Assessment of myocardial reperfusion by intravenous myocardial contrast echocardiography and coronary flow reserve after primary percutaneous transluminal coronary angioplasty [correction of angiography] in patients with acute myocardial infarction.

BACKGROUND: This study investigated whether the extent of perfusion defect determined by intravenous myocardial contrast echocardiography (MCE) in patients with acute myocardial infarction (AMI) treated by primary percutaneous transluminal coronary angioplasty (PTCA) relates to coronary flow reserve (CRF) for assessment of myocardial reperfusion and is predictive for left ventricular recovery. METHODS AND RESULTS: Twenty-five patients with first AMI underwent intravenous MCE with NC100100 with intermittent harmonic imaging before PTCA and after 24 hours. MCE before PTCA defined the risk region and MCE at 24 hours the "no-reflow" region. The no-reflow region divided by the risk region determined the ratio to the risk region. CFR was assessed immediately after PTCA and 24 hours later. Left ventricular wall motion score indexes were calculated before PTCA and after 4 weeks. CFR at 24 hours defined a recovery (CFR >/=1.6; n=17) and a nonrecovery group (CFR <1.6; n=8). Baseline CFR did not differ between groups. MCE ratio to the risk region was smaller in the recovery group compared with the nonrecovery group (34+/-49% vs 81+/-46%, P=0.009). A ratio to the risk region of

Quantitative assessment of the operative results after extended myectomy and surgical reconstruction of the subvalvular mitral apparatus in hypertrophic obstructive cardiomyopathy using dynamic three-dimensional transesophageal echocardiography.

OBJECTIVES: The aim of this study was to examine the value of dynamic three-dimensional (3D) transesophageal echocardiography (TEE) for the postoperative evaluation after extended myectomy and surgical reconstruction of the subvalvular mitral valve apparatus in patients with hypertrophic obstructive cardiomyopathy (HOCM). BACKGROUND: Two-dimensional imaging techniques such as echocardiography, computed tomography and magnetic resonance imaging have not been able to precisely quantify the effects of surgical therapy on the morphology of the left ventricular outflow tract (LVOT). METHODS: Multiplane TEE with 3D reconstruction was performed in 11 patients before and after the operation and in 16 normal control subjects for comparison. The preoperative maximal systolic pressure gradient in the LVOT was 69 +/- 59 mm Hg. The following variables were measured within the dynamic 3D data set: depth, width, length and cross-sectional area (CSA) gain caused by the myectomy trough, minimal CSA of the LVOT at each time point and its cyclic changes and maximal mitral leaflet deviation during systole. RESULTS: Functional class improved from 3.0 +/- 0.2 before the operation to 1.5 +/- 0.6 after it. The maximal systolic pressure gradient in the outflow tract decreased to 26 +/- 21 mm Hg postoperatively (p < 0.001). Minimal CSA of the outflow tract increased from 1.1 +/- 1.2 to 3.8 +/- 1.9 cm2 postoperatively (p < 0.001), similar to the value of the control group (4.2 +/- 1.5 cm2, p = NS). The area gain due to the myectomy trough was 1.3 +/- 1.0 cm2, corresponding to 48 +/- 12% of the total operative area difference. Maximal systolic depth of the myectomy was 7 +/- 2 mm, maximal width was 20 +/- 8 mm and length was 28 +/- 7 mm. Maximal deviation of the mitral leaflets fell from 15 +/- 7 to 6 +/- 7 mm postoperatively (p < 0.01). In five patients mass measurements of the intracavitary portion of the papillary muscle (PM) revealed an increase from 7.3 +/- 1.0 to 12.1 +/- 2.5 g due to surgical mobilization of PMs (p < 0.01). CONCLUSIONS: 3D TEE quantifies the differences in outflow tract morphology before and after surgery for HOCM. This technique may have an impact on the planning of operative interventions and allow for the evaluation of its results.

Transthoracic echocardiography using second harmonic imaging: diagnostic alternative to transesophageal echocardiography for the detection of atrial right to left shunt in patients with cerebral embolic events.

OBJECTIVES: We sought to evaluate whether transthoracic contrast echocardiography using second harmonic imaging (SHI) is a diagnostic alternative to transesophageal contrast echocardiography (TEE) for the detection of atrial right to left shunt. BACKGROUND: Paradoxic embolism is considered to be the major cause of cerebral ischemic events in young patients. Contrast echocardiography using TEE has proven to be superior to transthoracic echocardiography (TTE) for the detection of atrial shunting, SHI is a new imaging modality that enhances the visualization of echocardiographic contrast agents. METHODS: We evaluated 111 patients with an ischemic cerebral embolic event for the presence of atrial right to left shunt using an intravenous (IV) contrast agent in combination with three different echocardiographic imaging modalities: 1) TTE using fundamental imaging (FI); 2) TTE using SHI; and 3) TEE. The severity of atrial shunting and the duration of contrast visibility within the left heart chambers were evaluated for each imaging modality. Image quality was assessed separately for each modality by semiquantitative scoring (0 = poor to 3 = excellent). Presence of atrial right to left shunt was defined as detection of contrast bubbles in the left atrium within the first three cardiac cycles after contrast appearance in the right atrium either spontaneously or after the Valsalva maneuver. RESULTS: A total of 57 patients showed evidence of atrial right to left shunt with either imaging modality. Fifty-one studies were positive with TEE, 52 studies were positive with SHI, and 32 were positive with FI (p<0.001 for FI vs. SHI and TEE). The severity of contrast passage was significantly larger using SHI (61.6+/-80.2 bubbles) compared to FI (53.7+/-69.6 bubbles; p<0.005 vs. SHI) but was not different compared to TEE (43.9+/-54.3 bubbles; p = NS vs. SHI). The duration of contrast visibility was significantly longer for SHI (17.4+/-12.4 s) compared to FI (13.1+/-9.7 s; p<0.001) and TEE (11.9+/-9.6 s; p<0.02). Mean image quality improved significantly from FI (1.5+/-0.8) to SHI (2.0+/-0.8; p<0.001 vs. FI) and TEE (2.5+/-0.7; p<0.001 vs. SHI). CONCLUSIONS: In combination with IV contrast injections, TEE and SHI have a comparable yield for the detection of atrial right to left shunt. Both modalities may miss patients with atrial shunting. In young patients with an unexplained cerebrovascular event and no clinical evidence of cardiac disease, a positive SHI study may obviate the need to perform a TEE study to search for cardiac sources of emboli.

Predictive value of markers of myocardial reperfusion in acute myocardial infarction for follow-up left ventricular function.

This study evaluated recently suggested invasive and noninvasive parameters of myocardial reperfusion after acute myocardial infarction (AMI), assessing their predictive value for left ventricular function 4 weeks after AMI and reperfusion defined by myocardial contrast echocardiography (MCE). In 38 patients, angiographic myocardial blush grade, corrected Thrombolysis In Myocardial Infarction frame count, ST-segment elevation index, and coronary flow reserve (n = 25) were determined immediately after primary percutaneous transluminal coronary angioplasty (PTCA) for first AMI, and intravenous MCE was determined before, and at 1 and 24 hours after PTCA to evaluate myocardial reperfusion. Results were related to global wall motion index (GWMI) at 4 weeks. MCE 1 hour after PTCA showed good correlation with GWMI at 4 weeks (r = 0.684, p <0.001) and was in an analysis of variance the best parameter to predict GWMI 4 weeks after AMI. The ST-segment elevation index was close in its predictive value. Considering only invasive parameters of reperfusion myocardial blush grade was the best predictor of GWMI at 4 weeks (R(2) = 0.3107, p <0.001). A MCE perfusion defect size at 24 hours of > or =50% of the MCE perfusion defect size before PTCA was used to define myocardial nonreperfusion. In a multivariate analysis, low myocardial blush grade class was the best predictor of nonreperfusion defined by MCE. Thus, intravenous MCE allows better prediction of left ventricular function 4 weeks after AMI than other evaluated parameters of myocardial reperfusion. Myocardial blush grade is the best predictor of nonreperfusion defined by MCE and is the invasive parameter with the greatest predictive value for left ventricular function after AMI. Coronary flow parameters are less predictive.

Non-contrast second harmonic imaging improves interobserver agreement and accuracy of dobutamine stress echocardiography in patients with impaired image quality.

OBJECTIVE: To examine the influence of second harmonic imaging during dobutamine echocardiography on regional endocardial visibility, interobserver agreement in the interpretation of wall motion abnormalities, and diagnostic accuracy in patients with reduced image quality. DESIGN: Blinded comparison. SETTING: Tertiary care centre. PATIENTS: 103 consecutive patients with suspected coronary artery disease and impaired transthoracic image quality (>/= 2 segments with poor endocardial delineation). METHODS: Fundamental and second harmonic imaging were performed at each stage of a dobutamine stress echocardiography. Coronary angiography was undertaken within three weeks of dobutamine echocardiography in 75 patients. MAIN OUTCOME MEASURES: Evaluation of regional endocardial visibility (scoring from 0 = poor to 2 = good) and of segmental wall motion abnormalities for both modalities separately. A second blinded examiner analysed 70 studies to determine interobserver agreement. RESULTS: Mean (SD) visibility score for all segments was 1.2 (0.4) using fundamental imaging and 1.7 (0.2) using second harmonic imaging at rest (p < 0.001), and 1.1 (0.4) v 1.6 (0.3), respectively, at peak dobutamine dose (p < 0.001). The average number of segments with poor endocardial visibility was lower for second harmonic than for fundamental imaging (0.6 (1.1) v 3.8 (2.6) at rest, p < 0.001; 0.9 (1.3) v 4.3 (2.9) at peak dose, p < 0.001). Improvement was most pronounced in all lateral and anterior segments. The kappa value for identical study interpretation increased from 0. 40 to 0.69 (p < 0.05). Sensitivity for the diagnosis of coronary artery disease was 64% using fundamental imaging versus 92% using harmonic imaging (p < 0.001), while specificity remained unchanged at 75% for both imaging modalities. CONCLUSIONS: Second harmonic imaging enhances endocardial visibility during dobutamine echocardiography. Consequently, interobserver agreement on stress echocardiography interpretation and diagnostic accuracy are significantly improved compared to fundamental imaging. Thus, in difficult to image patients, dobutamine echocardiography should be performed using second harmonic imaging.

Evaluation of septal hypertrophy and systolic function in diseases that cause left ventricular hypertrophy: a 3-dimensional echocardiography study.

OBJECTIVES: The goals of this study were to determine regional systolic function of the septum and to relate it to regional wall thickness and wall stress. BACKGROUND: Wall thickening, a parameter of systolic function, is determined by wall thickness and wall stress. In patients with hypertrophic obstructive cardiomyopathy (HOCM), hypertrophic nonobstructive cardiomyopathy (HNCM), and hypertensive heart disease (HHD), regional systolic function of normal and hypertrophic septal regions has been incompletely characterized by 2-dimensional echocardiography. Thus, multiplane transesophageal echocardiography with 3-dimensional reconstruction of the septum was used. METHODS AND RESULTS: In 49 patients (15 controls, 11 with HOCM, 8 with HNCM, and 15 with HHD) 4 parallel (2 basal and 2 apical) equidistant short-axis cross sections from base to apex were obtained from the reconstructed septum. In each short-axis cross section, 6 wall-thickness measurements were made in 15 degrees intervals at end diastole and end systole, for a total of 48 measurements in each patient. Fractional thickening was calculated as wall thickening divided by end-diastolic wall thickness. Wall thickness of the basal cross sections was significantly thicker (P < .001) in HOCM and HNCM than in HHD. However, circumferential wall thickness was more evenly distributed in HNCM and HHD when compared with HOCM. In the basal cross sections, fractional thickening was similarly reduced in all hearts, though basal wall stress was significantly different in all groups (P < .001). In the apical cross sections, wall thickness was similar in all diseased hearts, but fractional thickening was better (P < .001) and wall stress lower (P < .001) in HNCM than in HOCM and HHD. CONCLUSIONS: In septal regions without or with only mild hypertrophy, regional systolic function is preserved and appears to be determined by hemodynamic factors such as wall stress. However, in regions with moderate to severe hypertrophy, systolic function is markedly and uniformly impaired in all groups, which seems not to be caused by differences in wall thickness and wall stress but by the degree of the myocardial disease process.

Determination of left ventricular mass and circumferential wall thickness by three-dimensional reconstruction: in vitro validation of a new method that uses a multiplane transesophageal transducer.

Elevated left ventricular mass and increased wall thickness have important prognostic implications in clinical medicine. However, these parameters have been incompletely characterized by one- and two-dimensional echocardiography. Therefore this study was performed to validate in vitro measurement of left ventricular mass and circumferential wall thickness with a multiplane transesophageal transducer and three-dimensional reconstruction. Results for mass measurements were also compared with a standard method for the determination of left ventricular mass, the Penn convention. Fourteen necropsied left ventricles were scanned in a water bath by a volume-rendering, three-dimensional reconstruction system. There was an excellent correlation and high agreement for determination of three-dimensional left ventricular mass (r = 0.98; standard error of the estimate [SEE] = 9.6 gm; y = 1.02x + 0.46) and wall thickness (r = 0.93; SEE = 1.4 mm; y = 0.95x + 1.64) compared with anatomic measurements. Left ventricular mass by a simulated Penn convention revealed a lower correlation and larger error compared with three-dimensional measurements (r = 0.72; SEE = 42.8 gm; y = 1.01x + 9.61). Therefore determination of left ventricular mass by three-dimensional reconstruction was validated in vitro and was superior to one-dimensional echocardiographic methods.

Transesophageal 3-dimensional echocardiography: in vivo determination of left ventricular mass in comparison with magnetic resonance imaging.

The objective of this study was to assess the accuracy and reproducibility of transesophageal 3-dimensional echocardiography (3DE) in comparison with magnetic resonance imaging (MRI) for the in vivo calculation of left ventricular mass (LVM). In addition, mass values obtained by M-mode echocardiography were compared with those calculated by MRI. Three-dimensional reconstruction of the left ventricle was performed from a transesophageal and transgastric transducer position with a multiplane transducer in 20 patients. Left ventricular mass was calculated from both transducer positions by using slices of various thicknesses, ranging from 5 to 20 mm. Reproducibility was determined by 5 repeated measurements of mass in each of 5 randomly selected left ventricles. M-mode echocardiography was performed according to the method described by Devereux. For MRI, multiple short-axis views with 10-mm slice thickness were acquired in inspiration hold. Correlation was high for mass determined by 3DE and MRI (for 10-mm slice thickness: r = 0.99; y = 0.99 x - 0.7 g; standard error of estimate = 8.5 g; P <.001). There was no statistical bias, and the limits of agreement ranged from +/-16.4 g to +/-27.2 g, depending on the slice thickness. Variability was lowest for a slice thickness of 10 mm (SD +/- 8.2 g). The reproducibility of mass determination was excellent (mean width of the 95% CI 12.8 g). Left ventricular mass values calculated from the transgastric and transesophageal transducer position were not different from each other (mean bias 0.6 +/- 9.1 g; P = ns). M-mode-based LVM calculations showed systematic overestimation and large measurement variability (bias 23.7 g; 95% CI +/- 92.8 g). Compared with MRI, transesophageal 3DE is an accurate and reproducible method for the determination of LVM and clearly superior to M-mode echocardiography.

Three-dimensional echocardiographic determination of left ventricular volumes and function by multiplane transesophageal transducer: dynamic in vitro validation and in vivo comparison with angiography and thermodilution.

The goal of this study was to validate 3-dimensional echocardiography by multiplane transesophageal transducer for the determination of left ventricular volumes and ejection fraction in an in vitro experiment and to compare the method in vivo with biplane angiography and the continuous thermodilution method. In the dynamic in vitro experiment, we scanned rubber balloons in a water tank by using a pulsatile flow model. Twenty-nine measurements of volumes and ejection fractions were performed at increasing heart rates. Three-dimensional echocardiography showed a very high accuracy for volume measurements and ejection fraction calculation (correlation coefficient, standard error of estimate, and mean difference for end-diastolic volume 0.998, 2.3 mL, and 0.1 mL; for end-systolic volume 0.996, 2.7 mL, and 0.5 mL; and for ejection fraction 0.995, 1.0%, and -0.4%, respectively). However, with increasing heart rate there was progressive underestimation of ejection fraction calculation (percent error for heart rate below and above 100 bpm 0.59% and -8.6%, P < .001). In the in vivo study, left ventricular volumes and ejection fraction of 24 patients with symmetric and distorted left ventricular shape were compared with angiography results. There was good agreement for the subgroup of patients with normal left ventricular shape (mean difference +/-95% confidence interval for end-diastolic volume 5.2+/-6.7 mL, P < .05; for end-systolic volume -0.5+/-8.4 mL, P = not significant; for ejection fraction 2.4%+/-7.2%, P = not significant) and significantly more variability in the patients with left ventricular aneurysms (end-diastolic volume 23.1+/-56.4 mL, P < .01; end-systolic volume 5.6+/-41.0 mL, P = not significant; ejection fraction 4.9%+/-16.0%, P < .05). Additionally, in 20 critically ill, ventilated patients, stroke volume and cardiac output measurements were compared with measurement from continuous thermodilution. Stroke volume as well as cardiac output correlated well to thermodilution (r = 0.89 and 0.84, respectively, P < .001), although both parameters were significantly underestimated by 3-dimensional echocardiography (mean difference +/-95% confidence interval = -6.4+/-16.0 mL and -0.6+/-1.6 L/min, respectively, P < .005).

Evaluation of regional systolic function in hypertrophic cardiomyopathy and hypertensive heart disease: a three-dimensional echocardiographic study.

Assessment of regional left ventricular (LV) function in patients with asymmetric LV hypertrophy is difficult with two-dimensional echocardiography mainly because of factors such as LV geometry, structure, regional wall stress, and ischemia. Multiplane transesophageal echocardiography with three-dimensional reconstruction of cross-sectional images was used for quantitative evaluation of regional wall thickness and fractional thickening. Fifteen patients (56 +/- 13 years old) with hypertrophic cardiomyopathy (LV ejection fraction 71% +/- 4%), 15 (62 +/- 13 years) with hypertensive heart disease (ejection fraction 66% +/- 8%) and 15 (53 +/- 11 years) healthy control subjects (ejection fraction 61% +/- 5%) were included in the analysis. Regional function was studied in four parallel equidistant short-axis cross sections from base to apex of the reconstructed left ventricle. In 15 degree intervals, 24 wall thickness measurements in each cross section were made at end-diastole and end-systole after endocardial and epicardial border tracing. A total of 192 measurements were obtained in each patient, and absolute wall thickening and fractional thickening were calculated. Absolute and fractional wall thickening showed a significant inverse relation to end-diastolic wall thickness in all heart conditions (r = 0.71, p < 0.0001). Regions of normal wall thickness in diseased patients were not hyperdynamic when compared with normal control subjects. Significant impairment in fractional thickening at identical end-diastolic thickness was observed in the septum compared with the lateral free wall in both hypertrophic cardiomyopathy and hypertensive heart disease. Thus regional systolic function is inversely related to end-diastolic wall thickness. The decrease in regional systolic function with increasing LV hypertrophy was similar in idiopathic and hypertensive cardiomyopathy. In both types of hypertrophy, significant differences in systolic function were observed in septal and lateral wall segments of similar wall thickness. This indicates that factors other than end-diastolic wall thickness influence myocardial thickening in patients with hypertrophy and preserved global function.

Stress cardiomyopathy mimicking acute coronary syndrome: case presentation and review of the literature.

Stress cardiomyopathy is a novel clinical syndrome affecting predominantly elderly female patients. It is characterized by severe reversible left ventricular dysfunction demonstrating a peculiar pattern of extensive apical wall motion abnormality known as "apical ballooning". The syndrome is typically precipitated by acute severe emotional, psychological or physical stress. It mimics acute coronary syndrome exhibiting typical clinical and electrocardiographic features of acute myocardial infarction. At angiography, however, significant coronary artery disease is invariably excluded. In the acute phase, the syndrome may be complicated by cardiogenic shock or ventricular fibrillation. Clinical data indicate that the disease is associated with an extensive increase of endogenous cathecholamine levels which may exhibit a direct toxic effect on the myocytes causing non-ischemic myocardial "stunning". This mechanism may have important implications for the management of patients in the acute phase of the disease. The prognosis of stress cardiomyopathy, however, seems favorable with recovery of global and regional myocardial function within a few weeks in the vast majority of patients. Yet, long-term outcome data in larger patient populations are lacking. We report the case of a female patient presenting with stress cardiomyopathy and review the current knowledge of the disease.

The impact of transesophageal echocardiography on daily clinical practice.

The development of transesophageal echocardiography (TEE) almost 20 years ago has tremendously widened the diagnostic potential of cardiac ultrasound and has, without doubt, strongly improved our pathophysiological understanding of many cardiovascular diseases such as aortic dissection, mitral valve disease or ischemic stroke. Especially the introduction of multiplane transducers that allow imaging of the cardiac structures from various scan plane orientations has yielded a level of diagnostic accuracy that is seldom attained by other imaging modalities. The outstanding image quality as well as the high temporal and spatial resolution provided by TEE renders the method especially suited to visualize small and rapidly moving structures, such as left atrial thrombus formation and valvular vegetations. In addition, TEE is exceptional in its capability to scan the heart from perspectives that cannot be easily attained by any other modality, thus enhancing its diagnostic yield. In the last few years the clinical application of TEE has been extended from a pure diagnostic tool to an indispensable monitoring adjunct for percutaneous interventional procedures as well as for the intra- and peri-operative monitoring in the operating theatre and on the intensive care unit. In the surroundings of emerging sophisticated technologies to image the heart and the great vessels within the thorax such as multi-slice computed tomography and cardiovascular magnetic resonance imaging TEE asserts a firm place in the diagnostic armamentarium for the cardiologist. This review will focus the impact of TEE in daily clinical practice and on possible future applications of the technique.

[Acute and chronic-constrictive pericarditis]. / Akute und chronisch-konstriktive Perikarditis.

Acute pericarditis is an inflammatory disease of the pericardium of variable etiology. A viral infection may sometimes precede symptoms but frequently the etiology re-mains unknown (idiopathic pericarditis). The disease is typically associated with left-sided chest pain and ECG abnormalities mimicking acute myocardial infarction. At physical examination the characteristic finding is a pericardial friction rub. A pericardial effusion of varying extent may be present or develop in the course of the disease. Pericardial tamponade, which may develop insidiously, represents a life-threatening complication. Pathophysiologically, filling of the cardiac chambers is impeded resulting in orthopnea, tachycardia, and eventually shock. Emergency pericardiocentesis is the treatment of choice. Constrictive pericarditis is the result of a chronic inflammation of the pericardium. Clinically it is characterized by dyspnea during exercise, symptoms of right heart failure and typical hemodynamic findings. Treatment primarily includes surgical removal of the thickened pericardium.

[Chronic myocardial ischemia: indications and limits of dobutamine stress echocardiography]. / Chronische Myokardischämie: Indikationen und Grenzen der Dobutamin-Stressechokardiographie.

Dobutamin echocardiography has turned out to be a reliable tool for the detection of myocardial viability in the setting of acute and chronic myocardial ischemia. Moreover, recent publications have highlighted the prognostic implications of the method in patients with acute myocardial infarction and in patients with chronic myocardial ischemia and reduced left ventricular function. In comparison to szintigraphy dobutamine echocardiography has shown higher specificity and accuracy for the prediction of functional recovery of chronic dysfunctional segments after revascularization procedures. Reasons for the discrepancy include the different methodological approaches of the two techniques for the detection of viability, i.e., functional recovery versus metabolic integrity and perfusion. Furthermore, existing evidence supports the concept that functional recovery is dependend on a threshold level of viable contracting myocardium, whereas metabolic integrity and perfusion will be even detected at a level below that necessary for functional recovery. Limitations of the method include poor transthoracic image quality in a variable subset of patients and the subjective nature of the analysis of wall motion abnormalities by the investigator.

[Imaging techniques in cardiology: three-dimensional echocardiography]. / Bildgebende Verfahren in der Kardiologie: 3D-Echokardiographie.

UNLABELLED: Three-dimensional echocardiography offers new opportunities for clinical cardiology and the solution of scientific questions. Data acquisition is possible using different techniques: (1) Realtime 3D echocardiography with matrix-array transducers is the most promising approach, but is still limited by several difficulties; (2) 3D reconstruction is based on a number of sequentially acquired 2D image planes (like in multiplane TEE), which are put together afterwards. There are 2 ways of data analysis. 1. Morphological analysis. Surface rendering of the endocardial border can create perspectives not achievable with conventional methods such as the "en face" view of atrial septal defects or the atrial view of the mitral valve. Prolapsing leaflets and the spatial relationship can be identified much easier than using 2D methods. In complex congenital heart disease 3D echo may provide better spatial orientation and easier communication with the cardiothoracic surgeons. 2. Quantitative analysis of volumes, masses, and surfaces is only possible after manual contour tracing with several cut planes generated from the 3D data set. This procedure is time consuming and limits the use in clinical routine, even though validation studies demonstrated that 3D echo determination of masses and volumes is superior to one- or two-dimensional techniques which are based on geometric assumptions. Furthermore, quantitative 3D analysis has a unique pre- and postinterventional diagnostic potential. FUTURE PERSPECTIVES: Combination with color Doppler data may lead to a more precise quantitation of valve regurgitations. Improvements of hard- and software will allow faster acquisition, reconstruction, and quantitative analysis. Assessment of regional myocardial perfusion may be possible in combination with left heart contrast agents. CONCLUSION: 3D echocardiography allows perspectives not achievable conventionally and has a great potential for precise quantitative and reproducible analysis of cardiac morphology which overcomes the limitations of 2D echocardiography.

M-mode echocardiography overestimates left ventricular mass in patients with normal left ventricular shape: a comparative study using three-dimensional echocardiography.

AIMS: We sought to evaluate whether left ventricular (LV) mass (M) determined by M-mode echocardiography is overestimated compared with LVM calculated by three-dimensional (3D) echocardiography (E) in patients with normal LV shape. METHODS AND RESULTS: A total of 112 studies in 56 patients (60+/-13 years) with hypertension (n=25) or aortic stenosis (n=31) and 30 control subjects (57+/-14 years) evaluated for cardiac sources of embolism were analyzed. LVM by M-mode and 3DE was highly correlated (r=0.85; p<0.001). However, there were broad limits of agreement (-58 to 110 g) demonstrating large variability between the methods. M-mode overestimated 3DE LVM by a mean of 15+/-24% (p<0.001) with overestimation in controls and the different patient groups. Variability was unrelated to increasing quartiles of LVM values. Using technique-specific partition values for normal LVM, the agreement between M-mode and 3DE for the detection of LV hypertrophy was 83% (Kappa=0.59; p<0.001). CONCLUSION: Although M-mode and 3DE correlate well for the calculation of LVM, there is a systematic difference between the two techniques leading to overestimation of LVM by the 1D technique. Thus, previously published cutoff values for normal LVM derived from M-mode may not apply for 3DE. However, the use of technique-specific partition values allows stratification of patients for the presence of LV hypertrophy with reasonable agreement.

Second-generation real-time three-dimensional echocardiography. Finally on its way into clinical cardiology?

Three-dimensional (3D) echocardiographic imaging has been introduced as a tool to improve the assessment of both morphologic and functional parameters of the cardiovascular system. In the past, data acquisition was limited due to time-consuming sequential acquisition of multiple triggered 2D image planes from 10-60 heart cycles using transesophageal rotational, transthoracic rotational or transthoracic freehand approaches. Recent improvements in the size of matrix array probes and in computing power of modern ultrasound equipment have significantly increased both spatial and temporal resolution of "second-generation" real-time 3D scanners. Although the superiority of 3D echocardiography in the determination of ventricular volume, ventricular mass or valvular orifice area had already been demonstrated in the late 1990s, widespread use in clinical cardiology was limited on account of difficulties in acquisition and post-processing. Clinical use of modern 3D echocardiography is boosted by the marked reduction in acquisition time and the unique possibility of on-line rendering on the ultrasound system. The ability to visualize a virtual 3D surface in real time-although limited to a sector size of about 30 degrees-offers new insights into cardiac pathomorpholgy even in patients with arrhythmias and may in realtime 3D-contrast flow analysis. Analysis of wide-angle 3D datasets (90 by 90 degree pyramidal shape) is possible by combining the 3D information of several [4-7] consecutive heart cycles. 3D datasets including the complete left ventricle provide comprehensive information on ventricular and mitral valve morphology and function. Qualitative and quantitative analyses of regional wall motion at rest and during stress become possible. Combination with 3D color Doppler data allows additional assessment of valvular function as well as determination of flow in the left ventricular outflow tract and across septal defects. The integration and future quantification of these new parameters together with on-line review allows new insights into cardiac function, morphology and synchrony that offer great potentials in the evaluation of right and left ventricular global and regional function, diagnosis of small areas of ischemia, congenital and valvular heart disease and effects of biventricular pacing in dilated heart asynchrony.

[3-D echocardiography: technical toy in search of a clinical application or logical evolution of diagnostic equipment?]. / 3D-Echokardiographie: technisches Spielzeug auf der Suche nach klinischer Anwendung oder logische Weiterentwicklung des diagnostischen Instrumentariums?

In recent years, 3D echocardiographic reconstruction and real time 3D echocardiography have been developed. Reconstruction techniques are based on one of two principles: acoustic or electromagnetic location devices that identify the spatial position of the transducer during imaging, or transducers that image from a fixed position varying the sector orientation in a predefined way. Animated, dynamic reconstructions of cardiac structures are possible, and the 3D data set can be sliced and viewed in any desired way after acquisition. The mitral annulus and congenital malformations of the heart have been imaged and studied successfully by 3D echo. Mass and volume calculations based on 3D data sets have been shown to be extraordinarily accurate by several investigators working with different techniques. Since the 3D data set is more comprehensive than any set of 2D images, such calculations are fundamentally superior to 2D or M-mode derived parameters. Color Doppler data can also be reconstructed into 3D data sets, with possible applications to proximal convergence zone calculations. However, broad implementation of 3D echo in clinical practice is hampered to date by cumbersome manual tracing to derive quantitative parameters and sometimes by insufficient image quality. Nevertheless, the rapid technical evolution, now including real-time 3D echo, ensures an important role for 3D echo in future echocardiography.