Objectives To study the prevalence and mechanisms underlying right ventricular (RV) dyssynchrony in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) using tissue Doppler echocardiography (TDE). Background ARVD/C is characterized by fibrofatty replacement of RV myocardium and RV dilatation. These pathologic changes may result in electromechanical dyssynchrony. Methods Electrocardiography, conventional and TDE was performed in 52 ARVD/C patients fulfilling Task Force criteria and 25 controls. RV end-diastolic and end-systolic areas, RV fractional area change (RVFAC), and left ventricular (LV) volumes and function were assessed. Mechanical synchrony was assessed by measuring differences in time-to-peak systolic velocity (TSV) between the RV free wall, ventricular septum and LV lateral wall. RV dyssynchrony was defined as the difference in TSV between the RV free wall and the ventricular septum, >2 SD above the mean value for controls. Results Mean difference in RV TSV was higher in ARVD/C compared to controls (55 ± 34 ms vs. 26 ± 15 ms, p<0.001). Significant RV dyssynchrony was not noted in any of the controls. Based on a cut-off value of 56 ms, significant RV dyssynchrony was present in 26 ARVD/C patients (50%). Patients with RV dyssynchrony had larger RV end-diastolic area (22 ± 5 vs. 19 ± 4 cm2, p=0.02), and lower RVFAC (29 ± 8 vs. 34 ± 8%, p=0.03) compared to ARVD/C patients without RV dyssynchrony. No differences in QRS duration, LV volumes and function were present between the two groups. Conclusions RV dyssynchrony may occur in up to 50% of ARVD/C patients, and is associated with RV remodeling. This finding may have therapeutic and prognostic implications in ARVD/C.
MRC reliably identified variant biliary anatomy. The preoperative MRC demonstrated congruence with the intraoperative cholangiogram and with the intraoperative findings. MRC is helpful in predicting risk of biliary complications in recipients, and identifies donors who would otherwise be excluded intraoperatively by cholangiography, thus limiting the risk of an unnecessary operation.
Purpose-To compare standard of care nuclear SPECT imaging with cardiac magnetic resonance imaging (MRI) for emergency room (ER) patients with chest pain and intermediate probability for coronary artery disease.Materials and Methods-Thirty-one patients with chest pain, negative electrocardiogram (ECG), and negative cardiac enzymes who underwent cardiac single photon emission tomography (SPECT) within 24 h of ER admission were enrolled. Patients underwent a comprehensive cardiac MRI exam including gated cine imaging, adenosine stress and rest perfusion imaging and delayed enhancement imaging. Patients were followed for 14 ± 4.7 months.Results-Of 27 patients, 8 (30%) showed subendocardial hypoperfusion on MRI that was not detected on SPECT. These patients had a higher rate of diabetes (P = 0.01) and hypertension (P = 0.01) and a lower global myocardial perfusion reserve (P = 0.01) compared with patients with a normal cardiac MRI (n = 10). Patients with subendocardial hypoperfusion had more risk factors for cardiovascular disease (mean 4.4) compared with patients with a normal MRI (mean 2.5; P = 0.005). During the follow-up period, patients with subendocardial hypoperfusion on stress MRI were more likely to return to the ER with chest pain compared with patients who had a normal cardiac MRI (P = 0.02). Four patients did not finish the MR exam due to claustrophobia.Conclusion-In patients with chest pain, diabetes and hypertension, cardiac stress perfusion MRI identified diffuse subendocardial hypoperfusion defects in the ER setting not seen on cardiac SPECT, which is suspected to reflect microvascular disease. Keywordsadenosine stress perfusion cardiac MRI; emergency room; chest pain; microvascular disease The evaluation and triage of patients with chest pain is a common challenge for emergency room (ER) physicians. Fast and accurate assessment of myocardial ischemia in a patient * Address reprint requests to: J.V.-C., Johns Hopkins University, Department of Radiology, Nelson Basement MRI 143, 600 N Wolfe Street, Baltimore, MD 21287. jclauss1@jhmi.edu. New technical developments over the past decade allow a comprehensive cardiac MRI examination, which includes myocardial perfusion, function, and viability assessment (4,5). Stress perfusion with MRI is an emerging noninvasive method for the evaluation of myocardial ischemia (6-9). Myocardial scar imaging with MRI aids in identifying small subendocardial myocardial infarctions that are not seen by cardiac SPECT (10). Furthermore, cardiac SPECT exposes the patient to 17-20 mSv of ionizing radiation (11) that is not present with MRI. NIH Public AccessSome patients presenting to the ER with chest pain likely of cardiac origin may not have flow limiting stenosis of the coronary arteries, but instead have small vessel or other cardiac disease that could potentially be identified by . Therefore, the aim of this study was to compare standard of care nuclear SPECT imaging with cardiac MRI for the evaluation of emergency room patients with chest pain and intermediate pr...
Historically, the presence of cardiac implantable electronic devices (CIEDs), including pacemakers and implantable cardioverter defibrillators (ICDs), was widely considered an absolute contraindication to magnetic resonance imaging (MRI). The recent development of CIEDs with MR Conditional labeling, as well as encouraging results from retrospective studies and a prospective trial on the safety of MRI performed in patients with CIEDs without MR Conditional labeling, have led to a reevaluation of this practice. The purpose of this report is to provide a concise summary of recent developments, including practical guidelines that an institution could adopt for radiologists who choose to image patients with CIEDs that do not have MR Conditional labeling. This report was written on behalf of and approved by the International Society for Magnetic Resonance in Medicine (ISMRM) Safety Committee. Level of Evidence 3. Technical Efficacy Stage 1.
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