Valvular Regurgitation Using Portable Echocardiography in a Healthy Student Population: Implications for Rheumatic Heart Disease Screening.

BACKGROUND: There is increasing use of portable echocardiography as a screening test for rheumatic heart disease (RHD). The prevalence of valvular regurgitation in healthy populations as determined using portable echocardiography has not been well defined. Minimal echocardiographic criteria for RHD have recently been clarified, but the overlap of normal and abnormal valvular regurgitation warrants further study. The aim of this study was to determine the spectrum of echocardiographic findings using portable echocardiography in children from a population with low prevalence of RHD. METHODS: Screening echocardiography was conducted in 396 healthy students aged 10 to 12 years using portable echocardiographic equipment. Echocardiograms were assessed according to 2012 World Heart Federation criteria for RHD. The prevalence of physiologic valvular regurgitation was compared with that found in previous studies of children using large-platform machines. RESULTS: Physiologic mitral regurgitation (MR) was present in 14.9% of subjects (95% CI, 11.7%-18.7%) and pathologic MR in 1.3% (95% CI, 0.6%-2.9%). Two percent (95% CI, 1.0%-3.9%) had physiologic aortic regurgitation, and none had pathologic aortic valve regurgitation. Physiologic tricuspid regurgitation was present in 72.7% of subjects (95% CI, 68.1%-76.9%) and physiologic pulmonary regurgitation in 89.6% (95% CI, 85.7%-91.8%). After cardiology review, no cases of definite RHD were found, but 0.5% of patients (95% CI, 0.1%-1.8%) had pathologic MR meeting World Heart Federation criteria for borderline RHD. Two percent (95% CI, 1.4%-4.6%) of the cohort had minor forms of congenital heart disease. CONCLUSIONS: The spectrum of physiologic cardiac valvular regurgitation in healthy children as determined using portable echocardiography is described and is within the range of previous studies using large-platform echocardiographic equipment. The finding of two children with pathologic-grade MR, likely representing the upper limit of physiologic regurgitation, has implications for echocardiographic screening for RHD in high-prevalence regions.

Congenital mitral valve lesions : Correlation between morphology and imaging.

Congenital malformations of the mitral valve are often complex and affect multiple segments of the valve apparatus. They may occur in isolation or in association with other congenital heart defects. The majority of mitral valve malformations are not simply classified, and descriptive terms with historical significance (parachute, mitral, or arcade) often lack the specificity that cardiac surgeons demand as part of preoperative echocardiographic morphological assessment. This paper examines the strengths and limitations of commonly used descriptions and classification systems of congenitally malformed mitral valves. It correlates pathological, surgical, and echocardiographic findings. Finally, it makes recommendations for the systematic evaluation of the congenitally malformed mitral valve using segmental echocardiographic analysis to assist precise communication and optimal surgical management.

Optimising echocardiographic screening for rheumatic heart disease in New Zealand: not all valve disease is rheumatic.

AIMS: Echocardiography detects a greater prevalence of rheumatic heart disease than heart auscultation. Echocardiographic screening for rheumatic heart disease combined with secondary prophylaxis may potentially prevent severe rheumatic heart disease in high-risk populations. We aimed to determine the prevalence of rheumatic heart disease in children from an urban New Zealand population at high risk for acute rheumatic fever. METHODS AND RESULTS: To optimise accurate diagnosis of rheumatic heart disease, we utilised a two-step model. Portable echocardiography was conducted on 1142 predominantly Maori and Pacific children aged 10-13 years. Children with an abnormal screening echocardiogram underwent clinical assessment by a paediatric cardiologist together with hospital-based echocardiography. Rheumatic heart disease was then classified as definite, probable, or possible. Portable echocardiography identified changes suggestive of rheumatic heart disease in 95 (8.3%) of 1142 children, which reduced to 59 (5.2%) after cardiology assessment. The prevalence of definite and probable rheumatic heart disease was 26.0 of 1000, with 95% confidence intervals ranging from 12.6 to 39.4. Portable echocardiography overdiagnosed rheumatic heart disease with physiological valve regurgitation diagnosed in 28 children. A total of 30 children (2.6%) had non-rheumatic cardiac abnormalities, 11 of whom had minor congenital mitral valve anomalies. CONCLUSIONS: We found high rates of undetected rheumatic heart disease in this high-risk population. Rheumatic heart disease screening has resource implications with cardiology evaluation required for accurate diagnosis. Echocardiographic screening for rheumatic heart disease may overdiagnose rheumatic heart disease unless congenital mitral valve anomalies and physiological regurgitation are excluded.

Transcatheter closure of secundum atrial septal defects with the Amplatzer septal occluder in adults and children-follow-up closure rates, degree of mitral regurgitation and evolution of arrhythmias.

AIM: To report the results of transcatheter atrial septal defect (ASD) closure with the Amplatzer septal occluder (ASO) from the single centre providing interventions for congenital heart disease in New Zealand. METHODS: A single centre retrospective review of all patients 1997-2004 inclusive, undergoing planned transcatheter ASD closure was undertaken. Implantation success, complications and latest patient follow-up are described. RESULTS: Percutaneous ASD closure was planned in 227 adults and children. (55% had additional medical co-morbidities.) The mean ASD size was 22+/-6 mm, and device size ranged from 5 to 40 mm. Closure was successful in 93%, unsuccessful in 5% and not attempted in 2%. There were two device embolisations, one immediately post-release and one within 24h. Minor procedural complications occurred in 5% of patients. There were no cases of suspected or proven device erosion. Ninety-two percent had documented follow-up beyond 6 months. At latest follow-up the closure rate was 98.5%. There was no significant change in the degree of mitral regurgitation. Sixteen of 24 with pre-closure arrhythmias resolved while 10 remained in atrial fibrillation. Six patients developed new arrhythmias but these were well controlled medically. CONCLUSION: There is a high implantation and closure rate using transcatheter ASD closure with the Amplatzer septal occluder in children and adults avoiding the need for cardiac surgery. Follow-up at one year shows there is no progression of mitral regurgitation, and supraventricular arrhythmias have usually resolved.

The influence of measured versus assumed uptake of oxygen in assessing pulmonary vascular resistance in patients with a bidirectional Glenn anastomosis.

AIMS: To determine the accuracy of data relating to pulmonary vascular resistance data in patients with a bidirectional Glenn anastomosis as calculated using predicted versus measured uptake of oxygen. METHODS: We studied retrospectively the data from 33 patients with a bidirectional Glenn anastomosis who underwent cardiac catheterisation prior to surgery to complete the Fontan circulation. Their weight ranged from 5.4 to 51.7 kg, and they were aged up to 12 years. Uptake of oxygen was measured using the Deltatrac II metabolic monitor. From the calculated indexed pulmonary vascular resistance, cases were stratified according to the risk of failure of the subsequent Fontan circulation. The six patients with a resistance of greater than 4 Um2 were deemed at high risk, the six with a resistance from 3 to 4 Um2 at moderate risk, and the 21 patients with a resistance less than 3 Um2 at low risk. Uptake of oxygen was also estimated from the predictive formulas of Lindahl, Lundell et al. and LaFarge and Miettinen. The indexed resistance was similarly calculated using these formulas and a comparable stratification of risk made from this data. RESULTS: The predicted values for uptake of oxygen were consistently higher than those measured, leading to an underestimation of indexed resistance, with mean difference between -0.62 and -1.57 Um2. This difference resulted in misclassification of between five and nine of the 12 patients considered at moderate or high risk as being at low-risk. No other haemodynamic data could reliably separate the subjects deemed at low-risk from those considered to be at high-risk. A transpulmonary gradient of greater than 7 mm of mercury was found to be 100 percent specific for elevated indexed resistance, but only 60 percent sensitive. CONCLUSIONS: In patients with bidirectional Glenn anastomoses, all formulas based on predictive uptake of oxygen lead to underestimation of the true indexed pulmonary vascular resistance, to an extent that could significantly influence clinical decision-making. The transpulmonary gradient is not a reliable surrogate for indexed pulmonary vascular resistance.