Associations between Selected ADRB1 and CYP2D6 Gene Polymorphisms in Children with Ventricular and Supraventricular Arrhythmias.

Background and Objectives: Tachycardia is a common cardiovascular disease. Drugs blocking ß1-adrenergic receptors (ADRB1) are used in the therapy of arrhythmogenic heart diseases. Disease-related polymorphisms can be observed within the ADRB1 gene. The two most important are Ser49Gly and Arg389Gly, and they influence the treatment efficacy. The family of the cytochrome P450 system consists of the isoenzyme CYP2D6 (Debrisoquine 4-hydroxylase), which is involved in phase I metabolism of almost 25% of clinically important drugs, including antiarrhythmic drugs. A study was conducted to detect the ADRB1 and CYP2D6 gene polymorphisms. Materials and Methods: The material for the test was whole blood from 30 patients with ventricular and supraventricular tachycardia and 20 controls. The samples were obtained from the Department of Pediatric Cardiology. The first to be made was the extraction of DNA using a GeneMATRIX Quick Blood DNA Purification Kit from EURx. The selected ADRB1 and CYP2D6 gene polymorphisms were detected by high-resolution melting polymerase chain reaction (HRM-PCR) analysis. Results: Based on the analysis of melt profile data for each PCR product, the identification of polymorphisms was carried out. Heterozygotes and homozygotes were found in the examined alleles. Conclusions: The frequency of the Arg389Gly polymorphism differs statistically significantly between the control group and patients with supraventricular and ventricular arrhythmias, as well as between these two groups of patients. Moreover, the Arg389Gly polymorphism was statistically more prevalent in the group of girls with SVT arrhythmia compared to girls with VT. A few carriers of homozygous and heterozygous systems of the S49G polymorphism were detected among patients with arrhythmias, as well as control group. The percentage of individuals carrying the CYP2D6 4 allele as either homozygous or heterozygous was observed in the study and control groups. The high prevalence of the CYP2D6*4 allele carriers in both groups prompts the optimization of beta-1 blocker therapy.

Life situation of a caregiver of a child with congenital heart defect and/or other cardiac problems: structure and preliminary validation of a new questionnaire.

Background: Illness in a child with cardiac disease causes stress, brings additional responsibilities, reorganizes family life, and changes the functioning of the family. Aim: This study aimed to validate a new questionnaire evaluating the life situations of caregivers/parents of children with congenital heart disease (CHD) and/or other cardiac diseases (OCD). Materials and methods: The questionnaire comprised 10 questions aimed at assessing the life situation of an ill child's caregiver in two main areas: personal and spiritual. The total score of the questionnaire assessing the life situation of the caregiver of a child with a CHD and/or OCD can range from 0 to 32 points, with scores <26 indicating a poor, 25 to 32 indicating an average, and >32 indicating a good level of life situation in the personal sphere of the caregiver. The questionnaire was assessed using Cronbach's alpha tests, and repeatability was assessed using Cohen's Kappa test (retest) within a time interval of two to 4 weeks from the first measurement. Results: The research covered 50 respondents. Cohesion in the personal sphere obtained a satisfactory value of Cronbach's α = 0.72, in the spiritual sphere: Cronbach's α = 0.83, and the result common for both sections was: Cronbach's α = 0.66. Conclusion: The Life Situation Assessment Questionnaire for caregivers of children with CHD and OCD is a reliable and homogeneous tool for measuring the functioning of parents in the event of a child's illness.

Efficacy and safety of zero-fluoroscopy approach for ablation of atrioventricular nodal reentry tachycardia: experience from more than 1000 cases.

BACKGROUND: Radiofrequency catheter ablation (RFCA) of the slow pathway in atrioventricular nodal reentry tachycardia (AVNRT) is associated with high efficacy and low risk of total perioperative or late atrioventricular block. This study aimed to evaluate the efficacy, safety, and feasibility of slow-pathway RFCA for AVNRT using a zero-fluoroscopy approach. METHODS: Data were obtained from a prospective multicenter registry of catheter ablation from January 2012 to February 2018. Consecutive unselected patients with the final diagnosis of AVNRT were recruited. Electrophysiological and 3-dimensional (3D) electroanatomical mapping systems were used to create 3D maps and to navigate only 2 catheters from the femoral access. Acute procedural efficacy was evaluated using the isoproterenol and/or atropine test, with 15-min observation after ablation. Each case of recurrence or complication was consulted at an outpatient clinic during long-term follow-up. RESULTS: Of the 1032 procedures, 1007 (97.5%) were completed without fluoroscopy. Conversion to fluoroscopy was required in 25 patients (2.5%), mainly due to an atypical location of the coronary sinus (n = 7) and catheter instability (n = 7). The mean radiation exposure time was 1.95 ± 1.3 min for these cases. The mean fluoroscopy time for the entire study cohort was 0.05 ± 0.4 min. The mean total procedure time was 44.8 ± 18.6 min. There were no significant in-hospital complications. The total success rate was 96.1% (n = 992), and the recurrence rate was 3.9% (n = 40). CONCLUSION: Slow-pathway RFCA can be safely performed without fluoroscopy, with a minimal risk of complications and a high success rate.

A tendency to worse course of multisystem inflammatory syndrome in children with obesity: MultiOrgan Inflammatory Syndromes COVID-19 related study.

Background: A new disease entity called multisystem inflammatory syndrome in children (MIS-C) is a rare consequence of COVID-19 infection. The pathophysiology and risk factors of MIS-C are still unclear, and the clinical manifestation ranges from milder forms to cases needing intensive care unit treatment. Based on available data, obesity is linked to pro-inflammatory stimulation. Moreover, several studies showed that obesity could play a role in COVID-19 severity and its comorbidities among the adult and children's populations. This study aimed to investigate the influence of overweightedness/obesity in childhood for the course of MIS-C in Poland. Methods: This study presented data from the national MultiOrgan Inflammatory Syndromes COVID-19 Related Study (MOIS-CoR) collected between 4 March 2020 and 20 February 2021. Of the 371 patients that met the Polish MIS-C criteria, 306 were included for further analysis. Results: Children who are obese (OB with body mass index (BMI) ≥95th percentile) and overweight (OV with BMI ≥85th percentile but <95th percentile) (28 and 49 patients, respectively) represented 25.1% (n=77) of all recruited patients. Complete recovery at the time of discharge presented in 93% of normal body weight (NW) participants and 90% of OV children (p>0.05). Among OB children, 76% recovered fully, which differed from the NW group (p=0.01). Calculated odds ratio (OR) of incomplete recovery for OB children was 4.2. Irrespective of body weight, there were no differences (p>0.05) in the length of hospitalization and the duration of symptoms (for OB, 13 and 16.5 days; for OV and NW, 10 and 14 days, respectively), as well as in the frequency of cardiovascular abnormalities, necessity of oxygen therapy (OB, 26.9%; OV, 23.9%; and NW, 20.7%), and intravenous immunoglobulin and glucocorticosteroid (GCS) treatment. Conclusion: The higher risk of incomplete recovery and observed tendency toward a worsening course of MIS-C in patients with obesity suggest the need for further studies to confirm and understand our findings.

Diagnostic Value of the TpTe Interval in Children with Ventricular Arrhythmias.

BACKGROUND: The changes in the period of ventricular repolarization, i.e., QT interval, QTp (Q-Tpeak) and TpTe interval (Tpeak-Tend), make it possible to assess the electrical instability of the heart muscle, which may lead to the development of life-threatening ventricular arrhythmia. The aim of the study was to determine and evaluate the use of differences in T-wave morphology and durations of repolarization period parameters (QT, TpTe) in resting ECGs for children with ventricular arrhythmias. METHODS: The retrospective analysis was made of the disease histories of 80 examined children with resting ECGs, which were admitted to the Children's Cardiology Department. The study group consisted of 46 children aged 4 to 18 with ventricular arrhythmias and the control group consisted of 34 healthy children between 4 and 18 years of age, with no arrhythmias. RESULTS: The duration of the TpTe interval was significantly (p < 0.001) longer in the group of children with ventricular arrhythmia with abnormal T-wave (bactrian/bifid, humid/biphasic) compared to the TpTe interval in children with ventricular arrhythmia with the normal repolarization period. The duration of the TpTe (p < 0.001), QTcB (p < 0.001) and QTcF (p < 0.001) intervals were significantly longer in the group of children with ventricular arrhythmias and with abnormal T-wave compared to the values of the TpTe, QTcB, and QTcF intervals of the control group with normal morphology of the repolarization period. Only the duration of the TpTe interval was significantly (p = 0.020) longer in the group of children with ventricular arrhythmia without clinical symptoms. CONCLUSIONS: Children with benign ventricular arrhythmias recorded on a standard ECG with prolonged TpTe and QT intervals and abnormal T-wave morphology require systematic and frequent cardiac check up with long term ECG recordings due to the possibility of future more severe ventricular arrhythmias. Further follow-up studies in even larger groups of patients are necessary to confirm the values of these repolarization parameters in clinical practice.

Expression levels of serum circulating microRNAs in pediatric patients with ventricular and supraventricular arrhythmias.

PURPOSE: Aberrant expression of various miRNA species has been implicated in numerous cardiac diseases, e.g., heart failure, hypertrophy, conduction disturbances, and arrhythmogenesis. The aim of this study was to determine whether miR-1, miR-133a, and miR-133b can serve as biomarkers in the diagnosis of ventricular (Va) and supraventricular (SVa) arrhythmias in pediatric patients. MATERIALS AND METHODS: Molecular analysis included 30 patients with SVa or Va (13-17.5 years; 14 boys/16 girls) and 20 non-arrhythmic controls. Arrhythmia was confirmed by 24-h Holter ECG recording. miRNA was extracted from serum using the miRNeasyR Serum/Plasma Kit. miScript SYBR Green PCR Kit (Qiagen) was used to quantify miRNA expression. RESULTS: The levels of miR-1 and miR-133a expression were significantly higher in the SVa group than in the controls (p â€‹= â€‹0.0327 and p<0.0001, respectively). Additionally, both groups of patients with arrhythmia presented significantly lower expression levels of miR-133b than the controls (p<0.01 for both comparisons). The level of miR-133a expression in the SVa group was significantly higher than in the Va group (p â€‹= â€‹0.0124). ROC analysis demonstrated that the expressions of miR-1 and miR-133a could differentiate between the SVa patients and arrhythmia-free controls (AUC â€‹= â€‹0.7091, p â€‹= â€‹0.07 and AUC â€‹= â€‹0.8021, p â€‹= â€‹0.007, respectively). Furthermore, the expression of miR-133b was shown to distinguish patients with SVa and Va from the arrhythmia-free controls (AUC â€‹= â€‹0.7273, p â€‹= â€‹0.07 and AUC â€‹= â€‹0.8030, p â€‹= â€‹0.04, respectively). CONCLUSIONS: miR-1, miR-133a, and miR-133b have the potential to become diagnostic biomarkers of arrhythmia in pediatric patients.

Prolongation of Electrocardiographic T Wave Parameters Recorded during the Head-Up Tilt Table Test as Independent Markers of Syncope Severity in Children.

The head-up tilt table test (HUTT) with the upright phase is used to help determine an imbalance of the sympathetic nervous system that is related to abnormal electrocardiographic repolarization in children with vasovagal syncope (VVS) and also in patients with the long QT syndrome (LQTS). The study attempted to evaluate T wave morphology and QT and TpTe (Tpeak-Tend) intervals recorded in ECG during the HUTT for a more accurate diagnosis of children with VVS. The group investigated 70 children with a negative HUTT result: 40 patients with VVS and 30 healthy volunteers without syncope. The RR interval as well as TpTe, and QTc intervals were measured in lead V5 of electrocardiogram (ECG) on admission to the hospital and during three phases of the HUTT. In syncopal children, which included 23 children with bifid or flat T waves and 17 patients with normal T waves in the upright phase, the QTc and TpTe were longer (p < 0.001) compared to the other test phases and longer (p < 0.001) than in the control group, respectively, with the risk of arrhythmias. Only in the control group, the TpTe was shorter (p < 0.001) in the upright phase than in the other tilt phases. The TpTe in the upright phase (>70 ms) was a good discriminator, and was better than the QTc (>427 ms). Prolongation of electrocardiographic TpTe and QT intervals, in addition to the (abnormal T wave morphology recorded during the HUTT, are helpful for identifying VVS children more predisposed to ventricular arrhythmias with a latent risk of LQTS. Further studies are required to assess the value of these repolarization parameters in clinical practice.

Echocardiography and Newer Imaging Techniques in Diagnosis and Long-Term Follow-Up of Primary Heart Tumors in Children.

BACKGROUND: Primary heart tumors (PHTs) in the pediatric population are very rare and do not manifest any characteristic symptoms. METHODS: A retrospective analysis of 61 cases was undertaken. Data from three centers for the years 2003-2018 were gathered. The tumors' clinical course, location, number, hemodynamic, treatment, and follow-up were evaluated. Echocardiography was complemented with magnetic resonance imaging, computer tomography, and histopathological examination. RESULTS: Out of 61 PHT diagnoses, 56 (91.8%) were circumstantial including all 16 (26.2%) prenatal tumors. The reasons for cardiological consultations were arrhythmia, syncopes, lowered physical performance, and murmurs. Only five patients (8.2%) were suspected of tumors based on previous symptoms of sclerosis tuberosa. Rhabdomyoma was the most frequently found PHT (60.7%). The tumors were predominantly located in the ventricles (49.1%) and intraventricular septum (14.9%) and tended to be single (70.5%). About 37.7% of patients suffered from coexistent multi-organ problems, two (3.28%) from congenital heart defects and one (1.64%) from Carney's syndrome. Tumor resection was performed on 26 (42.7%) patients, of which 16 (61.5%) underwent total and 10 (38.5%) partial tumor resection. During the follow-up (mean 4.3 years), 54 patients (88.5%) have improved or were stable, while seven (11.5%) died. CONCLUSIONS: Primary pediatric heart tumors are diagnosed completely circumstantially, and the most common is rhabdomyoma, although arrhythmia may suggest fibroma. Diagnosis of a heart tumor in children is not synonymous with fatal prognosis, and most of them require only constant observation. Life-saving operation allows improvement, while the prognosis for malignant tumors in children is definitely unfavorable.

The Differences in the Diagnostic Profile in Children with Vasovagal Syncope between the Result of Head-Up Tilt Table Test.

(1) Background: The features characterizing vasovagal syncope (VVS) are an important factor in the correct evaluation of diagnostic risk stratification in children and adolescents. The aim of the study was to determine the value of identifying the clinical characteristics in children with VVS. (2) Methods: We made a retrospective analysis of the medical records of 109 children with diagnosed VVS. We investigated the specific characteristics of syncope in children with VVS including the positive VVS (+) and negative VVS (-) result of the Head-Up Tilt Table Test (HUTT). (3) Results: We did not observe significant differences in the prodromal symptoms of VVS with HUTT response. In addition to typical prodromal symptoms, no difference in statistically reported palpitations (35/109 or 32.1%) and chest discomfort (27/109 or 27.7%) were recorded. Fear-pain-stress emotions as circumstances of syncope were more often reported by children with a negative HUTT (p = 0.02). Cramps-contractures (p = 0.016) and speech disorders (p = 0.038) were significantly higher in the group with negative HUTT. (4) Conclusions: There is a close relationship in the diagnostic profile between the negative and positive results of head-up tilt table test in children with vasovagal syncope.

The Repolarization Period during the Head-Up Tilt Test in Children with Vasovagal Syncope.

BACKGROUND: Electrocardiography (ECG) and the head-up tilt test (HUTT) are vital in clinical work-up in children with vasovagal syncope (VVS). Ventricular repolarization parameters (QT) measured during the HUTT can be indicative of electrical instability; however, these parameters are not frequently assessed. This study aimed to investigate if ventricular repolarization parameters measured during the HUTT could be indicative of future ventricular arrhythmias in children with syncope. METHODS: The shape and amplitude of the T-wave and parameters of the repolarization period (QT, QTpeak, Tpeak-Tend) were evaluated in a resting ECG performed on the first day of hospitalization and in ECGs performed during three phases of the HUTT. RESULTS: In the after-tilt phase of the HUTT, 19/30 children displayed a change in T-wave morphology. QTc was significantly longer in VVS I compared to that in VVS II patients, but not in the controls (p = 0.092). CONCLUSIONS: We need further follow-up studies to establish the clinical importance of abnormal dynamics of the repolarization period in children with VVS and negative HUTT. Therefore, children with abnormal T-wave refraction and prolonged duration of the TpTe should remain under the care of a cardiological outpatient.

Feasibility and performance of catheter ablation with zero-fluoroscopy approach for regular supraventricular tachycardia in patients with structural and/or congenital heart disease.

Patients with structural heart disease (SHD) are more difficult to ablate than those with a structurally healthy heart. The reason may be technical problems. We compared periprocedural data in unselected patients (including SHD group) recruited for zero-fluoroscopy catheter ablation (ZF-CA) of supraventricular arrhythmias (SVTs).Consecutive adult patients with atrioventricular nodal reentry tachycardia (AVNRT), accessory pathways (AP), atrial flutter (AFL), and atrial tachycardia (AT) were recruited. A 3-dimensional electroanatomical mapping system (Ensite Velocity, NavX, St Jude Medical, Lake Bluff, Illinois) was used to create electroanatomical maps and navigate catheters. Fluoroscopy was used on the decision of the first operator after 5 minutes of unresolved problems.Of the 1280 patients ablated with the intention to be treated with ZF approach, 174 (13.6%) patients with SHD (age: 58.2 ±â€Š13.6; AVNRT: 23.9%; AP: 8.5%; AFL: 61.4%; and AT: 6.2%) were recruited. These patients were compared with the 1106 patients with nonstructural heart disease (NSHD) (age: 51.4 ±â€Š16.4; AVNRT: 58.0%; AP: 17.6%; AFL: 20.7%; and AT: 3.7% P ≤ .001). Procedural time (49.9 ±â€Š24.6 vs 49.1 ±â€Š23.9 minutes, P = .55) and number of applications were similar between groups (P = 0.08). The rate of conversion from ZF-CA to fluoroscopy was slightly higher in SHD as compared to NSHD (13.2% vs 7.8%, P = .02) while the total time of fluoroscopy and radiation doses were comparable in the group of SHD and NSHD (P = .55; P = .48).ZF-CA is feasible and safe in majority of patients with SHD and should be incorporated into a standard approach for SHD; however, the procedure requires sufficient experience.

Electrocardiographic T-wave parameters in families with long QT syndrome.

BACKGROUND: T-wave parameters, especially the Tpeak-Tend interval (TpTe), reflect the total dispersion of repolarization, whose amplification may lead to the development of life-threatening ventricular arrhythmias observed in the long QT syndrome (LQTS). OBJECTIVES: The study attempted to evaluate QT, QTp (Q-Tpeak) and TpTe (Tpeak-Tend) intervals in unaffected and affected blood relatives of children with clinically confirmed LQTS as well as to determine whether the values of these repolarization parameters may be used in clinical practice. MATERIAL AND METHODS: The study group included 47 affected blood relatives (27 LQTS1 and 20 LQTS2) and 68 unaffected family members without clinically confirmed LQTS symptoms. The TpTe, QT and QTp intervals were measured manually in the lead V5 of standard ECGs and corrected using Bazett's and Fridericia's formulas. RESULTS: The RR, QT, QTp and TpTe intervals with their corrected values were significantly longer (p < 0.0001) in the affected subjects than in the unaffected subjects and, similarly, in LQTS1 and LQTS2 patients compared with the unaffected family members. The TpTe interval in LQTS2 showed only a tendency to be longer compared to LQTS1, but did not reach statistical significance (p = 0.0933). For affected blood relatives, only the TpTe interval (p < 0.0409) and QT interval, corrected with Bazett's (p < 0.0393) and Fridericia's (p < 0.0495) formulas, enabled differentiation between LQTS1 (mean TpTe = 103 ±15) and LQTS2 women (mean TpTe = 106 ±17). Moreover, there were statistically significant differences (p < 0.05) in the TpTe interval between the 6 sex subgroups: unaffected women and men as well as women and men with LQTS1 and LQTS2. CONCLUSIONS: The electrocardiographic Tpeak-Tend parameter, in addition to the QT interval, is helpful in identifying affected blood relatives of children with LQTS, particularly for the group of LQTS1 and LQTS2 women. Further studies are required to assess the clinical importance of the TpTe interval in families with long QT syndrome.

A simplified approach for evaluating sustained slow pathway conduction for diagnosis and treatment of atrioventricular nodal reentry tachycardia in children and adults.

PURPOSE: During incremental atrial pacing in patients with atrioventricular nodal reentrant tachycardia, the PR interval often exceeds the RR interval (PR > RR) during stable 1:1 AV conduction. However, the PR/RR ratio has never been evaluated in a large group of patients with pacing from the proximal coronary sinus and after isoproterenol challenge. Our study validates new site of pacing and easier method of identification of PR > RR. MATERIAL AND METHODS: A prospective protocol of incremental atrial pacing from the proximal coronary sinus was carried out in 398 patients (AVNRT-228 and control-170). The maximum stimulus to the Q wave interval (S-Q = PR), SS interval (S-S), and Q-Q (RR) interval were measured at baseline and 10 min after successful slow pathway ablation and after isoproterenol challenge (obligatory). RESULTS: The mean maximum PR/RR ratios at baseline were 1.17 ±â€¯0.24 and 0.82 ±â€¯0.13 (p < 0.00001) in the AVNRT and controls respectively. There were no PR/RR ratios ≥1 at baseline and after isoproterenol challenge in 12.3% of the AVNRT group and in 95.9% of the control group (p < 0.0001). PR/RR ratios ≥1 were absent in 98% of AVNRT cases after slow pathway ablation/modification in children and 99% of such cases in adults (P = NS). The diagnostic performance of PR/RR ratio evaluation before and after isoproterenol challenge had the highest diagnostic performance for AVNRT with PR/RR > = 1 (sensitivity: 88%, specificity: 96%, PPV-97%, NPV-85%). CONCLUSIONS: The PR/RR ratio is a simple tool for slow pathway substrate and AVNRT evaluation. Eliminating PR/RR ratios ≥1 may serve as a surrogate endpoint for slow pathway ablation in children and adults with AVNRT.

Early results of aortic arch reconstruction and bilateral pulmonary artery banding: modification of the Norwood operation for treatment of hypoplastic left heart syndrome.

BACKGROUND: In the period from 2003 to the end of 2015, 96 Norwood I procedures were performed in the Paediatric Heart Surgery Department in Katowice, Poland, in children with hypoplastic left heart syndrome (HLHS). AIM: This paper presents a retrospective analysis of early surgical results. METHODS: The patients consisted of two groups: group I included 59 children operated on in the years 2003-2012, in whom the stage I Norwood procedure with the Sano modification was performed with the aortic arch reconstructed by use of a ho-mogenous pulmonary artery patch or a bovine pericardial patch. Group II included 37 children after our modification of the Norwood I procedure, in which the aortic arch was reconstructed with an extracellular matrix patch and bilateral pulmonary artery banding was done. RESULTS: Aortic cross-clamping time was significantly shorter in group II (mean 52; range 38-62 min) than in group I (mean 57; range 39-72 min; p < 0.009). Eighteen (30.5%) children in group I and six (16.2%) in group II died. Although this dif-ference did not reach statistical significance (p = 0.12), it suggested that improved outcomes with the modified procedure are possible. The cause of death in group I was significantly more frequently due to massive postoperative bleeding (n = 6; 33.3%) than in group II (n = 1; 16.7%; p = 0.046). CONCLUSIONS: The introduction of this new surgical technique reduced postoperative bleeding rates, shortened the operation time, and might improve the mortality rate in the first-stage surgical treatment of children with HLHS.

Usefulness of cutting balloon angioplasty for the treatment of congenital heart defects.

BACKGROUND: Patients with complex congenital heart defects may have different hemodynamic prob-lems which require a variety of interventional procedures including angioplasty which involves using high-pressure balloons. After failure of conventional balloon angioplasty, cutting balloon angioplasty is the next treatment option available. The purpose of this study was to evaluate the safety and efficacy of cutting balloon angioplasty in children with different types of congenital heart defects. METHODS: Cutting balloon angioplasty was performed in 28 children with different congenital heart defects. The indication for cutting balloon angioplasty was: pulmonary artery stenosis in 17 patients, creating or dilatation of interatrial communication in 10 patients, and stenosis of left subclavian artery in 1 patient. RESULTS: In the pulmonary arteries group there was a significant decrease in systolic blood pressure (SBP) in the proximal part of the artery from the average 74.33 ± 20.4 mm Hg to 55 ± 16.7 mm Hg (p < 0.001). Distal to the stenosis there was an increase in SBP from 19.8 ± 3.82 mm Hg to 30.3 ± ± 13.3 mm Hg (p = 0.04). This result remained constant in the follow-up. In atrial septal defect/fenestra-tion group, cutting balloon angioplasty was performed after an unsuccessful classic Rashkind procedure. After cutting balloon angioplasty there was a significant widening of the interatrial communication. CONCLUSIONS: Cutting balloon angioplasty is a feasible and effective treatment option in different con-genital heart defects.

Electrocardiographic algorithms to guide the management strategy of idiopathic outflow tract ventricular arrhythmias.

INTRODUCTION    The current guidelines of the European Society of Cardiology outlined electrocardiographic (ECG) differentiation of the site of origin (SoO) in patients with idiopathic ventricular arrhythmias (IVAs). OBJECTIVES    The aim of this study was to compare 3 ECG algorithms for differentiating the SoO and to determine their diagnostic value for the management of outflow tract IVA. PATIENTS AND METHODS    We analyzed 202 patients (mean age [SD]: 45 [16.7] years; 133 women [66%]) with IVAs with the inferior axis (130 premature ventricular contractions or ventricular tachycardias from the right ventricular outflow tract [RVOT]; 72, from the left ventricular outflow tract [LVOT]), who underwent successful radiofrequency catheter ablation (RFCA) using the 3­dimensional electroanatomical system. The ECGs before ablation were analyzed using custom­developed software. Automated measurements were performed for the 3 algorithms: 1) novel transitional zone (TZ) index, 2) V2S/V3R, and 3) V2 transition ratio. The results were compared with the SoO of acutely successful RFCA. RESULTS    The V2S/V3R algorithm predicted the left­sided SoO with a sensitivity and specificity close to 90%. The TZ index showed higher sensitivity (93%) with lower specificity (85%). In the subgroup with the transition zone in lead V3 (n = 44, 15 from the LVOT) the sensitivity and specificity of the V2-transition­ratio algorithm were 100% and 45%, respectively. The combined TZ index+V2S/V3R algorithm (LVOT was considered only when both algorithms suggested the LVOT SoO) can increase the specificity of the LVOT SoO prediction to 98% with a sensitivity of 88%. CONCLUSIONS    The combined TZ­index and V2S/V3R algorithm allowed an accurate and simple identification of the SoO of IVA. A prospective study is needed to determine the strategy for skipping the RVOT mapping in patients with LVOT arrhythmias indicated by the 2 combined algorithms.

Preoperative single ventricle function determines early outcome after second-stage palliation of single ventricle heart.

BACKGROUND: Second-stage palliation with hemi-Fontan or bidirectional Glenn procedures has improved the outcomes of patients treated for single-ventricle heart disease. The aim of this study was to retrospectively analyze risk factors for death after second-stage palliation of single-ventricle heart and to compare therapeutic results achieved with the hemi-Fontan and bidirectional Glenn procedures. MATERIAL AND METHODS: We analyzed 60 patients who had undergone second-stage palliation for single-ventricle heart. Group HF consisted of 23 (38.3%) children who had been operated with the hemi-Fontan method; Group BDG consisted of 37 (61.7%) who had been operated with the bidirectional Glenn method. The analysis focused on 30-day postoperative mortality rates, clinical and echocardiographic data, and early complications. RESULTS: The patients' ages at the time of repair was 33 ± 11.2 weeks; weight was 6.7 ± 1.2 kg. The most common anatomic subtype was hypoplastic left heart syndrome, in 36 (60%) patients. The early mortality rate was 13.3%. Significant preoperative atrioventricular valve regurgitation, single-ventricle heart dysfunction, pneumonia/sepsis, and arrhythmias were associated with higher mortality rates after second-stage palliation. Multivariate analysis identified significant preoperative single-ventricle heart dysfunction as an independent predictor of early death after second-stage palliation. No differences were found in the analyzed variables after bidirectional Glenn compared with hemi-Fontan procedures. CONCLUSION: Significant preoperative atrioventricular valve regurgitation, arrhythmias and pneumonia/sepsis are closely correlated with mortality in patients with single-ventricle heart after second-stage palliation. Preoperative significant single-ventricle heart dysfunction is an independent mortality predictor in this group of patients. There are no differences in clinical, echocardiographic data, or outcomes in patients treated with the hemi-Fontan compared with bidirectional Glenn procedures.