Search

Objective: We investigated physiological systolic left ventricular (LV) myocardial mechanics and gradients to provide a database for later studies of diseased hearts. Methods: The analyses were performed in 131 heart-healthy individuals and included seven parameters of myocardial mechanics using speckle tracking echocardiography (STE). Results: Basal to apical and circumferentially significant physiological intraventricular parameter gradients of myocardial activity were determined. Global mean values and segmental ranges were peak systolic longitudinal strain -21.2 +/- 3.3%, 95% confidence interval [CI] -21.8% to -20.6%), gradient (basal to apical) -16.0% to -26.7%; peak systolic longitudinal strain rate -1.24 +/- 0.31%/s, 95% CI -1.29% to -1.19%/s, gradient (basal to apical) -0.91% to -1.61%/s; post-systolic index 2.6 +/- 3.2%, 95% CI 3.15%-2.05%, gradient (basal/medial/apical) 7.0/1.2/2.4%; pre-systolic stretch index 1.3 +/- 2.7%, 95% CI 1.77%-0.83%, gradient (basal/medial/apical) 6.5/0.2/1.3%; peak longitudinal displacement 12.2 +/- 2.6 mm, 95% CI 12.6-11.8 mm, gradient (basal to apical) 21.0-3.4 mm; time-to-peak longitudinal strain 370 +/- 43 ms, 95% CI 377-363 ms, gradient (basal to apical) 396-361 ms; and time-to-peak longitudinal strain rate 180 +/- 47 ms, 95% CI 188-172 ms, gradient (basal to apical) 150-200 ms. Conclusion: This study generated a database of seven STE-derived parameters of physiological segmental and global myocardial LV mechanics. The resulting sets of three-dimensional intraventricular mappings of the entire LV provide physiological parameter gradients in baso-apical and circumferential direction by applying the 17-segment polar model. This will facilitate comparison of systolic myocardial activity of the healthy LV with diseased or otherwise altered (eg, sports) hearts.

Aims Blood flow rate quantification using two-dimensional phase-contrast MRI (PC-MRI) results in averaging of flow information due to long acquisition times precluding the examination of short-term effects. The aim of this study was to determine respiration-related flow rate variations by non-electrocardiographic triggered real-time phase-contrast MRI (PC-MRI). Methods and results Real-time PC-MRI was applied to study respiration-driven blood flow fluctuations in the ascending aorta (AAo), superior vena cava (SVC), and inferior vena cava (IVC) under normal and forced breathing in 33 healthy children and 10 Fontan patients. Respiration-dependent flow rates were virtually generated by dividing the respiration curve into four segments: expiration, end-expiration, inspiration, and end-inspiration. Whereas in volunteers aortic flow rate was elevated during end-expiration (5.6 ± 3.0%) and decreased during end-inspiration (−5.8 ± 3.5%) in relation to mean blood flow ( P < 0.05), highest flow was detected during inspiration in SVC (10.5 ± 14.1%) and IVC (22.5 ± 12.1%) and lowest flow during expiration (−11.6 ± 13.5%, −13.2 ± 14.1%, P < 0.05). Differences were increased under forced breathing in AAo (10.4 ± 5.5%, −7.4 ± 6.5%, P < 0.05) and SVC (40.0 ± 30.3%, −30.0 ± 19.2%, P < 0.05), whereas were unchanged in IVC (16.5 ± 23.6%, −13.7 ± 21.6%, P = n.s.). Regarding patients, respiratory-dependent flow rate variability was increased and had to be related to the patient's individual quality of Fontan circulation. Conclusion Real-time PC-MRI allows a physiological assessment of respiratory-related flow rate fluctuations in healthy subjects as well as in Fontan patients. Its capability for detection of short-term effects in clinical routine was demonstrated.

To evaluate the diagnostic benefit of time-resolved CENTRA-keyhole contrast-enhanced cardiovascular magnetic resonance angiography (CE-CMRA) for improving arterial-venous separation of pulmonary vessels.Twenty-three patients (18 males; age = 58 +/- 11y) after radiofrequency pulmonary vein isolation to treat atrial fibrillation were examined using CENTRA-keyhole based multi-phase 3D CE-CMRA yielding 6 near-isotropic 3D datasets every 1.6 s (50-60 coronal partitions, 1.4 x 1.4 x 1.3 mm, SENSE-factor 3). Results were compared with conventional non-keyhole CE-CMRA (identical parameters, SENSE-factor 2).Data acquisition was accelerated by a speedup factor of approximately 9 compared with the reference CE-CMRA (SENSE 1.5*, keyhole 6*). No pulmonary venous stenoses were detected by either method, overall pulmonary venous diameters were 17.1 +/- 3.6 mm. Applying Bland-Altman analysis, vessel diameters differed by a mean of 0.1 mm + 2.1 mm/-2.0 mm (mean +/- 2 SD), indicating close agreement between both techniques. Interobserver variability was higher for CENTRA-keyhole (mean = 0.1 mm; mean +/- 2 SD: +2.5 mm/-2.3 mm) compared to conventional technique (0.0 mm; +1.6 mm/-1.5 mm), corresponding to a percentual deviation (mean +/- 2 SD) of the mean diameter of approximately +/- 15% (keyhole CE-CMRA) and +/- 10% (conventional CE-CMRA), respectively. Using keyhole-based time-resolved CE-CMRA, the contrast between pulmonary veins versus aorta/pulmonary artery was significantly increased (p0.05), which improved vessel depiction. In 12 cases, the contrast bolus arrival was delayed in one of the pulmonary veins by 1 dynamic frame (= 1.6 seconds); in 7 cases by 2 frames (= 3.2 seconds) and in 1 subject by 3 frames (= 4.8 seconds). The bolus usually appeared first in the upper right pulmonary vein whereas a delay occurred most often in the lower left pulmonary vein.Conventional CE-CMRA may be advantageous for accurate vessel size measures as evidenced by superior interobserver reproducibility in this study. Multi-dynamic CE-CMRA using CENTRA-keyhole with SENSE, however, allows for improved arterio-venous separation of pulmonary vessels and additional dynamical information on pulmonary venous perfusion, while maintaining high spatial resolution. Exact bolus timing is no longer needed.

Eine 32-jahrige Patientin, bei der als Kind eine Aortenisthmusstenose mittels Dacronpatchplastik korrigiert worden war, wurde wegen rezidivierender Hamoptysen stationar aufgenommen. Die radiologische Diagnostik zeigte eine aneurysmatische Erweiterung des distalen Aortenbogens. Bei der kurzfristig durchgefuhrten Operation fand sich ein groses Aortenbogenaneurysma, ausgehend von der Region der Patchplastik im Isthmusbereich, mit gedeckter Perforation in den linken oberen Lungenlappen. Nach Korrektur einer Aortenisthmusstenose mittels Patchplastik sollten Patienten lebenslang regelmasig im Hinblick auf die Moglichkeit einer Aneurysmabildung im Patchbereich untersucht werden.

We present the case of a 41-year-old woman who was admitted to our centre with progressive symptoms of congestive heart failure (NYHA class III) 5 years after a radical nephrectomy for renal cell carcinoma. Magnetic resonance imaging demonstrated a 5 x 3 cm homogeneous intracardial mass causing right ventricular outflow tract obstruction, not accessible to surgical resection. Serial echo-guided, percutaneous coil embolization of the cardial metastasis was performed with Contour SE Microparticles (150-250 or 300-500 microm) after identification of the target region of the metastasis by contrast injection (Levovist) through the balloon catheter into the coronary artery under transoesophageal echocardiographic control prior to induction of the necrosis, corresponding to the technique which has been described for septal ablation in hypertrophic obstructive cardiomyopathy. Follow-up after serial embolization showed a good haemodynamic and a marked clinical response (dyspnoea NYHA I-II) which lasted during the 19 month of survival after the index procedure.

Objective: To compare the modalities 3D-echocardiography (RT3DE) and cardiac magnetic resonance as well as semiautomatic non-model-based and model-based quantification software (SWP-MRI and SWT-MRI) regarding accuracy and agreement of left ventricular functional indices. Methods: 9 asymmetrically shaped gel phantoms (range: 20-350ml), 24 healthy children (age=11.4±3.3y) and 11 patients with abnormally shaped left ventricles (22.0±17.0y) were prospectively investigated. 3D-echocardiography was performed using a Vivid 7 ultrasound machine (V3 matrix transducer); postprocessing was done with a model-based analysis strategy (SWT-echo). CMR datasets were obtained using a multi-slice multi-phase steady‑state-free-precision acquisition (TR/TE/flip=2.8msecs/1.4msecs/60°) with a 1.5T MR system. Volume quantification was done using the same model-based software for CMR as well as non model-based software based on the summation of discs method. Agreement of EDV, ESV and EF between SWT-echo, SWP-mri vs. SWT-mri was determined by Bland Altman analysis. Results: Phantom study revealed high accuracy (

Objective Calcification is a principal problem in noninvasive coronary angiography (CA) performed with multislice computed tomography (MSCT). Magnetic resonance imaging (MRI) supposedly neglects calcium. We compared both modalities. Methods Sixty-eight patients admitted for CA underwent MSCT- and MRI-based noninvasive CA the day before. Stenosis detection (>or=50%) was visually performed and validated by quantitative CA. Results The patient-based overall sensitivity, specificity, positive predictive value, and negative predictive value were 96.2%, 95.2%, 92.6%, and 97.6% for MSCT versus 69.2%, 64.3, 54.5%, 64.3%, and 77.1% for MRI, respectively. The segment-based overall results were 74.7%, 97.8%, 75.7%, and 97.6% for MSCT versus 40%, 93.8%, 37.5%, and 94.4% for MRI, respectively. Investigating the impact of coronary calcifications in the patient group with a volume score of 300 microL or greater resulted in 100%, 80%, 92.3%, and 100% for MSCT versus 70.8%, 86.7%, 89.5%, and 65% for MRI, respectively. The segment group with considerable hardening artifacts resulted in 85.3%, 83.9%, 76.3%, and 90.4% for MSCT versus 52.9%, 92.9%, 81.8%, and 76.5% for MRI, respectively. Conclusions There are no major advantages of MRI in cases of advanced coronary calcification.

Echocardiography demonstrated pronounced asymmetric left ventricular (LV) hypertrophy and thickened right ventricular muscular components in a 54-year-old woman with a history of dyspnoea (NYHA III), and recurrent syncopes. Left ventricular outflow peak gradient was 80 mmHg at rest and 125 mmHg during Valsalva manoeuvre. Cardiac cine and gadolinium-enhanced T1 weighted magnetic resonance imaging (MRI) provided striking images of a right ventricular outflow tract obstruction and a markedly abnormal gadolinium uptake in the interventricular septum consistent with myocardial fibrosis. Right and left heart catherization, with simultaneous measurement of aortic and LV pressures revealed a 150 mmHg subaortic gradient and a 130 mmHg subpulmonic gradient at rest. Impediment to right ventricular (RV) outflow was due to massive hypertrophy of the crista supraventricularis with an 'hour-glass' deformity. A surgical intervention with LV septal myotomy-myectomy and RV ventriculotomy was performed successfully. Hypertrophic obstructive cardiomyopathy with significant RV and LV outflow tract obstruction is a very rare finding. Echocardiography and MRI can be used in combination for non-invasive evaluation of morphological and haemodynamic information because mechanisms of obstruction are different in each ventricle.

A 65-year-old man was admitted to his local hospital with troponin-positive acute coronary syndrome. The patient developed signs of acute heart failure and was immediately transferred to our center. Echocardiography demonstrated a pericardial mass (8×5 cm) with compression of the right atrium (Figure 1 and online-only Data Supplement Movie I) and a reduced contractility of the posterior left ventricular wall. Magnetic resonance imaging demonstrated a pericardial hematoma that was incompressible, not vascularized, and impinging on the right atrium (Figure 2 and online-only Data Supplement Movie II). Figure 1. Echocardiographic 4-chamber view with …

Background— Flow quantification in real time by phase-contrast MRI (PC-MRI) may provide unique hemodynamic information in congenital heart disease, but available techniques have important limitations. We sought to validate a novel real-time magnetic resonance flow sequence in children. Methods and Results— In 14 pediatric patients (mean age 5.2±2.0 years) with cardiac left-to-right shunt, pulmonary (Q p ) and aortic (Q s ) flow rates were determined by nontriggered free-breathing real-time PC-MRI with single-shot echo-planar imaging combined with sensitivity encoding, which yielded 25 phase images per second at 2.7×2.7-mm in-plane resolution (field of view 30×34 cm 2 ). Over a 9.5-second period that included 2 to 5 respiratory cycles, 16.6±2.6 subsequent stroke volumes (range 13 to 22) were acquired in each vessel. Results were compared with conventional retrospectively ECG-gated PC-MRI. Mean Q p /Q s by conventional PC-MRI was 1.91±0.64, and it was 1.94±0.68 (mean±SD) by real-time PC-MRI. For blood flow rate through pulmonary artery and aorta, we found differences of 2% to 3% (Bland-Altman analysis), with lower limits of agreement of −11% to −13% (mean−2 SD) and upper limits of 18% to 19% (mean+2 SD), which demonstrated good agreement between both methods. Mean difference for Q p /Q s was 1%, with limits of agreement ranging between −18% and 22% (mean±2 SD). High repeatability but some flow overestimation was observed in vitro (pulsatile flow phantom) with real-time PC-MRI, whereas conventional PC-MRI was accurate. Beat-to-beat stroke-volume variation was 6.1±2.3% in vivo and 3.7±0.3% in vitro. Conclusions— Beat-to-beat quantification of pulmonary and aortic flows and hence left-to-right shunt within a few seconds is reliable by nontriggered real-time PC-MRI with echo-planar imaging and sensitivity encoding. Good spatial/temporal resolution and a large field of view may render the sequence valuable for multiple applications in congenital heart disease.

To evaluate phase-contrast magnetic resonance (MR) imaging for sizing of secundum atrial septal defects (ASDs) and inflow MR angiography for detection of associated venous anomalies in pediatric patients with inconclusive transthoracic echocardiographic (TTE) results.Sixty-five children (mean age, 5.4 years +/- 2.7 [SD]) with ASD and inconclusive TTE results underwent phase-contrast MR imaging. Defect size and rim distances measured on MR imaging sections obtained in the ASD plane and from the defect to the venae cavae, aortic root, and atrioventricular valves were compared with transesophageal echocardiographic (TEE) findings (n = 30) during transcatheter closure or surgical measurements (n = 40) by using Bland-Altman analysis. Inflow MR angiography was compared with invasive cine angiocardiography for detection of associated venous anomalies.For ASD size, mean differences were less than 1 mm between MR imaging and TEE measurements (with upper and lower limits of agreement between 2.3 and -3.3 mm) and were between 1.2 and -1.6 mm between MR imaging and surgical measurements (with upper and lower limits of agreement between 4.7 and -5.2 mm). Septal rim measurements at MR imaging agreed fairly well with TEE and surgical results. Septal length was overestimated at MR imaging versus TEE (mean difference, 3.0 mm; upper and lower limits of agreement, between 8.0 and -2.8 mm), but MR imaging septal length measurements agreed with surgical results. Rim distance to coronary sinus was difficult to assess. MR imaging enabled referral of 25 of 30 patients for successful transcatheter closure; five patients were found to have too large defects after balloon sizing. Multiple ASDs and/or associated vascular anomalies in 17 of 65 patients were clearly identified at MR imaging, compared with results of TEE, surgery, and cardiac catheterization.In children with ASD and inconclusive TTE results, MR imaging can enable determination of defect size, rim distances to adjacent structures, and venous connections.

Background Routine blood volume quantification is generally performed by using two-dimensional velocity-encoded phase-contrast magnetic resonance imaging (PC-MRI). Due to their long acquisition times averaging of flow information occur leading to underestimation of peak velocities and preventing the examination of respirationrelated stroke volume (SV) variations. Methods Non-electrocardiographic triggered real-time PC-MRI using EPI combined with half-Fourier technique (TR/ TEeff/excitation angle = 12-14 ms/3.3 ms/40°, SENSEfactor = 4, temporal resolution = 24-28 ms) was applied to study respiration-driven SV fluctuations in the ascending aorta (AAo) and both caval veins (SVC, IVC) under natural and forced breathing in 34 healthy children and 10 pediatric Fontan patients. Data were collected during a 12-14 s time interval. The subject’s physiological data (ECG & respiration) were recorded simultaneously for matching with flow data. Virtual stroke volumes were generated dividing the respiration curve in four segments: expiration, breathing in, inspiration and breathing out. Spirometric measurements were performed to validate respiratory volumes. Statistical differences were analyzed by using ANOVA, paired Student t-test and Bland-Altman statistics. Results Stroke volume variability in healthy subjects was around 6% for AAo and >15% for SVC and IVC while breathing naturally. Under forced breathing variability increased to 9% and >34%, respectively. In Fontan patients a two to three-fold augmentation was observed in both respiratory maneuvers. Whereas in volunteers aortic SV was elevated during expiration (6%) and decreased during inspiration (-6%) in relation to mean respiratory SV, highest blood flow was detected during breathing in SVC (10%) and IVC (20%) and lowest blood flow during breathing out (-12%, -15%). Differences were increased under forced breathing. All differences were statistically significant. Regarding patients SV variability was drastically increased and had to be related to the patient’s individual quality of Fontan circulation. Intraobserver and interobserver varability of the four separated respiration-dependent SV was below 5%. Conclusions Due to its non-averaging character real-time PC-MRI allows a physiological assessment of respiratory-related SV fluctuations in healthy subjects as well as in Fontan patients and demonstrates its capability for detection of short-term effects in clinical routine work. It can be expected that real-time PC-MRI has the potential to classify the quality of Fontan hemodynamics. Funding None.

Background —Blood flow can be quantified noninvasively by phase-contrast cine MRI (PC-MRI) in adults. Little is known about the feasibility of the method in children with congenital heart disease. Methods and Results —In 50 children (mean age 6.2 years, range 1.1 to 17.7 years) with an atrial- or ventricular-level shunt, blood flow rate in the great vessels was determined by PC-MRI, and the ratio of pulmonary to aortic flow (Q̇p/Q̇s) was compared with Q̇p/Q̇s by oximetry. We found a difference of 2% and a range of −20% to +26% (limits of agreement, mean±2 SD). In another 7 children with congenital heart disease but no cardiac shunting (mean age 7.9 years, range 1.3 to 13.5 years), Q̇p/Q̇s by PC-MRI was 1.02 (SD ±0.06). No difference between systemic venous and aortic flow volumes was found (range −17% to +20%, n=37). Blood flow through a secundum atrial septal defect as assessed by PC-MRI (n=24) overestimated the shunt compared with the difference between pulmonary and aortic flows. The mean difference between 3 repeated PC-MRI measurements in each location was 5.3% (SD ±4.0%, n=522), demonstrating good precision. The interobserver variability was low. The accuracy of PC-MRI was confirmed by in vitro experiments. Conclusions —Determination of Q̇p/Q̇s by PC-MRI in children is quick, safe, and reliable compared with oximetry. Systemic venous flow can be quantified by PC-MRI, whereas through-plane shunt measurement within an atrial septal defect is inaccurate.