Echocardiographic Assessment of Pulmonary Arterial Hypertension Following Inhaled Nitric Oxide in Infants with Severe Bronchopulmonary Dysplasia.

OBJECTIVES: Inhaled nitric oxide (iNO) is an effective pulmonary vasodilator. However, the efficacy of iNO in former premature infants with established bronchopulmonary dysplasia (BPD) has not been studied. This study aimed to determine the efficacy of iNO in reducing pulmonary artery pressure in infants with severe BPD as measured by echocardiography. STUDY DESIGN: Prospective, observational study enrolling infants born at less than 32 weeks gestation and in whom (1) iNO therapy was initiated after admission to our institution, or (2) at the outside institution less than 48 h before transfer and received an echocardiogram prior to iNO initiation, and (3) had severe BPD. Data were collected at three time-points: (1) before iNO; (2) 12-48 h after initiation of iNO; and (3) 48-168 h after initiation of iNO. The primary outcome was the effect of iNO on pulmonary artery pressure measured by echocardiography in patients with severe BPD between 48 and 168 h after initiating iNO therapy. RESULTS: Of 37 enrolled, 81% had echocardiographic evidence of pulmonary arterial hypertension (PAH) before iNO and 56% after 48 h of iNO (p = 0.04). FiO2 requirements were significantly different between time-points (1) and (3) (p = 0.05). There were no significant differences between Tricuspid Annular Plane Systolic Excursion (TAPSE) Z-Scores, time to peak velocity: right ventricular ejection time (TPV:RVET), and ventilator changes. CONCLUSIONS: Although we found a statistically significant reduction of PAH between time-point (1) and (3), future trials are needed to further guide clinical care.

Echocardiographic strain analysis reflects impaired ventricular function in youth with pediatric-onset systemic lupus erythematosus.

BACKGROUND: Strain analysis with speckle-tracking echocardiography shows promise as a screening tool for silent myocardial dysfunction in pediatric-onset systemic lupus erythematosus (pSLE). We compared left ventricular (LV) systolic deformation (measured by strain) in children and adolescents with pSLE to controls, and assessed the relationship between strain, disease activity, and other noninvasive measures of cardiovascular health. METHODS: Twenty pSLE subjects ages 9-21 underwent comprehensive cardiovascular testing, including 2D speckle-tracking echocardiography, ambulatory blood pressure monitoring (ABPM), peripheral endothelial function testing, pulse wave velocity and analysis, and carotid ultrasound. Longitudinal apical-4 chamber (LSA4C ) and midpoint circumferential strain (CSmid ) were compared to that of 70 healthy controls using multivariable linear regression. Among pSLE subjects, Pearson correlation coefficients were calculated to evaluate relationships between global longitudinal or circumferential strain and other measures of cardiovascular health. RESULTS: Average SLE disease duration was 3.2 years (standard deviation [SD] 2.1). 2/20 pSLE subjects had persistent disease activity, and only one met criteria for hypertension by ABPM. LSA4C was significantly reduced in pSLE subjects compared to controls (mean -18.3 [SD 3.2] vs -21.8% [SD 2.2], P-value <.001). There was no significant difference in CSmid (-24.8 [SD 3.7] vs -25.7% [SD 3.4], P = .29). Among pSLE subjects, decreased nocturnal blood pressure dipping on ABPM was associated with reduced global circumferential strain (r -0.59, P = .01). CONCLUSIONS: Longitudinal myocardial deformation is impaired in pSLE patients despite clinical remission and may represent early myocardial damage. Strain analysis should be considered in addition to standard echocardiographic assessment during follow-up of patients with pSLE.

Cardiac Output Measurement Using the Ultrasonic Cardiac Output Monitor: A Validation Study in Newborn Infants.

OBJECTIVES: We aimed to determine the accuracy and validity of the Ultrasonic Cardiac Output Monitor (USCOM) measurements of cardiac output (CO) compared to echocardiography in newborn infants, and the inter-rater agreement of USCOM measurements. METHODS: In a single-center study we prospectively evaluated neonates undergoing an echocardiographic evaluation. USCOM measurements of CO were obtained at the pulmonary and aortic valve by 2 physicians blinded to the echocardiographic results. All echocardiographic measurements were performed blinded to USCOM measurements. We first enrolled an ascertainment cohort which was subsequently validated in an independent new cohort. Agreement between echocardiography and USCOM methods was assessed by Bland-Altman analysis. Intra-class correlation coefficients (ICC) assessed the agreement between the 2 operators. The ascertainment cohort correction factors were applied in a second validation cohort and agreement of the calibrated measures evaluated with repeat Bland-Altman comparisons. RESULTS: A total of 50 infants were enrolled in the initial cohort and 15 in the validation cohort. There was a high degree of correlation between the USCOM operators (ICC = 0.975). USCOM measurements of CO were significantly higher compared to echocardiography (left ventricular output bias 95 ± 52 mL/kg/min and right ventricular output bias 64 ± 30 mL/kg/min). There was no difference in the subgroup of infants with and without a ductus arteriosus. After the correction was applied to the validation cohort, there was no longer a significant difference between the measures. CONCLUSIONS: CO measured by USCOM consistently overestimated the results obtained from echocardiography. USCOM is not adequate to provide absolute estimates of CO. However, it may allow longitudinal hemodynamic assessment of sick neonates.

Atrioventricular valve morphology and dynamics in congenital heart disease as imaged with real-time 3-dimensional matrix-array echocardiography: comparison with 2-dimensional imaging and surgical findings.

OBJECTIVE: We sought to describe our initial experience with real-time 3-dimensional echocardiographic (RT3DE) imaging of atrioventricular valve (AVV) anomalies in pediatric patients to resolve a specific morphologic or dynamic detail, which, although suggested, could not be well resolved during the conventional 2-dimensional (2D)/Doppler examination. METHODS: In all, 41 patients (age range 1 day-24 years) with different AVV anomalies underwent RT3DE as part of their comprehensive echocardiographic assessment. Matrix-array transducers with a frequency range of 1 to 4 MHz were used. The first 27 patients were not consecutive, and the RT3DE findings interpreted by one examiner were compared directly with the 2D findings interpreted by a different examiner. In the following consecutive 14 patients, the RT3DE findings were compared with the surgical findings and with the interpretations of their corresponding 2D examinations by 3 examiners who were blinded to the findings of RT3DE for more objective comparison. RESULTS: RT3DE imaging was successful in resolving the raised question in all patients. The morphology of the valve leaflets and their chordal attachments, the mechanism and origin of regurgitation, and the geometry of the regurgitant volume were well delineated by RT3DE imaging. In the second group of patients, there was agreement between the morphologic details delineated by RT3DE (a total of 21 specific questions raised) and the surgical findings in those patients who had immediate surgery. On the other hand, RT3DE showed prominent AVV chordal attachments in the left ventricular outflow tract in one patient, which was not considered surgically relevant during the repair. CONCLUSIONS: Although RT3DE is still in its initial phase, has some technical limitations, and does not change the basic diagnosis made by 2D imaging, echocardiographic examination using the matrix-array transducer is a useful adjunct in delineating specific morphologic and dynamic details of the AVV in congenital heart disease.

Illustration of the additional value of real-time 3-dimensional echocardiography to conventional transthoracic and transesophageal 2-dimensional echocardiography in imaging muscular ventricular septal defects: does this have any impact on individual patient treatment?

OBJECTIVE: We sought to answer the question of whether the additional morphologic details obtained by real-time 3-dimensional (3D) echocardiographic (RT3DE) imaging of muscular ventricular septal defect (VSD) has any significant impact on treatment options of individual patient. BACKGROUND: Muscular VSD can be safely and effectively closed by interventional catheterization procedure using VSD devices under transesophageal echocardiographic (TEE) guidance. Recent application of RT3DE has shown great promise for imaging VSD with better display of the exact geometry, size, and location of the defect. METHODS: Nineteen patients with different types of VSDs were imaged with RT3DE matrix-array transducer; there were 6 cases with muscular VSD. Based on standard transthoracic echocardiographic and TEE imaging, one patient was considered a good candidate for perventricular VSD device occlusion, three patients were considered for surgical closure, and in two patients no intervention was deemed necessary. RESULTS: RT3DE successfully displayed the exact morphology of the VSD in all 6 patients, whereas transthoracic echocardiography and TEE showed the defect as a dropout with variable diameter in different views. Such planer images did not accurately predict the exact morphology in the patient in whom device occlusion was considered and the device embolized to the left ventricle in a few heartbeats. Surgical circular patch was used in two patients and primary suture was used in two patients in agreement with the 3D morphology. In two patients the 3D morphology of the VSD was small enough that no intervention was considered. CONCLUSIONS: RT3DE imaging of muscular VSD can accurately display the exact geometry of the defect, which can have significant impact on treatment strategies of individual patients. This new imaging modality should be an important adjunct to the standard transthoracic echocardiographic and TEE imaging of these defect before any intervention.

Real-time 3-dimensional echocardiographic imaging of congenital heart disease using matrix-array technology: freehand real-time scanning adds instant morphologic details not well delineated by conventional 2-dimensional imaging.

OBJECTIVE: We sought to investigate whether real-time (RT) 3-dimensional echocardiography (RT3D) using matrix-array technology could resolve a specific morphologic detail that could not be well resolved during conventional 2-dimensional (2D)/Doppler echocardiographic imaging of congenital heart disease. BACKGROUND: Although 2D echocardiography is currently the primary imaging modality of congenital heart disease, there are still some anatomic details that cannot be well delineated by that modality. METHODS: In all, 70 patients underwent RT3D examination using matrix-array transducer. Applying the standard sweeping technique as for 2D imaging, freehand RT imaging was used for immediate feedback. The 2D examinations of the last 23 consecutive patients were used to validate the additional value of RT3D by 3 examiners blinded to the findings of RT3D. RESULTS: The adequacy of 2D imaging to resolve the morphologic detail in question ranged from 30% to 70%, whereas RT3D imaging was considered successful in delineating the morphologic detail in 80% to 100% of patients instantly. The image resolution was superior or equivalent to that obtained by 2D imaging. Heart valves, septal defects, and volumetric valvular and vascular color flow morphologies were well delineated by RT3D. CONCLUSION: Matrix-array RT3D is a significant breakthrough technology that allowed instant visualization of cardiac anatomic details that could not be well delineated by 2D imaging. Further improvements of some technical limitations should make RT3D matrix-array cardiac imaging a significant modality in the field of echocardiographic imaging of congenital cardiac anomalies.

Cor triatriatum sinister with and without left ventricular inflow obstruction: visualization of the entire supravalvular membrane by real-time three-dimensional echocardiography. Impact on clinical management of individual patient.

We present 4 cases of cor triatriatum in whom the diagnosis was correctly made by 2-dimensional transthoracic echocardiography, which showed the supravalvular left atrial membrane that divides the left atrium into 2 chambers. The pulmonary veins were connected normally to the proximal left atrial chamber and the left atrial appendage was connected to the distal left atrial chamber. In 1 patient there was evidence of severe pulmonary venous obstruction to the mitral valve by Doppler examination, while in the other three, there was no venous obstruction. Patients were then examined by real-time 3-dimensional echocardiography (RT3DE, using x4 matrix array transducer connected to Sonos 7500 echocardiographic system Phillips, Andover, Mass, USA). This showed the exact morphology of the membrane and led to cancellation of planed surgical intervention in 1 case in which the membrane was only a broad band crossing the left atrial cavity. In addition to delineating the exact morphology of the intracavitary anomaly, this novel echocardiographic imaging modality should be an additive tool to better understand the natural history of these nonobstructive left atrial membranes via longitudinal follow-up of these patients.