Michael Handke

Dynamic assessment of right ventricular volumes and function by real-time three-dimensional echocardiography: a comparison study with magnetic resonance imaging in 100 adult patients.

BACKGROUND The aim of this study was to validate a novel real-time three-dimensional echocardiographic (RT3DE) analysis tool for the determination of right ventricular volumes and function in unselected adult patients. METHODS A total of 100 consecutive adult patients with normal or pathologic right ventricles were enrolled in the study. A dynamic polyhedron model of the right ventricle was generated using dedicated RT3DE software. Volumes and ejection fractions were determined and compared with results obtained on magnetic resonance imaging (MRI) in 88 patients with adequate acquisitions. RESULTS End-diastolic, end-systolic, and stroke volumes were slightly lower on RT3DE imaging than on MRI (124.0 +/- 34.4 vs 134.2 +/- 39.2 mL, P < .001; 65.2 +/- 23.5 vs 69.7 +/- 25.5 mL, P = .02; and 58.8 +/- 18.4 vs 64.5 +/- 24.1 mL, P < .01, respectively), while no significant difference was observed for ejection fraction (47.8 +/- 8.5% vs 48.2 +/- 10.8%, P = .57). Correlation coefficients on Bland-Altman analysis were r = 0.84 (mean difference, 10.2 mL; 95% confidence interval [CI], -31.3 to 51.7 mL) for end-diastolic volume, r = 0.83 (mean difference, 4.5 mL; 95% CI, -23.8 to 32.9 mL) for end-systolic volume, r = 0.77 (mean difference, 5.7 mL; 95% CI, -24.6 to 36.0 mL) for stroke volume, and r = 0.72 (mean difference, 0.4%; 95% CI, -14.2% to 15.1%) for ejection fraction. CONCLUSION Right ventricular volumes and ejection fractions as assessed using RT3DE imaging compare well with MRI measurements. RT3DE imaging may become a time-saving and cost-saving alternative to MRI for the quantitative assessment of right ventricular size and function.

Therapeutic Strategies After Examination by Transesophageal Echocardiography in 503 Patients With Ischemic Stroke

Background and Purpose— Transesophageal echocardiography (TEE) is the gold standard in detecting high-risk (ie, aortic thrombi) and potential sources (ie, patent foramen ovale [PFO]) of cerebral embolism. We sought to evaluate the additional information and therapeutic impact provided by TEE in stroke patients and to characterize patients in whom TEE is indispensable. Methods— We included 503 consecutive patients (mean age 62.2 years) with acute brain ischemia. Each patient received TEE and the following routine diagnostics: ultrasound of brain supplying arteries, ECG or Holter-ECG, transthoracic echocardiography, and brain imaging (computed tomography or MRI). Stroke etiology was classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. High-risk sources in TEE were: aortic thrombi or plaques ≥4 mm, thrombi in left atrial cavity/left atrial appendage, spontaneous echo contrast, and left atrial flow velocity <30 cm/s. Potential sources in TEE were PFO, atrial septal aneurysm, and aortic plaques <4 mm. Results— Stroke etiology was determined by routine diagnostics in 276 of 503 patients (54.9%). Of the remaining 227 patients (undetermined etiology), 212 (93.4%) were candidates for oral anticoagulation (OA). TEE revealed a high-risk source, with indication for OA in 17 of them (8.0%). A potential source leading to OA was found in an additional 48 patients (22.6%). The remaining 147 patients (69.3%) were treated by platelet inhibitors or statins. Conclusions— TEE strongly influenced secondary prevention and led to OA in one third of our patients with stroke of undetermined etiology. TEE is indispensable in all patients being candidates for OA when routine diagnostics cannot clarify stroke etiology.

Drug-Eluting Stents Compared with Bare Metal Stents Improve Late Outcome after Saphenous Vein Graft but Not after Large Native Vessel Interventions

Objectives: To define long-term efficacy of different stent types in saphenous vein graft (SVG) interventions. Methods: In BASKET (Basel Stent Cost Effectiveness Trial), major adverse cardiac events (MACE), i.e. cardiac death, myocardial infarction and symptom-driven target vessel revascularization (TVR) were assessed after 18 months comparing drug-eluting stents (DES) versus bare metal stents (BMS), and SVG and large native vessels (≧3.0 mm). Results: Large vessel interventions were performed in 605 patients. Patients with SVG interventions (n = 47, 8%) were older and had more often hypertension, prior myocardial infarction, prior revascularization and multivessel disease and less frequent ST-elevation myocardial infarction than patients with large native vessel interventions (n = 558, 92%). Stent number and length were higher in SVG than in large native vessel interventions. Baseline characteristics were similar for DES and BMS. In SVG stenting, long-term outcome was better in DES- than in BMS-treated patients (MACE 21 vs. 62%, p = 0.007, mainly due to TVR 18 vs. 46%, p = 0.045), but for large native vessel stenting, no significant difference was noted (MACE: 13 vs. 16%, p = 0.40). Conclusions: Among patients with SVG disease, treatment with DES resulted in a better long-term outcome than treatment with BMS. In contrast, no DES benefit was found in similarly sized native vessels regarding MACE.

In vivo analysis of aortic valve dynamics by transesophageal 3-dimensional echocardiography with high temporal resolution

OBJECTIVES Knowledge of aortic valve function has been obtained from experimental studies. The aim of the present study was to investigate characteristics of aortic valve motion in humans. METHODS Fifty-six patients were studied: 19 with normal valve and good systolic left ventricular function (Group NL), 12 with normal valve and reduced left ventricular function (Group CMP), and 25 with aortic stenosis and good left ventricular function (Group AS). The frame rate was doubled (50 Hz) compared with previous 3-dimensional systems. A mean of 38 +/- 9 images were acquired per cardiac cycle, with 14 +/- 4 images during the systole. The changes in shape and orifice area were analyzed over time. RESULTS With normal valves, valve movement proceeded in 3 phases: rapid opening, slow closing, rapid closing. Stenotic valves showed a slower opening and closing movement. The times to maximum opening in Groups NL, CMP, AS were 76 +/- 30, 88 +/- 18 (P =.06), and 130 +/- 29 (P <.01) ms, respectively. It was inversely correlated to the maximum orifice area (r = -0.59, P <.001). The opening velocities in Groups NL, CMP, AS were 42 +/- 23, 28 +/- 9 (P <.05), and 5 +/- 2 (P <.001) cm(2)/s, respectively. There was a close correlation between the opening velocity and the maximum orifice area (r = 0.87, P <.001). Slow valve closings occurred at a velocity of 8.0 +/- 5.2, 5.3 +/- 2.0 (P =.21), 2.8 +/- 1.1 (P <.01) cm(2)/s, respectively, and rapid closings in Groups NL and CMP at 50 +/- 23, 29 +/- 8 (P <.01) cm(2)/s. The results show good agreement with experimental data. CONCLUSION Rapid aortic valve movement can be recorded by 3-dimensional echocardiography and analyzed quantitatively. Time and velocity indices of valve dynamics are influenced by valvular and myocardial factors. A comparable in vivo analysis is not possible with any other imaging procedure.

Combined Measurement of Carotid Stiffness and Intima-Media Thickness Improves Prediction of Complex Aortic Plaques in Patients With Ischemic Stroke

Background and Purpose— We hypothesized that for the prediction or exclusion of aortic thrombi or plaques ≥4 mm, the combination of intima-media thickness (IMT) and distensibility (DC) of the common carotid arteries would be superior to the measurement of IMT alone. Methods— We prospectively included 208 stroke patients (mean age, 60 years) undergoing transesophageal echocardiography for screening of aortic plaques. IMT and DC were determined by ultrasound, and DC was quantified by measuring blood pressure and the common carotid arteries diameter change on M-mode ultrasound during the cardiac cycle. Results— Negative predictive values of IMT <0.9 mm and DC ≥24×10−3/kPa for the exclusion of aortic atheroma ≥4 mm were similar (92.0% and 91.7%, respectively). However, negative predictive values increased to 98.2% and to 100.0% for the exclusion of aortic thrombi when both parameters were combined. Positive predictive values of IMT ≥0.9 mm and DC <24 were lower (46.3%, 41.1%; respectively), but they also increased in combination (54.3%). Conclusions— Our findings suggest that IMT and DC represent different vessel wall properties and that measuring both parameters provides optimized characterization of carotid atherosclerosis. Combining IMT and DC increases the predictive power of carotid ultrasound, making transesophageal echocardiography dispensable for assessment of the aorta for those with normal carotid arteries and indispensable for those patients with carotid atherosclerosis.

Functional assessment of the left atrium by real-time three-dimensional echocardiography using a novel dedicated analysis tool: initial validation studies in comparison with computed tomography

AIMS A novel real-time three-dimensional echocardiography (RT3DE) analysis tool specifically designed for evaluation of the left atrium enables comprehensive evaluation of left atrial (LA) size, global, and regional function using a dynamic 16-segment model. The aim of this study was the initial validation of this method using computed tomography (CT) as the method of reference. METHODS AND RESULTS The study population consisted of 34 prospectively enrolled patients with clinical indication for pulmonary vein isolation. A dynamic polyhedron model of the left atrium was generated using RT3DE. LA maximum and minimum volumes (LA(max)/LA(min)) and emptying fraction (LAEF) were determined and compared with the results obtained by CT. High correlations between RT3DE and CT were found for LA(max) (r = 0.92, P < 0.001), LA(min) (r = 0.95, P < 0.001), and LAEF (r = 0.82, P < 0.001). LA(max) and LA(min) were lower by RT3DE than by CT (95.0 ± 44.7 vs. 119.8 ± 50.5 mL, P < 0.001 and 58.1 ± 41.3 vs. 83.3 ± 52.6 mL, P < 0.001, respectively), whereas LAEF was measured higher by RT3DE (42.8 ± 15.2 vs. 34.2 ± 15.4%, P < 0.001, respectively). RT3DE measurements closely correlated in terms of intra-observer (intra-class correlation r = 0.99, r = 0.99, r = 0.96, respectively) and inter-observer variability (r = 0.97, r = 0.98, r = 0.88, respectively). CONCLUSIONS LA volumes and EF as assessed by RT3DE correlate highly with CT measurements, albeit there is some bias between the imaging modalities. Most importantly, RT3DE measurements using the novel dedicated LA analysis tool are robust in terms of observer variability and thus suitable for follow-up analyses.

New Three-Dimensional Echocardiographic System Using Digital Radiofrequency Data—Visualization and Quantitative Analysis of Aortic Valve Dynamics With High Resolution Methods, Feasibility, and Initial Clinical Experience

Background Common 3D systems have only limited spatial and temporal resolution (frame rate of 25 Hz). Thin structures such as cardiac valves are not imaged exactly; rapid movement patterns cannot be precisely recorded. The objective of the present project was to achieve radiofrequency (RF) data transmission to the 3D workstation to improve image resolution. Methods and Results A commercially available echocardiographic system (5‐MHz transesophageal echocardiography probe) with an integrated raw data interface enables transmission of RF data (up to 40 megabytes per second). A 3D data set may contain up to 3 gigabytes, so that all of the high‐resolution ultrasound information of the 2D image is available. Frame rates of up to 168 Hz result in temporal resolution 6 times that of standard 3D systems. The applicability of the system and the image quality were tested in 10 patients. The structure of the aortic valve and the dynamic changes were depicted by volume rendering. The changes in the orifice areas were measured in frame‐by‐frame planimetry. The mean number of frames recorded per cardiac cycle was 122±16. The improved structural resolution enabled a detailed imaging of the morphology of the aortic cusps. The rapid systolic movement patterns were recorded with up to 51 frames. The high number of frames enabled creation of precise area‐time diagrams. Thus, the individual phases of aortic valve movement (rapid opening, slow valve closing, and rapid valve closing) could be analyzed quantitatively. Conclusion A 3D system based on RF data enables high‐resolution imaging of cardiac movement patterns. This offers new perspectives for qualitative and quantitative analyses, especially of cardiac valves. (Circulation. 2003;107:2876‐2879.)

Myxoma of the Mitral Valve: Diagnosis by 2-Dimensional and 3-Dimensional Echocardiography☆☆☆★

In this report we describe a 39-year-old patient who had left-sided hemiparesis. In search of a source of embolism, we performed transthoracic echocardiography, which did not show any abnormalities. Transesophageal echocardiography revealed a small tumor of the posterior mitral leaflet. Three-dimensional transesophageal echocardiography was subsequently performed and demonstrated more accurate information about the size, the morphology, and the attachment point of the tumor. Furthermore, the reconstruction provided excellent spatial visualization of the pathomorphology of the mitral valve and was a useful addition for optimal preoperative diagnostic management. The tumor was excised, and histologic examination confirmed the myxomatous character of the tumor. Mitral valve myxomas are rare. This is the first case reported of a mitral valve myxoma being visualized by 3D echocardiography.

Patent Foramen Ovale and Cryptogenic Stroke: A Matter of Age?

A patent foramen ovale (PFO) enables a right-to-left shunt in about a quarter of the population. The marked association between cryptogenic stroke and PFO supports the hypothesis that paradoxical embolism could be a relevant cause of stroke. Although this association has been described in several studies for patients <55 years of age, only limited data are available on the role of PFO in older patients. Recent studies, however, have also shown a significant association between cryptogenic stroke and PFO in patients >55 years of age. The relationship is especially marked in the presence of atrial septum aneurysm (ASA). This finding is in accordance with previous reports indicating that PFO and concomitant ASA is a high-risk feature. Factors promoting paradoxical embolism, such as deep vein thrombosis (DVT) and elevated right-heart pressure, are more frequently encountered in older than in younger patients. Independent of age, contrast-enhanced transthoracic and transesophageal echocardiography are the methods of choice for the detection and imaging of PFO and atrial septal aneurysm. Transcranial Doppler can be used as a screening method in patients with cryptogenic stroke to detect a right-to-left shunt. Proof of DVT strongly supports the suspicion of paradoxical embolism and should lead to oral anticoagulation. If paradoxical embolism is suspected without proof of DVT, both drug therapy with aspirin or warfarin and percutaneous closure of the PFO are available as therapeutic options. Recent studies have shown that percutaneous closure can be performed safely and with a low rate of recurrence both in older and younger patients. Thus far, however, there is no clear-cut evidence of superiority for either therapeutic strategy.

Quantitative assessment of aortic stenosis by three-dimensional anyplane and three-dimensional volume-rendered echocardiography.

Aortic stenosis is a challenge for three‐dimensional (3‐D) echocardiographic image resolution. This is the first study evaluating both 3‐D anyplane and 3‐D volume‐rendered echocardiography in the quantification of aortic stenosis. In 31 patients, 3‐D echocardiography was performed using a multiplane transesophageal probe. Within the acquired volume dataset, five parallel cross sections were generated through the aortic valve. Subsequently, volume‐rendered images of the five cross sections were reconstructed. The smallest orifice areas of both series were compared with the results obtained by two‐dimensional (2‐D) transesophageal planimetry and those calculated by Doppler continuity equation. No significant differences were found between Doppler (0.76 ± 0.18 cm2), 2‐D echocardiography (0.78 ± 0.24 cm2), and 3‐D anyplane echocardiography (0.72 ± 0.29 cm2). The orifice area measured smaller (0.54 ± 0.31 cm2, P < 0.001) by 3‐D volume‐rendered echocardiography. Bland‐Altmann analysis indicated that for 3‐D anyplane echocardiography, the mean difference from Doppler and 2‐D echocardiography was − 0.04 ± 0.24 cm2 and − 0.06 ± 0.23 cm2, respectively. For 3‐D volume‐rendered echocardiography, the mean difference was −0.23 ± 0.24 cm2 and − 0.25 ± 0.26 cm2, respectively. In the subgroup with good resolution in the 3‐D dataset, close limits of agreement were obtained between 3‐D echocardiography and each of the reference methods, while the subgroup with poor resolution showed wide limits of agreement. In conclusion, planimetry of the stenotic aortic orifice by 3‐D volume‐rendered echocardiography is feasible but tends to underestimate the orifice area. Three‐dimensional anyplane echocardiography shows better agreement with the reference methods. Accuracy is influenced strongly by the structural resolution of the stenotic orifice in the 3‐D dataset.