanobubbles could bind with PSMA-positive cells (C4-2 cells), while not with PSMA-negative cells (PC-3 cells), using in vitro binding experiments and flow cytometry at the cellular level. Finally, C4-2 and PC-3 xenografts in mice were used to observe changes in parameters of targeted and non-targeted nanobubbles in the contrast-enhanced ultrasound mode, and the distribution of Cy5.5-labeled targeted nanobubbles in fluorescent imaging of live small animals. Comparison of ultrasound indicators between targeted and non-targeted nanobubbles in C4-2 xenografts showed that they had similar peak times (P>0.05), while the peak intensity, half time of peak intensity, and area under the curve of ½ peak intensity were significantly different (P<0.05). In PC-3 xenografts, there were no differences in these four indicators. Fluorescent imaging indicated that targeted nanobubbles had an aggregation ability in C4-2 xenograft tumors. In conclusion, targeted nanobubbles carrying the anti-PSMA A10-3.2 aptamer have a targeted imaging effect in prostate cancer.

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.

Quantitative MRI biomarkers to characterize regional left ventricular perfusion and function in nonhuman primates during dobutamine-induced stress: A reproducibility and reliability study.

To identify reproducible and reliable noninvasive regional imaging biomarkers of cardiac function and perfusion at rest and under stress in healthy nonhuman primates (NHPs) that may be used in the future for the early characterization of preclinical heart failure models, to evaluate therapy, and for clinical translation. Seven naive cynomolgus macaques underwent test-retest 3T cardiac MRI tagging and dual-bolus perfusion experiments. Regional cardiac function biomarkers, such as peak circumferential strain (CS), average diastolic strain-rate (DSR), contractile reserve (CR), diastolic reserve, peak torsion, and torsion reserve were quantified. Further, regional myocardial blood flow (MBF), myocardial perfusion reserve (MPR), and myocardial perfusion reserve-to-contractile reserve (MPR/CR) were also derived. Inter- and intraobserver reproducibility and test-retest reliability analyses were conducted using the reliability and generalizability coefficients including correlation coefficient (CC) and intraclass correlation coefficient (ICC). Overall, peak CS, DSR, and MBF are robust biomarkers at both rest and stress with moderate-good inter- and intraobserver reproducibility and test-retest reliability. At rest: intra-/interobserver reproducibility (CC): peak CS (0.81/0.81), DSR (0.81/0.81), MBF (0.72/0.57), peak torsion (0.79/0.79); test-retest reliability: (CC/ICC): peak CS (0.62/0.75), DSR (0.24/0.55), MBF (0.66/0.62), and peak torsion (0.79/0.78). Under stress: intra-/interobserver reproducibility (CC): peak CS (0.61/0.60), DSR (0.50/0.50), MBF (0.63/0.61), MPR (0.43/0.43), and peak torsion (0.38/0.38); test-retest reliability: (CC/ICC): peak CS (0.58/0.58), DSR (0.24/0.43), MBF (0.58/0.58), MPR (0.43/0.38), and peak torsion (0.38/0.38). We demonstrated the feasibility of using cardiac MRI to characterize left ventricular functional and perfusion responses to stress in an NHP species, and specific robust biomarkers such as peak CS, DSR, MBF, diastolic reserve, and MPR have been identified for clinical translation and drug research. 1 J. Magn. Reson. Imaging 2017;45:556-569.

Human Umbilical Cord-Derived Mesenchymal Stromal Cells Improve Left Ventricular Function, Perfusion, and Remodeling in a Porcine Model of Chronic Myocardial Ischemia.

: Stem cell therapy has emerged as a new strategy for treatment of ischemic heart disease. Although umbilical cord-derived mesenchymal stromal cells (UC-MSCs) have been used preferentially in the acute ischemia model, data for the chronic ischemia model are lacking. In this study, we investigated the effect of UC-MSCs originated from Wharton's jelly in the treatment of chronic myocardial ischemia in a porcine model induced by ameroid constrictor. Four weeks after ameroid constrictor placement, the surviving animals were divided randomly into two groups to undergo saline injection (n = 6) or UC-MSC transplantation (n = 6) through the left main coronary artery. Two additional intravenous administrations of UC-MSCs were performed in the following 2 weeks to enhance therapeutic effect. Cardiac function and perfusion were examined just before and at 4 weeks after intracoronary transplantation. The results showed that pigs with UC-MSC transplantation exhibited significantly greater left ventricular ejection fraction compared with control animals (61.3% ± 1.3% vs. 50.3% ± 2.0%, p < .05). The systolic thickening fraction in the infarcted left ventricular wall was also improved (41.2% ± 3.3% vs. 46.2% ± 2.3%, p < .01). Additionally, the administration of UC-MSCs promoted collateral development and myocardial perfusion. The indices of fibrosis and apoptosis were also significantly reduced. Immunofluorescence staining showed clusters of CM-DiI-labeled cells in the border zone, some of which expressed von Willebrand factor. These results suggest that UC-MSC treatment improves left ventricular function, perfusion, and remodeling in a porcine model with chronic myocardial ischemia. Ischemic heart disease is the leading cause of death worldwide. Many patients with chronic myocardial ischemia are not suitable for surgery and have no effective drug treatment; they are called "no-option" patients. This study finds that umbilical cord-derived mesenchymal stromal cells transplanted by intracoronary delivery combined with two intravenous administrations was safe and could significantly improve left ventricular function, perfusion, and remodeling in a large-animal model of chronic myocardial ischemia, which provides a new choice for the no-option patients. In addition, this study used clinical-grade mesenchymal stem cells with delivery and assessment methods commonly used clinically to facilitate further clinical transformation.

Impact of imaging protocol on left ventricular ejection fraction using gated-SPECT myocardial perfusion imaging

BackgroundThere are limited data on the impact of the imaging protocol (single-day stress-rest, SD, vs. dual-day, DD) on the change in left ventricular (LV) ejection fraction (EF) (post-stress-rest) in relation to ischemia and on outcome. MethodsUsing propensity score matching procedure, 490 of 1121 patients with known CAD, undergoing a SD or a DD in a multicenter study, were evaluated. Stress and rest gated-SPECT myocardial perfusion imaging was used to quantify LV perfusion, EF, and volumes. Outcome was assessed at an average follow-up time of 3.2 years. ResultsPost-stress LVEF in SD and DD were comparable across all degrees of ischemia. The change in LVEF in patients with severe ischemia was, however, higher in the DD protocol, independent of the extent of CAD. At follow-up, 240 patients (49.0%) required coronary revascularization (CR) and 52 patients (10.6%) had hard events. The ischemic burden was independently associated with CR and hard-events; the post-stress LVEF was associated with CR but the change in EF was not predictive of either CR or hard events. ConclusionsIn patients with severe ischemia, underestimation of post-stress myocardial stunning could be observed with the SD protocol. Post-stress LVEF and the extent ischemia, but not the change in EF, are predictive of CR and hard events.

Perfusion and metabolic scintigraphy with (123)I-BMIPP in prognosis of cardiac resynchronization therapy in patients with dilated cardiomyopathy.

The objective of the study was to investigate the left ventricular (LV) myocardial perfusion and metabolism in patients with idiopathic dilated cardiomyopathy (DCM) and to identify the scintigraphic predictors of the efficacy of cardiac resynchronization therapy (CRT). The study comprised 63 patients with DCM and severe heart failure (NYHA class III-IV). Before CRT, all patients received gamma-scintigraphy with (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) and with (123)I-β-methyl-iodophenyl pentadecanoic acid ((123)I-BMIPP) for evaluation of myocardial perfusion and metabolism, respectively. Before and after 6months of CRT, all patients underwent echocardiography study to assess cardiac hemodynamics. After 6months of CRT, patients were divided into two groups: group 1 comprised responders in whom LV end systolic volume (LVESV) decreased by ≥15% (n=39); group 2 comprised non-responders in whom LVESV decreased by <15% (n=24). Before CRT, LV pumping function did not significantly differ between groups. Significant differences were found in the following preoperative scintigraphic parameters: myocardial perfusion defect size [7.4% (5.9; 13.2)% and 11.8 (8.8; 16.2)%, p<0.05] and metabolic defect size [7.4 (4.4; 14.7)% and 8.8 (8.8; 17.6)%, p<0.05]. Metabolic scintigraphy showed greater diagnostic efficacy in determining the indications for CRT compared with perfusion scintigraphy [areas under the ROC curves (AUC) of 0.722 and 0.612, respectively]. The best metabolic defect size threshold value of 7.35% predicted CRT efficacy with the sensitivity and specificity rates of 77.8 and 66.7%, respectively. Data of metabolic scintigraphy may be useful for the integrated prediction of CRT efficacy.

Semiautomated Global Quantification of Left Ventricular Myocardial Perfusion at Stress Dynamic CT:: Diagnostic Accuracy for Detection of Territorial Myocardial Perfusion Deficits Compared to Visual Assessment

To evaluate the diagnostic accuracy of semiautomated global quantification of left ventricular myocardial perfusion derived from stress dynamic computed tomography myocardial perfusion imaging (CTMPI) for detection of territorial perfusion deficits (PD). Dynamic CTMPI datasets of 71 patients were analyzed using semiautomated volume-based software to calculate global myocardial blood flow (MBF), myocardial blood volume, and volume transfer constant. Optimal cutoff values to assess the diagnostic accuracy of these parameters for detection of one- to three-vessel territories with PD in comparison to visual analysis were calculated. Nonsignificant differences (P = 0.694) were found for average global MBF in patients without PD and single-territorial PD. Significant differences were found for mean global MBF in patients with PD in two (P < 0.0058) and three territories (P < 0.0003). Calculated optimal thresholds for global MBF and myocardial blood volume resulted in a sensitivity, specificity, and negative predictive value of 100% for detection of three-vessel territory PD. For detection of ≥2 territories with PD, global MBF was superior to other parameters (sensitivity 81.3%, specificity 90.9%, and negative predictive value 94.3%). Semiautomated global quantification of left ventricular MBF during stress dynamic CTMPI shows high diagnostic accuracy for detection of ≥2 vessel territories with PD, facilitating identification of patients with multi-territorial myocardial PD.

Improvement of left ventricular myocardial perfusion after acidic fibroblast growth factor delivered by using ultrasound-targeted microbubble destruction in rats with diabetic cardiomyopathy: an preliminary study

Objective To investigate the protective effects of left ventricular myocardial perfusion after delivery of acidic fibroblast growth factor (aFGF) in rats with diabetic cardiomyopathy (DCM) by using ultrasound-targeted microbubble destruction (UTMD) with real-time myocardial contrast echocardiography(RT-MCE). Methods Among 64 male SD rats, 52 rats were randomly selected and were induced DCM by streptozotocin through intraperitoneal injecting, the other rats as normal control group. DCM rats were randomly divided into the DCM model group, aFGF only group, SonoVue-aFGF group and the SonoVue-aFGF+ UTMD group in this study. The aFGF only group rats were injected with aFGF solution through tail vein, the SonoVue-aFGF group were injected with SonoVue-aFGF solution through tail vein and SonoVue-aFGF+ UTMD group rats were injected with SonoVue-aFGF solution through tail vein and using UTMD simultaneously. All rats underwent conventional echocardiography and RT-MCE exams before and 4 weeks after intervention. Left ventricular ejection fraction (LVEF) and left ventricular fraction shortening(LVFS) were measured by conventional echocardiography. The plateau intensity (A), initial slope of the curve (β) and myocardial blood flow (A×β) of left ventricular anterior wall at the papillary muscle level were measured in left ventricular short-axis view by RT-MCE. Results Before intervention, LVEF and LVFS in the DCM model group, aFGF only group, SonoVue-aFGF group and the SonoVue-aFGF+ UTMD group were significantly lower than in the normal control group (P 0.05), however A and A×β in the SonoVue-aFGF+ UTMD group were significantly increased than those in the DCM model group(P<0.01). Compared with the same group before intervention, A and A×β in the SonoVue-aFGF+ UTMD group were higher (P<0.05) and these in the DCM model group were lower during four weeks after intervention (P<0.05). Conclusions Acidic fibroblast growth factor delivered by using UTMD can improve the left ventricular myocardial perfusion in diabetic cardiomyopathy rats. Key words: Echocardiography; Diabetic cardiomyopathies; Fibroblast growth factor; Microbubbles; Ventricular function, left

Adiposity Is Associated with Gender-Specific Reductions in Left Ventricular Myocardial Perfusion during Dobutamine Stress.

BackgroundObesity and visceral adiposity are increasingly recognized risk factors for cardiovascular disease. Visceral fat may reduce myocardial perfusion by impairing vascular endothelial function. Women experience more anginal symptoms compared to men despite less severe coronary artery stenosis, as assessed by angiography. Women and men have different fat storage patterns which may account for the observed differences in cardiovascular disease. Therefore, our objective was to evaluate the relationship between visceral adipose tissue distributions and myocardial perfusion in men and women.MethodsVisceral and subcutaneous fat distributions and myocardial perfusion were measured in 69 men and women without coronary artery disease using magnetic resonance imaging techniques. Myocardial perfusion index was quantified after first-pass perfusion with gadolinium contrast at peak dose dobutamine stress.ResultsWe observed inverse relationships between female gender (r = -0.35, p = 0.003), pericardial fat (r = -0.36, p = 0.03), intraperitoneal fat (r = -0.37, p = 0.001), and retroperitoneal fat (r = -0.36, p = 0.002) and myocardial perfusion index. Visceral fat depots were not associated with reduced myocardial perfusion at peak dose dobutamine in men. However, in women, BMI (r = -0.33, p = 0.04), pericardial fat (r = -0.53, p = 0.02), subcutaneous fat (r = -0.39, p = 0.01) and intraperitoneal fat (r = -0.30, p = 0.05) were associated with reduced myocardial perfusion during dobutamine stress.ConclusionsHigher visceral fat volumes are associated with reduced left ventricular myocardial perfusion at peak dose dobutamine stress in women but not in men. These findings suggest that visceral fat may contribute to abnormal microcirculatory coronary artery perfusion syndromes, explaining why some women exhibit more anginal symptoms despite typically lower grade epicardial coronary artery stenoses than men.