Contrast enhancement in electron beam tomography of the heart: comparison of a monomeric and a dimeric iodinated contrast agent in 59 patients.

RATIONALE AND OBJECTIVES: The aim of the study is to determine whether intravascular time-density course and visualization of the coronary arteries differ with use of a hyperosmolar monomeric versus an iso-osmolar dimeric contrast agent in electron beam tomography (EBT) of the heart. MATERIALS AND METHODS: Fifty-nine patients underwent EBT of the coronary arteries using the monomeric ioversol or the dimeric iodixanol at the same concentration of 320 mg I/mL. Contrast volume was determined relative to body surface area and injected over 40 seconds. Intravascular time-density curves were created for quantitative analysis. For qualitative assessment, visualization of coronary arteries on axial scans and three-dimensional reconstructions was scored. Patients were matched for contrast flow, transit time, and mean pulse rate for statistical analysis. RESULTS: Ioversol produced a significantly greater increase in intravascular density for up to 30 seconds after injection (P < .01) compared with iodixanol. No difference between the two contrast media was seen in the qualitative assessment. CONCLUSION: Monomeric and dimeric contrast media differ in their time-density curves at coronary EBT, a reason for which is not apparent. Qualitative evaluation of coronary arteries is not affected by this difference.

Acute myocardial ischemia after aortic valve replacement: a comprehensive diagnostic evaluation using dynamic multislice spiral computed tomography.

We describe the case of a 72-year-old man presenting with endocarditis and clinical signs of acute myocardial ischemia after biological aortic valve replacement. A comprehensive cardiac dynamic multislice spiral computed tomography demonstrated: (1) an endocarditic vegetation of the aortic valve; (2) a subvalvular leakage feeding a paravalvular pseudoaneurysm based on an aortic root abscess with subsequent compromise of the systolic blood flow in the left main coronary artery and the resulting myocardial perfusion deficit.

Pictorial review: electron beam computed tomography and multislice spiral computed tomography for cardiac imaging.

Electron beam computed tomography (EBCT) revolutionized cardiac imaging by combining a constant high temporal resolution with prospective ECG triggering. For years, EBCT was the primary technique for some non-invasive diagnostic cardiac procedures such as calcium scoring and non-invasive angiography of the coronary arteries. Multislice spiral computed tomography (MSCT) on the other hand significantly advanced cardiac imaging through high volume coverage, improved spatial resolution and retrospective ECG gating. This pictorial review will illustrate the basic differences between both modalities with special emphasis to their image quality. Several experimental and clinical examples demonstrate the strengths and limitations of both imaging modalities in an intraindividual comparison for a broad range of diagnostic applications such as coronary artery calcium scoring, coronary angiography including stent visualization as well as functional assessment of the cardiac ventricles and valves. In general, our examples indicate that EBCT suffers from a number of shortcomings such as limited spatial resolution and a low contrast-to-noise ratio. Thus, EBCT should now only be used in selected cases where a constant high temporal resolution is a crucial issue, such as dynamic (cine) imaging. Due to isotropic submillimeter spatial resolution and retrospective data selection MSCT seems to be the non-invasive method of choice for cardiac imaging in general, and for assessment of the coronary arteries in particular. However, technical developments are still needed to further improve the temporal resolution in MSCT and to reduce the substantial radiation exposure.

Quantification of functional mitral valve regurgitation in patients with congestive heart failure: comparison of electron-beam computed tomography with cardiac catheterization.

OBJECTIVES: We sought to determine the agreement between electron-beam computed tomography (CT) and cardiac catheterization for the quantification of mitral regurgitation and to evaluate their association with echocardiographic assessment. MATERIAL AND METHODS: Fifty patients with congestive heart failure were examined both by electron-beam CT and catheterization to calculate mitral regurgitation volume and fraction based on the difference between the left ventricular stroke and aortic flow volume. The severity of regurgitation was also compared with visual assessment by echocardiography (grade, 0-4+). RESULTS: The mean values for the mitral regurgitation volume and fraction did not differ significantly between electron-beam CT and catheterization (mean differences: 0.2 mL/m2 and -0.9%, P > 0.05 each, limits of agreement: -14.0 to 14.4 mL/m2 and -26.3 to 24.5%, respectively) and showed a good correlation (r = 0.79 and r = 0.76, respectively; P < 0.05 each). Good levels of correlation were observed between echocardiographic severity grading and quantitative measurements of regurgitation volume and fraction, which were somewhat better between echocardiography and electron-beam CT (rS = 0.78 and rS = 0.84, respectively; P < 0.05 each) than between echocardiography and catheterization (rS = 0.72 and rS = 0.81, respectively; P < 0.05 each). CONCLUSION: Our results suggest that electron-beam CT allows for quantification of mitral valve regurgitation with similar accuracy as cardiac catheterization. Measurements with both modalities correlated well with the results of echocardiographic assessment.

Image quality of noninvasive coronary angiography using multislice spiral computed tomography and electron-beam computed tomography: intraindividual comparison in an animal model.

OBJECTIVE: Comparison of coronary artery visualization by multislice spiral CT (MSCT) and electron-beam CT (EBCT). MATERIALS AND METHODS: Six minipigs underwent MSCT (collimation 4 x 1 mm, gantry rotation time 500 milliseconds, acquisition time per cardiac cycle 126 +/- 30 milliseconds) and EBCT (slice thickness 1.5 mm, acquisition time per scan 100 milliseconds). Visualized vessel length and contour sharpness was measured, contrast-to-noise ratios were calculated, and the frequency of motion artifacts were evaluated. RESULTS: MSCT depicted significantly longer segments of the coronary tree than EBCT (length: 248.8 vs. 222.8 mm; P < 0.05), delineated the vessel contours more sharply (slope of density curves: 219.2 vs. 160.2 DeltaHU/mm; P < 0.05), and had a higher contrast-to-noise ratio (13.4 vs. 7.3; P < 0.05). The frequency of motion artifacts did not differ between both modalities (94.7% vs. 95.7% of visualized vessel length; P > 0.05). CONCLUSIONS: Because its higher spatial resolution and lower image noise, MSCT seems to be superior to EBCT in the visualization of the coronary arteries. Despite different temporal resolutions motion artifacts seem to be similar with both modalities.

Effects of passive cardiac containment on left ventricular structure and function: verification by volume and flow measurements.

BACKGROUND: The cardiac support device (CSD, Acorn) is a compliant, textile-mesh graft placed around the ventricles to prevent further dilatation and to improve function in congestive heart failure. The aim of this study was to verify post-operative changes in left ventricular volumes, ejection fraction, blood flow, and myocardial mass. METHODS: Fourteen patients underwent contrast-enhanced, electrocardiography-triggered electron-beam computerized tomography before and 6 to 9 months after CSD implantation. We measured volume and flow using the slice-summation method and the indicator-dilution technique. RESULTS: We found significant changes for the following parameters: end-diastolic volume decreased from 382.9 +/- 140.2 ml to 311.3 +/- 138.7 ml, end-systolic volume from 310.4 +/- 132.4 ml to 237.4 +/- 133.8 ml, end-diastolic diameter from 75.3 +/- 7.8 mm to 70.7 +/- 11.6 mm, end-systolic diameter from 65.8 +/- 7.8 mm to 60.0 +/- 14.0 mm, and myocardial mass from 298.6 +/- 79.6 g to 263.1 +/- 76.8 g. Ejection fraction increased from 20.3% +/- 6.4% to 27.8% +/- 13.1%. We found no significant differences for stroke volume (from 72.5 +/- 24.6 ml to 73.8 +/- 23.6 ml), heart rate (from 80.5 +/- 11.0 beats per minute to 76.5 +/- 6.8 beats per minute), and total cardiac output (from 5.8 +/- 1.9 liter/min to 5.6 +/- 1.8 liter/min). Mitral regurgitation fraction decreased from 30.5% +/- 15.5% to 15.6% +/- 12.8%, increasing antegrade cardiac output from 3.8 +/- 0.9 liter/min to 4.7+/-1.5 liter/min. For most parameters, pre- and post-operative values in these patients differed significantly from those in an age- and gender-matched control group. In each patient, we observed a small hyperdense stripe along the pericardium after surgery, but we observed no local complications. CONCLUSION: Three-dimensional structural and functional data obtained by computerized tomography volume and flow measurements confirm the safety and efficacy of CSD implantation.

Passive external cardiac constraint improves segmental left ventricular wall motion and reduces akinetic area in patients with non-ischemic dilated cardiomyopathy.

OBJECTIVE: To verify changes in left ventricular (LV) volumes and regional myocardial wall motion after implantation of a textile cardiac support device (CSD) for passive external constraint in non-ischemic dilated cardiomyopathy. METHODS: In nine male patients participating in a non-randomized clinical trial LV volumes were determined and the segmental LV wall motion was studied by contrast-enhanced electron-beam CT in a sectionwise manner at three ventricular levels (base, middle and apex of ventricle) before and 32+/-6 months after CSD implantation. In 16 myocardial segments ejection fraction and wall thickening were measured semiautomatically after drawing the myocardial contours. The wall motion score index was calculated based on semiquantitative visual grading in each segment. RESULTS: The global LV volumes decreased significantly from 304.3 +/- 90.9 to 231.5 +/- 103.9 ml at end-diastole and from 239.7 +/- 83.7 to 164.0 +/- 97.7 at end-systole (P<0.05). Overall ejection fraction increased from 14.8 +/- 8.2 to 25.7 +/- 17.1% (P<0.05). A segment-by-segment analysis demonstrated a significant increase of regional ejection fraction in the basal myocardium as well as in the mid-inferior, mid-inferolateral, and mid-anterolateral myocardium. Overall wall thickening increased from 16.4 +/- 13.3 to 24.2 +/- 18.1% (P<0.05), but without significant differences in a segment-by-segment comparison. The mean wall motion score index improved from 2.70 +/- 0.26 to 2.20 +/- 0.71 (P<0.05), with an increased wall motion in eight (89%) patients. A section-by-section analysis demonstrated significantly improved wall motion in the inferior and lateral segments at each ventricular level. Postoperatively, the number of akinetic and markedly hypokinetic segments decreased significantly (P<0.05) from 56 (39%) to 26 (18%) and from 76 (53%) to 56 (37%), respectively. CONCLUSION: CSD implantation improves segmental wall motion, predominantly in the inferior and lateral myocardium, and reduces the number of akinetic and hypokinetic segments.

Diameter changes of occluded venous coronary artery bypass grafts in electron beam tomography: preliminary findings.

OBJECTIVE: To differentiate acute from chronic graft occlusions through diameter measurements by means of electron beam tomography (EBT). METHODS: Contrast enhanced EBT volume studies were carried out in 37 patients with one or more occluded venous coronary bypass grafts. Seventeen of 37 patients did not meet the inclusion criteria and were excluded from the assessment. The remaining 20 patients had a total of 39 bypasses (16 patent, 23 occluded) and were assigned to one of three groups: group A consisted of patent grafts only (patent grafts, 13 patients). Group B comprised 11 of 23 occluded grafts diagnosed within 10 days after bypass surgery (acutely occluded grafts, ten patients). Group C contained 12 of 23 bypass occlusions that were at least 6 months old as documented by coronary angiography (chronically occluded grafts, ten patients). The mean graft diameter was determined by repetitive measurements on a workstation through blinded readers. The Mann-Whitney-U-test for unpaired samples was used for statistical evaluation. RESULTS: Mean graft diameter for groups A-C (patent, acutely, and chronically occluded bypasses, respectively) was 3.9 mm (+/-0.6; n=16), 5.4 mm (+/-1.9; n=11), and 0.3 mm (+/-.9; n=12), respectively (P<0.01 each). Sensitivity and specificity for the detection of acute and chronic occlusions were 87 and 92% (cut-off 4.5 mm), respectively, and 92 and 96% (cut-off 1 mm), respectively. CONCLUSIONS: EBT may allow for non-invasive differentiation between acute and chronic venous coronary bypass occlusions. This could help prevent unnecessary invasive recanalization procedures. Body veins may conserve their ability to increase in diameter in acute thrombosis when transplanted as coronary bypasses.

Precision of forty slice spiral computed tomography for quantifying aortic valve stenosis: comparison with echocardiography and validation against cardiac catheterization.

OBJECTIVES: We evaluated the precision of multislice spiral computed tomography (MSCT) for the quantification of aortic valve stenosis in comparison with echocardiography and cardiac catheterization. MATERIALS AND METHODS: An electrocardiogram-gated MSCT scan (detector collimation 40 x 6.25 mm, gantry rotation time 420 milliseconds, pitch 0.2, tube voltage 120 KV, tube current 333 mA) was performed in 32 patients with known aortic valve stenosis. In each patient the aortic valve orifice area (AVA) was determined by planimetry on MSCT and compared with the results obtained from transthoracic Doppler echocardiography (using the continuity equation) and cardiac catheterization (using the Gorlin formula). RESULTS: Planimetry of the AVA on MSCT was feasible in all cases. The AVA on MSCT (1.11 +/- 0.49 cm2) was significantly larger compared with echocardiography (0.81 +/- 0.37 cm2, P < 0.001) and cardiac catheterization (0.87 +/- 0.45 cm2, P < 0.001). The correlations between MSCT and echocardiography (r = 0.86, limits of agreement +/-0.52 cm2) and also between MSCT and cardiac catheterization (r = 0.90, limits of agreement +/-0.44 cm2) were good, but inferior to the correlation between echocardiography and cardiac catheterization (r = 0.94, limits of agreement +/-0.32 cm2). Using an AVA of 1.0 cm at cardiac catheterization as reference standard, the best cut-off level for detecting severe-to-critical stenosis at MSCT was an AVA of 1.20 cm, resulting in a sensitivity, specificity, and accuracy of 91%, 100%, and 94%, respectively. CONCLUSIONS: AVA determined by MSCT correlates well with echocardiography and cardiac catheterization. However, AVA derived from MSCT is consistently larger, requiring an adjustment of cut-off values for the classification of stenosis severity and therapeutic decision making.

Formalin-fixed blood clots--additional histological findings on computed tomography-guided fine-needle aspiration biopsies in comparison with core biopsies.

OBJECTIVE: We investigated the diagnostic yield of histological examined formalin-fixed blood clots (FFBCs) in comparison with the established procedures of fine-needle aspiration biopsy (FNAB) and core biopsy (CB) obtained by percutaneous puncture under computed tomography (CT) guidance. METHODS: A total of 76 CT-guided punctures with removal of tissue by means of all 3 different techniques (FFBC, FNAB, and CB) were performed. Specimens were obtained from the lung (n=18), mediastinum (n=10), upper abdominal organs (n=32), pelvis (n=4), retroperitoneum (n=4), bones (n=7), and neck (n=1). All results were correlated with the clinical course of the patients (minimum, 6 months; mean period, 10 months). The results of each technique were compared. Results of a combined use of FFBC and FNAB were analyzed. RESULTS: The overall sensitivity (regardless of biopsy site) was 79% for FFBC, 83% for FNAB, and 95% for CB. In chest biopsies, FFBC reached a sensitivity of 92%, FNAB of 86%, and CB of 96%. In liver biopsies, the sensitivities were 47%, 70%, and 88% for FFBC, FNAB, and CB and, for the remaining biopsy sites, 90%, 90%, and 100%, respectively. The combination of FFBC and FNAB showed higher sensitivities than FFBC and FNAB alone. Overall sensitivity for the combination was 88%, with 92%, 72%, and 100% for thorax, liver, and other locations. A definitive diagnosis was made by FFBC in 87% of cases, by FNAB in 74%, and by CB in 88%. The combination of FFBC and FNAB showed a definite diagnosis in 90% of the cases. A tentative diagnosis has been established in 12%, 7%, 5%, and 4%, respectively. In 4 cases (5%), all 3 techniques failed to yield reliable diagnoses. CONCLUSIONS: The examination of FFBCs is a useful supplement to the established technique of CT biopsy. In combination with FNAB, FFBC has a comparable sensitivity as CB in chest punctures and other extrahepatic lesions.

Early and late effects of passive epicardial constraint on left ventricular geometry: ellipsoidal re-shaping confirmed by electron-beam computed tomography.

BACKGROUND: Previous studies have shown that passive epicardial constraint using a cardiac support device (CSD) reduces left ventricular (LV) size. However, specific data describing LV shape and the time course of changes in LV geometry are still incomplete. Thus, the aim of this study was-using 3-dimensional data sets obtained by computed tomography (CT)-to test the hypothesis that the CSD not only alters LV size but also LV shape, and that short-term post-operative changes in LV geometry are maintained during long-term follow-up. METHODS: Ten patients with non-ischemic dilated cardiomyopathy underwent electron-beam CT examination before and again at 2.6 +/- 0.5 and 32.4 +/- 8.7 months after CSD implantation. At end-diastole and end-systole LV volumes, the length-to-width diameter ratio and a sphericity index were determined and ejection fraction and end-systolic meridional and circumferential wall stress were calculated. RESULTS: Implantation of the CSD led to a significant reduction in LV size, a more ellipsoidal LV shape and a subsequent decrease of LV wall stress post-operatively (p < 0.05 for each), but no substantial changes were found between short- and long-term follow-up (p > 0.05 each). Mean pre-operative and early and late post-operative end-diastolic values were 310.4 +/- 87.8, 235.5 +/- 102.0 and 229.4 +/- 103.1 ml for volume; 1.27 +/- 0.20, 1.37 +/- 0.20 and 1.38 +/- 0.20 for diameter ratio; and 0.78 +/- 0.22, 0.67 +/- 0.26 and 0.65 +/- 0.23 for sphericity index. A similar pattern was observed for end-systolic values. Ejection fraction was 23.4 +/- 6.2%, 32.9 +/- 11.6% and 34.4 +/- 14.9%. End-systolic meridional and circumferential wall stress was 182.2 +/- 45.6, 128.2 +/- 52.6, 130.6 +/- 56.7 kdyn/cm(2) and 411.5 +/- 94.0, 297.4 +/- 108.4 and 302.8 +/- 117.5 kdyn/cm(2), respectively. CONCLUSIONS: Three-dimensional data obtained by CT demonstrate that passive cardiac constraint leads not only to a size reduction but also to an ellipsoidal re-shaping. Our data indicate that these effects are primarily a short-term consequence of the CSD implantation but are maintained during long-term follow-up.

Assessment of mitral valve regurgitation at electron-beam CT: comparison with Doppler echocardiography.

PURPOSE: To prospectively compare mitral valve regurgitation fractions calculated at electron-beam computed tomography (CT) (Doppler echocardiography as reference standard) and to evaluate accuracy of electron-beam CT volume and flow measurements compared with magnetic resonance (MR) imaging results. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Volume and flow measurements were performed at electron-beam CT in 219 patients (197 men, 22 women; mean age, 61.5 years +/- 10.4 [standard deviation]), of whom 157 had known isolated mitral valve regurgitation. Regurgitation volume was calculated as the difference between left ventricular total and forward stroke volumes. Regurgitation fractions were compared with corresponding echocardiographic grades (grades 0-IV) by using Spearman rank correlation and a weighted kappa test. In 22 patients, CT volume and flow measurements were compared with MR results by using intraclass correlation. RESULTS: Regurgitation fractions at CT correlated well with echocardiographic grading (rank correlation coefficient, r(S) = 0.82; P < .05). Mean regurgitation fractions for echocardiographic grades 0, I, II, III, and IV were 3.1% +/- 6.2, 12.7% +/- 9.9, 25.3% +/- 12.3, 40.4% +/- 11.5, and 55.9% +/- 13.7, respectively. The most suitable thresholds for differentiating echocardiographic grades were calculated regurgitation fractions of 6%, 20%, 30%, and 44%; with these thresholds, individual echocardiographic grades were differentiated (grades 0 vs I-IV, 0-I vs II-IV, 0-II vs III-IV, and 0-III vs IV, respectively) with sensitivities of 89%, 87%, 86%, and 93% and specificities of 81%, 87%, 92%, and 91%, respectively. There was perfect agreement in classification of mitral valve insufficiency between electron-beam CT and echocardiography in 134 (61%) patients and a mismatch by one grade in 72 (33%) and by two grades in 13 (6%) (kappa = 0.84). Intraclass correlation coefficients between CT and MR imaging for total and forward stroke volumes and regurgitation volume and fraction were 0.88, 0.79, 0.93, and 0.89, respectively. CONCLUSION: Electron-beam CT provides quantitative information on severity of mitral valve regurgitation, but semiquantitative classification of regurgitation showed mismatch between electron-beam CT and Doppler echocardiography by at least one grade in more than one-third of all patients.

Disintegration and stepwise expulsion of a large uterine leiomyoma with restoration of the uterine architecture after successful uterine fibroid embolization: case report.

Uterine fibroid embolization (UFE) is a new minimally-invasive treatment option for leiomyomata of the uterus leading to symptomatic improvement and shrinkage of the fibroids. We present a case of restoration of the uterine architecture after disintegration and stepwise expulsion of infarcted leiomyoma tissue 7 months after UFE for leiomyoma-related menorrhagia.

Electron beam computed tomography and ventilation perfusion scintigraphy in the diagnosis of pulmonary embolism.

The purpose of this study, performed in patients with suspected pulmonary embolism (PE), was to compare V/Q scans and electron beam computed tomography (CT) scans on a patient-by-patient and segment-by-segment basis. Both a segment-based and a lobe-based analysis was performed in those patients positive for PE. The diagnosis of PE was assumed on the basis of a mismatch at V/Q scanning or a filling defect in a pulmonary vessel at contrast-enhanced electron beam CT. In 37/45 patients (24 female, 21 male, 58+/-16 years) with suspected PE, the diagnosis of PE was confirmed or excluded by both modalities, resulting in a correlation of 82% between electron beam CT and V/Q scanning. In the 28 patients positive for PE according to one or both modalities, 504 segments were evaluated. Of these 504 segments, 248 (nearly 50%) showed perfusion defects on V/Q scans, of which only 90 (36%) displayed emboli at electron beam CT. Overall, a total of only 135 of the 504 segments (27%) were abnormal at electron beam CT. More than 50% of the patients with discrepant results did not show an embolus at electron beam CT. It is concluded that there is a good correlation (82%) between V/Q scanning and electron beam CT on a patient-by-patient basis but a markedly less good correlation (62%) in a segment-based analysis.

Comparison of electron beam computed tomography with magnetic resonance imaging in assessment of right ventricular volumes and function.

OBJECTIVE: Intraindividual comparison of right ventricular volumes and function using electron beam computed tomography (EBT) and magnetic resonance imaging (MRI). METHODS: Twenty-seven patients with a known cardiac history were referred for evaluation of ventricular function parameters. The following standardized protocols were used: contrast-enhanced multislice mode EBT and gradient echo sequence MRI. Right ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) were calculated using a slice summation method. Interobserver variability was calculated. RESULTS: The correlation between the 2 methods was: r = 0.901 for EDV, r = 0.938 for ESV, r = 0.823 for SV, and r = 0.953 for EF. Electron beam computed tomography overestimated EDV and ESV slightly when compared with MRI (P < 0.05). No significant differences (P > 0.05) were found between SV and EF. Mean values determined by EBT and MRI were as follows: 168.6 +/- 62.3 mL and 153.7 +/- 59.1 mL for EDV, 104.7 +/- 60.4 mL and 95.1 +/- 54.8 mL for ESV, 63.2 +/- 19.3 mL and 58.7 +/- 19.8 mL for SV, and 40.2% +/- 14.1% and 40.2% +/- 13.6% for EF, respectively. Interobserver variability ranged between 1.0% and 3.2%. CONCLUSION: Electron beam computed tomography shows good agreement with a close correlation and an acceptable interobserver variability for right ventricular volumes and global function, with a small but significant overestimation of EDV and ESV when compared with MRI.

Quantification of mitral valve regurgitation by left ventricular volume and flow measurements using electron beam computed tomography: comparison with magnetic resonance imaging.

PURPOSE: This study was designed to evaluate electron beam computed tomography (CT) for quantifying mitral regurgitation in comparison with magnetic resonance (MR) imaging as a reference method. METHOD: Forty-three patients, among them 33 with known mitral regurgitation, underwent electron beam CT and MR imaging. Total left ventricular stroke volume (TSV), antegrade stroke volume (ASV), and mitral regurgitation volume (MRV) and fraction (MRF) were determined and compared between the two modalities. Additionally electron beam CT measurements were compared with the corresponding echocardiographic findings. RESULTS: Significant differences between electron beam CT and MR imaging were found for measurements of TSV and MSV but not for ASV and MRF. There was a close linear correlation between both modalities for all parameters. Furthermore, there was good agreement between electron beam CT and echocardiography, although electron beam CT shows a tendency to overestimate mitral regurgitation slightly. CONCLUSION: The results indicate that electron beam CT offers an additional procedure for quantifying mitral regurgitation and that it may be used as an alternative to MR imaging.

Changes in right ventricular dimensions and performance after passive cardiac containment.

BACKGROUND: Previous studies have shown that the cardiac support device (CSD) improves left ventricular structure and function in patients with heart failure by preventing further cardiac enlargement. The aim of this study was to identify effects on the right ventricle (RV). METHODS: Ten male patients with idiopathic dilated cardiomyopathy underwent electron-beam computed tomographic (CT) examination within 1 month before, and 6 to 9 months after CSD implantation. The RV end-diastolic and end-systolic volumes (EDV, ESV) and diameters (EDD, ESD), stroke volume (SV), ejection fraction (EF), total and forward RV output (RVO, fRVO), and tricuspid regurgitation fraction (TRF) were calculated. RESULTS: The EDV measurements decreased from 182.1 +/- 49.6 to 137.5 +/- 37.0 mL, ESV from 114.8 +/- 47.0 to 68.3 +/- 23.8 mL, EDD from 48.2 +/- 6.6 to 41.6 +/- 7.1 mm, and ESD from 39.6 +/- 6.9 to 32.7 +/- 6.5 mm (p < 0.05 for each). Ejection fraction increased from 38.5 +/- 8.9 to 52.0% +/- 7.7% and fRVO from 4.0 +/- 0.8 to 4.6 +/- 1.1 L/min (each with p < 0.05). TRF decreased from 18.2 +/- 14.1 to 10.4% +/- 13.5%, whereas SV and RVO remained nearly unchanged. Postoperatively, RV volumes, EF, and fRVO were not different from 15 age- and gender-matched normal control patients. CONCLUSIONS: Implantation of a CSD leads to a decrease in RV size and improved RV performance. These data together with the results of previous studies demonstrating improved left ventricular structure and function confirm the biventricular nature of recovery with the CSD.

Effect of partial left ventriculectomy on left and right ventricular volumes and function as assessed with electron beam tomography: preliminary results.

Our objective was to determine if left ventricular reduction surgery affects left and right ventricular volumes and function. Twenty-three patients with end-stage heart failure underwent contrast-enhanced electron beam tomographic function studies before and twice after partial left ventriculectomy (PLV). The PLV was combined with other cardiosurgical procedures in 20 of 23 patients. Left and right ventricular enddiastolic volume (LVEDV, RVEDV), stroke volume (LVSV, RVSV), ejection fraction (LVEF, RVEF), and enddiastolic diameter (LVEDD, RVEDD) were determined by manual tracing of endo- and epicardial borders at enddiastole and endsystole. Patients were scanned 31 days (+/-34) before and 18 days (+/-13) and 8 months (+/-4) after PLV. Mean pre- and early and late postoperative values for LVEDV, LVSV, LVEF, and LVEDD were 387.9 ml (+/-125.5 ml), 255.6 ml (+/-79.3 ml; p<0.01), and 253.7 ml (+/-97.8 ml; p<0.05), 79.7 ml (+/-25.2 ml), 74.8 ml (+/-17.9; n.s.), and 79.1 ml (+/-26.5 ml; n.s.), 21.6% (+/-7.3%), 31.9% (+/-13.4%; p<0.05), and 34.1% (+/-14.1%; p<0.05), and 72.0 mm (+/-10.6 mm), 64.3 mm (+/-8.5 mm; p<0.05), and 63.5 mm (+/-9.4 mm; p<0.05), respectively. Mean pre- and postoperative values for RVEDV, RVSV, RVEF, and RVEDD were 177.7 ml (+/-72.8 ml), 172.4 ml (+/-59.2 ml; n.s.), and 178.9 ml (+/-60.8 ml; n.s.), 60.3 ml (+/-21.6 ml), 68.8 ml (+/-19.9 ml; n.s.), and 78.3 ml (+/-25.3 ml; n.s.), 38.1% (+/-15.4%), 43.7% (+/-16.3%; p<0.05), and 45.1% (+/-11.2%; n.s.), and 50.4 mm (+/-10.9 mm), 48.1 mm (+/-8.7 mm; n.s.), and 48.5 mm (+/-9.8 mm; n.s.), respectively. The PLV may induce a significant early reduction of left ventricular volumes and improvement of biventricular function; however, our results must be judged carefully as the majority of patients in this study underwent additional cardiosurgical procedures, the contributory effect of which on the overall outcome remains unclear.

Electron beam tomography of interpulmonary saddle embolism: extent and vascular distribution.

PURPOSE: The purpose of this work was to assess morphology and secondary signs of interpulmonary emboli extending across the bifurcation of the main pulmonary artery (PA). METHOD: Retrospective evaluation of 780 electron beam tomographic studies of the chest yielded 17 cases of interpulmonary saddle embolism. Length, diameter, vascular distribution of the emboli, and secondary findings were prospectively assessed by two blinded reviewers. Follow-up studies were carried out in 12 of 17 patients (71%). RESULT: Mean total length of the emboli was 46.6 cm (range 20.9-81.5 cm). The mean diameter of the saddle embolus was significantly smaller at the level of the bifurcation than in the left or right PA (4.5, 7.7, and 7.4 mm, respectively; p < 0.01). Dilatation of the right heart was found in 10 of 17 cases (59%). At follow-up, the saddle state was no longer present in 8 of 12 patients (67%). CONCLUSION: Interpulmonary saddle emboli appear to be a transient form of acute pulmonary embolism, the site of predilection for rupture of the embolus being the level of the bifurcation. Their frequency may therefore be underestimated.