Ablation of CTI-dependent flutter using different ablation technologies: acute and long-term outcome from the LEONARDO study.

BACKGROUND: A novel ablation catheter has been released to map and ablate the cavo-tricuspid isthmus (CTI) in patients with atrial flutter (AFL), improving ablation efficiency. METHODS: We evaluated the acute and long-term outcome of CTI ablation aiming at bidirectional conduction block (BDB) in a prospective, multicenter cohort study enrolling 500 patients indicated for typical AFL ablation. Patients were grouped on the basis of the AFL ablation method (linear anatomical approach, Conv group n = 425, or maximum voltage guided, MVG group, n = 75) and ablation catheter (mini-electrodes technology, MiFi group, n = 254, or a standard 8-mm ablation catheter, BLZ group, n = 246). RESULTS: Complete BDB according to both validation criteria (sequential detailed activation mapping or mapping only the ablation site) was achieved in 443 patients (88.6%). The number of RF applications needed to achieve BDB was lower in the MiFi MVG group vs both the MiFi Conv group and the BLZ Conv group (3.2 ± 2 vs 5.2 ± 4 vs 9.3 ± 5, p < 0.0001 for all comparisons). Fluoroscopy time was similar among groups, whereas we observed a reduction in the procedure duration from the BLZ Conv group (61.9 ± 26min) to the MiFi MVG group (50.6 ± 17min, p = 0.048). During a mean follow-up of 548 ± 304 days, 32 (6.2%) patients suffered an AFL recurrence. No differences were found according to BDB achieved by both validation criteria. CONCLUSIONS: Ablation was highly effective in achieving acute CTI BDB and long-term arrhythmia freedom irrespective of the ablation strategy or the validation criteria for CTI chosen by the operator. The use of an ablation catheter equipped with mini-electrodes technology seems to improve ablation efficiency. CLINICAL TRIAL REGISTRATION: Atrial Flutter Ablation in a Real World Population. (LEONARDO). CLINICALTRIALS: gov Identifier: NCT02591875.

A reliable fossa ovalis impedance mapping for safer transseptal puncture: A new vision beyond voltage.

INTRODUCTION: Transseptal puncture (TSP) is widely used in clinical practice but is negatively affected by a nonneglectable rate of complications and X-ray exposure. To address these problems, we investigated whether or not impedance mapping could correctly identify fossa ovalis (FO) and safely guide TSP. METHODS AND RESULTS: Electroanatomic mapping was performed with CARTO 3 system version 7 and a ThermoCool® SmartTouch® mapping catheter was employed. In each patient, an impedance map and a bipolar voltage map of the whole interatrial septum were collected, acquiring at least 150 points with a contact force ≥2 g and using the pattern matching filter. Thirty-five patients were enrolled. A low impedance area was clearly identified in 34 of them. In 30 patients (88%), the FO was located in the low impedance area. The map was obtained in sinus rhythm in 17 cases (50%); in 15 of these (88%), the TSP site, the patent foramen ovale, or the FO tenting area fell inside the low impedance area. The same numbers were observed when mapping during atrial fibrillation. CONCLUSION: To the best of our knowledge, this is the first study that provides the reliability and reproducibility of impedance mapping in identifying FO, an affordable and feasible tool that could be potentially introduced into clinical practice.

Ajmaline Challenge To Unmask Infrahisian Disease In Patients With Recurrent And Unexplained Syncope, Preserved Ejection Fraction, With Or Without Conduction Abnormalities On Surface ECG.

Background: Pharmacological challenge with class I antiarrhythmic drug is a recommended diagnostic test in patients with unexplained syncope only in the presence of bundle branch block, when non-invasive tests have failed to make the diagnosis. Its role in patients with minor or no conduction disturbances on 12-leads ECG has not been evaluated yet. It is also not clear which are the values of His-Ventricular interval to be considered diagnostic. We sought to evaluate the role of ajmaline challenge in unmasking the presence of an infrahisian disease in patients with recurrent and unexplained syncope, regardless of the existence of conduction disturbances on surface ECG. Materials And Methods: Patients with history of recurrent syncope, preserved EF and a negative first level workup were enrolled. Conduction disturbances on ECG were not considered as an exclusion criteria. During EPS, basal HV conduction was determined. In the presence of a HV >70 msec the study was interrupted and the patient was implanted with a pacemaker. If the HV was ≤ 70 msec, ajmaline was infused and HV was reassessed. The maximum value of HV was considered. A prolongation ≥ 100 msec was considered as diagnostic and indicative of conduction disease, and the patient underwent pacemaker implantation. Patients with an HV <100 msec were implanted with an ILR. Results: Sixteen consecutive patients were studied (age 76±5.2 years). Nine patients had conduction disturbances at baseline ECG (group ECG+). Among them, 5 had a basal diagnostic HV interval and 4 had a non-diagnostic HV interval. In the latter group, abnormal response to ajmaline was observed in 3 patients. In this group only one patient was implanted with an ILR, 8 patients were implanted with a pacemaker. Among the seven patients without conduction disturbances (group ECG-), no one had a diagnostic basal HV interval. After drug administration, 4 patients had a non-diagnostic response and were implanted with an ILR, while 3 patient had a pathological response and were implanted with a pacemaker. No difference was found in the values of maximum HV interval prolongation after ajmaline between the two groups (P = 0.89). During a mean follow up of 13±3 months, no patient has developed a syncopal episode. One patient in group ECG- and negative drug test was implanted after 3 months with a permanent pacemaker because of a two to one asymptomatic AV block at ILR interrogation. Conclusions: Ajmaline challenge is a useful tool to unmask the presence of a infrahisian disease in patients with preserved EF, unexplained syncope and negative workup, even in the absence of conduction disturbances on 12-leads ECG. It is a simple and safe test that may disclose the detection of the disease. In these patients, an earlier pacemaker implantation of a pacemaker, may avoid the consequences of a syncopal recurrence. Values of HV interval > 70 msec in basal conditions and ≥ 100 msec after ajmaline administration seem appropriate to unmask infrahisian disease. Larger population is required to validate this hypothesis.

[Complete atrioventricular block as the first clinical manifestation of a tick bite (Lyme disease)]. / Blocco atrioventricolare completo come prima presentazione clinica di puntura di zecca (malattia di Lyme).

A 52-year-old male patient presented to the emergency department because of malaise and frequent dizziness. The ECG revealed high-grade atrioventricular block that required placement of a temporary pacemaker. There were no other abnormalities in physical and echocardiographic examination, and coronary angiography excluded the presence of coronary artery disease. IgM and IgG antibodies against Borrelia were positive, and antibiotic therapy with ceftriaxone at the dose of 2 g/die for 15 days resulted in rapid regression of atrioventricular block. Seven-day ECG recording immediately after discharge and 24h ECG monitoring at 40 days confirmed the total disappearance of atrioventricular block. This represents a case of atrioventricular block as the first manifestation of Borrelia infection (Lyme disease). A prompt diagnosis and antibiotic therapy usually result in complete resolution of atrioventricular block without the need for a permanent pacemaker.

C242T polymorphism in CYBA gene (p22phox) and risk of coronary artery disease in a population of Caucasian Italians.

BACKGROUND: specific polymorphisms of genes regulating intracellular redox balance and oxidative stress are related to atherogenesis. Some studies have identified a relationship between progression of atherosclerosis and C242T mutation in CYBA gene coding for p22phox, a subunit of the NADH/NADPH oxidase system. DESIGN: we investigated whether the C242T nucleotide transition is associated with the presence of coronary artery disease (CAD) in a population of 494 Caucasian Italians undergoing coronary angiography to diagnose the cause of chest pain. RESULTS: the frequency of the T mutant allele that we found in 276 patients with angiographically documented CAD was significantly higher compared to what we observed in 218 subjects with normal coronary arteries (Controls) (respectively: 0.400 and 0.332, p<0.01). The prevalence of the T allele was even stronger when we compared: 1) early onset (age < or =55) vs late onset (age > or =65) single-vessel CAD patients (respectively: 0.75 and 0.48, p<0.05), and 2) the subgroup of CAD patients with at least one > or =98% stenosis in a coronary vessel vs those with no > or =98% stenosis in a coronary vessel (respectively: 0.425 and 0.365, p<0.05). CONCLUSIONS: these results support the increased risk of developing early CAD and of having rapid progression of coronary stenosis in subjects carrying the C242T nucleotide transition among the Italian population.