Showing papers by "Steffen E. Petersen published in 2004"
TL;DR: Delayed-enhancement MRI is a powerful predictor of myocardial viability after surgery, suggesting an important role for this technique in clinical viability assessment.
Abstract: Background— Despite the accepted utility of delayed-enhancement MRI in identifying irreversible myocardial injury, no study has yet assessed its role as a viability tool exclusively in the setting of coronary artery bypass surgery (CABG), and no study has repeated delayed-enhancement MRI late after revascularization. In a clinical trial in which patients underwent CABG by either the off-pump or on-pump surgical technique, we hypothesized that (1) preoperative delayed-enhancement MRI would have high diagnostic accuracy in predicting viability and (2) the occurrence of perioperative myocardial necrosis would affect late regional wall motion recovery. Methods and Results— Fifty-two patients undergoing multivessel CABG were studied by preoperative and early (day 6) and late (6 months) postoperative cine MRI for global and regional functional assessment and delayed-enhancement MRI for assessment of irreversible myocardial injury. Preoperatively, 611 segments (21%) had abnormal regional function, whereas 421 se...
329 citations
TL;DR: OPCABG results in significantly better left ventricular function early after surgery but does not reduce the incidence or extent of irreversible myocardial injury.
Abstract: Background— There is biochemical evidence that off-pump coronary artery bypass grafting (OPCABG) reduces myocardial injury compared with the use of cardiopulmonary bypass (ONCABG), but the functional significance of this is uncertain. We hypothesized that OPCABG surgery would result in reduced postoperative reversible (stunning) and irreversible myocardial injury, as assessed by cardiovascular MRI (CMRI). Methods and Results— In a single-center randomized trial, 60 patients undergoing multivessel total arterial revascularization were randomly assigned: 30 to OPCABG and 30 to ONCABG. Patients underwent preoperative and early postoperative cine MRI for assessment of global left ventricular function, and contrast-enhanced CMRI for assessment of irreversible myocardial injury. Serial troponin I measurements were obtained perioperatively and correlated with the CMRI findings. The mean preoperative cardiac index was similar in the 2 surgical groups (2.9±0.7 ONCABG; 2.9±0.8 OPCABG; P=0.9). After surgery, the car...
193 citations
TL;DR: Direct quantification of multiple parameters of vascular function using high-resolution MRI will provide powerful new approaches to the assessment of vascular disease pathogenesis, diagnosis, and treatment.
129 citations
Journal Article•
TL;DR: In this article, the authors aimed to test whether pathological LVH, such as occurs in hypertrophic cardiomyopathy (HCM), hypertensive heart disease, or aortic stenosis, and physiological LVH in athletes, can be distinguished by means of left ventricular volume and geometric indices, derived from cardiovascular magnetic resonance imaging.
Abstract: Purpose. Determination of the underlying etiology of left ventricular hypertrophy (LVH) is a common, challenging, and critical clinical problem. The authors aimed to test whether pathological LVH, such as occurs in hypertrophic cardiomyopathy (HCM), hypertensive heart disease, or aortic stenosis, and physiological LVH in athletes, can be distinguished by means of left ventricular volume and geometric indices, derived from cardiovascular magnetic resonance imaging. Methods. A total of 120 subjects were studied on a 1.5 Tesla MR (Sonata, Siemens Medical Solutions, Erlangen, Germany) scanner, comprising healthy volunteers (18), competitive athletes (25), patients with HCM (35), aortic stenosis (24), and hypertensive heart disease (18). Left ventricular mass index, ejection fraction, end-diastolic, end-systolic and stroke volume index, diastolic wall thickness, wall thickness ratio and diastolic and systolic wall-to-volume ratios were determined. Results. Left ventricular (LV) mass indices were similar for al...
111 citations
TL;DR: The size of nonviable myocardium quantitatively as a function of time post-contrast when inversion time is held constant in patients post-myocardial infarction using two contrast agent (CA) doses underscores the fact that a standardized imaging protocol that defines how the appropriate inversions time should be selected is needed for comparison of results obtained at various cMR sites.
Abstract: Background: Delayed contrast‐enhanced magnetic resonance imaging (ceMRI) has been shown to identify areas of irreversible myocardial injury due to infarction (MI) with high spatial resolution, allowing precise quantification of nonviable (hyperenhanced) myocardium. The aim of our study was to investigate the size of nonviable myocardium quantitatively as a function of time post‐contrast when inversion time is held constant in patients post‐myocardial infarction using two contrast agent (CA) doses. Methods: Nine patients with chronic MI underwent two MR scans on a 1.5 Tesla system. Contrast‐enhanced MRI data in two short‐axis (SA) slices were continuously acquired until 40 minutes after CA injection [gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA), 0.1 mmol/kg body weight = single dose] interrupted only for a complete stack of SA slices encompassing the entire left ventricle (LV) between minutes 20 and 28. Left ventricular mass showing hyperenhancement was determined. The measurement was repeated ...
42 citations
TL;DR: High resolution cardiac MRI applied in patients with acute infarction and new Q waves in leads V1-V4 demonstrates the presence of predominantly apical, but not isolated septal or anteroseptal infarctions.
Abstract: Aim Delayed enhancement MRI (DE-MRI) of the heart has been shown to reliably identify areas of irreversible myocardial damage. We sought to determine if the term anteroseptal MI is appropriate by correlating electrocardiographic, angiographic, cine MRI and DE-MRI findings. Methods and results Nineteen patients admitted to our hospital with their first acute anterior MI and whose ECG showed new Q waves in leads V1-V4 were studied. All patients underwent cardiac catheterization, cine MRI, and DE-MRI. The mean left ventricular ejection fraction was 53%+/-16%. All 19 patients had evidence of delayed hyperenhancement in one or more myocardial segments (mean number of affected segments 5.5+/-2.1). The mean mass of hyperenhanced myocardium was 14+/-8 grams, or 10%+/-6% of absolute LV mass. Nineteen (100%) and 15 (79%) patients showed evidence of delayed hyperenhancement of the apex and apical anterior segments respectively. Seven (37%) patients showed evidence of mid ventricular anteroseptal hyperenhancement and none had any hyperenhancement of basal anteroseptal segments. Conclusion High resolution cardiac MRI applied in patients with acute infarction and new Q waves in leads V1-V4 demonstrates the presence of predominantly apical, but not isolated septal or anteroseptal infarction.
18 citations
TL;DR: By combining the latest MRI methods and semiautomated image analysis methods, this work is able to reproducibly determine the geometric parameters of blood vessels by combining a data analysis method based on vessel wall unwrapping and a gradient detection algorithm for MR data postprocessing.
Abstract: Magnetic resonance imaging (MRI) is uniquely suited to study the pathophysiology of arteriosclerosis. So far, magnetic resonance (MR) measurements of vessel dimensions have mainly been done by manual tracing of vessel wall contours. However, such data postprocessing is very time‐consuming and has limited accuracy due to difficulties in precise tracing of the thin vessel wall. Purpose: To assess the accuracy and reproducibility of quantitative vascular MR imaging applying a data analysis method based on (1) vessel wall unwrapping, followed by (2) a gradient detection algorithm for MR data postprocessing. Vascular MR imaging studies were done both in vessel phantoms and in healthy volunteers (n = 29) on a clinical 1.5 T MR scanner. A dark blood double‐inversion turbo spin echo sequence with fat suppression was applied, with proton‐density‐weighted and breath‐hold acquisition for aortic imaging and T2‐weighted acquisition for carotid imaging. Intraobserver and interobserver variability were systematically ev...
12 citations
TL;DR: In this paper, coronary MR-angiography is used for the detection of significant coronary stenoses in a multicenter trial demonstrating good sensitivity and specificity for detecting significant left main and three vessel disease.
Abstract: Since initial reports in the early 1990s cardiac magnetic resonance imaging (CMR) has matured and is likely to become an established method for routine cardiac diagnostics. The development of faster gradient-echo sequences and stronger magnetic fields has led to improved temporal and spatial resolution. Myocardial viability can be examined by morphological and functional analysis. Contrast enhanced MRI (ceMRI), perfusion measurements and regional wall motion analysis are the major diagnostic tools. The ability to image in arbitrary double oblique planes provides comprehensive visualization of the heart. The introduction of the MR navigator technique allowed for free-breathing motion corrected 3D coronary MR angiography with improved spatial resolution. Using this approach proximal and mid parts of the coronary arteries have been visualized. Subsequently, sensitivity and specificity for the detection of significant coronary stenoses has been evaluated in a multicenter trial demonstrating good sensitivity and specificity for the detection of significant left main and three vessel disease. However, specificity for the detection of single vessel disease was relatively low. Improved motion compensation techniques and novel imaging sequences (SSFP) are currently under investigation to further refine this technique. Despite these promising results coronary MR-angiography is not likely to replace conventional coronary angiography especially with regard to in-plane spatial resolution, coronary collateralization and in-stent restenosis. In contrast, coronary MR-angiography can provide useful morphological informations including functional analysis of the coronary vascular bed. The combination of a conventional cathlab with CMR may provide CMR-guided myocardial interventions. With further improvements in the catheter technology, CMR interventions using real-time imaging guidance will allow to take advantage of the excellent soft tissue contrast of CMR and the simultaneous visualization of the pulmonary, aortic and coronary vessels. CMR is advantageous for screening and follow-up examinations, and it offers comprehensive assessment of cardiac morphology and function in one single examination.
11 citations
TL;DR: A patient with four sequential potentially stenosing and stenosed parts of the proximal systemic circulation: hypertrophic cardiomyopathy, bicuspid aortic valve, coarctation of the aorta and a hypoplastic aorti arch as a part of Noonan’s syndrome is reported on.
Abstract: Das Noonan-Syndrom ist gekennzeichnet durch kraniofaziale
Dysmorphien wie Ptosis der Augenlider, Pterygium colli und durch
einen tiefen nuchalen Haaransatz, durch Skelettveranderungen wie
Kleinwuchs, Klinodaktylie, Kiel- und Trichterbrust und durch
Organfehlbildungen, hauptsachlich Herzfehler, seltener einer
Retentio testis und Nierenfehlbildungen. Das Noonan-Syndrom
weist ein ahnliches Erscheinungsbild auf wie das
Ullrich-Turner-Syndrom. Im Gegensatz zu dieser
Chromosomenaberration sind aber Patienten beiderlei Geschlechts
betroffen, sie weisen einen unauffalligen Chromosomensatz (46,
XX bzw. 46, XY) auf und sind zeugungsfahig. Bei etwa der Halfte
der Patienten mit Noonan-Syndrom bestehen kardiovaskulare
Fehlbildungen. In der Mehrzahl der Falle finden sich
Fehlbildungen des rechten Herzens wie Pulmonalstenose und
Septumdefekte. Fehlbildungen des linken Herzens wie
Aortenklappenstenose und Aortenisthmusstenose sind dagegen
selten. Wir berichten uber einen Patienten mit Noonan-Syndrom
und vier sequentiellen Pathologika im Systemkreislauf mit
Obstruktionspotenzial: Hypertrophische Kardiomyopathie,
bikuspide Aortenklappe, Aortenisthmusstenose und hypoplastischem
Aortenbogen. Erstmals wird in diesem Zusammenhang eine
Madelung-ahnliche Deformitat im Handgelenksbereich
beobachtet.
5 citations
01 Jan 2004
TL;DR: In this article, coronary MR-angiography is used for the detection of significant coronary stenoses in a multicenter trial demonstrating good sensitivity and specifity for detecting significant left main and three vessel disease.
Abstract: Since initial reports in the early 1990s cardiac magnetic resonance imaging (CMR) has matured and is likely to become an established method for routine cardiac diagnostics. The development of faster gradient-echo sequences and stronger magnetic fields has led to improved temporal and spatial resolution. Myocardial viability can be examined by morphological and functional analysis. Contrast enhanced MRI (ceMRI), perfusion measurements and regional wall motion analysis are the major diagnostic tools. The ability to image in arbitrary double oblique planes provides comprehensive visualization of the heart. The introduction of the MR navigator technique allowed for free-breathing motion corrected 3D coronary MR angiography with improved spatial resolution. Using this approach proximal and mid parts of the coronary arteries have been visualized. Subsequently, sensitivity and specificity for the detection of significant coronary stenoses has been evaluated in a multicenter trial demonstrating good sensitivity and specifity for the detection of significant left main and three vessel disease. However, specificity for the detection of single vessel disease was relatively low. Improved motion compensation techniques and novel imaging sequences (SSFP) are currently under investigation to further refine this technique. Despite these promising results coronary MR-angiography is not likely to replace conventional coronary angiography especially with regard to in-plane spatial resolution, coronary collateralization and in-stent restenosis. In contrast, coronary MR-angiography can provide useful morphological informations including functional analysis of the coronary vascular bed. The combination of a conventional cathlab with CMR may provide CMR-guided myocardial interventions. With further improvements in the catheter technology, CMR interventions using real-time imaging guidance will allow to take advantage of the excellent soft tissue contrast of CMR and the simultaneous visualization of the pulmonary, aortic and coronary vessels. CMR is advantageous for screening and follow-up examinations, and it offers comprehensive assessment of cardiac morphology and function in one single examination.
2 citations
Journal Article•
Journal Article•
TL;DR: Questions are raised about not only the clinical significance of increased cTnI levels after P-CABG, but also the higher degree of cardioprotection allegedly supplied by OP-CabG, despite a similar incidence and magnitude of new irreversible myocardial injury in both groups, despite the greater release of cardiac troponin I.
Abstract: Release After Off-Pump Versus On-Pump Coronary Surgery In a recent study by Selvanayagam and colleagues aimed at evaluating reversible and irreversible myocardial injury in patients undergoing off-pump (OP-) versus on-pump (P-) coronary artery bypass surgery (CABG),1 the authors documented a similar incidence and magnitude of new irreversible myocardial injury in both groups, despite the greater release of cardiac troponin I (cTnI) after P-CABG. These findings raise questions about not only the clinical significance of increased cTnI levels after P-CABG, but also the higher degree of cardioprotection allegedly supplied by OP-CABG. The extent of cTnI release does not necessarily correlate with occurrence or magnitude of irrevocable myocardial injury. Although the inaccuracy of cTnI levels in the “quantification” of postsurgical myocardial infarction seems to be mainly related to the “washout phenomenon,” the lack of correlation between cTnI release and occurrence of irreversible myocardial injury may be ascribed to iatrogenic stressors, intrinsic to the P-CABG surgical approach, and not typically associated with enduring myocardial injury. Release of cTnI after P-CABG was detected in bypass patients in the absence of ischemic conditions,2 as well as associated with myocardial stunning3 (a common occurrence after P-CABG), and elevated preload, independently of cardiac ischemia.4 This release, potentially occurring in cardiopulmonary bypass together with that inevitably associated with surgical manipulations, may possibly explain higher, though benign, cTnI levels, detected in P-CABG versus OP-CABG. Reperfusion, whether pharmacologically or mechanically achieved, results in earlier and augmented cTnI release versus no reperfusion. This was substantiated by a recent study showing that P-CABG had graft patency rates significantly greater than OP-CABG, despite higher cTnI levels at 6 to 12 hours postoperatively.5 Additional studies are therefore needed to confirm whether an earlier and greater cTnI release in P-CABG patients should be paradoxically welcomed as a marker of earlier and greater reperfusion.