How I do it: feasibility of a new ultrasound probe fixator to facilitate high quality stress echocardiography.

BACKGROUND: Stress echocardiography (SE) has recently regained momentum as an important diagnostic tool for the assessment of both ischemic and non-ischemic heart disease. Performing SE during physical exercise is challenging due to a suboptimal patient position and vigorous movements of the patient's chest. This hampers a stable ultrasound position and reduces the diagnostic performance of SE. A stable ultrasound probe position would facilitate producing high quality images during continuous measurements. With Probefix (Usono, Eindhoven, The Netherlands), a newly developed tool to fixate the ultrasound probe to the patient's chest, stabilization of the probe during physical exercise is possible. IMPLEMENTATION AND RESULTS: The technique of SE with the Probefix and its' feasibility are evaluated in a small pilot study. Probefix fixates the ultrasound probe to the patient's chest, using two chest straps and a fixation device. The ultrasound probe position and angle may be altered with a relative high degree of freedom. We tested the Probefix for continuous echocardiographic imaging in 12 study subjects during supine and upright ergometer stress tests. One patient was unable to perform exercise and in two study subjects good quality images were not achieved. In the other patients (82%) a stable probe position was obtained, with subsequent good quality echocardiographic images during SE. CONCLUSION: We have demonstrated the feasibility of the Probefix support during ergometer tests in supine and upright positions and conclude that this external fixator may facilitate continuous monitoring of cardiac function in a group of patients.

Accuracy of speckle tracking in the context of stress echocardiography in short axis view: An in vitro validation study.

AIM: This study aimed to test the accuracy of a speckle tracking algorithm to assess myocardial deformation in a large range of heart rates and strain magnitudes compared to sonomicrometry. METHODS AND RESULTS: Using a tissue-mimicking phantom with cyclic radial deformation, radial strain derived from speckle tracking (RS-SpT) of the upper segment was assessed in short axis view by conventional echocardiography (Vivid q, GE) and post-processed with clinical software (EchoPAC, GE). RS-SpT was compared with radial strain measured simultaneously by sonomicrometers (RS-SN). Radial strain was assessed with increasing deformation rates (60 to 160 beats/min) and increasing pulsed volumes (50 to 100 ml/beat) to simulate physiological changes occurring during stress echocardiography. There was a significant correlation (R2 = 0.978, P <0.001) and a close agreement (bias ± 2SD, 0.39 ± 1.5%) between RS-SpT and RS-SN. For low strain values (<15%), speckle tracking showed a small but significant overestimation of radial strain compared to sonomicrometers. Two-way analysis of variance did not show any significant effect of the deformation rate. For RS-SpT, the feasibility was excellent and the intra- and inter-observer variability were low (the intraclass correlation coefficients were 0.96 and 0.97, respectively). CONCLUSIONS: Speckle tracking demonstrated a good correlation with sonomicrometry for the assessment of radial strain independently of the heart rate and strain magnitude in a physiological range of values. Though speckle tracking seems to be a reliable and reproducible technique to assess myocardial deformation variations during stress echocardiography, further studies are mandated to analyze the impact of angulated and artefactual out-of-plane motions and inter-vendor variability.

Stress echocardiography with smartphone: real-time remote reading for regional wall motion.

The diffusion of smart-phones offers access to the best remote expertise in stress echo (SE). To evaluate the reliability of SE based on smart-phone filming and reading. A set of 20 SE video-clips were read in random sequence with a multiple choice six-answer test by ten readers from five different countries (Italy, Brazil, Serbia, Bulgaria, Russia) of the "SE2020" study network. The gold standard to assess accuracy was a core-lab expert reader in agreement with angiographic verification (0 = wrong, 1 = right). The same set of 20 SE studies were read, in random order and >2 months apart, on desktop Workstation and via smartphones by ten remote readers. Image quality was graded from 1 = poor but readable, to 3 = excellent. Kappa (k) statistics was used to assess intra- and inter-observer agreement. The image quality was comparable in desktop workstation vs. smartphone (2.0 ± 0.5 vs. 2.4 ± 0.7, p = NS). The average reading time per case was similar for desktop versus smartphone (90 ± 39 vs. 82 ± 54 s, p = NS). The overall diagnostic accuracy of the ten readers was similar for desktop workstation vs. smartphone (84 vs. 91%, p = NS). Intra-observer agreement (desktop vs. smartphone) was good (k = 0.81 ± 0.14). Inter-observer agreement was good and similar via desktop or smartphone (k = 0.69 vs. k = 0.72, p = NS). The diagnostic accuracy and consistency of SE reading among certified readers was high and similar via desktop workstation or via smartphone.

Resonancia magnética para la detección no invasiva de la enfermedad microcirculatoria asociada a la vasculopatía de alotrasplante: validación de la determinación intracoronaria / Magnetic resonance for noninvasive detection of microcirculatory disease associated with allograft vasculopathy: intracoronary measurement validation

Introducción y objetivos. La vasculopatía del aloinjerto cardiaco afecta tanto al compartimento coronario epicárdico como al de la microcirculación. Se ha propuesto el uso de las técnicas de imagen de perfusión de la resonancia magnética como instrumento útil para la evaluación de la microcirculación, principalmente fuera del contexto del trasplante de corazón. La pendiente de velocidad del flujo-presión diastólica hiperémica instantánea, que es un índice de la fisiología intracoronaria, ha mostrado mejor correlación con el remodelado microcirculatorio en la vasculopatía del aloinjerto cardiaco que la de otros índices como la reserva de velocidad del flujo coronario. Con objeto de investigar el potencial de las técnicas de imagen de perfusión de resonancia magnética para detectar la presencia de remodelado microcirculatorio en la vasculopatía de aloinjerto cardiaco, se ha comparado los datos de perfusión de resonancia magnética con los índices fisiológicos intracoronarios invasivos, para estudiar la microcirculación en una población de pacientes con trasplante de corazón que presentaban una enfermedad macrovascular no obstructiva demostrada por la ecografía intravascular. Métodos. Se estudió a 8 pacientes con trasplante de corazón (media de edad, 61 ± 12 años; el 100% varones) que presentaban una vasculopatía del aloinjerto epicárdica definida por ecografía intravascular, estenosis coronarias no significativas y una resonancia magnética de estrés con dobutamina con evaluación visual del movimiento de la pared/perfusión negativa. Se determinaron los datos de perfusión de resonancia magnética cuantitativa en estrés y en reposo para establecer el índice de reserva de perfusión miocárdica, de manera no invasiva, y se determinaron cuatro índices fisiológicos intracoronarios evaluados de manera invasiva. Resultados. Los datos posprocesados mostraron una media del índice de reserva de perfusión miocárdica de 1,22 ± 0,27, mientras que la reserva de flujo fraccional, la reserva de velocidad del flujo coronario, la resistencia microvascular hiperémica y la pendiente de velocidad del flujo-presión diastólica hiperémica instantánea fueron de 0,98 ± 0,02, 2,34 ± 0,55, 2,00 ± 0,69 y 0,91 ± 0,65 cm/s/mmHg respectivamente. El índice de reserva de perfusión miocárdica presentó una correlación intensa tan solo con la pendiente de velocidad del flujo-presión diastólica hiperémica instantánea (r = 0,75; p = 0,033). Conclusiones. El índice de reserva de perfusión miocárdica obtenido a partir de la resonancia magnética de estrés con dobutamina completa resulta una técnica fiable para la detección no invasiva de la enfermedad coronaria microcirculatoria asociada a la vasculopatía de aloinjerto cardiaco (AU)

Introduction and objectives. Cardiac allograft vasculopathy affects both epicardial and microcirculatory coronary compartments. Magnetic resonance perfusion imaging has been proposed as a useful tool to assess microcirculation mostly outside the heart transplantation setting. Instantaneous hyperemic diastolic flow velocity-pressure slope, an intracoronary physiology index, has demonstrated a better correlation with microcirculatory remodelling in cardiac allograft vasculopathy than other indices such as coronary flow velocity reserve. To investigate the potential of magnetic resonance perfusion imaging to detect the presence of microcirculatory remodeling in cardiac allograft vasculopathy, we compared magnetic resonance perfusion data with invasive intracoronary physiological indices to study microcirculation in a population of heart transplantation recipients with macrovascular nonobstructive disease demonstrated with intravascular ultrasound. Methods. We studied 8 heart transplantation recipients (mean age, 61 [12] years, 100% male) with epicardial allograft vasculopathy defined by intravascular ultrasound, nonsignificant coronary stenoses and negative visually-assessed wall-motion/perfusion dobutamine stress magnetic resonance. Quantitative stress and rest magnetic resonance perfusion data to build myocardial perfusion reserve index, noninvasively, and 4 invasive intracoronary physiological indices were determined. Results. Postprocessed data showed a mean (standard deviation) myocardial perfusion reserve index of 1.22 (0.27), while fractional flow reserve, coronary flow velocity reserve, hyperemic microvascular resistance and instantaneous hyperemic diastolic flow velocity-pressure slope were 0.98 (0.02), cm/s/mmHg, 2.34 (0.55) cm/s/mmHg, 2.00 (0.69) cm/s/mmHg and 0.91 (0.65) cm/s/mmHg, respectively. The myocardial perfusion reserve index correlated strongly only with the instantaneous hyperemic diastolic flow velocity-pressure slope (r = 0.75; P = .033). Conclusions. Myocardial perfusion reserve index derived from a comprehensive dobutamine stress magnetic resonance appears to be a reliable technique for noninvasive detection of microcirculatory coronary disease associated with cardiac allograft vasculopathy (AU)

Eco-Doppler de ejercicio en pacientes con miocardiopatía hipertrófica. Factores determinantes de la limitación funcional / Exercise eco-doppler in hypertrophic cardiomyopathy patients. Determinant factors of exercise intolerance

Introducción y objetivos. En pacientes con miocardiopatía hipertrófica, los datos ecocardiográficos en reposo han mostrado una pobre correlación con la capacidad de ejercicio. Investigamos si la ecografía Doppler de esfuerzo podría explicar mejor la limitación funcional. Métodos. Estudiamos a 87 pacientes consecutivos, remitidos para test cardiopulmonar y ecografía de esfuerzo. Se realizó estudio basal y en el pico de ejercicio para evaluar el gradiente máximo, la regurgitación mitral y las velocidades diastólicas mitral y del Doppler tisular del anillo. Resultados. Desarrollaron obstrucción con el ejercicio 43 pacientes. Estos alcanzaron un menor consumo de oxígeno (21,3 ± 5,7 frente a 24,6 ± 6,1ml/kg/min; p = 0,012), presentaban mayor volumen auricular izquierdo (42,1 ± 14,5 frente a 31,1 ± 11,6ml/m2; p < 0,001) y desarrollaron más regurgitación mitral y mayor relación E/E’ con el ejercicio. Los datos de ejercicio mejoraron el poder predictivo de la capacidad funcional (R2 ajustada = 0,49 frente a R2 ajustada = 0,38 en reposo). La edad, el volumen auricular izquierdo, la relación E/E’ con el ejercicio y la obstrucción fueron los factores independientes asociados con la capacidad funcional. En los pacientes sin obstrucción, los volúmenes de las cavidades izquierdas fueron los factores determinantes. Conclusiones. En pacientes con miocardiopatía hipertrófica, la obstrucción con el esfuerzo y el volumen auricular izquierdo son los principales determinantes de la limitación funcional. Los parámetros diastólicos de esfuerzo mejoran la predicción de la capacidad funcional, aunque su poder predictivo no supera el 50%. En pacientes sin obstrucción, los volúmenes de las cavidades izquierdas son los factores determinantes (AU)

Introduction and objectives. At-rest echocardiography is a poor predictor of exercise capacity in patients with hypertrophic cardiomyopathy. We aimed to test the performance of treadmill exercise Doppler echocardiography in the prediction of functional limitations in these patients. Methods. Eighty-seven consecutive patients with hypertrophic cardiomyopathy underwent treadmill exercise echocardiography with direct measurement of oxygen consumption. Both at rest and at peak exercise, the mitral inflow, mitral regurgitation, left ventricular outflow tract obstruction and mitral annulus velocities were assessed. Results. Forty-three patients developed left ventricular outflow tract obstruction during exercise, which significantly decreased oxygen consumption (21.3 [5.7] mL/kg/min vs 24.6 [6.1] mL/kg/min; P=.012), and had greater left atrial volume (42.1 [14.5] mL/m2 vs 31.1 [11.6] mL/m2; P<.001) and a higher degree of mitral regurgitation and E/E’ ratio during exercise. Exercise variables improved the predictive value of functional capacity (adjusted R2 rose from 0.38 to 0.49). Independent predictors of oxygen consumption were age, left atrial volume, E/E’ ratio and the presence of left ventricular outflow tract obstruction. In a subset of patients without left ventricular outflow obstruction, only left ventricular and atrial volume indexes were independent predictors of exercise capacity. Conclusions. In patients with hypertrophic cardiomyopathy, left ventricular outflow tract obstruction and left atrial volume are the main predictors of exercise capacity. Exercise echocardiography is a better predictor of functional performance than at-rest echocardiography, although its predictive power is under 50%. In nonobstructed patients, left atrial and ventricular volumes were the independent factors (AU)

Alteration of left ventricular function with dobutamine challenge in patients with myocardial bridge.

BACKGROUND/AIMS: The aim of this study was to identify changes in left ventricular (LV) performance in patients with a myocardial bridge (MB) in the left anterior descending coronary artery during resting and in an inotropic state. METHODS: Myocardial strain measurement by speckle-tracking echocardiography and conventional LV wall-motion scoring was performed in 18 patients with MB (mean age, 48.1 ± 1.7 years, eight female) during resting and intravenous dobutamine challenge (10 and 20 µg/kg/min). RESULTS: Conventional LV wall-motion scoring was normal in all patients during resting and in an inotropic state. Peak regional circumferential strain increased dose dependently upon dobutamine challenge. Longitudinal strains of the anterior and anteroseptal segments were, however, reduced at 20 µg/kg/min and showed a dyssynchronous pattern at 20 µg/kg/min. Although there were no significant differences in radial strain and displacement of all segments at rest compared with under 10 µg/kg/min challenge, radial strain and displacement of anterior segments at 20 µg/kg/min were significantly reduced compared with posterior segments at the papillary muscle level (44.8 ± 14.9% vs. 78.4 ± 20.1% and 5.3 ± 2.3 mm vs. 8.5 ± 1.8 mm, respectively; all p < 0.001), and showed plateau (40%) or biphasic (62%) patterns. CONCLUSIONS: Reduced LV strain of patients with MB after inotropic stimulation was identified. Speckle-tracking strain echocardiography identified a LV myocardial dyssynchrony that was not demonstrated by conventional echocardiography in patients with MB.

Alteration of Left Ventricular Function with Dobutamine Challenge in Patients with Myocardial Bridge

BACKGROUND/AIMS: The aim of this study was to identify changes in left ventricular (LV) performance in patients with a myocardial bridge (MB) in the left anterior descending coronary artery during resting and in an inotropic state. METHODS: Myocardial strain measurement by speckle-tracking echocardiography and conventional LV wall-motion scoring was performed in 18 patients with MB (mean age, 48.1 +/- 1.7 years, eight female) during resting and intravenous dobutamine challenge (10 and 20 microg/kg/min). RESULTS: Conventional LV wall-motion scoring was normal in all patients during resting and in an inotropic state. Peak regional circumferential strain increased dose dependently upon dobutamine challenge. Longitudinal strains of the anterior and anteroseptal segments were, however, reduced at 20 microg/kg/min and showed a dyssynchronous pattern at 20 microg/kg/min. Although there were no significant differences in radial strain and displacement of all segments at rest compared with under 10 microg/kg/min challenge, radial strain and displacement of anterior segments at 20 microg/kg/min were significantly reduced compared with posterior segments at the papillary muscle level (44.8 +/- 14.9% vs. 78.4 +/- 20.1% and 5.3 +/- 2.3 mm vs. 8.5 +/- 1.8 mm, respectively; all p < 0.001), and showed plateau (40%) or biphasic (62%) patterns. CONCLUSIONS: Reduced LV strain of patients with MB after inotropic stimulation was identified. Speckle-tracking strain echocardiography identified a LV myocardial dyssynchrony that was not demonstrated by conventional echocardiography in patients with MB.

Stress Doppler echocardiography in valvular heart diseases: utility and assessment.

This article is a review on the role of stress echocardiography in valvular heart diseases, describing what the validated indications are, how to perform the test and the utility of performing this examination. Most valve diseases are characteristically dynamic and this dynamic component is best appreciated by exercise Doppler echocardiography. Dobutamine stress echocardiography is also useful in patients with severe aortic stenosis and left ventricular dysfunction. The main advantage of stress echocardiography is to concomitantly allow the evaluation of symptoms, exercise capacity and the hemodynamic consequences of valve diseases, especially in patients with severe valve diseases who deny symptoms or present equivocal symptoms. It also provides important prognostic information and may help to optimize surgical timing in difficult cases. Whether these data should be integrated in the management of patients needs further validation.

Emerging clinical role of strain imaging in echocardiography.

Myocardial strain is a measure of tissue deformation and strain rate is the rate at which deformation occurs. When applied to the heart, strain and strain rate give fundamental information on myocardial properties and mechanics that would otherwise be unavailable. Site specificity and angle independency are two unique characteristics of strain and strain rate data. Strain and strain rate can be obtained with tissue Doppler imaging or with 2D speck tracking. These two techniques derive information on strain and strain rate in two fundamentally different ways and each has its own advantages and limitations. Tissue Doppler imaging yields velocity information from which strain and strain rate are mathematically derived whereas 2D speckle tracking yields strain information from which strain rate and velocity data are derived. Data obtained from these two different techniques may not be equivalent due to limitations inherent with each technique. Strain and strain rate imaging have been used to assess myocardial function in a wide range of cardiac conditions. They are useful in detecting early left ventricular (LV) dysfunction in the setting of systemic diseases with cardiac involvement, in differentiating transmural from non-transmural infarction, and in identifying LV contractile reserve in regurgitant valve lesions. When used with dobutamine echocardiography, strain and strain rate imaging can identify viable myocardium and aid the detection of myocardial ischaemia. Strain and strain rate imaging can also be used to assess right ventricular and left atrial function. Despite significant promises, strain and strain rate imaging is technically challenging and signal to noise ratio may be potentially affected by a wide range of factors. As a result, strain and strain rate imaging have been slow to get incorporated into everyday clinical practice. Ongoing research and further technical development are likely to improve the quality of the data and the more general acceptance of these new modalities of imaging in echocardiography.

Three-dimensional echocardiography.

Over the past two to three decades echocardiography has come a considerable distance from the early M-mode machines, and has become an indispensable diagnostic tool in any cardiovascular department. It has long been proved to be safe and cost-effective, and its clinical versatility has steadily increased with the continued integration of newer techniques, such as two-dimensional and harmonic imaging, Doppler and much more. One of the more recent developments in the field is three-dimensional echocardiography (3DE). 3DE, in various forms, has been used as a research tool for many years now, but lately improvements in software and transducer technology have begun to facilitate its integration into clinical practice. As with any technique, 3DE has its strengths and weaknesses, and these must be fully appreciated if it is to be utilised effectively.

Three-dimensional stress echocardiography: the promise and limitations of volumetric imaging.

PURPOSE OF REVIEW: Three-dimensional (3D) volumetric imaging has potential advantages in stress echocardiography, including the ability to provide an unlimited number of planes for analysis and more rapid acquisition than conventional two-dimensional (2D) imaging. This review focuses on the advantages and disadvantages of 3D volumetric imaging and the current and future role of the technique in stress echocardiography. RECENT FINDINGS: Three-dimensional volumetric imaging uniformly shortens the time required for acquisition of stress images. The success of imaging is high with pharmacologic stress but the feasibility is not established with exercise stress. The lower spatial and temporal resolution of 3D imaging and artifacts introduced by suboptimal subvolume integration are limitations of the current 3D technique. The ability to provide more planes for analysis has not been clearly shown to improve the accuracy of stress echocardiography. However, 3D imaging eliminates apical foreshortening, which is common with 2D imaging, and may improve detection of apical wall motion abnormalities. SUMMARY: In general, 3D imaging has shown rates of success and accuracy comparable to those of 2D imaging in pharmacologic stress echocardiography. Further studies are needed in larger and more heterogeneous patient populations. As improvements in 3D technology continue, successful application of the technique to exercise echocardiography is likely. Development of automated image registration, quantitative analysis techniques, and single beat acquisition is needed to fully exploit the potential of 3D imaging in the stress laboratory.

Experimental assessment of a new research tool for the estimation of two-dimensional myocardial strain.

One-dimensional strain imaging has been shown to be angle dependent. To address this problem, a new methodology, 2D-strain, has become available. The aim of this study was to validate this methodology in an in vivo set-up against sonomicrometry. In five open chest sheep, ultrasound gray-scale images were acquired of the inferolateral wall from two different angles. The longitudinal and radial strain components were simultaneously extracted using the novel 2D-strain methodology. The extracted values were compared with sonomicrometry using Bland-Altman statistics and correlation coefficients. A good agreement was found for the longitudinal strain component, while, for the radial strain estimates, the accuracy was less. 2D-strain is a fast and accurate tool to assess longitudinal strain from apical views. Further improvements are needed for the method to be sufficiently accurate in estimating the deformation perpendicular or close to perpendicular to the ultrasound beam.

New technologies applied to stress echocardiography: myocardial contrast echocardiography.

The development of new echocardiographic contrast agents that can be injected intravenously and can opacify left-sided cardiac chambers has offered a contribution in the field of stress-echocardiography for two main reasons: (1) the improvement of visualization of the endocardial border and thus facilitating recognition of wall motion abnormalities during pharmacological stress or physical exercise; and (2) the obtaining of information on myocardial perfusion during stress examinations. This review will consider: (1) the improvement of diagnostic accuracy during pharmacological stress or physical exercise obtained with the administration of echo-contrast agents; (2) the results of major studies for comparison of the myocardial contrast echocardiography technique versus single-photon emission computed tomography (SPECT) and coronary angiography; (3) the added value for studying perfusion other than wall motion analysis during stress echo; and (4) the advantages and limitations of different stress modalities. New multicenter studies should now definitively clarify the choice of the best contrast agents and create protocols for myocardial contrast echocardiography using different methods of image acquisition in order to unify the diagnostic process before a 'label approved' for perfusion of contrast echocardiographic agents. Finally, caution should be considered when contrast agents are used in the acute phase of myocardial infarction or ischemia.

[Modern echocardiography: possibilities and limitations]. / Moderne Echokardiographie: Möglichkeiten und Grenzen.

Echocardiography has revolutionized the cardiac evaluation in non-invasive cardiology. Two-dimensional and colour Doppler echocardiography have the potential to provide quantitative insighths into the hearts anatomy, valve and ventricular function in a excellent time and spacial resolution. In addition integration of Doppler allows the quantification of stenotic lesions and hemodynamics. Stressechocardiography has gained wide acceptance for the evaluation of ischemia. Reduced echoquality can be overcome by latest probe technology (harmonic imaging and postprocessing), transesophageal echocardiography and echocontrast studies. However echocontrast will be used for myocardial perfusion imaging also. Three dimensional echocardiography is ready for clinical application. Good formation and continuous training in echocardiography according to international guidelines will help to reduce interobserver and intraobserver variability.

Assessment of regional myocardial strain by a novel automated tracking system from digital image files.

Myocardial strain imaging by Doppler tissue echocardiography is a useful method to quantify regional left ventricular function. However, this method has a problem of its Doppler angle dependency. We attempted to quantify myocardial strain by a newly developed automated tracking system from digital image files. In 6 anesthetized open-chest dogs, a pair of ultrasonic crystals was implanted at the inner site and outer site of the left ventricular wall to measure myocardial radial strain. B-mode echocardiographic images and trajectories of crystals were recorded simultaneously. Three conditions were examined by intravenous infusion of dobutamine. We used a pattern matching algorithm, which allowed us to track objects from one frame to the next. In 18 image sequences obtained in the 6 dogs, there was an excellent correlation in maximal myocardial strain between the two methods ( r = 0.92, P < .0001). Thus, this system is a promising tool to provide automated quantification of regional myocardial strain.

Feasibility and safety of noninvasive pacemaker stress echocardiography with externally triggered stimulation.

The aim of this study was to assess the feasibility and safety of stress echocardiography by triggering an implanted pacemaker through an external stimulator. The implanted pacemaker was set in triggered mode with unipolar sensitivity of <2 mV. The external stimulator, connected to 2 skin electrodes, tracked the implanted pacemaker at increasing rates. Fifteen patients (mean age 65 +/- 8 years) with suspected coronary artery disease entered the study, and complete tests were performed in all patients. No adverse effects were reported. The method of externally triggered stimulation is feasible, safe, and allows a diagnosis in every patient with a pacemaker without additional cost.

Biplane stress echocardiography using a prototype matrix-array transducer.

BACKGROUND: Rapid image acquisition after cessation of exercise is essential for accurate stress echocardiography. Recently, a prototype matrix-array transducer has been developed that allows simultaneous acquisition of 2 imaging planes (biplane [BP] imaging). METHODS: In all, 19 healthy volunteers underwent 2 separate stress echocardiographic studies. Images were acquired in traditional 2-dimensional or BP format pre-exercise and postexercise. RESULTS: Total image acquisition time for 2-dimensional stress echocardiography was 38 +/- 8 seconds versus 29 +/- 8 seconds for BP imaging (P <.05). Heart rates were acquired closer to age-predicted maximum with BP imaging in the apical 3- and 2-chamber and parasternal long- and short-axis views (82%, 75%, 70%, 70% for BP vs 76%, 72%, 68%, 66% for 2-dimensional, respectively). CONCLUSION: BP imaging using a recently developed matrix-array probe allows more rapid imaging postexercise, resulting in acquisition of poststress images at higher heart rates without compromising image quality.

Pediatric stress echocardiography.

Traditional health evaluations are performed while the patient is at rest. Stress echocardiography extends these examinations by providing data in a physiologic setting more closely mimicking the typically active state of children. The test represents a fusion of the fields of two-dimensional echocardiography and cardiovascular stress testing and can be used to assess myocardial perfusion in patients with suspected coronary artery pathology or to evaluate cardiac gradients or functional reserve in patients with noncoronary artery pathology. Testing should be performed with a trained sonographer and attending physician and in collaboration with adult cardiology colleagues. Stress can be administered to the patient through either exercise or pharmacologic agents. Echocardiography is used to assess regional wall motion abnormalities when evaluating myocardial perfusion or gradients and/or function when assessing the patient without coronary artery issues. Conditions with potential coronary artery pathology for which stress echocardiography is appropriate include Kawasaki disease, transplant graft vasculopathy, arterial switch operation for transposition of the great arteries, anomalous coronary artery origins or courses, pulmonary atresia with intact ventricular septum, hyperlipidemia, insulin-dependent diabetes mellitus, and supravalvar aortic stenosis. Stress echocardiography can also be helpful in determining the behavior during activity of gradients in conditions such as hypertrophic cardiomyopathy or aortic and pulmonic stenosis, of cardiac pressures in pulmonary hypertension and of ventricular function in conditions such as dilated cardiomyopathy or mitral and aortic regurgitation.