Perfusion Territories Research Articles

Three-Dimensional Cardiac Image Fusion Using New CT Angiography and SPECT Methods

The purpose of this study was to develop a method of fused images of coronary CT angiography and myocardial perfusion SPECT. Four patients with ischemic heart disease underwent 3D volume-rendering fused images using a conversion program and volume-rendering fusion function of a computer workstation. The fusion images clearly showed the relationship of relevant coronary arteries and the abnormal perfusion territory in all patients and were useful for the evaluation of coronary artery disease.

Correlation of Vasa Vasorum Neovascularization and Plaque Progression in Aortas of Apolipoprotein E −/− /Low-Density Lipoprotein −/− Double Knockout Mice

We hypothesized that apolipoprotein E (apoE)(-/-)/low-density lipoprotein (LDL)(-/-) double knockout mice might develop vasa vasorum (VV) in association with advanced lesion formation. Aortas from apoE(-/-)/LDL(-/-) mice aged 16, 18, 20, or 80 weeks were infused in situ with Microfil, harvested, and scanned with micro-computed tomography (CT). We characterized plaque volume and CT "density" as well as VV luminal volume along the aorta using Analyze 6.0 software. Results were complemented by a detailed histological plaque classification according to American Heart Association guidelines. From 16 to 80 weeks, plaque volume and VV opacified lumen volume increased with age (P<0.001). The 3-dimensional micro-CT images of arterial and venous VV trees allowed perfusion territories to be delineated. The spatial location and magnitude of VV density and adventitial inflammation were strongly correlated in advanced atherosclerotic lesions (r=0.91) and identified as an independent correlate to advanced lesions. At age 80 weeks, VV luminal volume was increased 20-fold compared with animals at age 16 weeks (P<0.001). Micro-CT showed that adventitial VV communicate with intraplaque microvessels. Our results show that apoE(-/-)/LDL(-/-) double knockout mice develop VV and advanced atheromas along the aorta. Lesion volume was closely associated with amount of neovascularization in advanced atheromas.

Peri-procedural myocardial injury: 2005 update

During the past three decades, percutaneous coronary intervention has become one of the cardinal treatment strategies for stenotic coronary artery disease. Technical advances, including the introduction of new devices such as stents, have expanded the interventional capabilities of balloon angioplasty. At the same time, there has been a decline in the rate of major adverse cardiac events, including Q-wave acute myocardial infarction, emergency coronary artery bypass grafting, and cardiac death. Despite these advances, the incidence of post-procedural cardiac marker elevation has not substantially decreased since the first serial assessment 20 years ago. As of now, these post-procedural cardiac marker elevations are considered to represent peri-procedural myocardial injury (PMI) with worse long-term outcome potential. Recent progress has been made for the identification of two main PMI patterns, one near the intervention site (proximal type, PMI type I) and one in the distal perfusion territory of the treated coronary artery (distal type, PMI type II) as well as for preventive strategies. Integrating these new developments into the wealth of clinical information on this topic, this review aims at giving a current perspective on the entity of PMI.

Prinzmetal Angina in an Adolescent

A previously asymptomatic 17-year-old male athlete presented with acute onset of left-sided chest pain that awakened him from sleep. The pain was described as “crushing,” radiated to the left arm and jaw, and associated with diaphoresis. He was evaluated in the emergency department of our hospital and was found to have an abnormal ECG with ST-segment elevation in the anterolateral leads (Figure 1A). Initial troponin I and creatine kinase-MB (CK-MB) were elevated, 5.7 ng/mL (0 …

Usefulness of Real-Time Myocardial Perfusion Imaging to Evaluate Alterations of Myocardial Blood Flow in Patients With Stable Angina Pectoris Undergoing Elective Percutaneous Coronary Interventions

Release of cardiac enzymes has been reported in patients with stable angina who undergo elective percutaneous coronary intervention (PCI) and has been associated with adverse clinical outcomes. The aim of the present study was to investigate whether impaired microvascular integrity can be detected using myocardial contrast echocardiography in patients undergoing elective PCI, and whether it is related to the extent of postprocedural troponin T elevation. We investigated consecutive patients with stable angina (n = 19) who were scheduled for elective angioplasty with stent placement. Myocardial contrast echocardiography was performed before and 2 to 4 hours and 24 hours after coronary intervention. Contrast images were analyzed visually and quantitatively measuring the peak signal intensity (A) and the slope of the signal intensity rise (beta) in 16 myocardial segments. The product of A x beta was calculated in each segment to estimate the regional myocardial blood flow. Troponin T was collected serially before and 2 to 4 hours and 24 hours after PCI. Five patients (26%) had elevated troponin T 24 hours after PCI (range 0.03 to 0.46 microg/L). Eight patients (42%), including all 5 patients with elevated troponin T levels, demonstrated impaired microvascular integrity 2 to 4 hours after PCI in >or=2 myocardial segments (range 2 to 4) within the perfusion territory of the target vessel. Of the 11 patients without evidence of impaired myocardial perfusion by myocardial contrast echocardiography, none had elevated troponin T levels at follow-up. Quantitative analysis of myocardial blood flow showed that impaired perfusion after PCI was partially reversible. Thus, A x beta had decreased significantly at 2 to 4 hours after PCI (3.4 +/- 1.6 vs 8.8 +/- 3.4 dB/s baseline, p <0.01), reincreased after 24 hours (6.4 +/- 2.3 dB/s at 24 hours vs 3.4 +/- 1.6 dB/s at 2 to 4 hours, p <0.01), but did not return to baseline (8.8 +/- 3.4 dB/s at baseline vs 6.4 +/- 2.3 dB/s at 24 hours, p <0.01). The perfusion defect size 2 to 4 hours after PCI was closely related to the troponin T levels after 24 hours (r(2) = 0.80, p <0.0001). In conclusion, impaired microvascular integrity is partially present in patients with stable angina who undergo elective PCI, is partially reversible, and is closely related to the release of troponin T. Because judgment of interventional success has shifted downstream to tissue level perfusion, myocardial contrast echocardiography may be useful to monitor such alterations in myocardial tissue perfusion.

In vivo flow territory mapping of major brain feeding arteries

The ability to visualize the perfusion territories of major feeding arteries to the brain is important for many clinical applications. Since the work of Duret in 1874 on vascularization of the brain, many textbooks and atlases have shown schematic drawings of the supply areas of the major cerebral arteries. Recent postmortem studies demonstrated that the variability of the cerebral vascular territories is significantly greater than previously assumed. The aim of the present study was to investigate in vivo, the variability of flow territories of major brain feeding arteries. Flow territory mapping of the anterior (internal carotid arteries) and posterior (basilar artery) circulation was performed in 115 (58 ± 9 years of age) subjects with selective arterial spin labeling MRI. Flow territory maps for the entire population indicated significant variation in flow territories. However, when the subjects are further categorized into groups with a complete circle of Willis, with a missing A1 segment and with a unilateral or bilateral fetal-type posterior cerebral artery, the results showed considerably lower variation within groups. It is therefore concluded that, the variation observed from the entire population is mainly caused by anatomical variants of the circle of Willis. To relate focal brain lesions to underlying flow territories in individual cases, knowledge of the anatomy of the circle of Willis is essential.

Recurrent Embolism in the Course of Marantic Endocarditis

Marantic or nonbacterial thrombotic endocarditis (NBTE) associated with systemic embolism is usually a complication of advanced or terminal malignancies. We report on the case of a 46-year-old woman in whom nonbacterial thrombotic endocarditis (NBTE)-related cerebral embolism was the first clinical sign of ovarian neoplasm, which was diagnosed after cardiac surgery. Marantic endocarditis should alert the physician to make every effort to diagnose the possible background of this clinical phenomenon. Early identification of NBTE, treatment of the underlying disease, and the associated coagulopathy could possibly prevent cardiac surgery.

Long-term follow-up after deferral of coronary intervention based on myocardial fractional flow reserve measurement

To assess long-term results after deferring coronary intervention (percutaneous coronary intervention (PCI)) of an intermediate lesion with a value of myocardial fractional flow reserve (FFR) > or = 0.75 in a 'real life' patient population with no respect to results of stress tests (if performed) or coronary disease extent. PCI of an intermediate lesion was deferred in a group of 85 consecutive patients (54 men, 61+/-10 years) on the basis of the result of FFR > or = 0.75 (mean FFR, 0.89+/-0.06%). FFR was measured in 111 stenoses (mean diameter stenosis, 54+/-8%, left anterior descending coronary artery, 65 (58%), left circumflex coronary artery, 24 (22%), right coronary artery, 22 (20%). Multi-vessel disease (defined as visually assessed diameter reduction of more than 50% in at least two arteries of more than 1.5 mm diameter, supplying at least two of the three major coronary artery perfusion territories) was present in 67% of patients (one-vessel disease, 28 patients (33%), two-vessel disease, 39 patients (46%), three-vessel disease, 18 patients (21%). Recorded events during follow-up were as follows: all-cause death, cardiac death, non-fatal myocardial infarction, ischemia-driven target lesion transcatheter revascularization (TLR) and coronary artery bypass graft (CABG). Angina class (Canadian Cardiovascular Society (CCS) classification) and the need for anti-anginal drugs were recorded. Follow-up was completed in 85 patients (100%). Mean duration of follow-up was 22.6+/-6.6 months (range 4-33 months). Events occurred in 11 patients (13%). Seven patients died; this included two cardiac deaths. A non-fatal myocardial infarction occurred in one patient, one patient needed TLR and three patients underwent CABG. Estimated 33 month cardiac-event-free survival (Kaplan-Meier) was 91+/-4%. Angina class decreased [1.6+/-1.2 compared with 0.8+/-0.8 (P < 0.0001)] without difference with respect to the use of anti-anginal drugs (1.7+/-0.8 compared with 1.7+/-0.9, P = NS). Deferring coronary interventions of intermediate stenosis based on FFR measurement is safe with respect to long-term follow-up, irrespective of the extent of coronary artery disease.

Fusion imaging using a hybrid SPECT-CT camera improves port perfusion scintigraphy for control of hepatic arterial infusion of chemotherapy in colorectal cancer patients

Exclusive and homogeneous perfusion of the liver is considered essential for the efficacy of hepatic arterial infusion of chemotherapy (HAI). The aim of this study was to evaluate port perfusion scintigraphy in colorectal cancer patients using a hybrid SPECT-CT system for control of minimally invasive intra-arterial port systems within the scope of a phase II trial. In 24 consecutive patients, the perfusion territories of intra-arterial hepatic port systems were assessed by port scintigraphy with( 99m)Tc-labelled macroaggregated albumin employing planar imaging, SPECT and SPECT-CT (acquired with a hybrid SPECT-CT camera). The results of blinded reading of the scintigraphic modalities concerning the intra- and extrahepatic perfusion pattern were compared with combined image analysis (angiography and contrast-enhanced dedicated CT) and patient history for validation. Extrahepatic perfusion was correctly seen in three patients, while suspected extrahepatic perfusion could be excluded in one. In 46 liver lobes, perfusion patterns were correctly visualised by SPECT-CT in 100% of cases (planar, 67%; SPECT, 86%). Assessing the perfusion pattern inside the liver on a segmental basis (segments, n=138), SPECT-CT revealed correct segmental assignment of tracer distribution in 100% and was significantly superior to SPECT alone (accuracy, 84%; p<0.001). The scintigraphic findings resulted in changes in therapeutic management in 8/24 patients (33%); in two of these the relevant findings were visualised only by SPECT-CT. In patients receiving HAI, port perfusion scintigraphy by fusion imaging with a hybrid SPECT-CT system provides important information for therapy optimisation and appears to be superior to SPECT alone.

Continuous artery‐selective spin labeling (CASSL)

A new technique for selective spin labeling of individual arteries is presented. It is based on continuous arterial spin labeling (CASL) with an amplitude-modulated control experiment. Precessionary motion of the labeling gradient about the axis of the artery, combined with an appropriate frequency modulation of the labeling RF pulse, restricts the adiabatic inversion to the desired artery. In phantom studies, it was found that the level of selectivity could be controlled by the sequence parameters, and that the achievable labeling efficiency was at a level of approximately 80% compared to a regular, nonselective CASL experiment. In a volunteer study we acquired high-quality images of the perfusion territories of the internal carotid artery (ICA), the basilar artery (BA), the middle cerebral artery (MCA), and both anterior cerebral arteries (ACAs). The results show the method's flexibility for different geometries and flow velocities. Potential applications include perfusion territory imaging of smaller cerebral arteries, and selective angiography techniques.

Pulsed star labeling of arterial regions (PULSAR): A robust regional perfusion technique for high field imaging

Regional perfusion imaging (RPI) has recently been introduced as a potentially powerful technique to map the perfusion territories of patients with vascular diseases in a fully noninvasive manner. However, this technique suffers from the problems of the transfer insensitive labeling technique upon which it is based. In particular, RPI is very sensitive to magnetic field inhomogeneities, and therefore the definition of the labeled bolus can deteriorate at field strength higher than 1.5 T. Furthermore, the slab-selective triple-pulse postsaturation sequence used originally will also be impaired due to the same problem, rendering RPI unusable at higher field. In this work, an adiabatic-based signal targeting with alternating radiofrequency pulses sequence is proposed as a labeling scheme to solve the problems related to variations in local magnetic field, together with an improved four-pulse water suppression enhanced through T(1) effects technique as a presaturation scheme.

Brain perfusion territory imaging applying oblique‐plane arterial spin labeling with a standard send/receive head coil

A new method for the selective spin labeling of left- or right-sided supplying arteries of the brain without the need for additional RF coils is demonstrated. A clinical 1.5 T scanner was used. The spatial selectivity of the labeling process is based on the limited coverage of the excitation field of a standard send/receive head coil together with an oblique positioning of the labeling plane. A computer simulation was used to optimize key labeling parameters under the condition of laminar flow. The validity of the computer model results was confirmed by MRI measurements with a flow model. For human studies, a double-inversion continuous arterial spin labeling (CASL) sequence was modified to allow for arbitrary positioning of the labeling plane. The obtained perfusion-weighted images showed a clear delineation of the perfusion territories of the selected arteries in the anterior circulation of the brain and good gray/white matter contrast.

Regional differences of myocardial infarct development and ischemic preconditioning

The spatial and temporal development of myocardial infarction depends on the area at risk (AAR), the severity and duration of blood flow reduction (energy supply) as well as on heart rate and regional wall function (energy demand). Both supply and demand can vary within the AAR of a given heart, potentially resulting in differences in infarct development. We therefore retrospectively analyzed infarct size (IS, %AAR, TTC) in 24 anesthetized pigs in vivo following 90 min hypoperfusion and 120 min reperfusion of the LAD coronary artery, which supplies parts of the LV septum (LVS) and anterior free wall (LVAFW). The total LAD perfusion territory averaged 49.8 +/- 14.2 (SD) g (49.2 +/- 8.4% of LV); 61.4 +/- 8.1% of the AAR was LVAFW. IS within the LVS was 25.3 +/- 15.1%, while IS within the LVAFW was 16.6 +/-10.1% (p<0.05). While ischemic blood flow (radiolabeled microspheres) did not differ between LVS (0.05 +/- 0.02 ml/min/g) and LVAFW (0.05 +/- 0.03 ml/min/g), perivascular connective tissue (56 +/- 9 vs. 38+/-7 microm(2), p < 0.05) and the capillary-to-myocyte distance (1.65 +/- 0.23 vs. 1.18 +/- 0.23 mm, p < 0.05) were larger in LVS than in LVAFW. Interestingly, IS in LVS (9.3 +/- 9.6%, n = 24) and LVAFW (9.2 +/- 9.1%) were reduced to the same absolute extent by ischemic preconditioning with one cycle of 10 min ischemia and 15 min reperfusion, suggesting that a similar regional difference exists also in the protection afforded by ischemic preconditioning. The mechanism(s) for that remain(s) to be established. In pigs, regional differences in infarct development and protection from it exist in the LAD perfusion territory, which are independent of ischemic blood flow but apparently related to pre-existing structural differences.

Real-time myocardial contrast echocardiography for the detection of stress-induced myocardial ischemia

Real-time contrast echocardiography (MCE) is a new promising technique for assessing myocardial perfusion. The purpose of this study was to test whether realtime MCE can be used to detect functionally significant coronary artery stenosis in patients with known or suspected coronary artery disease. Myocardial contrast echocardiographic studies were compared with nearly simultaneous 99mTc-sestamibi single photon emission computed tomography (SPECT) as a clinical standard reference to evaluate regional myocardial perfusion defects. Real-time MCE based on continuous infusion of Optison (8-10 ml/h) was performed in 66 patients during standard 99mTc-SPECT dipyridamole (0.56 mg/kg x 4 min) stress testing. Images were obtained in apical 4- and 2-chamber views, each divided into 6 segments. Tracer uptake and myocardial opacification were visually analyzed for each segment by two pairs of blinded observers and graded as normal, mildly reduced, severely reduced, or absent. In 792 myocardial segments, myocardial opacification by MCE was uninterpretable in 143 (18%) segments and tracer uptake by SPECT was not clearly defined in 92 (12%) segments. Interobserver variability for MCE was good with concordance rates of 83% (kappa=0.72) for rest- and 86% (kappa=0.76) for stress images. Overall concordance between MCE and SPECT was good (83%, kappa=0.63) at a segmental level. In the diagnosis of fixed and reversible defects, and of normal perfusion, concordance rates were 73, 65 and 83%, respectively. When analysis was performed at the regional level, we found comparable levels of concordance rates for LAD (83%, kappa=0.59), LCX (86%, kappa=0.64) and RCA (80%, kappa=0.68) perfusion territories. These findings suggest that realtime MCE is a clinically acceptable method to evaluate myocardial perfusion defects during dipyridamole stress testing.

Autologous vascular smooth muscle cell-based myocardial gene therapy to induce coronary collateral growth.

For therapeutic angiogenesis to achieve clinical relevance, it must be effective, with minimal side effects to other end organ systems. We developed a cardiac-specific gene delivery mechanism by transfecting autologous vascular smooth muscle cells (VSMC) with VEGF and administering these cells via intracoronary injection. We evaluated the efficacy of this protocol by its ability to stimulate angiogenesis in the presence of a subthreshold stimulus for collateralization. A modified canine repetitive coronary occlusion model was utilized in these experiments with left anterior descending coronary artery occlusions for 2 min every 2 h four times per day for 21 days. An intramyocardial catheter in the perfusion territory of the left anterior descending coronary artery measured proteins in the myocardial interstitial fluid. VSMC from jugular vein explants were isolated, amplified in culture for 3 wk, and transfected with a plasmid expressing VEGF-165 and/or enhanced green fluorescent protein. Cells were injected before commencement of occlusions. VEGF levels in myocardial interstitial fluid were significantly higher in VEGF-transfected animals than in sham (repetitive occlusions without cell transplantation) and control (repetitive occlusions with enhanced green fluorescent protein-transfected cells) animals at the onset of occlusions (P < 0.05). In the VEGF group, collateral flow was increased at day 7 and remained higher than in sham and control groups thereafter. We found that intracoronary administration of VEGF-transfected autologous VSMC effectively promotes collateral development. This approach may provide a way to confine delivery of a gene to a specified organ, thus minimizing complications related to gene transfection in nontargeted organ systems.

Localization and Quantification of Myocardium at Risk by Myocardial Perfusion SPECT During Coronary Artery Occlusion

The aim of this study was to analyze the distribution and extent of the myocardium at risk using polar maps obtained with myocardial perfusion SPECT. Myocardial perfusion of territories irrigated by the left anterior descending (LAD), right coronary (RCA) and left circumflex artery (CX) was studied with the help of a technetium-radiolabeled tracer during occlusion of the vessels in the course of percutaneous coronary angioplasty. We studied 50 patients (24 LAD, 15 RCA and 11 CX). The 99mTc compound was injected immediately after inflation of the balloon, and the artery was occluded for approximately 90 seconds. Tomographic images were acquired, and polar maps showing the extent of the ischemic region (uptake < 50% of maximum) were generated. Mean percentage extent of the ischemic territory was 49.8 +/- 10.3% (minimum 35%, maximum 67%), for the proximal LAD, 39.8 (8.3%) (minimum 20%, maximum 51%) for the mid LAD, 20.3 (7.6%) (minimum 8.3%, maximum 35%) for the RCA, and 21.3 (10.8%) (minimum 10.2%, maximum 30%) for the CX. The contours and extent of the jeopardized myocardial territory found during coronary occlusion allowed us to generate polar maps that illustrated actual coronary risk. The distribution and extent of the areas at risk differed from those in polar maps generated by most current applications used with myocardial perfusion SPECT.

Effect of prone position and attenuation correction on test characteristics of myocardial perfusion imaging in female patients with breast shadow artifacts

Background: Anterior wall defects due to breast decrease specificity of myocardial perfusion imaging (MPI) in female patients (pts.). We compared prone position uncorrected (PRN), supine uncorrected (NO AC), and attenuation corrected (AC) MPI for perfusion scores, sensitivity, specificity, and diagnostic accuracy in women. Methods: 68 female pts. (70±12 yrs) with (+) or without (-) left anterior descending (LAD) coronary artery stenosis ≥ 70% underwent rest TL-201/stress Tc-99m sestamibi MPI as follows: NO AC + simultaneous AC. 45/68 pts. also had PRN. All pts. had: breast shadow on the raw data; anterior, anteroseptal, or apical defects in the LAD distribution as per AHA/ASNC position statement; no anterior wall infarct; diagnostic angiography within 30 days of MPI. Summed stress perfusion scores were based on a 5-point/17-segment model, and % myocardium in the LAD territory perfusion defects (% LV) was calculated from the scores. Friedman rank test was used for %LV, and McNemar's test for statistical significance (p<0.05) between tests' results. Results: See Table %LV ALL % LV LAD(−) %LV LAD(+) Sensitivity Sensitivity Accuracy PRN (n = 45) 4% 3% (n = 33) 6% (n = 12) 50% 94% 82% NO AC (n = 68) 6% 4% (n = 46) 9% (n = 22) 86% 61% 68% AC (n = 68) 8% 5% (n = 46) 12% (n = 22) 83% 79% 80% p 0.0001 0.005 0.007 ns 0.001 PRN and AC vs. NO AC 0.02 PRN and AC vs. NO AC Conclusion: %LV was lowest with PRN, and highest with AC MPI. Compared with NO AC, AC and PRN MPI had increased specificity and accuracy but a trend to a lower sensitivity was observed for PRN.

310 Echocardiographic predictors of short term evolution of patients with cardiogenic shock

Methods: Twenty nine patients (M/F: 19/10, age 67±9 years) with stable angina, and without prior myocardial infarction underwent cardiac catheterization, during which wall motion analysis (centerline method), quantitative coronary angiography (QCA) and CTFC (using a frame counter on a cine viewer) were measured. All patients had a standard 2-D and Doppler echocardiography and Pulsed wave TDI of systolic (Sm) and diastolic velocities (early: Em, late: Am) from the perfusion territories of the left anterior descendens (LAD), the circumflex (CX) and the right coronary artery (RCA), using the apical views, before and 24 hours after PCI. Results: All patients underwent elective PCI (19 LAD, 4 CX and 6 RCA stenoses, range 61 - 94%). There was TIMI grade 3 flow before and after PCI. Regional wall motion (centerline method and wall motion score with echocardiography) was normal in all patients before and after PCI. Significant improvement in the following parameters was observed post PCI (mean ± SD): QCA, 72±12% to 8± 6%; cTFC, 35 ±19 to 22±8; Sm, 5.4±1.1 to 8±1.4; p < 0.005 for all. An improvement was also seen in diastolic function E/A ratio from 0.87±0.23 to 0.97±0.2. A significant correlation was found between cTFC and stenosis severity pre PCI (r=0.58, p=0.0028), and the improvement in cTFC and the regional Sm values post PCI (r = 0.79, p<0.0001). Multiple regression analysis showed that only improvement in the cTFC was important in predicting regional functional recovery within 24-hours post PCI (p=0.0005). In conclusion, TDI could detect regional abnormal function in non infarcted but hypoperfused myocardium, which was undetected by conventional methods. The cTFC correlates with stenosis severity, and that improvement in cTFC (coronary flow) predicts early functional recovery after PCI.

308 Corrected TIMI frame count correlates with stenosis severity and predicts functional improvement after percutaneous coronary intervention

Introduction: The corrected TIMI frame count (cTFC) has been shown to be an index of coronary flow. Tissue Doppler imaging (TDI) can detect early ventricular dysfunction not detected by conventional methods. We hypothesize that: 1. TDI can detect abnormal regional function in non infarcted but chronically hypoperfused myocardium, 2. Improved cTFC post percutaneous coronary intervention (PCI) is associated with early functional improvement. Methods: Twenty nine patients (M/F: 19/10, age 67±9 years) with stable angina, and without prior myocardial infarction underwent cardiac catheterization, during which wall motion analysis (centerline method), quantitative coronary angiography (QCA) and CTFC (using a frame counter on a cine viewer) were measured. All patients had a standard 2-D and Doppler echocardiography and Pulsed wave TDI of systolic (Sm) and diastolic velocities (early: Em, late: Am) from the perfusion territories of the left anterior descendens (LAD), the circumflex (CX) and the right coronary artery (RCA), using the apical views, before and 24 hours after PCI. Results: All patients underwent elective PCI (19 LAD, 4 CX and 6 RCA stenoses, range 61 94%). There was TIMI grade 3 flow before and after PCI. Regional wall motion (centerline method and wall motion score with echocardiography) was normal in all patients before and after PCI. Significant improvement in the following parameters was observed post PCI (mean ± SD): QCA, 72±12% to 8±6%; cTFC, 35±19 to 22±8; Sm, 5.4±1.1 to 8±1.4; p < 0.005 for all. An improvement was also seen in diastolic function E/A ratio from 0.87±0.23 to 0.97±0.2. A significant correlation was found between cTFC and stenosis severity pre PCI (r=0.58, p=0.0028), and the improvement in cTFC and the regional Sm values post PCI (r = 0.79, p<0.0001). Multiple regression analysis showed that only improvement in the cTFC was important in predicting regional functional recovery within 24-hours post PCI (p=0.0005). In conclusion, TDI could detect regional abnormal function in non infarcted but hypoperfused myocardium, which was undetected by conventional methods. The cTFC correlates with stenosis severity, and that improvement in cTFC (coronary flow) predicts early functional recovery after PCI.

Losses of NG2 and NeuN immunoreactivity but not astrocytic markers during early reperfusion following severe focal cerebral ischemia

The ability of glia to recover essential functions following a period of focal cerebral ischemia is likely to be one important factor influencing the severity of tissue damage that subsequently develops. In this study, we have compared changes in immunoreactivity of markers specific for astrocytes, NG2-positive glia and neurons in tissue subregions during early reperfusion following 3 h of middle cerebral artery occlusion to provide insights into possible differential susceptibility of these cell populations. Under the conditions used, infarction ultimately encompasses most of the perfusion territory of the occluded artery. Nonetheless, alterations in immunoreactivity during the first 3 h of recirculation were restricted to brain regions that had been subjected to severe ischemia. In the striatum, cellular immunoreactivity for NG2 and neuronal markers, NeuN and microtubule-associated protein 2, was greatly reduced by 1 h of reperfusion and declined further at 3 h. NG2 labeling of blood vessels in the striatum appeared post-ischemically, mimicking expression of this protein during development. Less severe changes were seen in the neuronal markers in overlying cerebral cortex. In contrast to the losses of other cellular proteins, immunoreactivity for the astrocytic marker, glial fibrillary acidic protein, was preserved in all tissue that had been subjected to severe ischemia and labeling of another astrocytic protein, glutamine synthetase, was increased by 3 h of reperfusion. These findings provide the first evidence of marked sensitivity of NG2-immunoreactivity to severe ischemia and suggest a greater initial resistance of astrocytes compared with neurons and NG2-positive glia to ischemia–reperfusion damage.