High-power short-duration catheter ablation of atrial fibrillation: is it really a new era? Comparison between new and old radiofrequency contact force-sensing catheters.

BACKGROUND: The clinical performance of high-power, short-duration (HPSD) pulmonary vein isolation (PVI) with the novel flexible tip TactiFlex™ (TFSE) catheter, as compared to standard-power, long-duration (SPLD) PVI using the TactiCath™ (TCSE) catheter among patients undergoing catheter ablation (CA) of atrial fibrillation (AF) is currently unknown. METHODS: We conducted a prospective, observational, single-centre study including 40 consecutive patients undergoing PVI for paroxysmal/persistent AF, using HPSD ablation with the novel TFSE catheter (HPSD/TFSE group). Based on propensity score-matching, forty patients undergoing SPLD PVI with the TCSE catheter were identified (SPLD/TCSE group). In the HPSD/TFSE group, RF lesions were performed by delivering 40-50 W for 10-20 s, while in the SPLD/TCSE group, RF power was 30-35 W, targeting a lesion size index (LSI) of 4.0-5.5. The co-primary study outcomes were time required to complete PVI and first pass isolation (FPI). RESULTS: PVI was achieved in 100% of patients in both groups, and no major adverse events were observed. Remarkably, PVI time was shorter in the HPSD/TFSE, compared to the SPLD/TCSE group(9 [7-9] min vs. 50 [37-54] min; p < 0.001), while FPI rate was non-significantly higher in the former group(91% [146/160] vs 83% [134/160]; p = 0.063). Shorter procedural (108 [91-120] min vs. 173 [139-187] min, p < 0.001), total RF (9 [7-11] min vs. 43 [32-53] min, p < 0.001), fluoroscopy times(15 [10-19] min vs. 18 [13-26] min, p = 0.014), and lower DAP (1461 [860-2181] vs. 7200 [3400-20,800], p < 0.001) were recorded in the HPSD/TFSE group. A higher average impedance drop was obtained with HPSD/TFSE CA(17[17-18]Ω vs. 16 [15-17] Ω, p < 0.001). CONCLUSIONS: In our initial clinical experience, HPSD PVI with the TFSE catheter proved faster than SPLD PVI with the TCSE catheter, at least equally effective in terms of FPI, and it was associated with greater impedance drop.

Technological advances in ventricular tachycardia catheter ablation: the relentless quest for novel solutions to old problems.

BACKGROUND: Several novel technologies allowing catheter ablation (CA) with a favorable safety/efficacy profile have been recently developed, but not yet extensively clinically tested in the setting of ventricular tachycardia CA. METHODS: In this technical report, we overview technical aspects and preclinical/clinical information concerning the application of three novel CA technologies in the ventricular milieu: a pulsed field ablation (PFA) generator (CENTAURI™, Galaxy Medical) to be used with linear, contact force-sensing radiofrequency ablation catheters; a contact force-sensing radiofrequency ablation catheter equipped with six thermocouples and three microelectrodes (QDOT Micro™, Biosense-Webster), allowing high-resolution mapping and temperature-controlled CA; and a flexible and mesh-shaped irrigation tip, contact force-sensing radiofrequency ablation catheter (Tactiflex, Abbott). We also report three challenging VT cases in which CA was performed using these technologies. RESULTS: The CENTAURI system was used with the Tacticath™ (Abbott) ablation catheter to perform ventricular PFA in a patient with advanced heart failure, electrical storm, and a deep intramural septal substrate. Microelectrode mapping using QDOT Micro™ helped to refine substrate assessment in a VT patient with congenitally corrected transposition of the great arteries, and allowed the identification of the critical components of the VT circuit, which were successfully ablated. Tactiflex™ was used in two challenging CA cases (one endocardial and one epicardial), allowing acute and mid-term control of VT episodes without adverse events. CONCLUSION: The ideation and development of novel technologies initially intended to treat atrial arrhythmias and successfully implemented in the ventricular milieu is contributing to the progressive improvement in the clinical benefits derived from VT CA, making this procedure key for successful management of increasingly complex patients.

Microelectrode voltage mapping for substrate assessment in catheter ablation of ventricular tachycardia: A dual-center experience.

INTRODUCTION: The assessment of the ventricular myocardial substrate critically depends on the size of mapping electrodes, their orientation with respect to wavefront propagation, and interelectrode distance. We conducted a dual-center study to evaluate the impact of microelectrode mapping in patients undergoing catheter ablation (CA) of ventricular tachycardia (VT). METHODS: We included 21 consecutive patients (median age, 68 [12], 95% male) with structural heart disease undergoing CA for electrical storm (n = 14) or recurrent VT (n = 7) using the QDOT Micro catheter and a multipolar catheter (PentaRay, n = 9). The associations of peak-to-peak maximum standard bipolar (BVc ) and minibipolar (PentaRay, BVp ) with microbipolar (BVµMax ) voltages were respectively tested in sinus rhythm with mixed effect models. Furthermore, we compared the features of standard bipolar (BE) and microbipolar (µBE) electrograms in sinus rhythm at sites of termination with radiofrequency energy. RESULTS: BVµMax was moderately associated with both BVc (ß = .85, p < .01) and BVp (ß = .56, p < .01). BVµMax was 0.98 (95% CI: 0.93-1.04, p < .01) mV larger than corresponding BVc , and 0.27 (95% CI: 0.16-0.37, p < .01) mV larger than matching BVp in sinus rhythm, with higher percentage differences in low voltage regions, leading to smaller endocardial dense scar (2.3 [2.7] vs. 12.1 [17] cm2 , p < .01) and border zone (3.2 [7.4] vs. 4.8 [20.1] cm2 , p = .03) regions in microbipolar maps compared to standard bipolar maps. Late potentials areas were nonsignificantly greater in microelectrode maps, compared to standard electrode maps. At sites of VT termination (n = 14), µBE were of higher amplitude (0.9 [0.8] vs. 0.4 [0.2] mV, p < .01), longer duration (117 [66] vs. 74 [38] ms, p < .01), and with greater number of peaks (4 [2] vs. 2 [1], p < .01) in sinus rhythm compared to BE. CONCLUSION: microelectrode mapping is more sensitive than standard bipolar mapping in the identification of viable myocytes in SR, and may facilitate recognition of targets for CA.

Safety and Efficacy of Stereotactic Arrhythmia Radioablation for the Treatment of Ventricular Tachycardia: A Systematic Review.

Catheter ablation (CA) is a fundamental therapeutic option for the treatment of recurrent ventricular arrhythmias. Notwithstanding the tremendous improvements in the available technology and the increasing amount of evidence in support of CA, in some patients the procedure fails, or is absolutely contraindicated due to technical or clinical issues. In these cases, the clinical management of patients is highly challenging, and mainly involves antiarrhythmic drugs escalation. Over the last 5 years, stereotactic arrhythmia radioablation (STAR) has been introduced into clinical practice, with several small studies reporting favorable arrhythmia-free outcomes, without severe side effects at a short to mid-term follow-up. In the present systematic review, we provide an overview of the available studies on stereotactic arrhythmia radioablation, by describing the potential indications and technical aspects of this promising therapy.

Post intubation tracheal stenosis in children.

Many authors have reported that tracheal stenosis is a complication that can follow tracheal intubation in both adults and children. The symptoms, when they do appear, can be confused with asthma, with subsequent treatment providing only mild and inconsistent relief. We report here the case of an 8 year old girl admitted to our hospital for whooping cough that was not responding to therapy.

Optimal position of a long-term central venous catheter tip in a pediatric patient with congenital diseases.

Progress in medical and scientific research has increased the chances of survival for young patients with congenital diseases, children who, in the past, would not have had any chance of survival. Nowadays, congenital diseases can be treated with appropriate replacement therapies. These treatments can be difficult to administer in young patients because of the high frequency of administration (sometimes more than a dose per week), the use of intravenous infusion and the long-term or life-term requirement.

Central venous catheters in neonates: from simple monolumen to port catheter.

The use of central venous catheters (CVCs) represents an important step in the management of the surgical, onco-hematology and critically ill patients. CVCs in neonates, like in adult patients, are mainly used to infuse hyperosmolar solutions, to take blood samples and for hemodynamic monitoring. The need for CVCs is higher in neonates than in adults. Poor peripheral access and the high demand for IV access and blood samples are already valuable indications for a CVC.