Maria Pia Calabrò

Atrial Electroanatomic Remodeling After Circumferential Radiofrequency Pulmonary Vein Ablation Efficacy of an Anatomic Approach in a Large Cohort of Patients With Atrial Fibrillation

Background—Circumferential radiofrequency ablation around pulmonary vein (PV) ostia has recently been described as a new anatomic approach for atrial fibrillation (AF). Methods and Results—We treated 251 consecutive patients with paroxysmal (n=179) or permanent (n=72) AF. Circular PV lesions were deployed transseptally during sinus rhythm (n=124) or AF (n=127) using 3D electroanatomic guidance. Procedures lasted 148±26 minutes. Among 980 lesions surrounding individual PVs (n=956) or 2 ipsilateral veins with close openings or common ostium (n=24), 75% were defined as complete by a bipolar electrogram amplitude <0.1 mV inside the lesion and a delay >30 ms across the line. The amount of low-voltage encircled area was 3594±449 mm2, which accounted for 23±9% of the total left atrial (LA) map surface. Major complications (cardiac tamponade) occurred in 2 patients (0.8%). No PV stenoses were detected by transesophageal echocardiography. After 10.4±4.5 months, 152 patients with paroxysmal AF (85%) and 49 with permanent AF (68%) were AF-free. Patients with and without AF recurrence did not differ in age, AF duration, prevalence of heart disease, or ejection fraction, but the LA diameter was significantly higher (P <0.001) in permanent AF patients with recurrence. The proportion of PVs with complete lesions was similar between patients with and without recurrence, but the latter had larger low-voltage encircled areas after radiofrequency (expressed as percent of LA surface area;P <0.001). Conclusions—Circumferential PV ablation is a safe and effective treatment for AF. Its success is likely due to both PV trigger isolation and electroanatomic remodeling of the area encompassing the PV ostia.

Catheter Ablation of Paroxysmal Atrial Fibrillation Using a 3D Mapping System

BACKGROUND We treated paroxysmal recurrent atrial fibrillation (AF) with radiofrequency (RF) catheter ablation by creating long linear lesions in the atria. To achieve line continuity, a 3D electroanatomic nonfluoroscopic mapping system was used. METHODS AND RESULTS In 27 patients with recurrent AF, a catheter incorporating a passive magnetic field sensor was navigated in both atria to construct a 3D activation map. RF energy was delivered to create continuous linear lesions: 3 lines (intercaval, isthmic, and anteroseptal) in the right atrium and a long line encircling the pulmonary veins in the left atrium. After RF application, the atria were remapped to validate completeness of the block lines, demonstrated by late activation of the areas circumscribed by the lines. The mean procedure duration was 312+/-103 minutes (range, 187 to 495), with mean fluoroscopy time of 107+/-44 minutes (range, 32 to 185 minutes). No acute complications occurred, but 1 patient experienced early prolonged sinus pauses and received a pacemaker. During the first day, 17 patients (63%) had AF episodes, but at discharge, 25 patients were in sinus rhythm. After a follow-up of 6. 0 to 15.3 months (average, 10.5+/-3.0 months), 16 patients are asymptomatic, 3 have an almost complete disappearance of symptoms, 1 patient is improved, and 7 patients have their AF attacks unchanged. CONCLUSIONS Paroxysmal recurrent drug-refractory AF can be treated by RF catheter ablation. Creation of long continuous linear lesions necessary to compartmentalize the atria is facilitated by a nonfluoroscopic electroanatomic mapping system.

Myocardial ischaemia in neonates with perinatal asphyxia electrocardiographic, echocardiographic and enzymatic correlations

Abstract In asphyxiated neonates, hypoxia is often responsible for myocardial ischaemia. To evaluate cardiac involvement in neonates with respiratory distress, ECG and echocardiographic recordings were performed, and cardiac enzymes determined. These data were related to clinical presentation and patient outcome. Three groups of neonates were studied: 22 healthy newborn infants (group I) with 5 min Apgar scores >9 and pH >7.3; 15 neonates with moderate respiratory distress (group II) which had Apgar scores ranging between 7 and 9, and pH between 7.2 and 7.3; and 13 neonates with severe asphyxia, Apgar scores <7, and pH <7.2 (group III). The ECGs were evaluated according to the 4-grade classification proposed by Jedeikin et al. [8]. On the echocardiograms, fractional shortening and aortic flow curve parameters were taken into account. Serum creatine kinase (CK), creatine kinase-MB isoenzyme (CK-MB) and lactate dehydrogenase were determined. All of groups I and II survived, but 5 out of 13 in group III died within the 1st week. Grade 3 or 4 ECG changes were observed only in group III patients, while all group II and 3 patients of group I showed grade 2 ECG changes. Fractional shortening, peak aortic velocity and mean acceleration were significantly reduced in group III, whereas the only abnormality found in group II was a reduced fractional shortening. CK, CK-MB, CK-MB/CK ratio and lactate dehydrogenase were all increased in group III, while in group II only CK-MB and the CK-MB/CK ratio were abnormal. Conclusion Severely asphyxiated newborn infants reflect relevant ischaemic electro- cardiographic changes, depressed left ventricular function and marked cardiac enzyme increase. These alterations are far less pronounced in neonates with mild respiratory distress.

High-mobility group box 1 (HMGB1) in childhood: from bench to bedside

High-mobility group box protein 1 (HMGB1) is a nonhistone nuclear protein that has a dual function. Inside the cell, HMGB1 binds DNA, regulating transcription and determining chromosomal architecture. Outside the cell, HMGB1 activates the innate system and mediates a wide range of physiological and pathological responses. HMGB1 exerts these actions through differential engagement of multiple surface receptors, including Toll-like receptor (TLR)2, TLR4, and receptor for advanced glycation end products (RAGE). HMGB1 is implicated as a late mediator of sepsis and is also involved in inflammatory and autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Interestingly, HMGB1 was associated with tumor progression, becoming a potential therapeutic target, due to its involvement in the resistance to chemotherapy. Its implication on the pathogenesis of systemic vasculitis and inflammatory bowel diseases has also been evaluated. Moreover, it regulates neuroinflammation after traumatic brain injuries or cerebral infectious diseases. The aim of this review is to analyze these different roles of HMGB1, both in physiological and pathological conditions, discussing clinical and scientific implications in the field of pediatrics. Conclusion: HMGB1 plays a key role in several pediatric diseases, opening new scenarios for diagnostic biomarkers and therapeutic strategies development.

ECG parameters in children and adolescents treated with aripiprazole and risperidone.

Atypical antipsychotics (AP) are increasingly being used in children and adolescents for the treatment of psychiatric disorders. Atypical AP may cause QT prolongation on the electrocardiogram (ECG), which predisposes patients to an increased risk of developing threatening ventricular arrhythmias. Although this phenomenon has been exhaustively reported in adults, few studies investigated the safety of these drugs in pediatric patients. We performed an open-label, prospective study to assess the arrhythmic risk of aripiprazole and risperidone in a pediatric population. A total of 60 patients (55 M/5F, mean age 10.2+2.6 years, range 4-15 years), receiving a new prescription of aripiprazole or risperidone in monotherapy underwent a standard ECG before and after two months from the beginning of antipsychotic treatment. Basal and post-treatment ECG parameters, including mean QT (QTc) and QT dispersion (QTd), were compared within treatment groups. Twenty-nine patients were treated with aripiprazole (mean dosage 7.4+3.1mg/day) and 31 with risperidone (mean dosage 1.5+1mg/day). In our series, no patient exhibited pathological values of QTc or QTd before and after treatment for both drugs. However, treatment with risperidone was associated with a slight increase of both mean QTc and QTd values (407.4+11.9 ms vs 411.2+13.0 ms, p<0.05; and 40.0+4.4 ms vs 44.7+5.5 ms, p<0.001, respectively). Treatment with aripiprazole was associated with no changes of mean QTc, even if a small increase of QTd, (40.6+6.5 ms vs 46.3+7.2 ms, p<0.01) was observed. Although our data suggest a slight effect of aripiprazole and risperidone on ventricular repolarization, it is unlikely that such a change results in clinically relevant effects. The treatment with risperidone and aripiprazole in children with psychiatric disorders is not associated with clinically relevant modifications of QT interval. Caution in prescribing these drugs, however, is necessary in patients with family history of a genetic predisposition to arrhythmias in order to warrant a reliable assessment of drug-induced QT prolongation.

Supraventricular Tachycardia in Infants: Epidemiology and Clinical Management

Supraventricular tachycardias (SVTs) are observed in 0,1-0,4% of the paediatric population and represent an important clinical problem with related significant health and social issues. Most tachycardias are paroxysmal, being associated with sudden onset and termination, and only a relatively small number of them is permanent, namely chronic. Paroxysmal tachycardias, in addition, can be either sustained (lasting > 30 seconds) or non-sustained whenever their duration is less. Most SVTs are due to re-entry, and only atrial tachycardia and and junctional ectopic tachycardia are caused by enhanced automaticity. Atrial tachycardia, however, can also be due, although rarely, to re-entry or to triggered activity. A prompt recognition of these arrthmias in children by pediatric cardiologist is essential for a correct clinical managemet of the patients. In this review, the epidemiologic data regarding the SVTs in pediatric age are reported along with the description of the pathophysiological mechanisms and the analysis of electrocardiographic findings to be considered for a correct clinical diagnosis and a rational therapeutic approach to these arrhythmias.

Spontaneous termination of ventricular fibrillation

A 65 year old woman with hypertension and permanent atrial fibrillation had suffered two brief syncopal episodes. She was on losartan, digoxin, and aspirin. The ECG showed atrial fibrillation and incomplete left bundle branch block; the QT interval was 0.36 s and the QTc 0.414 s. The echocardiogram revealed mild dilatation and dysfunction of …

Isolated Left Ventricular Noncompaction

(ECHOCARDIOGRAPHY, Volume 21, July 2004)

Evaluation of acute cardiovascular effects of immediate-release methylphenidate in children and adolescents with attention-deficit hyperactivity disorder.

Attention-deficit hyperactivity disorder is a frequent condition in children and often extends into adulthood. Use of immediate-release methylphenidate (MPH) has raised concerns about potential cardiovascular adverse effects within a few hours after administration. This study was carried out to investigate acute effects of MPH on electrocardiogram (ECG) in a pediatric population. A total of 54 consecutive patients with attention-deficit hyperactivity disorder (51 males and 3 females; mean age =12.14±2.6 years, range 6–19 years), receiving a new prescription of MPH, underwent a standard ECG 2 hours before and after the administration of MPH 10 mg per os. Basal and posttreatment ECG parameters, including mean QT (QT interval when corrected for heart rate [QTc]), QTc dispersion (QTd) interval duration, T-peak to T-end (TpTe) intervals, and TpTe/QT ratio were compared. Significant modifications of both QTc and QTd values were not found after drug administration. QTd fluctuated slightly from 25.7±9.3 milliseconds to 25.1±8.4 milliseconds; QTc varied from 407.6±12.4 milliseconds to 409.8±12.7 milliseconds. A significant variation in blood pressure (systolic blood pressure 105.4±10.3 vs 109.6±11.5; P<0.05; diastolic blood pressure 59.2±7.1 vs 63.1±7.9; P<0.05) was observed, but all the data were within normal range. Heart rate moved from 80.5±15.5 bpm to 87.7±18.8 bpm. No change in TpTe values was found, but a statistically significant increase in TpTe/QTc intervals was found with respect to basal values (0.207±0.02 milliseconds vs 0.214±0.02 milliseconds; P<0.01). The findings of this study show no significant changes in ECG parameters. TpTe values can be an additional parameter to evaluate borderline cases.

Oxidative stress and persistent pulmonary hypertension of the newborn treated with inhaled nitric oxide and different oxygen concentrations

Objectives: The aim of this study was to determine the effects of inhaled NO with different oxygen concentrations on the inflammatory cascade in newborns with hypoxic respiratory failure secondary to persistent pulmonary hypertension. Methods: 60 newborns received iNO and 30 of them received an initial oxygen concentration of 45% (group 1), while the other 30 newborns received an initial oxygen concentration of 80% (group 2). The levels of inflammatory cytokines (IL-6, IL-8, TNF-α) were measured. The clinical outcome was also recorded. Results: The findings show that interleukin concentrations (IL-6, IL-8, TNF-α) were significantly decreased between 0 and 72 hours (p < 0.01) in the newborns exposed to initial oxygen concentration of 45% and significantly increased in the other group. Conclusions: When inhaled, NO was co-administered with concentration of O2 <45%, anti-inflammatory responses occurred, in accord with evidence in the published literature. The benefits of iNO on the clinical outcome in the current study demonstrate that inhaled NO in both groups was associated with improved short-term oxygenation.