Hiroko Asakai

Predictors of myocardial recovery in pediatric tachycardia-induced cardiomyopathy

BACKGROUND Tachycardia-induced cardiomyopathy (TIC) carries significant risk of morbidity and mortality, although full recovery is possible. Little is known about the myocardial recovery pattern. OBJECTIVE The purpose of this study was to determine the time course and predictors of myocardial recovery in pediatric TIC. METHODS An international multicenter study of pediatric TIC was conducted. Children ≤18 years with incessant tachyarrhythmia, cardiac dysfunction (left ventricular ejection fraction [LVEF] <50%), and left ventricular (LV) dilation (left ventricular end-diastolic dimension [LVEDD] z-score ≥2) were included. Children with congenital heart disease or suspected primary cardiomyopathy were excluded. Primary end-points were time to LV systolic functional recovery (LVEF ≥55%) and normal LV size (LVEDD z-score <2). RESULTS Eighty-one children from 17 centers met inclusion criteria: median age 4.0 years (range 0.0-17.5 years) and baseline LVEF 28% (interquartile range 19-39). The most common arrhythmias were ectopic atrial tachycardia (59%), permanent junctional reciprocating tachycardia (23%), and ventricular tachycardia (7%). Thirteen required extracorporeal membrane oxygenation (n = 11) or ventricular assist device (n = 2) support. Median time to recovery was 51 days for LVEF and 71 days for LVEDD. Two (4%) underwent heart transplantation, and 1 died (1%). Multivariate predictors of LV systolic functional recovery were age (hazard ratio [HR] 0.61, P = .040), standardized tachycardia rate (HR 1.16, P = .015), mechanical circulatory support (HR 2.61, P = .044), and LVEF (HR 1.33 per 10% increase, p=0.005). For normalization of LV size, only baseline LVEDD (HR 0.86, P = .008) was predictive. CONCLUSION Pediatric TIC resolves in a predictable fashion. Factors associated with faster recovery include younger age, higher presenting heart rate, use of mechanical circulatory support, and higher LVEF, whereas only smaller baseline LV size predicts reverse remodeling. This knowledge may be useful for clinical evaluation and follow-up of affected children.

Arterial ischemic stroke in children with cardiac disease

Objective: To describe the spectrum of cardiac disorders, timing in relation to interventional procedures, and outcome in children with cardiac disease and arterial ischemic stroke (AIS). Methods: Children younger than 18 years with cardiac disease and radiologically confirmed AIS admitted to the Royal Childrens Hospital Melbourne between 1993 and 2010 were retrospectively identified using ICD-9 and ICD-10 searches. Results: Seventy-six children with cardiac disease and radiologically confirmed AIS were identified with the median age at diagnosis of 5 months (interquartile range 0–58). Cardiac lesions included cyanotic congenital heart disease (CHD) in 42 (55%), acyanotic heart disease in 24 (29%), cardiomyopathies/myocarditis in 6 (8%), infective endocarditis in 3 (4%), and primary arrhythmias in 3 (4%). Stroke occurred following cardiac procedures in 52 patients (68%): 41 post cardiac surgery (4.6 strokes per 1,000 surgical procedures) and 11 post cardiac catheterization (1.7 strokes per 1,000 catheterizations). The median time from procedure to diagnosis of stroke was 3 days (interquartile range 2–7), with 68% (95% confidence interval 58%–79%) of strokes estimated to occur within the periprocedural period. Prevalence of periprocedural stroke varied by diagnostic category, but was most common in patients with cyanotic CHD undergoing palliative surgery (22/2,256, 1%) (p < 0.005). There were 3 AIS-related deaths, and 54 survivors (84%) had persisting neurologic deficits. Conclusions: Infants with cyanotic CHD were most frequently affected by AIS during the periprocedural period. Prospective cohort studies are required to determine effective primary and secondary prevention strategies.

Accelerated Cardiomyocyte Proliferation in the Heart of a Neonate With LEOPARD Syndrome-Associated Fatal Cardiomyopathy

LEOPARD syndrome (LS) is a form of RASopathy caused by mutations in the PTPN11 gene an upstream regulator of RAS/MAPK signaling. Although hypertrophic cardiomyopathy (HCM) is a shared cardiac phenotype among RASopathies, HCM complicating patients with LS is characteristic for its unique early-onset and progressive features. We herein report a neonate with LS who presented with an extremely severe form of HCM. Autopsy revealed remarkable evidence of active cardiomyocyte proliferation contributing to the overt cardiomegaly. The case suggests an intriguing association between the observed dramatic increase in cardiomyocyte mitotic activity and the fatal clinical course of LS-associated HCM. The patient was the second daughter born to nonconsanguineous parents with no significant family history. Marked biventricular hypertrophy was noted on fetal echocardiography at the 28th week of gestation. After an uneventful delivery, the patient was immediately admitted to the neonatal intensive care unit. Physical examination at birth revealed multiple dysmorphic features, including a wide forehead, low set ears, hypertelorism, and wide set nipples. No skin lesions, such as cafe-au-lait spots or lentigines, were noticed, whereas mild hearing loss was detected by newborn screening. The findings were suggestive of LS. Imaging studies were remarkable for cardiomegaly (Figure …

Atrioventricular block after ASD closure

Objective Secundum atrial septal defect (ASD) is a common congenital heart defect. There is limited data on both early and late atrioventricular (AV) block post ASD closure. The aim of this study was to determine the incidence and risk factors of AV block associated with ASD closure. Methods A retrospective analysis of all patients who underwent ASD closure either with a device or surgical method at the Royal Childrens Hospital Melbourne between 1996 and 2010 was performed. Baseline demographics, procedural details and follow-up data were collected from medical records. Results A total of 378 patients were identified; 242 in the device group and 136 in the surgical group. Fourteen patients (3.7%) had AV block (1 with second degree and 13 with first degree) at a median follow-up of 28 months; 11/242 (4.5%) in the device group and 3/135 (2.2%) in the surgical group (p=0.39). Six patients had new-onset AV block after ASD closure. In the device subgroup, patients with AV block at follow-up had a larger indexed device size compared with those without (22 (15–31) vs 18(7–38), p=0.02). Multivariate analysis revealed the presence of AV block either pre procedure or post procedure to be the only variables associated with late AV block. Conclusions Late AV block in patients with repaired ASD is rare and most likely independent of the technique used. In the device subgroup, the only risk factor identified to be associated with late AV block was the presence of either preprocedural or postprocedural AV block, so long-term follow-up for these patients should be provided.

Isoproterenol stress test during catheterization of patients with coarctation of the aorta.

Background:  The exercise test is considered useful in selecting high‐risk patients with repaired coarctation of the aorta (CoA), but it is difficult to obtain the cooperation of pediatric patients. The present study determines the feasibility of the isoproterenol stress test (IST) among pediatric patients with CoA.

Identification of liver fibrosis using the hepatic vein waveform in patients with Fontan circulation: Liver fibrosis in Fontan patients

Liver fibrosis caused by congestive hepatopathy has emerged as an important complication after Fontan procedure. We evaluated the utility of the hepatic vein (HV) waveform using Doppler ultrasound for identification of liver fibrosis in Fontan patients.

Current Trends in Implantable Cardioverter-Defibrillator Therapy in Children ― Results From the JCDTR Database ―

BACKGROUND Implantable cardioverter defibrillators (ICDs) are being used with increasing frequency in children. Our aim was to examine the current trend of pediatric ICD implantation in Japan. Methods and Results: Data was extracted from the Japanese Cardiac Device Treatment Registry (JCDTR), a nation-wide registry started in 2006. All patients aged less than 18 years who had an ICD implantation registered between 2006 and 2016 were included in the analysis. A total of 201 patients were included, with a median age of 16 years (range 1-18). The underlying cardiac diagnosis was primary electrical disease (67%), cardiomyopathy (26%) and congenital heart disease (4%), with idiopathic ventricular fibrillation (29%) and long QT syndrome (21%) being the 2 most common diagnoses. Implantation indication was primary prevention in only 30 patients (15%). There were 27 patients (13%) aged ≤12 years, with a larger proportion of patients with cardiomyopathy (33%). The indication in younger children was secondary prevention in all cases. Younger children may be under-represented in our study given the nature of the database as it is a predominantly adult cardiology database. CONCLUSIONS In the past decade, ICD implantation has been performed in approximately 20 children per year in Japan, mostly for secondary prevention. There was no increase in the trend nor a change in age distribution.

Minimally invasive, pericardial implantable cardioverter-defibrillator placement in a young child

We report the successful minimally invasive placement of a pericardial implantable cardioverter‐defibrillator (ICD) in a 16‐kg child. A transvenous ICD dual coil was advanced through a small subxiphoid incision and screwed into the oblique sinus pericardium under fluoroscopic guidance. An additional sense‐pace lead was sutured onto the right ventricular apex, and the generator was placed in the upper abdominal wall through the same incision. Threshold testing demonstrated successful defibrillation at 15 J. After implantation, the patient had two episodes of appropriate shock for ventricular fibrillation. The ICD system continues to show stable impedance at 6 months of follow‐up.