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1.
Assuero Giorgetti Gianmario Sambuceti Danilo Neglia Oberdan Parodi 《Journal of nuclear cardiology》1999,6(1):19-19
Background The clinical correlations between stress-induced normalization of previously negative T waves (NTW) and regional myocardial
blood flow (MBF) regulation and tissue viability remain debatable.
Methods and Results To confirm these correlations, 14 patients with previous anterior myocardial infarction (13 Q waves) and NTW on baseline electrocardiographic
precordial leads and 10 healthy subjects were studied by means of positron emission tomography (PET). The MBF values were
obtained in the anterior infarcted myocardial regions in either resting condition or during dipyridamole infusion, using N-13
ammonia as a flow tracer. Seven subjects had normalization of NTW (Group 1) and 7 had persistent NTW (Group 2) during dipyridamole
infusion. The resting MBF values were similar for both Group 1 and Group 2 (0.43±0.13 versus 0.51±0.15 mL·min−1.g−1, respectively; P=not significant) and were significantly lower than in the anterior myocardial regions of healthy subjects (1.03±0.23 mL·min−1.g−1, P<.001). After administration of dipyridamole, the MBF was significantly higher in Group 1 than in Group 2 (0.88±0.37 versus
0.55±0.17 mL·min−1.g−1, respectively; P<.05) and markedly lower than in healthy subjects (3.78±0.64 mL·min−1.g−1, respectively; P<.05) and markedly lower than in healthy subjects (3.78±0.64 mL·min−1.g−1, P<.001). Coronary reserves (dipyridamole/resting MBF) were 2.03±0.40 and 1.14±0.44 in Group 1 and Group 2, respectively (P<.002).
Conclusion Despite similar values of resting perfusion, infarcted dysfunctional areas with or without NTW during stress may present different
regional MBF responses; normalization of NTW demonstrates higher coronary flow reserve than persistent NTW, suggesting a better
preserved coronary microcirculatory function in the former, indicative of the presence of myocardial viability.
Presented in part at the 3rd International Congress on Nuclear Cardiology, Florence, April 1997. 相似文献
2.
Renata De Maria Alberto Repossini Wafer Dabdoob Marina Parolini Vincenzo Cianci Alberto Bestetti Giorgio Binetti Vincenzo Arena Oberdan Parodi 《Journal of nuclear cardiology》2007,14(6):860-868
Background
Whether patency of a second diseased vessel still impacts myocardial perfusion when complete revascularization of the left
anterior descending coronary artery (LAD) territory has been achieved is currently undetermined. In patients with 2-vessel
coronary artery disease and complex LAD lesions, we evaluated the impact of single LAD or integrated revascularization on
single photon emission computed tomography-assessed reversible myocardial ischemia.
Methods and Results
Thirty-five candidates for revascularization with double-vessel disease including the LAD and a preoperative stress single
photon emission computed tomography study were studied. Revascularization was performed by minimally invasive direct coronary
artery bypass (MIDCAB) alone (n=15) or by an integrated procedure with second-vessel angioplasty, either soon after surgery
(n=13) or at 2 months (n=7), according to the extent of reversible perfusion defects in the second vessel territory. At 1
year, the total ischemic area decreased from 9.3±5.1 to 0.8±1.5 in MIDCAB-only patients and from 8.2±4.9 to 1.6±2.9 in the
integrated group (P=.87 for treatment and P<.001 for time). The ischemic area in the second vessel territory similarly decreased in both groups (P=.81 for treatment and P<.001 for time).
Conclusions
In 2-vessel coronary artery disease involving the LAD, MIDCAB alone achieves, in a substantial proportion of patients, functionally
complete revascularization even in the nonrevascularized second vessel territory.
The study was supported by grant ICS030.6 RF99/15 from the Italian National Ministry of Health. 相似文献
3.
Bernhard L. Gerber MD FESC Ho Thien Thanh MD Véronique Roelants MD Agnès Pasquet MD David Vancraeynest MD Jean -Louis J. Vanoverschelde MD FESC 《Journal of nuclear cardiology》2008,15(3):363-374
Background: We examined flow-function relationships in humans with chronic coronary artery disease (CAD) in relation to the transmural
extent of necrosis, aiming to distinguish the various pathophysiologic conditions that cause chronic ischemic dysfunction,
ie, chronic hibernation (perfusion-contraction match) from chronic stunning (perfusion-contraction mismatch).
Methods and Results: Twenty-two patients (18 men, 61±13 years) with CAD and chronic contractile dysfunction (ejection fraction, 26%±13%) and 6
volunteers underwent tagged and gadolinium (Gd)-DTPA contrast-enhanced magnetic resonance imaging as well as 13NH3-positron emission tomography. The relationship between regional circumferential shortening strain (ECC), transmural necrosis,
and absolute transmural myocardial perfusion (MBF) was examined quantitatively in dysfunctional segments (<10% ECC). Noninfarcted
(<25% transmurality), dysfunctional myocardium presented a perfusion-contraction mismatch, as indicated by a 72% reduction
(to −5% ±4% shortening) of ECC, versus only a 12% (to 63±20 mL/min/100 g) reduction of transmural MBF. With increasing amounts
of necrosis, reductions between perfusion versus contraction became increasingly matched, ie, dysfunctional segments with
a greater than 75% transmural extent of necrosis had a 57% reduction of MBF (to 30±17 mL/min/100 g), for a similar severe
reduction of 80% of ECC (to −3% ± 3% shortening).
Conclusions: Noninfarcted, dysfunctional human myocardium mostly presents with a perfusion-contraction mismatch, consistent with stunning.
By contrast, dysfunctional myocardium presenting with a perfusion-contraction match is always associated with significant
amounts of necrosis. 相似文献
4.
J. Tim Marcus Marco J. W. Gtte Albert C. van Rossum Joost P. A. Kuijer Robert M. Heethaar Leon Axel Cees A. Visser 《Magnetic resonance in medicine》1997,38(5):803-810
Early after infarction in the perfusion bed of the left anterior descending coronary artery, cine MRI with spatial modulation of magnetization (SPAMM) tagging (7-mm grid) was used for short- and long-axis cardiac imaging. Two-dimensional strain analysis of triangular finite elements was performed between end-diastole and end-systole. Patients (n = 10) were compared with age-matched healthy subjects (n = 8). The anteroseptal region at midventricular level was considered representative for “infarcted” and the posterolateral region at basal level was considered “remote”. The left ventricular end-diastolic volume index was larger in the patients (69 ± 15 ml/m2 versus 56 ± 4 ml/m2, P < 0.05). Short-axis images showed in the infarcted region a decrease of first principal strain (greatest systolic lengthening: 1.10 ±. 06 versus 1.27 ± 0.04, P < 0.0001), and in the remote region an increase (1.48 ± 0.11 versus 1.36 ± 0.07, P < 0.025). The lateral and inferior ventricular regions at mid- and basal levels were found to function normally. Long-axis images yielded similar results. Early after infarction, regions with dysfunction, normal function, and hyperfunction can be delineated with MR tagging. The compensatory increased contraction in the remote region is possibly triggered by the Frank-Starling mechanism. 相似文献
5.
Marcus Carlsson Alastair J Martin Philip C Ursell David Saloner Maythem Saeed 《Magnetic resonance in medicine》2009,61(3):595-602
Microembolization is common after coronary interventions, and therefore this MRI study aimed to quantify the effect of coronary microembolization on left ventricular (LV) function. The left anterior descending artery (LAD) was selectively catheterized in an XMR suite (Philips Medical Systems, Best, The Netherlands) in eight pigs to deliver MR contrast media to measure the LAD territory using first‐pass perfusion and for intracoronary delivery of the embolic agent. Cine, tagged, and delayed contrast‐enhanced MRI (DCE‐MRI) was performed to assess LV volumes, ejection fraction, radial and circumferential strain, and viability at baseline, 1 h, and 1 week after microembolization. Histopathology and histochemical staining were used to characterize and measure the extent of microinfarction. The LAD territory was 35% ± 2% LV mass. Patchy microinfarction on DCE‐MRI at 1 week was 22.0% ± 3.6% LAD territory (7.5% LV mass). Microembolization caused persistent decline in ejection fraction (baseline = 49% ± 1%, 1 h = 29% ± 1%, P = 0.02 and 1 week = 36% ± 1%, P = 0.03) and increased end‐diastolic (79.6 ± 3.9 ml, 85.5 ± 4.5 ml, P = 0.03 and 92.4 ± 6.2 ml, P = 0.06, respectively) and end‐systolic (40.8 ± 2.1 ml, 60.2 ± 3.4 ml, P = 0.02 and 59.3 ± 4.8 ml, P = 0.03, respectively) volumes. The microembolized territory was manifested as dysfunctional regions for 1 week on cine and tagged MRI. Histopathology revealed occlusive microemboli surrounded by necrotic tissue undergoing repair. Microinfarction was visualized after coronary microembolization and caused LV dysfunction disproportionate to the size of myocardial damage. It also changed LV geometry and decreased radial and circumferential strain over the course of 1 week. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc. 相似文献
6.
Andrew E. Arai Carl C. Gaither Frederick H. Epstein Robert S. Balaban Steven D. Wolff 《Magnetic resonance in medicine》1999,42(1):98-109
Velocity-encoded phase contrast magnetic resonance imaging (MRI) has the potential to quantify regional myocardial contractile function with a sensitivity to motion comparable to implanted ultrasonic crystals. An MRI sequence and post-processing algorithm were developed to measure myocardial velocity gradients on a 1.5 T MRI scanner. These methods were validated on a rotating phantom and applied to dogs before (n = 11) and during prolonged coronary occlusion (n = 5). In phantom validation studies, the average absolute error corresponded to motion equivalent to 0.03 ± 0.04 mm (mean ± SD) during the repetition time of the experiment. Rigid body corrections during post-processing significantly simplified the interpretation of myocardial velocity vectors. In vivo, rigid body motion contributes substantially to the recorded myocardial velocities in systole and diastole and can give the false impression of regional wall motion abnormalities. After rigid body correction, normal systolic and diastolic velocity vectors in short-axis views of the left ventricle were primarily directed toward the center of the left ventricle. Transmural radial strain rate was 2.0 ± 0.6 sec−1 during systole and −3.6 ± 1.1 sec−1 during early diastole in normal canine hearts. Ischemic myocardium was easily discriminated from normal left ventricle by velocity-encoded phase contrast MRI both qualitatively and quantitatively (P < 0.01 in systole and P < 0.05 in early diastole). Although the myocardial velocity images have a spatial resolution on the order of a millimeter, the velocity encoding describes the mechanical consequences of focal myocardial ischemia with sensitivity to submillimeter displacement of the pixels. The three-dimensional nature of velocity-encoded MRI is particularly well suited to the study of the complex motion of the heart in vivo. Magn Reson Med 42:98–109, 1999. © 1999 Wiley-Liss, Inc. 相似文献
7.
Abdou Elhendy Ron T. van Domburg Jeroen J. Bax Peter R. Nierop Roelf Valkema Marcel L. Geleijnse Jaroslaw D. Kasprzak Arthur F. L. Liqui-Lung Jan H. Cornel Jos R. T. C. Roelandt 《Journal of nuclear cardiology》1998,5(5):491-497
Objective To assess the accuracy of dobutamine stress myocardial perfusion single photon emission computed tomographic imaging (SPECT)
for the diagnosis of vascular stenosis after coronary artery bypass grafting (CABG).
Background Exercise thallium scintigraphy is a clinically useful method for the diagnosis of graft stenosis after CABG. Although dobutamine
perfusion scintigraphy is an alternative method for the evaluation of patients with limited exercise capacity, its value in
the diagnosis of vascular stenosis after CABG has not been studied.
Methods Dobutamine (up to 40 μg/kg/min)-atropine (up to 1 mg) stress test in conjunction with myocardial perfusion SPECT imaging (201Tl or 99m technetium sestamibi [MIBI]) was performed in 71 patients (mean age 58±9 years, 57 men) with limited exercise capacity
referred for evaluation of myocardial ischemia 3.7±3.5 years after CABG. Significant vascular stenosis was defined as ≥50%
luminal diameter stenosis of a graft or a native nongrafted coronary artery and was predicted on the basis of reversible perfusion
abnormalities.
Results Significant vascular stenosis was detected in 52 patients. Sensitivity, specificity, and accuracy of reversible perfusion
defects at dobutamine SPECT for the overall diagnosis of vascular stenosis were 81%, confidence interval (CI) 72 to 90, 79%,
CI 69 to 88, and 80%, CI 71 to 90, respectively. Significant vascular stenosis was detected in 73 arterial regions. Sensitivity,
specificity, and accuracy of dobutamine SPECT for the diagnosis of regional vascular stenosis were 66%, CI 58 to 74, 83%,
CI 76 to 89, and 74%, CI 67 to 81, respectively. Patients with multivessel stenosis had a higher number of ischemic segments
(1.6±1.3 vs 1±1, P<.05) and ischemic perfusion score (3.2±2.7 vs 2.2±2.3, P<.05) than patients with single-vessel stenosis, respectively. Significant graft stenosis was detected in 67 graft regions.
Sensitivity, specificity, and accuracy of dobutamine SPECT for the diagnosis of regional graft stenosis were 64%, CI 56 to
73, 85%, CI 78 to 91, and 74%, CI 66 to 82, respectively.
Conclusion Dobutamine stress myocardial perfusion SPECT imaging is a useful method for the diagnosis of significant vascular stenosis
after CABG in patients with limited exercise capacity.
Supported in part by the Department of Cardiology, Cairo University Hospital, Cairo, Egypt and by a grant from the NUFFIC,
the Hague, the Netherlands. 相似文献
8.
Grigorios Korosoglou MD Simon Futterer MD Per M. Humpert MD Nina Riedle BS Dirk Lossnitzer MD Birgit Hoerig RN Henning Steen MD Evangelos Giannitsis MD Nael F. Osman MD Hugo A. Katus MD 《Journal of magnetic resonance imaging : JMRI》2009,29(5):1053-1061
Purpose
To investigate regional strain response during high‐dose dobutamine stress cardiac magnetic resonance imaging (DS‐CMR) using myocardial tagging and Strain‐Encoded MR (SENC).Materials and Methods
Stress induced ischemia was assessed by wall motion analysis, by tagged CMR and by SENC in 65 patients with suspected or known CAD who underwent DS‐CMR in a clinical 1.5 Tesla scanner. Coronary angiography deemed as the standard reference for the presence or absence of CAD (≥50% diameter stenosis) in all patients.Results
SENC and conventional tagging detected abnormal strain response in six and five additional patients, respectively, who were missed by cine images and proved to have CAD by angiography (P < 0.05 for SENC versus cine, P = 0.06 for tagging versus cine and p = NS for SENC versus tagging). On a per‐vessel level, wall motion analysis on cine images showed high specificity (95%) but moderate sensitivity (70%) for the detection of CAD. Tagging and SENC yielded significantly higher sensitivity of 81% and 89%, respectively (P < 0.05 for tagging and P < 0.01 for SENC versus wall motion analysis, and p = NS for SENC versus tagging), while specificity was equally high (96% and 94%, respectively, P = NS for all).Conclusion
Both the direct color‐coded visualization of strain on CMR images and the generation of additional visual markers within the myocardium with tagged CMR represent useful adjuncts for DS‐CMR, which may provide incremental value for the detection of CAD in humans. J. Magn. Reson. Imaging 2009;29:1053–1061. © 2009 Wiley‐Liss, Inc. 相似文献9.
Michael Markl Rahul Rustogi Mauricio Galizia Amita Goyal Jeremy Collins Asad Usman Bernd Jung Daniela Foell James Carr 《Magnetic resonance in medicine》2013,70(2):517-526
Monitoring post cardiac transplant (TX) status relies on frequent invasive techniques such as endomyocardial biopsies and right heart cardiac catheterization. The aim of this study was to noninvasively evaluate regional myocardial structure, function, and dyssynchrony in TX patients. Myocardial T2‐mapping and myocardial velocity mapping of the left ventricle (basal, midventricular, and apical short‐axis locations) was applied in 10 patients after cardiac transplantation (49 ± 13years, n = 2 with signs of mild rejection, time between TX and MRI = 1–64 months) and compared to healthy controls (n = 20 for myocardial velocity mapping and n = 14 for T2). Segmental analysis based on the 16‐segment American Heart Association model revealed increased T2 (P = 0.0003) and significant (P < 0.0001) reductions in systolic and diastolic radial and long‐axis peak myocardial velocities in TX patients without signs of rejection compared to controls. Multiple comparisons of individual left ventricular segments demonstrated reductions of long‐axis peak velocities in 50% of segments (P < 0.001) while segmental T2 values were not significantly different. Systolic radial as well as diastolic radial and long‐axis dyssynchrony were significantly (P < 0.04) increased in TX patients indicating less coordinated contraction, expansion, and lengthening. Correlation analysis revealed moderate but significant (P < 0.010) inverse relationships between myocardial T2 and long‐axis peak velocities suggesting a structure–function relationship between altered T2 and myocardial function. Magn Reson Med 70:517–526, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
10.
Gerold Porenta Simon Cherry Johannes Czernin Richard Brunken William Kuhle Tetsuo Hashimoto Heinrich R. Schelbert 《European journal of nuclear medicine and molecular imaging》1999,26(11):1465-1574
The aims of this study were: (1) to measure noninvasively and near simultaneously myocardial blood flow, oxygen consumption,
and contractile function and (2) to analyze myocardial energy expenditure and efficiency at rest and during dobutamine stress
in normal humans. Dynamic and gated carbon-11 acetate positron emission tomography (PET) imaging was performed in 11 normal
subjects. The initial uptake of 11C-acetate was measured to estimate myocardial blood flow. Oxygen consumption was derived from the monoexponential slope of
the 11C-clearance curve recorded during myocardial washout. ECG-gated systolic and diastolic images were acquired during the peak
myocardial 11C activity to measure left ventricular radius, myocardial wall thickness, and long axis length. Myocardial oxygen consumption
and parameters of cardiac geometry were used to determine myocardial energetics and cardiac efficiency by tension-area area
analysis. Myocardial blood flow averaged 0.8±0.06 ml min–1 g–1 at rest and 1.48±0.15 ml min–1 g–1 during dobutamine stress. Oxygen delivery and consumption were 151±13 and 88±15 μl O2 min–1 g–1 at rest and increased to 291±31 and 216±31 μl O2 min–1 g–1, respectively, during pharmacological stress (P<0.001). Oxygen extraction increased from 59%±8% at rest to 76%±9% during stress (P<0.001). Mechanical efficiency was 29%±6% at rest and 32%±6% during dobutamine stress (P=NS) while external work efficiency was 16%±6% at rest and increased to 21%±4% (P<0.01) during dobutamine stress. Stepwise linear regression analysis identified rate-pressure product and external cardiac
work as major correlates of oxygen consumption. In summary, rapid dynamic and gated PET 11C acetate imaging provides the unique capability to study noninvasively determinants of myocardial energy delivery, expenditure,
and efficiency.
Received: 15 March and in revised form 28 May 1999 相似文献
11.
Debiao Li Paritosh Dhawale Patricia J. Rubin E. Mark Haacke Robert J. Gropler 《Magnetic resonance in medicine》1996,36(1):16-20
The purpose of this study was to examine the differential myocardial signal responses due to the blood oxygen level dependent (BOLD) effect in magnetic resonance imaging (MRI) under differing conditions of myocardial oxygen supply and demand. The signal response was measured when myocardial blood flow was increased in excess of oxygen demand or when flow was increased in response to increased myocardial oxygen demand. Normal volunteers were studied using a segmented, interleaved, double-echo, gradient-echo sequence at baseline conditions and during pharmacological stress with either dipyridamole (n = 5) or dobutamine (n = 6). Changes in T2* in the myocardium during stress were calculated. Peak coronary flow velocity was measured at rest and during stress using a breath-hold phase contrast technique. Administration of dipyridamole induced a 124 ± 27% increase in coronary blood flow which resulted in a 46 ± 22% increase in T2*, consistent with a decrease in myocardial venous deoxyhemoglobin concentration as myocardial oxygen supply exceeds demand. In contrast, the administration of dobutamine resulted in a 41 ± 25% increase in coronary blood flow but no significant change in T2* (?5 ± 19%), consistent with a lack of change in myocardial venous deoxyhemoglobin concentration and balanced oxygen supply and demand. Thus, alterations in the relationship between myocardial oxygen supply and demand appear to be detectable using BOLD MRI. 相似文献
12.
Linda R. Peterson Pablo F. Soto Pilar Herrero Kenneth B. Schechtman Carmen Dence Robert J. Gropler 《Journal of nuclear cardiology》2007,14(4):573-581
Background Both physiologic and pathophysiologic conditions affect the myocardium’s substrate use and, consequently, its structure, function,
and adaptability. The effect of sex on myocardial oxygen, glucose, and fatty acid metabolism in humans is unknown.
Methods and Results We studied 25 young subjects (13 women and 12 men) using positron emission tomography, quantifying myocardial blood flow,
myocardial oxygen consumption (MVO2), and glucose and fatty acid extraction and metabolism. MVO2 was higher in women than in men (5.74±1.08 μmol·g−1·min−1 vs 4.26±0.69 μmol·g−1·min−1,P<.005). Myocardial glucose extraction fraction and utilization were lower in women than in men (0.025±0.019 vs 0.062±0.028
[P<.001] and 133±96 nmol·g−1·min−1 vs 287±164 nmol·g−1·min−1 [P<.01], respectively). There were no sex differences in myocardial blood flow, fatty acid metabolism, or plasma glucose, fatty
acid, or insulin levels. Female sex was an independent predictor of increased MVO2 (P=.01) and decreased myocardial glucose extraction fraction and utilization (P<.005 andP<.05, respectively). Insulin sensitivity was an independent predictor of increased myocardial glucose extraction fraction
and utilization (P<.01 andP=.01, respectively).
Conclusions Further studies are necessary to elucidate the mechanisms responsible for sex-associated differences in myocardial metabolism.
However, the presence of such differences may provide a partial explanation for the observed sex-related differences in the
prevalence and manifestation of a variety of cardiac disorders.
This work was supported by grants HD145902 (Building Interdisciplinary Research in Women’s Health), RR00036 (General Clinical
Research Center), DK56341 (Clinical Nutrition Research Unit), K23-HL077179, RO1-AG15466, PO1-HL13581, and HL73120 from the
National Institutes of Health (Bethesda, Md) and grant 051893 (AHA02255732) from the Robert Wood Johnson Foundation (Princeton,
NJ). 相似文献
13.
Dara L. Kraitchman Alistair A. Young Daniel C. Bloomgarden Zahi A. Fayad Lawrence Dougherty Victor A. Ferrari Raymond C. Boston Leon Axel 《Magnetic resonance in medicine》1998,40(2):311-326
A single integrated examination using regional measurements of perfusion from contrast-enhanced MRI and three-dimensional (3D) strain from tissue-tagged MRI was developed to differentiate infarcted myocardium from adjacent tissue with functional abnormalities. Ten dogs were studied at baseline and 10 days after a 2-hour occlusion of the left anterior descending coronary artery (LAD). Strain was determined using a 3D finite element model. Two-dimensional measurements of hypoenhancing regions were highly correlated with myocardial viability (r = 0.96). Signal intensity versus time curves obtained from contrast-enhanced MRI were used for quantitative perfusion analysis. The remote and adjacent noninfarcted tissue of the dogs with LAD occlusion, as well as the infarcted tissue, exhibited abnormal deformation patterns as compared to normal dogs positive predictive value (PPV) of strain determination of infarction = (66%). Integration of contrast-enhanced MRI results with 3D strain analysis enabled the delineation of the myocardial infarction (PPV = 100%) from functionally compromised myocardium. This integrated cardiac examination shows promise for noninvasive serial assessment of potentially jeopardized noninfarcted myocardium to study the process of infarct remodeling and expansion. 相似文献
14.
Gert Klug MD Thomas Trieb MD Michael Schocke MD Michael Nocker MD Elisabeth Skalla MD Agnes Mayr MD Martha Nowosielski MD Kathrin Pedarnig MD Thomas Bartel MD Nico Moes MD Otmar Pachinger MD Bernhard Metzler MD 《Journal of magnetic resonance imaging : JMRI》2009,29(2):298-304
Purpose
To assess with cardiac magnetic resonance imaging (CMR) the relationship between treatment delay and improvement of regional left ventricular function after primary percutaneous transluminal coronary angioplasty (p‐PTCA) for acute myocardial infarction (AMI).Materials and Methods
We performed cine‐ and late‐enhancement (LE) CMR in 40 patients with first AMI after restoring TIMI 3 flow with p‐PTCA and at a follow‐up 4 months later. Infarcted segments were determined from LE images. Regional left ventricular function was quantified from cine‐CMR images. Segmentation followed the American Heart Association 17‐segments model. Patients were divided into groups with delay <3 hours, 3–6 hours, 6–12 hours, and a delay >12 hours.Results
Segmental wall thickening (SWT) significantly iproved only in segments reperfused within 6 hours (P < 0.001). Follow‐up SWT was significantly higher if segments were reperfused early (<3 hours: 74 ± 4%, 3–6 hours: 57 ± 4%, 6–12 hours: 48 ± 7%, <3 to 3–6: P < 0.003, and <3 to 6–12 hours: P < 0.001). The extent of improvement was greater if delay was <3 hours compared to segments with a delay of >3 hours (<3 hours: +21 ± 3%, 3–6 hours: +8 ± 4%, 6–12 hours: +6 ± 3%; <3 hours to 3–6 hours, and 6–12 h, P < 0.02).Conclusion
We quantitatively demonstrated that time to p‐PTCA treatment significantly influences regional functional recovery of infarcted myocardium at a 4‐month follow‐up. J. Magn. Reson. Imaging 2009;29:298–304. © 2009 Wiley‐Liss, Inc. 相似文献15.
John H. Lee Mohammad Abuannadi Philip G. Jones Timothy Bateman Randall Thompson James H. O’Keefe 《Journal of nuclear cardiology》2008,15(4):526-529
Background. Chest pain occurs frequently during dobutamine stress testing and is commonly attributed to ischemia. However, the pathophysiologic
significance of dobutamine-induced chest pain is uncertain. The purpose of this study is to explore the correlation between
dobutamine-induced chest pain and evidence of ischemia on myocardial perfusion imaging (MPI).
Methods and Results. This study included 1608 patients who underwent dobutamine stress MPI at the Mid America Heart Institute (Kansas City, Mo)
and were analyzed retrospectively. Patients were divided into those with chest pain during dobutamine infusion versus those
without it. Multivariate and χ
2 analyses were conducted to explore the relationship between chest pain and ischemic changes on MPI. Of 1608 patients, 208
(13%) had chest pain with dobutamine whereas 1400 (87%) did not. MPI ischemia was seen in 47% of patients with chest pain
and 43% without chest pain (P=.28). Chest pain was not any more predictive of ischemia when analyzed separately by gender (P=.31). Multivariate analysis did not identify chest pain as a predictor of ischemia (P=.19). Significant predictors of scintigraphic ischemic changes were age (P=.001), gender (P<.0001), smoking (P=.0149), and known coronary artery disease (P<.0001).
Conclusion. This large retrospective study suggests that chest pain during dobutamine stress testing is not a predictor of ischemia
when analyzed against reversible perfusion defects on SPECT MPI. 相似文献
16.
Jo Mahenthiran Bilal R. Khan Stephen G. Sawada Mithilesh K. Das 《Journal of nuclear cardiology》2007,14(3):347-353
Background Fragmented QRS (FQRS) complexes, not typical of a bundle branch block, are a marker of regional myocardial injury. The extent
of stress myocardial perfusion imaging (MPI) abnormalities with FQRS patterns is not known.
Methods and Results Twelve-lead electrocardiograms (ECGs) in 501 patients undergoing stress MPI were studied. FQRS was defined as a QRS duration
of 120 milliseconds or less, with notches or slurs of QRS complexes, on 2 contiguous leads of a coronary artery territory.
Abnormal MPI was defined as a regional summed stress score (SSS) and summed rest score (SRS) of 3 or greater based on a 17-segment
model. Patients with a typical bundle (n=26), paced rhythm (n=2), and Q waves (n=64) were excluded. Of the remaining 409 patients
(mean age, 58±13 years; 52% male), 155 (38%) had FQRS on the ECG. FQRS patients had a higher mean SSS, SRS, and global summed
difference score and a lower left ventricular ejection fraction (all P<.001), as well as greater regional stress MPI scar (69% vs 11%, P<.001), FQRS pattern sensitivity was 75% and specificity was 94% for a corresponding regional MPI scar. On logistic regression,
SSS, SRS, summed difference score, left ventricular ejection fraction, and regional scar were univariate predictors of the
FQRS pattern on the ECG (all P<.01), and any regional scar (odds ratio, 32; P<.001) was a multivariate predictor.
Conclusions FQRS complexes on an ECG are a marker of higher stress MPI perfusion and functional abnormalities. Regional FQRS patterns
denote the presence of a greater corresponding focal regional myocardial scar on stress MPI 相似文献
17.
Demetrius L. Dicks MD Marcus Carlsson MD PhD Einar Heiberg PhD Alastair Martin PhD David Saloner PhD Hakan Arheden MD PhD Maythem Saeed DVM PhD 《Journal of magnetic resonance imaging : JMRI》2009,30(1):69-76
Purpose
To use velocity‐encoded phase contrast (PC) MRI in assessing the effect of coronary microembolization on longitudinal and radial myocardial strain.Materials and Methods
A combined X‐ray and MR system (XMR) was used for selective left anterior descending artery catheterization and microinfarct assessment in swine (n = 6). The embolized area at risk was defined on perfusion MRI followed by administration of a 7500 count (size = 100–300 μm) of the embolic agent. Quantification of strain and microinfarction was performed at 1 h and 1 week using PC‐MRI and delayed enhancement (DE) MRI, respectively. At postmortem, sliced hearts were stained to define microinfarction.Results
Baseline longitudinal and radial strain did not differ between area‐at‐risk and remote myocardium. The embolized territory (area at risk) showed significant decline in longitudinal strain from ?11.5 ± 3.2% to 1.8 ± 2.5% at 1 h (P < 0.05) and ?3.9 ± 1.1% at 1 week (P < 0.05). Similarly, regional radial strain progressively declined from 23.6 ± 2.5% at baseline to 12.5 ± 3.7% at 1 h (P < 0.05) and 4.8 ± 5.0% at 1 week (P < 0.01). The size of microinfarction was not significantly different between DE‐MRI and histochemical staining.Conclusion
PC‐MRI is sensitive in assessing changes in regional longitudinal and radial strain after coronary embolization. Longitudinal and radial strain of the hyperenhanced patchy microinfarction demonstrates persistent decline over the course of 1 week. J. Magn. Reson. Imaging 2009;30:69–76. © 2009 Wiley‐Liss, Inc.18.
Alberto Cuocolo Wanda Acampa Emanuele Nicolai Leonardo Pace Mario Petretta Marco Salvatore 《Journal of nuclear cardiology》2000,7(1):8-15
Background This study was designed to determine the most effective quantitative threshold for thallium-201 and technetium 99m sestamibi
uptake on tomographic imaging after rest injection for the detection of myocardial viability in patients with chronic myocardial
infarction.
Methods and Results Thallium and sestamibi cardiac tomography at rest was performed in 43 patients with chronic myocardial infarction and impaired
left ventricular (LV) function undergoing coronary revascularization. In all patients, echocardiography and radionuclide angiography
were performed at baseline and repeated 12 months later to evaluate recovery of regional LV function and LV ejection fraction,
respectively. Optimal threshold cutoff points to separate reversible from irreversible dysfunction were determined by receiver
operating characteristic analysis. When all dysfunctional segments were considered, the best cutoff point in the identification
of reversible LV dysfunction for both thallium and sestamibi activity was 67%. When only akinetic or dyskinetic segments were
considered, the best cutoff point in the identification of reversible LV dysfunction was 58% for thallium and 55% for sestamibi.
In these segments, the area under the receiving operating characteristic curves constructed for thallium and sestamibi activity
were 0.74±0.05 and 0.75±0.04, respectively (P=not significant). LV ejection fraction was 33%±7% at baseline and increased to 37%±7% after revascularization (P<.0001). A significant relation between the number of akinetic or dyskinetic but viable myocardial segments and revascularization-induced
changes in LV ejection fraction was observed for both thallium (r=0.60, P<.0001) and sestamibi (r=0.64, P<.0001) imaging.
Conclusions In patients with chronic myocardial infarction, quantitative analysis of thallium and sestamibi activity on tomographic imaging
at rest predicts recovery of regional and global LV dysfunction after revascularization procedures. The most effective quantitative
threshold for detecting reversible LV dysfunction is comparable for thallium and sestamibi tomographic imaging. However, the
optimal cutoff point is different for both tracers when all dysfunctional segments are considered or when the analysis is
focused only on segments with more severe functional impairment (ie, akinetic or dyskinetic segments). 相似文献
19.
Rüssel IK Zwanenburg JJ Germans T Marcus JT Allaart CP de Cock CC Götte MJ van Rossum AC 《Journal of magnetic resonance imaging : JMRI》2007,26(6):1452-1460
Purpose
To investigate whether mechanical dyssynchrony (regional timing differences) or heterogeneity (regional strain differences) in myocardial function should be used to predict the response to cardiac resynchronization therapy (CRT).Materials and Methods
Baseline mechanical function was studied with MRI in 29 patients with chronic heart failure. Using myocardial tagging, two mechanical dyssynchrony parameters were defined: the standard deviation (SD) in onset time (Tonset) and in time to first peak (Tpeak,first) of circumferential shortening. Electrical dyssynchrony was described by QRS width. Further, two heterogeneity parameters were defined: the coefficient of variation (CV) in end‐systolic strain and the difference between peak septal and lateral strain (DiffSLpeakCS). The relative increase in maximum rate of left ventricle pressure rise (dP/dtmax) quantified the acute response to CRT.Results
The heterogeneity parameters correlated better with acute response (CV: r = 0.58, DiffSLpeakCS: r = 0.63, P < 0.005) than the mechanical dyssynchrony parameters (SD(Tonset): r = 0.36, SD(Tpeak,first) r = 0.47, P = 0.01, but similar to electrical dyssynchrony (r = 0.62, P < 0.001). When a heterogeneity parameter was combined with electrical dyssynchrony, the correlation increased (r > 0.70, Pincr < 0.05).Conclusion
Regional heterogeneity in myocardial shortening correlates better with response to CRT than mechanical dyssynchrony, but should be combined with electrical dyssynchrony to improve prediction of response beyond the prediction from electrical dyssynchrony only. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc. 相似文献20.
Dana C. Peters PhD Evan A. Appelbaum MD Reza Nezafat PhD Basem Dokhan BS Yuchi Han MD Kraig V. Kissinger RT Beth Goddu RT Warren J. Manning MD 《Journal of magnetic resonance imaging : JMRI》2009,30(4):794-800