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.

Arrhythmic manifestation in ß-thalassemia cardiomyopathy: a complex management.

A young male with ß-thalassemia major was implanted with a single-chamber Implantable cardioverter-defibrillator (ICD) for a cardiac arrest due to ventricular fibrillation. He received multiple inappropriate shocks due to atrioventricular nodal re-entrant tachycardia (AVNRT) treated with radiofrequency catheter ablation and then to high-rate atrial tachycardia refractory to amiodarone and not inducible during electrophysiological study. He refused empirical pulmonary vein isolation. Upgrading to biventricular ICD and performing atrioventricular node ablation avoided further inappropriate shocks.

Incidence of Ventricular Arrhythmias and 1-Year Predictors of Mortality in Patients Treated With Implantable Cardioverter-Defibrillator Undergoing Generator Replacement.

Background When implantable cardioverter defibrillator (ICD) battery is depleted most patients undergo generator replacement (GR) even in the absence of persistent ICD indication. The aim of this study was to assess the incidence of ventricular arrhythmias and the overall prognosis of patients with and without persistent ICD indication undergoing GR. Predictors of 1-year mortality were also analyzed. Methods and Results Patients with structural heart disease implanted with primary prevention ICD undergoing GR were included. Patients were stratified based on the presence/absence of persistent ICD indication (left ventricular ejection fraction ≤35% at the time of GR and/or history of appropriate ICD therapies during the first generator's life). The study included 371 patients (82% male, 40% with ischemic heart disease). One third of patients (n=121) no longer met ICD indication at the time of GR. During a median follow-up of 34 months after GR patients without persistent ICD indication showed a significantly lower incidence of appropriate ICD shocks (1.9% versus 16.2%, P<0.001) and ICD therapies. 1-year mortality was also significantly lower in patients without persistent ICD indication (1% versus 8.3%, P=0.009). At multivariable analysis permanent atrial fibrillation, chronic advanced renal impairment, age >80, and persistent ICD indication were found to be significant predictors of 1-year mortality. Conclusions Patients without persistent ICD indication at the time of GR show a low incidence of appropriate ICD therapies after GR. Persistent ICD indication, atrial fibrillation, advanced chronic renal disease, and age >80 are significant predictors of 1-year mortality. Our findings enlighten the need of performing a comprehensive clinical reevaluation of ICD patients at the time of GR.

The atherosclerosis of the sinus node artery is associated with an increased history of supra-ventricular arrhythmias: a retrospective study on 541 standard coronary angiograms.

Background. The ischemic damage of the sinus node (SN) is a well known cause of cardiac arrhythmias and can be a consequence of any flow abnormality in the sinus node artery (SNA). Accordingly we aimed this retrospective study to: (1) evaluate the suitability of the standard coronary angiography to study the SNA and (2) determine if the percentage of subjects with a positive retrospective history of supra-ventricular arrhythmias (SVA) differs in patients with normal and diseased SNA ascertained at the time of coronary angiography. Methods and Results. Out of the 541 coronary angiograms reviewed the SNA was visible for its entire course in 486 cases (89.8%). It was found to arise from the right side of the coronary circulation in 266 cases (54.7%) slightly more often than from the left, 219 cases (45.1%). One patient had 2 distinct SNA arising from either side of the coronary circulation. For the second objective, we studied the 333 patients with: (a) coronary artery disease (CAD), (b) properly evaluable SNA and (c) complete clinical history available. In 51 (15.3%) a SNA disease was found, 41.2% of them had a positive SVA history, mainly atrial fibrillation (AF), whereas only 7.4% of patients with a positive history of SVA could be found in the non-SNA diseased. This difference was statistically significant (P < 0.001). Conclusions. (1) The evaluation of the SNA is feasible in clinical practice during a standard coronary angiography; (2) this may be relevant since angiographically detectable SNA disease was significantly associated with a positive history of SVA.