Normal reference ranges for the left ventricular mass and left ventricular mass index in preterm infants.

OBJECTIVE: The objective of this study is to establish normal reference ranges for the left ventricular mass (LVM) and LVM index (LVMI) in preterm infants according to the body surface area (BSA) and assess their correlation with body weight and gestational age. SUBJECTS AND METHODS: In a prospective study, 268 preterm babies who fulfilled the criteria for inclusion were examined. Echocardiograms were performed to measure the LVM and LVMI on 0-6 day (s) of life and at weekly intervals until the babies reached 36 weeks. The preterm infants were divided into six groups according to their BSA: 0.07-0.08 m2, 0.09-0.10 m2, 0.11-0.12 m2, 0.13-0.14 m2, 0.15-0.16 m2, and 0.17-0.19 m2. RESULTS: The mean gestational age was 29.8 (±2.38 standard deviation [SD]) weeks, ranging from 24 to 35 weeks. The mean body weight was 1479 (±413 SD) g, ranging from 588 to 3380 g, and the mean BSA was 0.13 m2, ranging from 0.07 to 0.19 m2. The LVM correlated well with the gestational age, body weight, and BSA. The LVMI correlated well with body weight and BSA. Reference ranges with the mean ± SD, range, and interquartile range were calculated for the LVM and LVMI according to the BSA. A significant gradual increase was observed in a LVM with increasing BSA. Overall, a progressive and significant increase in the LVM was observed during the first 9 weeks of life. CONCLUSION: The LVM and LVMI exhibited a significant correlation with the BSA and body weight. This study provides reference data that can be used as a normal reference tool for the LVM and LVMI for preterm infants based on the BSA.

Long-term follow-up and outcomes of discrete subaortic stenosis resection in children.

BACKGROUND: Studies of long-term outcomes of discrete subaortic stenosis (DSS) are rare. Therefore, we reviewed the long-term outcomes of subaortic membrane resection in children with isolated DSS over 16 years from a single institution. MATERIALS AND METHODS: We retrospectively reviewed the records of patients (n = 27) who underwent resection of DSS between 2000 and 2017. Patients with major concomitant intracardiac anomalies were excluded. Indications for surgery were mean left ventricular outflow tract (LVOT), Doppler gradient >30 mmHg, and/or progressive aortic insufficiency. RESULTS: The mean age at diagnosis was 3.77 ± 3.49 years (range, 0.25-13 years) and the mean age at surgery was 6.36 ± 3.69 years (range, 1-13 years). All patients underwent resection of subaortic membrane. The mean LVOT Doppler gradient decreased from 40.52 ± 11.41 mmHg preoperatively to 8.48 ± 5.06 mmHg postoperatively (P < 0.001). The peak instantaneous LVOT Doppler gradient decreased from 75.41 ± 15.22 mmHg preoperatively to 18.11 ± 11.44 mmHg postoperatively (P < 0.001). At the latest follow-up, the peak gradient was 17.63 ± 8.93 mmHg. The mean follow-up was 7.47 ± 3.53 years (median 6.33 years; range 2.67-16 years). There was no operative mortality or late mortality. Recurrence of subaortic membrane occurred in 7 (25.92%, 7/27) patients who underwent primary DSS operation. Four (14.81%, 4/27) patients required reoperation for DSS recurrence at a median time of 4.8 years (3.1-9.1 years) after the initial repair. Risk factors for reoperation were age <6 years at initial repair. Eighteen (66.66%, 18/27) patients had AI preoperatively and progression of AI occurred in 70.37% (19/27). This included 4 (22.22%, 4/18) patients who had worsening of their preoperative AI. Short valve-to-membrane distance was found to be prognostically unfavorable. One (3.7%, 1/27) patient had an iatrogenic ventricular septal defect, and 2 (7.4%, 2/27) patients had complete AV block following membrane resection. CONCLUSIONS: Resection of subaortic membrane in children is associated with low mortality. Higher LVOT gradient, younger age at initial repair, and shorter valve-to-membrane distance were found to be associated with adverse outcome. Recurrence and reoperation rates are high, and progression of aortic insufficiency following subaortic membrane resection is common. Therefore, these patients warrant close follow-up into adult life.

Normal reference ranges for aortic diameters in preterm infants.

OBJECTIVE: To establish normal reference ranges and Z-scores for aortic diameters in preterm infants according to the body surface area and assess their correlation with body weight, body surface area, and gestational age. PATIENTS AND METHODS: In a prospective study, 268 preterm infants who fulfilled the criteria for inclusion were examined. Echocardiograms were performed to measure the ascending aorta, transverse aorta, and aortic isthmus diameters on 0 days to 6 days of life and at weekly intervals until the babies reached 36 weeks. Body surface area was divided into 13 groups from 0.07 m2 to 0.19 m2. RESULTS: The mean gestational age was 29.8 [± 2.38 standard deviation (SD)] weeks, ranging from 24 weeks to 35 weeks. The mean body weight was 1479 (± 413 SD) g, ranging from 588 g to 3380 g, and the mean body surface area was 0.13 m2, ranging from 0.07 m2 to 0.19 m2. All the aortic diameters correlated well with both body weight and body surface area. Reference ranges with the mean ±â€¯SD, range, and Z-scores were calculated for aortic diameters according to the body surface area. A significant gradual increase was observed in ascending aorta, transverse aorta, and aortic isthmus diameters with increasing body surface area. Overall, a progressive and significant increase in ascending aorta, transverse aorta, and aortic isthmus diameters was observed during the first 9 weeks of life. CONCLUSION: The ascending aorta, transverse aorta, and aortic isthmus diameters exhibited a significant correlation with the body surface area and body weight. This study provides reference data with Z-scores that can be used as a normal reference tool for the ascending aorta, transverse aorta, and aortic isthmus diameters for preterm infants based on the body surface area.

Normal reference ranges for cardiac valve cross-sectional areas in preterm infants.

OBJECTIVE: To establish normal reference ranges for cardiac valve crosssectional areas (CSAs) in preterm infants and their correlation with gestational age, body weight, and chronological age. MATERIALS AND METHODS: In a prospective study, 268 preterm babies fulfilling the criteria for inclusion were examined. Echocardiograms were performed to measure aortic, pulmonary, mitral, and tricuspid valve CSAs on 0-6 day (s) of life and at weekly intervals until they reached 36 weeks. Gestational age was divided into three groups, 24-27, 28-31, and 32-35 weeks, and body weight was divided into five groups, ≤999, 1000-1499, 1500-1999, 2000-2499, and ≥2500 g. Overall group differences were compared for each period of life: 0-6 days and 1-2, 3-4, and ≥5 weeks. RESULTS: The mean gestational age was 29.8 (±2.38 standard deviation [SD]) weeks, ranging between 24 and 35 weeks, and the mean body weight was 1479 (±413 SD) g, ranging between 588 and 3380 g. All cardiac valve CSAs correlated well with body weight. A significant gradual increase was observed in all valve CSAs with body weight during each period of life. Overall, a progressive and significant increase in all valve CSAs was observed during the first 9 weeks of life. CONCLUSIONS: Cardiac valve CSAs were found to be significantly correlated with body weight. The study also provides reference data, which can be used as a normal reference tool for valve CSAs in preterm infants against gestational age, body weight, and chronological age.

Normal Reference Ranges for Pulmonary Artery Diameters in Preterm Infants.

To establish normal reference ranges and Z-scores for pulmonary artery diameters in preterm infants and their correlation with body surface area, body weight, and chronological age. In a prospective study, 268 preterm infants, who fulfilled the inclusion criteria were examined. Echocardiograms were performed to measure the main pulmonary artery, right pulmonary artery, and left pulmonary artery diameters on day(s) 0 to -6 of life and at weekly intervals until they reached 36 weeks of age. Body surface area was divided into thirteen groups from 0.07 to 0.19 m2. The mean gestational age was 29.8 (±2.38 SD) weeks, ranging between 24 and 35, the mean body weight was 1479 (±413 SD) grams, ranging between 588 and 3380, and the mean body surface area was 0.13 m2, ranging between 0.07 and 0.19 m2. All the pulmonary artery diameters correlated well with both body weight and body surface area. Reference ranges, with mean ± SD, range, and Z-scores for aortic diameters according to body surface area were calculated. A significant gradual increase was observed in main and branch pulmonary artery diameters with increasing body surface area. Overall, a progressive and significant increase for main and branch pulmonary artery diameters was observed during the first nine weeks of life. The main and branch pulmonary artery diameters were found to have significant correlation with body surface area. The study also provides reference data with Z-scores, which can be used as a normal reference tool for measuring the main pulmonary artery, right, and left pulmonary artery diameters of preterm infants against body surface area.

Normal Reference Ranges for Cardiac Valve Annulus in Preterm Infants.

OBJECTIVE: The purpose of this study was to establish normal reference ranges for the cardiac valve annulus size in preterm infants and their correlation with gestational age, body weight and chronological age. SUBJECTS AND METHODS: In a prospective study, 268 pre-term babies, who fulfilled the criteria for inclusion, were examined in Kuwait during the years 2008-2010. Echocardiograms were performed to measure the aortic, pulmonary, mitral and tricuspid valve annulus size on 0-6 day(s) of life and at weekly intervals until they reached 36 weeks. The gestational age was grouped into three: 24-27, 28-31 and 32-35 weeks, and body weight into five: ≤999, 1000-1499, 1500-1999, 2000-2499 and ≥2500 g. The overall group differences were compared for each period of life: 0-6 days, 1-2, 3-4 and ≥5 weeks. RESULTS: The mean gestational age was 29.8 (±2.38 SD) weeks, ranging between 24 and 35, and the mean body weight 1479 (±413 SD) grams, ranging between 588 and 3380. At the first scan (0-6 days of life), all cardiac valve measurements correlated well with both body weight and gestational age (P < 0.001). In the subsequent weeks valve diameters correlated well with body weight, while gestational age was found to have significant correlation (P < 0.01) with aortic and mitral valves only. A significant gradual increase was noticed in all valve annulus measurements with body weight during each period of life. Overall, a progressive and significant increase for all four cardiac valve annulus measurements was observed during the first nine weeks of life. CONCLUSION: The cardiac valve annulus measurements were found to have significant correlation with body weight. All the cardiac valve measurements correlated well with gestational age (P < 0.01) only up to 2 weeks. The study also provides reference data, which can be used as a normal reference tool for cardiac valve diameters for preterm infants against the gestational age, body weight and chronological age.

Normal reference ranges for left ventricular dimensions in preterm infants.

OBJECTIVE: To establish normal reference ranges for the left ventricular dimensions in preterm infants and their correlation with gestational age, body weight and chronological age. MATERIALS AND METHODS: In a prospective study, 268 preterm babies, who fulfilled the criteria for inclusion, were examined in Kuwait during the years (2008-2010). Echocardiograms were performed to measure the left ventricular dimensions on 0-6 day(s) of life and at weekly intervals until they reached 36 weeks. The gestational age was grouped into three: 24-27, 28-31 and 32-35 weeks, and body weight into five: ⩽999, 1,000-1,499, 1,500-1,999, 2,000-2,499 and ≥2,500 grams. The overall group differences were compared for each period of life: 0-6 days, 1-2, 3-4 and ≥5 weeks. RESULTS: The mean gestational age was 29.8 (± 2.38 SD) weeks, ranging between 24 and 35, and the mean body weight 1,479 (± 413 SD) grams, ranging between 588 and 3380. At the first scan (0-6 days of life), all the left ventricular measurements correlated well (P < 0.001) with body weight, and the same was observed with gestational age, except for left ventricular posterior wall thickness at end-systole and end-diastole. A significant gradual increase was noticed in all the dimensions with body weight during each period of life. However, with respect to gestational age, an increase was observed in all the dimensions during first four weeks, but the rate of increase became less after 5 weeks of life. Overall, a progressive and significant increase in all left ventricle measurements was observed during the first nine weeks of life. CONCLUSION: The left ventricular dimension measurements were found to have significant correlation with both gestational age and body weight. The study also provides reference data, which can be used as normal reference tool for left ventricular dimensions for preterm infants against the gestational age, body weight and chronological age.

Occlusion of Fontan fenestrations using Amplatzer septal occluder.

The objective of the study is to assess efficacy and safety of the Amplatzer septal device for percutaneous occlusion of Fontan fenestration. Fenestration improves postoperative outcomes in children undergoing Fontan repair. Many of these fenestrations close spontaneously; persistent fenestrations ultimately cause desaturation and can be a potential cause of paradoxical embolism. This is a retrospective review of 26 consecutive patients who underwent transcatheter closure of Fontan fenestration in a tertiary cardiac center in Kuwait. After assessment of hemodynamic suitability for fenestration closure, appropriate balloon sizing of fenestration was obtained. The median age was 9.2 years (range = 1.5-18.3 years). Occlusion was accomplished using a 4-7 ml single Amplatzer septal device in 12 patients and 8-13 ml devices in the other 13 patients; 2 devices were deployed in one patient. Median fluoroscopic and procedure times were 22 and 143.5 min, respectively. One immediate complication was the embolization and successful retrieval of the Amplatzer duct occluder. The fenestration was subsequently occluded by Amplatzer septal device. A 100% occlusion rate of fenestration was achieved in both lateral tunnel and extracardiac conduit types of Fontans. Mean (SD) arterial oxygen saturation increased from 84.7% (4.7) to 95.2% (1.7, P < 0.001) 10 min after deployment of the occluder; Fontan mean circuit pressure had a minimal acceptable increment from 12.9 mmHg (3.2) to 14.6 mmHg (2.6, P < 0.001). No complications or device failures were seen during follow up. The Amplatzer septal occluder device is effective in closing both Fontan fenestrations. Longer single or dual anti-platelet therapy may be considered to prevent thrombotic events. Long-term outpatients follow up with transthoracic echocardiographic monitoring for systemic venous congestion or thrombosis is warranted.

Novel TFAP2B mutation in nonsyndromic patent ductus arteriosus.

Mutations in the gene encoding the TFAP2B transcription factor can cause Char syndrome with cardiac, craniofacial, and hand abnormalities. However, TFAP2B mutations result in great phenotypic variability, which is believed to reflect different expression patterns of tissue-specific TFAP2 coactivators. We investigated a consanguineous family with isolated patent ductus arteriosus (PDA) for mutations in TFAP2B. Our study suggests that a novel splicing mutation in TFAP2B can cause isolated PDA without other clinical features.

The impact of interruption of anomalous systemic arterial supply on scimitar syndrome presenting during infancy.

OBJECTIVES: We sought to evaluate the impact of interruption of anomalous systemic arterial supply (ASAS) on clinical course and management outcome of scimitar syndrome (SS) presenting during infancy. BACKGROUND: No systematic study has been reported so far on this subject, although there are conflicting sporadic reports indicating variable effect. METHODS: Out of 23 children diagnosed to have SS during the past 25 years, 16 symptomatic infants had ASAS. After interrupting ASAS (coil embolization -14, surgical ligation -2), they were prospectively followed up to define their clinical course and management outcome. RESULTS: All 16 infants had sizable ASAS and 9 had variable scimitar vein (SV) stenosis. Fifteen (94%) had pulmonary hypertension and significant left to right shunt. Post intervention, there was variable reduction of shunt in 14 and pulmonary artery pressure in 15 cases. All showed varying clinical improvement. One died of septicemia shortly afterwards. Definitive surgery was deferred for optimal results in seven children for a mean period of 8 months (range 1 month to 3 years). Remaining eight children did not require definitive surgery. One among them had closure of stenosed partial SV by Amplatzer duct occluder ("physiologic correction"). Two children on short term and six children on long term follow-up (mean 5.2 years; range 3.3-10.3 years) are doing well. CONCLUSION: Interruption of ASAS helps to avoid or defer definitive surgery for SS during infancy. Therefore, we recommend coil embolization of ASAS as initial palliation, and long term surveillance to assess need for further intervention.

Transcatheter closure of large pulmonary arteriovenous fistula including pulmonary artery to left atrial fistula with Amplatzer septal occluder.

OBJECTIVES: We sought to evaluate the safety and efficacy of Amplatzer septal occluder (ASO) to close very large pulmonary arteriovenous fistula (PAVF). BACKGROUND: Transcatheter coil embolization, the standard treatment for PAVF, has potential complications particularly in patients with very large fistulas. Several recently available devices have been tried effectively, however, they too have limitations. METHODS: During 2004, three patients (aged 17-56 years), diagnosed with large PAVF including one with pulmonary artery (PA) to left atrial (LA) fistula, had interventional closure prospectively using ASO. Following hemodynamic evaluation and angiographic localization of PAVF, the feeding artery (FA) was selectively cannulated with Amplatzer delivery sheath. ASO, with the right atrial (RA) disc diameter equal to or up to 4 mm larger than the maximum diameter of FA, was delivered through it in such a way that the left atrial disc assumed an oblong shape and the right atrial disc retained its designed flat configuration for better anchorage and thrombogenicity. RESULTS: All patients had very large PAVF fed by a single FA (size 12-24 mm), which was closed completely, without complications, using ASO (size 7-16 mm; RA disc diameter 15-26 mm). Their arterial saturation rose from mean 72.3% to 97.3%. Follow up (1.5-3 years) showed disappearance of the radiological shadows and stable arterial saturations (mean 97.7%). CONCLUSIONS: We conclude that, using the new criteria for device size selection and modified technique of implantation, very large PAVFs including PA to LA fistula can be closed safely, effectively and nonsurgically with ASO.

Common arterial trunk associated with a homeodomain mutation of NKX2.6.

Persistent truncus arteriosus (PTA) is a failure of septation of the cardiac outflow tract (OFT) into the pulmonary artery and the aorta. A common arterial trunk (CAT) is often diagnosed as PTA in the absence of evidence of embryological mechanism. We have used autozygosity mapping of a large consanguineous family segregating CAT to map the causative locus to chromosome 8p21. An F151L mutation was identified in the homeodomain of NKX2.6, a transcription factor expressed in murine pharyngeal endoderm and embryonic OFT myocardium. Although expression of Nkx2.6 during murine embryogenesis is strongly suggestive of a role for this gene in heart development, mice homozygous for a targeted mutation of Nkx2.6 are normal. However, in these mice, it has been shown that Nkx2.5 expression expands into regions lacking Nkx2.6, suggesting functional complementation. As transcriptional targets of NKX2.6 are unknown, we investigated functional effects of the mutation in transcriptional and protein interaction assays using NKX2.5 as a surrogate. Introduction of F157L into human NKX2.5 substantially reduced its transcription activating function, its synergism with partners at the atrial natriuretic factor (ANF) and connexin-40 (Cx40) promoters and its specific DNA binding. We tested NKX2.5 target promoters for NKX2.6 activity. NKX2.6 was inactive at ANF but weakly activated transcription of a Cx40 promoter, whereas the F151L mutant lacked this activity. These findings indicate a previously unsuspected role for NKX2.6 in heart development, which should be re-evaluated in more sophisticated model systems.

Transcatheter coil closure of pulmonary arteriovenous malformations in children.

Pulmonary arteriovenous fistula (PAVF) is a rare vascular malformation of the lung that may lead to cyanosis, epistaxis, hemoptysis, and neurological deficits or cerebral abscess. The purpose of this study is to assess the effectiveness of percutaneous transcatheter embolization of PAVF in pediatric patients. Transcatheter embolization of PAVF using spring coils was performed in three patients (two males and one female) who presented between 1989 and 1999. The age at presentation ranged from 8 months to 3 years (mean 19.6 months). All patients had cyanosis and clubbing. Neurological, dermatological, or other cardiac manifestations were absent. The arterial oxygen saturations at presentation ranged from 60 to 72% (mean 64%). During eight procedures, multiple coils (total of 41 coils, average 14 coils per patient) were delivered to occlude the fistulas successfully. There was complete occlusion of the fistulas in all patients after the multiple interventions. The aortic saturations increased from a mean of 66% to a mean of 95%. Chest radiographs demonstrated dramatic regression of the pulmonary shadows in all three patients. There were no complications encountered during the procedures or during follow-up. Transcatheter coil embolization of PAVF is a safe and effective method of treatment in the pediatric age group. Patients may require multiple procedures to completely occlude the fistulas. Long-term follow-up is essential to ensure absence of recurrence due to recanalization.