Organisation of paediatric echocardiography laboratories and governance of echocardiography services and training in Europe: current status, disparities, and potential solutions. A survey from the Association for European Paediatric and Congenital Cardiology (AEPC) imaging working group

BACKGROUND

There is limited data on the organisation of paediatric echocardiography laboratories in Europe.

METHODS

A structured and approved questionnaire was circulated across all 95 Association for European Paediatric and Congenital Cardiology affiliated centres. The aims were to evaluate: (1) facilities in paediatric echocardiography laboratories across Europe, (2) accredited laboratories, (3) medical/paramedical staff employed, (4) time for echocardiographic studies and reporting, and (5) training, teaching, quality improvement, and research programs.

RESULTS

Respondents from forty-three centres (45%) in 22 countries completed the survey. Thirty-six centres (84%) have a dedicated paediatric echocardiography laboratory, only five (12%) of which reported they were European Association of Cardiovascular Imaging accredited. The median number of echocardiography rooms was three (range 1-12), and echocardiography machines was four (range 1-12). Only half of all the centres have dedicated imaging physiologists and/or nursing staff, while the majority (79%) have specialist imaging cardiologist(s). The median (range) duration of time for a new examination was 45 (20-60) minutes, and for repeat examination was 20 (5-30) minutes. More than half of respondents (58%) have dedicated time for reporting. An organised training program was present in most centres (78%), 44% undertake quality assurance, and 79% perform research. Guidelines for performing echocardiography were available in 32 centres (74%).

CONCLUSION

Facilities, staffing levels, study times, standards in teaching/training, and quality assurance vary widely across paediatric echocardiography laboratories in Europe. Greater support and investment to facilitate improvements in staffing levels, equipment, and governance would potentially improve European paediatric echocardiography laboratories.

Quantitative evaluation of aortic valve regurgitation in 4D flow cardiac magnetic resonance: at which level should we measure?

PURPOSE

To find the best level to measure aortic flow for quantification of aortic regurgitation (AR) in 4D flow CMR.

METHODS

In 27 congenital heart disease patients with AR (67% male, 31 ± 16 years) two blinded observers measured antegrade, retrograde, net aortic flow volumes and regurgitant fractions at 6 levels in 4D flow: (1) below the aortic valve (AV), (2) at the AV, (3) at the aortic sinus, (4) at the sinotubular junction, (5) at the level of the pulmonary arteries (PA) and (6) below the brachiocephalic trunk. 2D phase contrast (2DPC) sequences were acquired at the level of PA. All patients received prior transthoracic echocardiography (TTE) with AR severity grading according to a recommended multiparametric approach.

RESULTS

After assigning 2DPC measurements into AR grading, agreement between TTE AR grading and 2DPC was good (κ = 0.88). In 4D flow, antegrade flow was similar between the six levels (p = 0.87). Net flow was higher at level 1-2 than at levels 3-6 (p < 0.05). Retrograde flow and regurgitant fraction at level 1-2 were lower compared to levels 3-6 (p < 0.05). Reproducibility (inter-reader agreement: ICC 0.993, 95% CI 0.986-0.99; intra-reader agreement: ICC 0.982, 95%CI 0.943-0.994) as well as measurement agreement between 4D flow and 2DPC (ICC 0.994; 95%CI 0.989 - 0.998) was best at the level of PA.

CONCLUSION

For estimating severity of AR in 4D flow, best reproducibility along with best agreement with 2DPC measurements can be expected at the level of PA. Measurements at AV or below AV might underestimate AR.

Accuracy of Cardiac Magnetic Resonance Imaging Diagnosis of Pediatric Cardiac Masses: A Multicenter Study

OBJECTIVES

The goals of this study were to: 1) evaluate the cardiac magnetic resonance (CMR) characteristics of pediatric cardiac masses from a large international cohort; 2) test the accuracy of previously developed CMR-based diagnostic criteria; and 3) expand diagnostic criteria using new information.

BACKGROUND

After diagnosis of a cardiac mass, clinicians must weigh the benefits and risks of ascertaining a tissue diagnosis. Limited data are available on the accuracy of previously developed noninvasive pediatric CMR-based diagnostic criteria.

METHODS

CMR studies (children 0-18 years of age) with confirmatory histological and/or genetic diagnosis were analyzed by 2 reviewers, without knowledge of prior diagnosis. Diagnostic accuracy was graded as: 1) single correct diagnosis; 2) correct diagnosis among a differential; or 3) incorrect diagnosis.

RESULTS

Of 213 cases, 174 (82%) had diagnoses that were represented in the previously published diagnostic criteria. In 70% of 174 cases, both reviewers achieved a single correct diagnosis (94% of fibromas, 71% of rhabdomyomas, and 50% of myxomas). When ≤2 differential diagnoses were included, both reviewers reached a correct diagnosis in 86% of cases. Of 29 malignant tumors, both reviewers indicated malignancy as a single diagnosis in 52% of cases. Including ≤2 differential diagnoses, both reviewers indicated malignancy in 83% of cases. Of 6 CMR sequences examined, acquisition of first-pass perfusion and late gadolinium enhancement were independently associated with a higher likelihood of a single correct diagnosis.

CONCLUSIONS

CMR of cardiac masses in children leads to an accurate diagnosis in most cases. A comprehensive imaging protocol is associated with higher diagnostic accuracy.

Assessment of the thymus at echocardiography in fetuses at risk for 22q11.2 deletion

OBJECTIVES

An absent or hypoplastic thymus is common in patients with 22q11.2 deletion (del22q11.2). We sought to determine whether fetal echocardiography could identify absence of the thymus as a diagnostic tool in pregnancies at risk for fetal del22q11.2.

METHODS

We evaluated the fetal thymus in 16 consecutive pregnancies at risk for fetal del22q11. Fourteen of the fetuses had a conotruncal cardiac lesion, one had a twin with a conotruncal lesion, and in one the mother had a diagnosis of del22q11.2. The fetal thymus assessment was performed by an individual who was not aware of the del22q11.2 status of the fetus.

RESULTS

By 2D imaging, the thymus was identified in the anterosuperior mediastinum as a subtle hypoechogenic area. In nine cases, the thymus was demonstrated prenatally and none had del22q11.2. However, in one case the thymus was only seen on follow-up fetal echocardiography. In six cases, the thymus could not be identified and all six had del22q11.2. In one additional case, analyzed retrospectively, the thymus could not be assessed. The status of the thymus was confirmed on postnatal echocardiography or autopsy in 11 of the 15 cases assessed prenatally.

CONCLUSIONS

Our study suggests that fetal echocardiography can assess the thymus in most cases at risk for del22q11.2. This information may be useful in counseling women/couples who decline amniocentesis or who are awaiting amniocentesis results.

Cardiac rhythm disturbances in children on hemodialysis

Cardiovascular complications are the leading causes of morbidity and mortality in adult dialysis patients. The aim of this study was to evaluate the cardiovascular system of children on hemodialysis (HD), with special focus on rhythm disturbances. Nine patients, aged 15.6+/-4.1 years, underwent electrocardiographic examination (ECG) including 12-lead ECG, Holter-ECG, QT dispersion, signal-averaged ECG, and exercise testing. Echocardiography and 24-h blood pressure measurement were also performed. Patients had been on HD for a median period of 7 months (range 1-29 months). Normal findings were obtained with 12-lead ECG, exercise testing, QT dispersion, and signal-averaged ECG. Holter-ECG showed short runs of slow monomorphic ventricular tachycardia in two patients. Echocardiography was normal except for ventricular hypertrophy in two patients. In conclusion, rhythm disturbances were rare, with slow monomorphic ventricular tachycardias being the only significant finding. The absence of late potentials and normal QT dispersion suggest that myocardial electrical excitability and recovery are preserved in children on HD.

Early postoperative arrhythmias after cardiac operation in children

BACKGROUND

Arrhythmias are a recognized complication of cardiac operations. However, little is known about the incidence, treatment, and risk factors for early postoperative arrhythmias in children after cardiac operations.

METHODS

Diagnosis and treatment of early postoperative arrhythmias were prospectively analyzed in an intensive care unit in 100 consecutive children with a median age of 17 months (range, 1 day to 191 months) who had undergone cardiac operation. Patients were grouped in three different categories of surgical complexity.

RESULTS

During a median postoperative time of 1 day (range, 0 to 15 days), 64 critical arrhythmias occurred in 48 patients. Arrhythmias consisted of sinus bradycardia in 30, atrioventricular block II to III in 7, supraventricular tachyarrhythmias in 14, and premature complexes in 13 instances. Treatment of 52 arrhythmias was successful and included pacing in 41, intravenous amiodarone in 8, body cooling in 5, overdrive pacing in 3, and electrolyte correction in 2 cases, with more than one treatment modality in 8 cases. Risk factors for arrhythmias were lower body weight (p < 0.05), longer cardiopulmonary bypass duration (p < 0.05), and a category of higher surgical complexity (p < 0.001).

CONCLUSIONS

Early postoperative arrhythmias occur frequently after cardiac operations in children. Sinus bradycardia, atrioventricular block II to III, and supraventricular tachyarrhythmias are the most frequent arrhythmias, which, however, can be treated effectively by means of temporary pacing, cooling, and antiarrhythmic drug therapy. Lower body weight, longer cardiopulmonary bypass duration, and a higher surgical complexity are risk factors for early postoperative arrhythmias.

Trichothiodystrophy with severe cardiac and neurological involvement in two sisters

Trichothiodystrophy or sulphur-deficient brittle hair is a clinical marker for several autosomal recessive neurocutaneous syndromes. The typical hair abnormality is frequently associated with many alterations affecting the skin, nervous system, eyes and bones as well as the immune, gonadal and endocrine systems. We report the first cases of dilated cardiomyopathy in two sisters with trichothiodystrophy, leading to cerebral infarction in the younger one. In addition, both suffer from severe hearing impairment, osteosclerosis, and psychomotor retardation with central hypomyelination.

CONCLUSION

Severe cardiac involvement and stroke may be associated features of trichothiodystrophy.

DDD pacing mode survival in children with a dual-chamber pacemaker

BACKGROUND

The persistence of DDD pacing is well documented in adults, however, in children survival of the DDD pacing mode is less clear.

METHODS

We studied the survival of dual-chamber (DDD) pacing in 36 children aged 1 week to 16 years who underwent implantation of a dual-chamber pacing system between January 1986 and October 1998. The children were divided in the following two groups: 26 had epicardial pacing systems and 10 had endocardial pacing systems.

RESULTS

During long-term follow-up 11 patients lost the DDD pacing mode. The DDD pacing survival rate at 3 months and 1, 2, and 5 years was 80%, 77%, 73%, and 69%, respectively. Age, weight, congenital heart disease, and epicardial pacing leads were not found to be risk factors for loss of DDD pacing mode. However, P-wave values of less than 2.5 mV at implantation of epicardial leads were associated with loss of the DDD pacing mode.

CONCLUSIONS

The majority of children remain in the DDD pacing mode during long-term follow-up. A P-wave value of less than 2.5 mV at implantation of epicardial leads is a risk factor for loss of the DDD pacing mode.