Newly Developed Sex-Specific Z Score Model for Coronary Artery Diameter in a Pediatric Population.

BACKGROUND: This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice. METHODS: This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit. RESULTS: Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula. CONCLUSION: A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

High neutrophil : lymphocyte ratio is associated with refractory Kawasaki disease.

BACKGROUND: The clinical significance of the neutrophil : lymphocyte ratio (NLR) has not yet been fully elucidated in Kawasaki disease (KD). The purpose of this study was to investigate the relationship between NLR and response to i.v. immunoglobulin (IVIG), and its effect on coronary abnormalities in KD. METHODS: A total of 196 KD patients treated with IVIG were analyzed. Baseline NLR was evaluated immediately before IVIG therapy and the patients classified into two groups according to NLR. The clinical data, other inflammatory biomarkers, and coronary complications were also assessed. RESULTS: Kawasaki disease patients with NLR ≥ 5 had a greater incidence of IVIG refractoriness than the NLR < 5 group (31.7% vs 4.3%, P < 0.001), but this was not related to the development of coronary abnormalities. The change in NLR after IVIG (i.e. ΔNLR) was significantly decreased in the coronary abnormality group (2.65 ± 1.88 vs 3.81 ± 2.55, P = 0.042). On multivariate analysis, high NLR and CRP were independent predictors of IVIG refractoriness during the acute phase of KD (P = 0.032 in NLR; P = 0.029 in CRP, respectively). CONCLUSIONS: High NLR was closely associated with resistance to IVIG, but it was not related to the occurrence of coronary abnormalities in KD. Low ΔNLR after IVIG, however, was significantly associated with coronary artery abnormalities.

Interatrial septal thickness is associated with the extent of left atrial complex fractionated atrial electrograms and acute procedural outcome in patients with persistent atrial fibrillation.

AIMS: The interatrial septal thickness (IAST) reflects the changes of the atrial wall in patients with atrial fibrillation (AF). Complex fractionated atrial electrograms (CFAEs) were consistently positioned on the interatrial septum, especially in the remodelled left atrium (LA). We sought to characterize the relationship between IAST and LA CFAE area, as well as the acute procedural and clinical outcomes of catheter ablation in persistent AF patients. METHODS AND RESULTS: This study included 71 patients who underwent catheter ablation for drug-refractory persistent AF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by LA and right atrial CFAE-guided ablation. Interatrial septal thickness was measured 1 cm inferior to the fossa ovalis on cardiac computed tomography (CT). The extent of LA CFAEs was assessed by CFAE area and index (CFAE area/LA surface area × 100). Patients were grouped into tertiles according to the value of IAST. The mean IAST of the first, second, and third tertile was 4.69 ± 0.79, 6.44 ± 0.45, and 9.12 ± 1.42 mm, respectively (P < 0.001). The mean CFAE areas (5.6 ± 6.9, 18.5 ± 20.3, and 24.3 ± 26.6 mm(2), P = 0.005) and CFAE indexes (3.1 ± 4.2, 9.2 ± 10.7, and 11.8 ± 15.3, P = 0.025) in LA were significantly different among the three groups. More patients in the highest IAST tertile did not terminate AF during catheter ablation (12.5% vs. 26.1% vs. 37.5%, P = 0.048). CONCLUSIONS: Interatrial septal thickness measured by cardiac CT is associated with the extent of CFAE area within the LA and is related to acute procedural success of catheter ablation. These findings suggest that IAST reflects the degree of atrial substrate and remodelling in patients with persistent AF.

Radiofrequency catheter ablation of atrial tachyarrhythmias after an atrial switch operation in a patient with univentricular heart combined with transposition of the great arteries.

A 31-year-old patient previously underwent a Mustard operation presented with palpitations. Atrial tachycardia and paroxysmal atrial fibrillation were documented on the surface electrocardiogram. Under the guidance of a three-dimensional electroanatomic mapping system, ablation of the isolated left-sided pulmonary vein and a cavo-tricuspid isthmus-dependent intra-atrial macro re-entry circuit eliminated atrial tachycardia and paroxysmal atrial fibrillation without the recurrence of atrial tachyarrhythmia.

Relationship between complex fractionated atrial electrograms during atrial fibrillation and the critical site of atrial tachycardia that develops after catheter ablation for atrial fibrillation.

INTRODUCTION: Complex fractionated atrial electrograms (CFAEs) are a substrate modification target in patients with atrial fibrillation (AF). However, whether CFAEs can be also arrhythmogenic grounds of atrial tachycardia (AT) presenting after AF ablation remains to be determined. We investigated the relationship between CFAEs and the critical site of AT after CFAE-guided AF ablation. METHODS AND RESULTS: Seventy-two patients showing AT after pulmonary vein isolation and further CFAE-guided ablation were included. The termination sites of the 95 distinct ATs were annotated on color-coded CFAE cycle maps. Of the 95 ATs, 61 (64.2%) had a termination site at the border zone of CFAE or in a highly dense CFAE area. The cycle length (CL) of the ATs terminated in the CFAE area was significantly shorter than the CL of those terminated in the non-CFAE area. The cut-off CL for ATs terminated at the CFAE area was 270 milliseconds, with sensitivity/specificity of 70%/75%. In 67.2% of the ATs terminating at the CFAE-related area, the major termination sites were the anterior wall near the LA appendage, septum and roof, whereas the peri-mitral isthmus was the most common termination site of ATs in the non-CFAE area. CONCLUSIONS: The areas showing CFAE and their border zones were frequently associated with termination of ATs presenting after AF ablation. The mean CL of ATs originating near CFAEs was significantly shorter than that of those terminated in non-CFAE areas. The targeted CFAE areas also provided the arrhythmogenic milieu for AT developing after AF ablation.

The spatial distribution of atrial fibrillation termination sites in the right atrium during complex fractionated atrial electrograms-guided ablation in patients with persistent atrial fibrillation.

BACKGROUND: The role of right atrial (RA) ablation guided by complex fractionated atrial electrograms (CFAE) in atrial fibrillation (AF) has been debated. This study evaluated the spatial distribution of RA CFAE, the critical sites, and the predictors of successful termination of longstanding persistent AF during RA ablation. METHODS: A total of 97 patients with persistent AF who received automated detection of CFAE mapping and ablation at the RA for sustained AF after pulmonary vein isolation and left atrial (LA) CFAE-guided ablation were analyzed. The AF termination patterns and CFAE areas were analyzed. RESULTS: Forty-eight (49%) patients successfully converted to atrial tachycardia (AT) or sinus rhythm (SR) during CFAE-guided ablation at the RA. Of these, 7 (15%) patients converted directly to SR, and 41 (85%) converted via AT. The crista terminalis (CT) was the most common site for AT conversion during RA CFAE ablation, followed by the RA appendage and RA septum. Patients with larger RA volumes (> 145 mm3) had lower rates of SR or AT conversion during RA CFAE ablation. Patients with AF termination during RA CFAE ablation had less late recurrence than those without AF termination (P = 0.003). CONCLUSION: A half of patients with persistent AF refractory to LA ablation successfully converted to AT or SR during automated CFAE-guided ablation at the RA. The most common critical sites for AF termination were the CT and RA appendage and septum. Patients with AF termination during procedure whether LA CFAE only or after RA CFAE ablation had better outcome with less late recurrence of atrial tachyarrhythmia compared to those without AF termination.

Electrocardiographic and electrophysiological characteristics of premature ventricular complexes associated with left ventricular dysfunction in patients without structural heart disease.

AIMS: The mechanism responsible for premature ventricular complex (PVC)-mediated left ventricular (LV) dysfunction remains unclear. We sought to determine the electrocardiographic and electrophysiological characteristics of PVC-mediated LV dysfunction. METHODS AND RESULTS: One hundred and twenty-seven patients who underwent radiofrequency catheter ablation (RFCA) for frequent PVCs (PVCs burden ≥10%/24 h) and had no significant structural heart disease were investigated. Left ventricular dysfunction (ejection fraction < 50%) was present in 28 of 127 patients (22.0%). The mean PVC burden (31 ± 11 vs. 22 ± 10%, P < 0.001), the presence of non-sustained ventricular tachycardia (53.6 vs. 33.3%, P = 0.05), and the presence of a retrograde P-wave following a PVC (64.3 vs. 30.3%, P = 0.001) were significantly greater in those with LV dysfunction than in those with normal LV function. The cut-off PVC burden related to LV dysfunction was 26%/day, with a sensitivity of 70% and a specificity of 78%. The PVC morphology, QRS axis, QRS width, coupling interval, the presence of interpolation, and PVC emergence pattern during exercise electrocardiogram were not significantly different between the two groups. The origin sites of PVCs, the acute success rate, and the recurrence rate during follow-up after RFCA were similar. In a multivariate analysis, the PVC burden (odds ratio 2.94, 95% confidence interval 0.90-3.19, P = 0.006) and the presence of retrograde P-waves (odds ratio 2.79, 95% confidence interval 1.08-7.19, P = 0.034) were independently associated with PVC-mediated LV dysfunction. CONCLUSION: A higher PVC burden (>26%/day) and the presence of retrograde P-waves were independently associated with PVC-mediated LV dysfunction.

Prediction of long-term outcomes of catheter ablation of persistent atrial fibrillation by parameters of preablation DC cardioversion.

AIM: It has been demonstrated that atrial fibrillation (AF) frequently recurred after cardioversion (CV) using direct current (DC) or radiofrequency catheter ablation (RFCA) in patients with persistent (PeAF) or longstanding persistent AF (LPAF). We hypothesized that the atrial substrate impeding successful CV would also produce difficulty in catheter ablation, and therefore, the outcomes of RFCA for PeAF and LPAF could be predicted by the parameters determined at the time of DC CV. METHOD: From 2006 to 2009, 94 patients with PeAF and LPAF who had undergone elective DC CV before RFCA were studied. The parameters associated with DC CV, including number of shocks, cumulative energy adjusted, highest energy adjusted, with or without intravenous amiodarone use, and other clinical parameters were assessed. RESULT: Thirty-two out of the 94 patients (34%) experienced AF recurrence during the follow-up of 19.8 ± 12.3 months after RFCA. The average time to recurrence of AF after RFCA was 9.2 ± 3.2 months. Of the 62 patients, 29 patients (31%) remained sinus rhythm (SR) without antiarrhythmic drug (AAD). The patients who maintained SR had smaller body mass index (BMI) (P = 0.048), shorter duration of AF (P = 0.012), and lower prevalence of diabetes mellitus (P = 0.023) compared with patients in whom AF recurred. Total number of shocks, total energy, and highest shock energy during CV were lower (P < 0.001, P = 0.002, P = 0.048, respectively) in patients with SR during the follow-up. The outcome in patients who used amiodarone IV prior to CV, however, was not different from that in those who did not use amiodarone IV. CONCLUSION: DC energy parameters for successful CV before RFCA were useful to predict the long-term outcome after RFCA in patients with PeAF and LPAF. The presence of the atrial substrate making DC CV difficult might reflect atrial substrate that subsequently related to the recurrence of AF after RFCA in chronic AF. These DC energy parameters may be related to the chronicity or electroanatomical remodeling of AF.

Clinical significance of induced atrial tachycardia after termination of longstanding persistent atrial fibrillation using a stepwise approach.

INTRODUCTION: The utility of inducibility test of atrial tachycardia (AT) in patients with longstanding persistent atrial fibrillation (AF; LPAF) is unclear. This study aimed to evaluate the significance of induced AT and the impact of their ablation on the clinical outcome. METHODS: In 194 patients with LPAF (>1 year) who underwent catheter ablation (pulmonary vein isolation with substrate ablation), an inducibility test was performed after AF termination. RESULTS: AT was induced in 108 (56%) patients (induced AT group); neither AT nor AF was inducible in 37 (19%, noninduction group). During 39 ± 21 months, AT recurred in 30 patients (28%), AF in 19 (17%), and no arrhythmia in 56 (52%) among induced AT group, although there was a recurrence of AT in 9 (24%, P = 0.68), AF in 6 (16%, P = 0.85), and no arrhythmia in 22 (60%, P = 0.42) among noninduction group (P = NS). Note that 10 patients with repeated ablation in induced AT group revealed 8 different and 2 similar recurrent ATs compared to the induced ATs at first session. The mean cycle length of induced AT that terminated by ablation (271 ± 64 ms) was longer than that without (249 ± 58 ms, P < 0.05). In induced AT group, AT recurrence rate in patients who achieved AT termination by ablation was lower than those without termination (5% vs 36%, P < 0.05). CONCLUSIONS: ATs that are inducible after LPAF termination do not necessarily become clinical AT. However, patients who achieved noninducibility of AT by ablating slower cycle length of AT had better outcomes.

TLR-4 agonistic lipopolysaccharide upregulates interleukin-8 at the transcriptional and post-translational level in vascular smooth muscle cells.

Despite extensive studies on cellular responses to activation of Toll-like receptor-4 (TLR-4), it is not evident weather its activation affects gene expression of interleukin-8 (IL-8) in vascular smooth muscle cells (VSMCs). Therefore, this study has investigated whether and how TLR-4 influences IL-8 expression in VSMCs. Exposure of aortic smooth muscle cells to TLR-4 agonistic lipopolysaccharide (LPS) not only enhanced release of IL-8 protein but also induced IL-8 gene transcript via promoter activation. The LPS-induced activation of IL-8 promoter was attenuated by dominant-negative MKK1, but not by dominant-negative MKK3. The promoter activation was also impaired by dominant negative CCAAT/enhancer binding protein (C/EBP), IkappaB, and dominant negative c-Jun. In comparison with the mutation of the AP-1 binding site, the mutation of NF-kappaB site and C/EBP binding site in the IL-8 promoter region more significantly impaired the promoter activation. Moreover, both promoter activity and release of IL-8 were inhibited by U0126 and curcumin, but not by SB202190, epigallocatechin 3-gallate and resveratrol. The present study reports that TLR-4-agonistic LPS upregulates IL-8 at the transcriptional and post-translational level in VSMCs, and that ERK1/2, NF-kappaB, and C/EBP play major roles in the upregulation of IL-8.

Technical modification of the neoaortic reconstruction in Norwood procedure: sparing of anterior wall of the main pulmonary artery.

The growth potential of the neoaorta after the stage I Norwood procedure could be limited when the patient has a small ascending aorta. Patients with hypoplastic left heart syndrome usually have a large main pulmonary artery (MPA) and from its posterior wall both pulmonary arteries arise. We describe a modified technique that spares a large anterior wall of the MPA in the neoaortic reconstruction of Norwood procedure to enhance the growth potential of the neoaorta.

Discrimination of Kawasaki disease with concomitant adenoviral detection differentiating from isolated adenoviral infection.

PURPOSE: Human adenovirus infection mimics Kawasaki disease (KD) but can be detected in KD patients. The aim of this study was to determine the clinical differences between KD with adenovirus infection and only adenoviral infection and to identify biomarkers for prediction of adenovirus-positive KD from isolated adenoviral infection. METHODS: A total of 147 patients with isolated adenovirus were identified by quantitative polymerase chain reaction. In addition, 11 patients having KD with adenovirus, who were treated with intravenous immunoglobulin therapy during the acute phase of KD were also evaluated. RESULTS: Compared with the adenoviral infection group, the KD with adenovirus group was significantly associated with frequent lip and tongue changes, skin rash and changes in the extremities. In the laboratory parameters, higher C-reactive protein (CRP) level and presence of hypoalbuminemia and sterile pyuria were significantly associated with the KD group. In the multivariate analysis, lip and tongue changes (odds ratio [OR], 1.416; 95% confidence interval [CI], 1.151-1.741; P=0.001), high CRP level (OR, 1.039; 95% CI 1.743-1.454; P= 0.021) and sterile pyuria (OR 1.052; 95% CI 0.861-1.286; P=0.041) were the significant predictive factors of KD. In addition, the cutoff CRP level related to KD with adenoviral detection was 56 mg/L, with a sensitivity of 81.8% and a specificity of 75.9%. CONCLUSION: Lip and tongue changes, higher serum CRP level and sterile pyuria were significantly correlated with adenovirus-positive KD.

Does patch closure of subarterial ventricular septal defect affect the growth of pulmonary valve?

OBJECTIVE: Patch closure of the subarterial ventricular septal defect requires suture placement at the pulmonary annulus. We aimed to identify whether patch closure of subarterial ventricular septal defect would affect the growth of pulmonary annulus in comparison with that of perimembranous ventricular septal defect. METHODS: Of 361 patients who underwent patch closure of ventricular septal defect from January 1992 to December 1999, 98 (51 subarterial, 47 perimembranous) had echocardiographic data available for measurement of both preoperative and postoperative (more than 5 years after operation) pulmonary and aortic annular diameters. The pulmonary/aortic annular diameter ratio and their growth rates in the subarterial group were compared with those in the perimembranous group. The perioperative variables correlated with the pulmonary annular growth in subarterial group were also identified. RESULTS: The mean follow-up duration was 7.2 years. Preoperative pulmonary/aortic annular diameter ratio was 1.45 (range, 0.94-2.31) in the subarterial group and 1.57 (range, 1.15-2.51) in the perimembranous group (p=0.059). The latest postoperative ratio was significantly lower in the subarterial group [subarterial: 1.02 (range, 0.77-1.41) vs perimembranous: 1.36 (range, 1.11-1.75), p<0.01]. Twenty-three patients (45%) in the subarterial group had the ratio less than 1. The pulmonary annular growth rate in the subarterial group was lower than that in the perimembranous group (subarterial: 0.34 mm/year, perimembranous: 1.03 mm/year, p<0.01). Preoperative pulmonary/aortic annular diameter ratio (r=0.885, p<0.01), age at operation (r=-0417, p<0.01), weight at operation (r=-0.357, p<0.05), and ventricular septal defect size (r=0.298, p<0.05) were found to have correlation with pulmonary annular growth in the subarterial group. CONCLUSIONS: Our data show that pulmonary annular growth after patch repair of subarterial ventricular septal defect is suboptimal compared with perimembranous ventricular septal defect. Careful attention must be paid to the possible late clinical implication caused by impaired pulmonary annular growth after patch repair of subarterial ventricular septal defect.

Neonatal arrhythmias: diagnosis, treatment, and clinical outcome.

Arrhythmias in the neonatal period are not uncommon, and may occur in neonates with a normal heart or in those with structural heart disease. Neonatal arrhythmias are classified as either benign or nonbenign. Benign arrhythmias include sinus arrhythmia, premature atrial contraction, premature ventricular contraction, and junctional rhythm; these arrhythmias have no clinical significance and do not need therapy. Supraventricular tachycardia, ventricular tachycardia, atrioventricular conduction abnormalities, and genetic arrhythmia such as congenital long-QT syndrome are classified as nonbenign arrhythmias. Although most neonatal arrhythmias are asymptomatic and rarely life-threatening, the prognosis depends on the early recognition and proper management of the condition in some serious cases. Precise diagnosis with risk stratification of patients with nonbenign neonatal arrhythmia is needed to reduce morbidity and mortality. In this article, I review the current understanding of the common clinical presentation, etiology, natural history, and management of neonatal arrhythmias in the absence of an underlying congenital heart disease.

Percutaneous epicardial ablation of incessant atrial tachycardia originating from the left atrial appendage.

A 38-year-old woman presented with antiarrhythmic drug-refractory atrial tachycardia (AT). Holter recording demonstrated incessant episodes of AT followed by a long sinus pause. Electrophysiologic study revealed that the earliest endocardial activation was observed at the neck of the left atrial appendage (LAA). After unsuccessful endocardial ablation, epicardial access via a percutaneous subxiphoid approach demonstrated that the earliest epicardial atrial activation was observed on the opposite site to the endocardial LAA neck suggestive of ligament of Marshall (LOM) muscle sleeve as regarding the epicardial sharp potentials under guidance of a circular mapping catheter. Application of radiofrequency (RF) energy at this site terminated the tachycardia. After tachycardia ablation, the sinus pause also resolved.

Swallowing-induced atrial tachyarrhythmias successfully ablated at the left posterior interatrial septum in patient with wolff-Parkinson-white syndrome.

We reported a case of a 55-year-old patient who presented with palpitation after swallowing. Initial surface electrocardiogram revealed ventricular preexcitation utilizing a left lateral bypass tract. The orthodromic atrioventricular reentrant tachycardia (AVRT) was induced during electrophysiologic studies. After successful ablation of the AVRT utilizing a left lateral free wall bypass tract, 2 different atrial tachycardias (ATs) were induced under isoproterenol infusion. When the patient swallowed saliva or drank water, 2 consecutive beats of atrial premature complexes (APCs) preceded another non-sustained AT repeatedly, which was coincident with the patient's symptom. The preceding APC couplet had the same activation sequence with one induced AT, and the subsequent non-sustained AT had the same activation sequence with the other induced AT, respectively. We first targeted the preceding 2 consecutive APCs at the left posterior interatrial septum. The following non-sustained AT was also eliminated following ablation of the APCs. After ablation, the patient remained free from the swallowing-induced atrial tachyarrhythmias during the one year follow-up.