Pediatric ventricular assist device therapy for advanced heart failure-Hong Kong experience.

Ventricular assist devices (VADs) are life-saving options for children with heart failure unresponsive to medical therapy as a bridge to transplantation or cardiac recovery. We present a retrospective review of 13 consecutive children who underwent implantation of VAD between 2001 and 2018 in our center. The median age was 12 years (1-17 years), weight was 45 kg (10-82 kg). Etiologies of heart failure were dilated cardiomyopathy (CMP) (n = 8), myocarditis (n = 2), ischemic CMP (n = 1), restrictive CMP (n = 1) and congenital heart disease (n = 1). Pre-implantation ECMO was used in 5, mechanical ventilation in 4, renal replacement therapy in 2 and IABP in 1. Devices used were: Berlin Heart EXCOR left VAD (LVAD), biventricular VAD (BIVAD) (n = 5, 2), CentriMag LVAD, BIVAD (n = 1, 2), HeartWare (n = 2), HeartMate II (n = 1). Median duration of support was 45 days (3-823 days). Overall survival was 85%. Four patients were successfully bridged to transplantation, 2 died while on a device, 4 remain on support and 3 were weaned from VAD. Late death occurred in 2 transplanted patients. Complications included bleeding requiring reoperation in 1, neurologic events in 3, driveline infections and pericardial effusion in 2 each. In one patient, CentriMag BIVAD provided support for 235 days, which is longest reported duration on such a VAD in the Asia Pacific region. Survival for pediatric patients of all ages is excellent using VADs. Given the severity of illness in these children morbidity and mortality is acceptable. VADs could potentially be used as a long-term bridge to transplantation in view of the donor shortage in the pediatric population.

Long term CentriMag biventricular support using hybrid cannulation as a bridge to transplant in a pediatric patient.

Paracorporeal continuous-flow ventricular assist devices designed for short-term support can also potentially provide long-term circulatory support as bridges to transplantation in children. We describe the long-term use of the CentriMag biventricular assist device with multiple pump changes in a 9-year-old boy with idiopathic-dilated cardiomyopathy. The initially implanted Berlin Heart EXCOR pumps were replaced by CentriMag due to thromboembolic complications. The CentriMag pumps were exchanged 15 times due to clot and fibrin formation or when the pumps reached their expiration dates. Connecting CentriMag to Berlin Heart EXCOR cannulae effectively served as an alternative long-term hybrid bridge to transplantation for 235 days. The patient successfully underwent a transplant after 284 days. Judicious pump monitoring and timely pump exchanges can potentially overcome device-related complications and extend the duration on support.

The different facets of "culture" in genetic counseling: A situated analysis of genetic counseling in Hong Kong.

In this article, we problematize the concept of "culture" in genetic counseling. With globalization and increased mobility of both genetic professionals and clients, there is an increased acknowledgement of the impact of "culture" on a counseling process. There is, however, little agreement on what "culture" is. The essentialist understanding that has long been dominant in the medical literature views culture as a set of shared beliefs, attitudes and practices among a group of people. Such an approach does not account for the individual differences and the dynamic nature of genetic counseling encounters. Following Zayts and Schnurr (2017), we use the distinction between two orders of culture: culture1 that refers to the static, generalized understanding of culture that is external to the specific context, and culture2 , an analytic concept that denotes dynamic enactments of culture, emerging in the interaction. We use empirical data from genetic counseling sessions to illustrate these different facets of culture and to consider how and why speakers draw on them. The clinical implications of the study include highlighting the importance of cultural awareness among counselors, including cultural self-awareness, and demonstrating how authentic interactional data could be used to enhance cultural training in genetic counseling.

SCN5A mutations in 442 neonates and children: genotype-phenotype correlation and identification of higher-risk subgroups.

Aims: To clarify the clinical characteristics and outcomes of children with SCN5A-mediated disease and to improve their risk stratification. Methods and results: A multicentre, international, retrospective cohort study was conducted in 25 tertiary hospitals in 13 countries between 1990 and 2015. All patients ≤16 years of age diagnosed with a genetically confirmed SCN5A mutation were included in the analysis. There was no restriction made based on their clinical diagnosis. A total of 442 children {55.7% boys, 40.3% probands, median age: 8.0 [interquartile range (IQR) 9.5] years} from 350 families were included; 67.9% were asymptomatic at diagnosis. Four main phenotypes were identified: isolated progressive cardiac conduction disorders (25.6%), overlap phenotype (15.6%), isolated long QT syndrome type 3 (10.6%), and isolated Brugada syndrome type 1 (1.8%); 44.3% had a negative electrocardiogram phenotype. During a median follow-up of 5.9 (IQR 5.9) years, 272 cardiac events (CEs) occurred in 139 (31.5%) patients. Patients whose mutation localized in the C-terminus had a lower risk. Compound genotype, both gain- and loss-of-function SCN5A mutation, age ≤1 year at diagnosis in probands and age ≤1 year at diagnosis in non-probands were independent predictors of CE. Conclusion: In this large paediatric cohort of SCN5A mutation-positive subjects, cardiac conduction disorders were the most prevalent phenotype; CEs occurred in about one-third of genotype-positive children, and several independent risk factors were identified, including age ≤1 year at diagnosis, compound mutation, and mutation with both gain- and loss-of-function.

Evaluating High-Confidence Genes in Conotruncal Cardiac Defects by Gene Burden Analyses.

Background In nonsyndromic conotruncal cardiac defects, the use of next-generation sequencing for clinical diagnosis is increasingly adopted, but gene-disease associations in research are only partially translated to diagnostic panels, suggesting a need for evidence-based consensus. Methods and Results In an exome data set of 245 patients with conotruncal cardiac defects, we performed burden analysis on a high-confidence congenital heart disease gene list (n=132) with rare (<0.01%) and ultrarare (absent in the Genome Aggregation Database) protein-altering variants. Overall, we confirmed an excess of rare variants compared with ethnicity-matched controls and identified 2 known genes (GATA6, NOTCH1) and 4 candidate genes supported by the literature (ANKRD11, DOCK6, NPHP4, and STRA6). Ultrarare variant analysis was performed in combination with 3 other published studies (n=1451) and identified 3 genes (FLT4, NOTCH1, TBX1) to be significant, whereas a subgroup analysis involving 391 Chinese subjects identified only GATA6 as significant. Conclusions We suggest that these significant genes in our rare and ultrarare burden analyses warrant prioritization for clinical testing implied for rare inherited and de novo variants. Additionally, associations on ClinVar for these genes were predominantly variants of uncertain significance. Therefore, a more stringent assessment of gene-disease associations in a larger and ethnically diverse cohort is required to be prudent for future curation of conotruncal cardiac defect genes.

Impact of temporary interruption of right ventricular pacing for heart block on left ventricular function and dyssynchrony.

BACKGROUND: The increasing data suggest an association between chronic right ventricular (RV) and left ventricular (LV) dysfunction. We sought to determine the effect of temporary interruption of long-term RV pacing on LV function and mechanical dyssynchrony in children and young adults with complete heart block. METHODS: Twelve patients aged 20.0 + or - 7.4 years with congenital heart block (group I) and six patients aged 22.7 + or - 11.0 years with surgically acquired heart block (group II) with RV pacing were studied. The pacing rate was reduced to less than patient's intrinsic heart rate and maintained for 5 minutes. The LV ejection fraction (EF), three-dimensional systolic dyssynchrony index (SDI), two-dimensional global longitudinal strain and strain rate, and Doppler-derived isovolumic acceleration before and after interruption of RV pacing were compared. RESULTS: The LVEF and GLS increased while QRS duration decreased after the pacing interruption in both the groups (all P < 0.05). While SDI decreased in both groups I (6.8 + or - 2.3%- 3.8 + or - 0.8%, P = 0.001) and II (9.2 + or - 4.1%-5.0 + or - 1.6%, P = 0.032), it remained higher in group II than in group I (P = 0.046) after the pacing interruption. The prevalence of LV dyssynchrony (SDI > 4.7%) decreased in group I (83%-25%, P = 0.006) but not in group II (67%-50%, P = 0.50). The %increase in LVEF correlated positively with %reduction of LV SDI (r = 0.80, P = 0.001). CONCLUSIONS: Temporary interruption of chronic RV pacing acutely improves LV dyssynchrony and systolic function in children and young adults, the magnitude of which is greater in patients with congenital than those with surgically acquired heart block.

Aortic dissection in a Chinese patient 31 years after surgical repair of tetralogy of Fallot.

Aortic dilation has been increasingly recognized in congenital heart diseases, and aortic dissection is one of the important complications. We report a case of aortic dissection in a patient 31 years after repair of tetralogy of Fallot (TOF) and review reported cases. While aortic dissection is uncommon, aortic dilation is common among patients with repaired TOF and it appeared progressive in some patients. Based on the reported cases, progressive aortic dilation appeared as the pre-requisite for aortic dissection, although other factors might be involved. Regular surveillance and monitoring for aortic complications should be incorporated into clinical practice. .

Preoperative Venovenous Extracorporal Membrane Oxygenation for Transposition of Great Arteries With Severe Pulmonary Hypertension in a Newborn.

Severe persistent pulmonary hypertension in a newborn combined with transposition of great arteries increases the risk of early death before the arterial switch operation. We report the case of a newborn with transposition of great arteries and ventricular septal defect associated with severe pulmonary hypertension. Profound hypoxemia, despite successful balloon atrial septostomy and conventional supportive measures with mechanical ventilation, inhaled nitric oxide, and inotropes, led to the use of venovenous extracorporeal membrane oxygenation to rapidly stabilize the child preoperatively. Different from most reported cases on this scenario, we intentionally opted for a venovenous mode of support despite the presence of circulatory compromise.

Kawasaki disease in siblings and a review of drug treatment.

We have managed two anonymized siblings with Kawasaki disease (KD). The occurrence of KD in the elder brother alerted us to the occurrence of incomplete KD in the younger brother. Both siblings were treated with intravenous immunoglobulin and a high dose of dipyridamole with resolution of the coronary artery aneurysm. Dipyridamole was used instead of aspirin because both siblings were glucose-6-phosphate dehydrogenase deficient for which aspirin was contraindicated. To prevent damage to the coronary arteries, treatment should be started as soon as the diagnosis is made. There have been a lot of advances in medical therapy in recent years, which are reviewed together with conventional proven therapy for KD. Early diagnosis and prompt treatment are important to achieve optimal treatment outcome in KD. Family history of KD among siblings enables clinicians for an earlier diagnosis so as to prevent the disease complications particularly in patients with incomplete features.

Missing pouches in high-density mapping of atrial tachyarrhythmia in congenital heart diseases.

BACKGROUND: The use of high-density electroanatomical mapping in the Chinese population for congenital heart disease (CHD) is not well reported. METHODS: Retrospective review of consecutive transcatheter ablation of atrial tachyarrhythmia using high-density mapping for CHD patients (at least moderate complexity) in the only tertiary congenital heart center in the territory from January 2017 to January 2019 was conducted. Orion mapping catheter in Rhythmia system (Boston Scientific) was used to create activation and voltage maps. Parameters including mechanism of arrhythmia, acute success, and follow-up data were recorded. RESULTS: Eight patients were identified (median age 35.5 years) who underwent transcatheter ablation of atrial arrhythmia. More than one reentry circuits of IART were identified in five patients. It took a median of 32.4 minutes with 15,952 (IQR 13,395-18,530) mapping points per map. Cavo-annulus isthmus-dependent mechanism was the predominant reentry mechanism. Acute success with the elimination of all inducible tachycardia was achieved in six patients (75%), and partial success in two patients. There was recurrence of atrial arrhythmia in four patients (50%), in which three patients could be maintained in sinus rhythm with low-dose antiarrhythmic medication. Targeted substrate ablation was performed in six patients with multiple IART circuits. Critical anatomical pouches were identified in three patients, which were missed in the initial mapping using Orion basket mapping catheter. CONCLUSIONS: High acute success rate of atrial arrhythmia ablation can be achieved using high-density anatomical mapping in CHD. Substrate ablation was required with multiple IART circuits identified. Vigilance should be sought to identify anatomical pouches.

Porcine Versus Pericardial Pulmonary Valve Replacement in Adults With Prior Congenital Cardiac Surgery: Midterm Outcomes.

BACKGROUND: Postcongenital heart surgery pulmonary regurgitation requires subsequent pulmonary valve replacement. We sought to compare the outcomes of pulmonary valve replacement after using bioprosthetic valves, porcine versus pericardial bioprosthesis. METHOD: Retrospective single-center study of consecutive pulmonary valve replacement in patients with pulmonary regurgitation following initial congenital cardiac surgery. From 2004 to 2016, 82 adult patients (53 males, 29 females) underwent pulmonary valve replacement at a mean age of 28.7 ± 8 years (range 18-52 years) with a mean time to pulmonary valve replacement of 24 ± 7 years (range 13-43 years). Porcine bioprosthetic valves (group 1, n = 32) and pericardial valves (group 2, n = 50) were used. Cardiac magnetic resonance imaging was performed (n = 54) at a mean of 18 ± 13 months before and 24 ± 21 months after pulmonary valve replacement. RESULTS: No significant difference was seen between the groups except that the mean follow-up was longer for group 1 (5.02 ± 2.06 vs 4.08 ± 3.21 years). In-hospital mortality was 1.1%. Follow-up completeness was 100% with no late death. Mean right ventricular end-systolic and end-diastolic volumes reduced significantly in both the groups ( P < .001), whereas right ventricular ejection fraction remained unchanged (group 1, P = .129; group 2, P = .675) . Only the left ventricular end-diastolic volume increased in both the groups, but the increase was significant for group 2 only (group 1, P = .070; group 2, P = .015), whereas the left ventricular end-systolic and ejection fraction remained unchanged in both the groups. There was no reoperation for pulmonary valve replacement. Freedom from intervention was 93.8% (group 1) and 100% (group 2) at eight years after pulmonary valve replacement ( P = .407). CONCLUSION: Midterm outcomes of pulmonary valve replacement in our adult cohort were satisfactory. Both types of bioprosthetic valves performed comparably for eight years and were a good option in adults.

Cardiovascular symptoms and signs in evaluating cardiac murmurs in children.

BACKGROUND: The aim of the present study was to determine the usefulness of cardiovascular symptoms and signs in the recognition of significant congenital heart lesions that required surgical or catheter interventions in different pediatric age groups. METHODS: A retrospective chart review was carried out of 110 patients with significant heart anomalies that required surgical or catheter interventions (group I) and 113 children, presenting with cardiac murmurs, with congenital heart conditions not requiring any interventions. (group II). RESULTS: Clinical symptoms or signs were significantly more common in group I than in group II subjects (85% vs 32%, P < 0.0001). The odds of having significant lesions requiring interventions in the presence of either cardiovascular symptoms or signs were 37.5 (95% confidence interval [CI]: 6.5-218.1) for neonates, 14.5 (95%CI: 4.7-51.7) for infants, and 8.0 (95%CI: 3.3-19.2) for children and adolescents. In neonates, the negative predictive values of the absence of symptoms or signs in isolation were relatively low at 64% and 65%, respectively. In children beyond infancy, the positive predictive values of the presence of symptoms or signs in isolation were also low at 62% and 68%, respectively. CONCLUSIONS: Clinical assessment of cardiovascular symptoms and signs remains useful in the evaluation of the significance of pathological cardiac murmurs in children in the present era of technology. Nonetheless, the predictive values vary with different pediatric age groups.

Achieving biventricular circulation in patients with moderate hypoplastic right ventricle in pulmonary atresia intact ventricular septum after transcatheter pulmonary valve perforation.

OBJECTIVE: Transcatheter valve perforation for pulmonary atresia intact ventricular septum is the standard of care for patients with mild right ventricular hypoplasia. However, its role in moderate right ventricular hypoplasia has been less well defined. We sought to report the long-term outcome of patients with moderate hypoplastic right ventricle who had undergone the procedure. DESIGN, SETTINGS, AND PATIENTS: We performed a retrospective analysis on patients who had undergone transcatheter pulmonary valve perforation from January 1996 to January 2015 at our institution. The procedures would be carried out irrespective of the right ventricular size, as long as there were no absolute contraindications. INTERVENTION AND OUTCOME MEASURES: Demographic and procedural data were correlated with outcome measures. Outcomes analyzed included procedural success, reintervention rates, final circulation type, and functional class. Multivariate analysis and receiver operator curve were used to identify for parameters in predicting biventricular circulation. RESULTS: The procedural success rate was 92% (33 out of 36) in this group with moderate right ventricular hypoplasia (tricuspid valve z score -4.2 ± 3.0, 69.4% of patients with z score <-2.5). Early reintervention rate was 39%, mostly being insertion of modified Blalock-Taussig shunt. Overall reintervention-free survival was 53%, 30%, and 19% at 1, 6, and 12 months postintervention. Despite no significant catch-up right ventricular growth, majority of survivors (84%) enjoyed a biventricular circulation with good functional status. A tricuspid to mitral valve ratio >0.79 was a good predictor of biventricular outcome. (specificity of 100%, positive predictive value 100%) CONCLUSION: Encouraging long-term results with biventricular circulation and functional status were demonstrated with transcatheter pulmonary valve perforation in patients even with moderate hypoplastic right ventricle, which is comparable to that with mild right ventricular hypertrophy. The baseline tricuspid to mitral valve ratio was identified as a potentially useful tool in predicting biventricular circulation.

Novel and traditional cardiovascular risk factors in children after Kawasaki disease: implications for premature atherosclerosis.

OBJECTIVES: We determined the profile of cardiovascular risk factors in children late after Kawasaki disease (KD) and compared it with that of age-matched healthy children. BACKGROUND: Concerns have been raised regarding the possibility of a predisposition of KD to premature atherosclerosis later in life. METHODS: A cohort of 102 subjects were studied: 37 KD patients with coronary aneurysms (group I), 29 KD patients with normal coronary arteries (group II), and 36 healthy age-matched children (group III). The fasting total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I, apoB, and homocysteine levels were compared among the three groups. In addition, blood pressure and brachioradial arterial stiffness, as determined by pulse wave velocity (PWV), were measured and compared. RESULTS: Group I subjects had lower HDL cholesterol (p = 0.016) and apoA-I levels (p = 0.044) and higher apoB levels (p = 0.029) and PWV (p = 0.001) than group III control subjects. Likewise, the apoB levels (p = 0.007) and PWV (p = 0.042) were higher in group II than in III subjects, although their HDL cholesterol (p = 0.54) and apoA-I (p = 0.52) levels were similar. The LDL cholesterol levels were higher in group I and II patients than in controls, although not statistically significant (p = 0.17). Blood pressure and homocysteine levels did not differ among the groups. CONCLUSIONS: An adverse cardiovascular risk profile, as characterized by a proatherogenic alteration of the lipid profile and increased arterial stiffness, occurs in children after KD. The profile is worse in those with than in those without coronary aneurysms.

Cardiac rhythm and symptomatic arrhythmia in right atrial isomerism.

BACKGROUND: The conduction system in right atrial isomerism may be complicated by the presence of paired sinus nodes and twin atrioventricular nodes. With a large cohort of infants and children with right atrial isomerism, we sought to investigate the nature of atrial rhythm, its prevalence, factors predisposing patients to symptomatic cardiac arrhythmia, and the relation of arrhythmia to long-term morbidity and mortality. METHODS: Standard 12-lead baseline electrocardiograms were performed in 110 infants and children with right atrial isomerism at a median age of 1 day, and their clinical records were reviewed. The type, timing, and precipitating factors of symptomatic cardiac arrhythmia that occurred in 15 patients, among a cohort of 85 patients who had or were awaiting surgical interventions, were noted. RESULTS: All patients except 1 had a sinus rhythm with intact atrioventricular conduction. Of these, 87% (95/109) had single P-wave morphology, whereas 13% (14/109) had multiple P-wave morphologies. For patients with a single P-wave morphology, the frontal P-wave axis was between 0 degrees and 90 degrees in 62% (59/95), 90 degrees and 180 degrees in 23% (22/95), and superior in 15% (14/95). There was no relation between either P-wave axis or morphology and cardiac anatomy. Symptomatic cardiac arrhythmia occurred in 15 of 85 patients (18%); 11 of the 15 patients had supraventricular tachycardia, and 1 patient each had atrial tachycardia, atrial flutter, ventricular tachycardia, and congenital complete heart block. The arrhythmias occurred before surgery in 4 patients, early after surgery in 5 patients, and late after surgery in 6 patients. Although 3 of the 7 patients who died suddenly had a history of symptomatic arrhythmia, arrhythmia was the documented cause of mortality in only 1 of the 32 fatalities (3.1%). Freedom from arrhythmia at 1, 5, 10, 15, and 20 years was 93% +/- 3%, 86% +/- 4%, 80% +/- 6%, 73% +/- 9%, and 48% +/- 15% (mean +/- SE), respectively. No risk factors for symptomatic arrhythmia were identified by means of logistic regression. CONCLUSIONS: The atrial pacemaker varies in location within and between patients with right atrial isomerism. Although symptomatic cardiac arrhythmias are not uncommon, they do not seem to relate to the overall high mortality rate and occurrence of sudden death in this patient group. Nonetheless, detailed assessment and aggressive management of cardiac arrhythmias once they occur are warranted because of the precarious single ventricular hemodynamics.

Impact of preoperative aortic cusp prolapse on long-term outcome after surgical closure of subarterial ventricular septal defect.

BACKGROUND: Previous reports on the long-term outcome of surgical closure of subarterial ventricular septal defect were based on a relatively small number of patients. METHODS: We reviewed the long-term outcome of 135 patients who underwent closure of their defect and, in light of the findings, assessed the impact of preoperative aortic cusp prolapse and surgical interventions on occurrence of aortic regurgitation (AR) in the long-term. The patients were categorized into three groups for comparison: group I consisted of 79 patients with no aortic cusp prolapse and underwent simple closure of ventricular septal defect, group II comprised 39 patients with mild to moderate cusp prolapse who similarly had only closure of the defect performed, whereas group III comprised 17 patients who had additional aortic valvoplasty for greater than moderate to severe cusp prolapse. RESULTS: Group I patients had significantly higher pulmonary arterial pressure (p < 0.001) and ratio of pulmonary blood flow to systemic blood flow (p < 0.001). None of these patients had AR before their operation, and none experienced AR afterward at a median follow-up of 6.1 years. Of the 39 group II patients, 30 (77%) had trivial or mild AR preoperatively. The AR improved in 15 patients, remained trivial or mild in 14 and absent in 7, but progressed to trivial or mild in 3 at a median follow-up of 3.1 years. None required further interventions. In contrast, 14 (82%) of the 17 group III patients had moderate to severe AR before operation. The regurgitation improved in 10, but remained moderate or severe in 4 and worsened further in 3 at a median follow-up of 4.6 years. The freedom from failure of aortic valvoplasty was (mean +/- standard error of the mean) 71%+/-11%, 64%+/-12%, and 43%+/-19% at 1, 5, and 10 years, respectively. An older age at latest follow-up was the only identifiable significant risk factor (p = 0.03). CONCLUSIONS: Our data do not support the need of aortic valvoplasty for mild to moderate aortic cusp prolapse. Close follow-up is warranted in those with greater than moderate to severe cusp prolapse despite valvoplasty as there is continued failure on follow-up. Nothing, however, is better than early closure of defects before development of aortic valve complications.

Permanent ventricular pacing from coronary sinus after Fontan operation using newly designed left ventricular lead.

The functional single ventricles in Fontan procedures are isolated from the systemic return and thereby precluding conventional endocardial ventricular pacing. We reported a young patient who underwent Fontan operation at the age of 8 years old. He presented with significant bradyarrhythmias 13 years later requiring pacing therapy. A specially designed self-retained left ventricular (LV) pacing lead was implanted successfully through the coronary sinus and its anterolateral branch with satisfactory and stable chronic thresholds by one year's follow-up.

Left ventricular torsional mechanics and diastolic function in congenital heart block with right ventricular pacing.

BACKGROUND: The effects of right ventricular (RV) pacing on left ventricular (LV) diastolic function are unknown. This study aimed to test the hypothesis that right ventricular (RV) pacing is associated with LV diastolic dysfunction and impairment of LV torsion in children and young adults with congenital heart block. METHODS: Eighteen patients aged 20 ± 7 years and 12 healthy controls aged 19 ± 7 years were studied. Transmitral and mitral annular diastolic velocities and global longitudinal diastolic strain rate were determined and compared between the 2 groups. Parameters of LV torsion including peak systolic basal and apical rotations, and systolic twisting and diastolic untwisting velocities were further determined by speckle tracking echocardiography. In 12 patients, these parameters were compared before and after interruption of RV pacing. RESULTS: Compared with controls, patients had significantly lower mitral early diastolic annular velocity (p=0.007), LV global diastolic strain rate (p<0.001), basal (p<0.001) and apical (p=0.002) rotations, peak systolic torsion (p<0.001), and peak systolic twisting velocities (p=0.009). In patients, the peak diastolic untwisting velocity correlated with peak systolic torsion (r=0.64, p=0.004) and peak systolic twisting velocity (r=0.74, p<0.001). No significant improvement in LV diastolic function or torsion was observed during pacing interruption (all p>0.05). CONCLUSION: Right ventricular pacing in childhood is associated with LV diastolic dysfunction and impaired LV torsion, which do not improve with pacing interruption.