Background Although radiofrequency (RF) catheter ablation of cavo‐tricuspid isthmus (CTI) is an established treatment for typical right atrial flutter (RAFL), it remains to be established whether local tissue impedance (LI) is able to predict effective CTI ablation and what LI drop values during ablation should be used to judge a lesion as effective. We aimed to investigate the ability of LI to predict ablation efficacy in patients with RAFL. Methods RF delivery was guided by the DirectSense™ algorithm. Successful single RF application was defined according to a defragmentation of atrial potentials (DAP), reduction of voltage (RedV) by at least 80% or changes on unipolar electrogram (UPC). The ablation endpoint was the creation of bidirectional conduction block (BDB) across the isthmus. Results 392 point‐by‐point RF applications were analyzed in 48 consecutive RAFL patients. The mean baseline LI was 105.4 ± 12Ω prior to ablation and 92.0 ± 11Ω after ablation (p < 0.0001). According to validation criteria, absolute drops in impedance were larger at successful ablation sites than at ineffective ablation sites (DAP: 17.8 ± 6Ω vs. 8.7 ± 4Ω; RedV: 17.2 ± 6Ω vs. 7.8 ± 5Ω; UPC: 19.6 ± 6Ω vs. 10.1 ± 5Ω, all p < 0.0001). LI drop values significantly increased according to the number of criteria satisfied (ranging from 7.5Ω to 19.9). BDB was obtained in all cases. No procedure‐related adverse events were reported. Conclusions A LI‐guided approach to CTI ablation was safe and effective in treating RAFL. The magnitude of LI drop was associated with effective lesion formation and BDB and could be used as a marker of ablation efficacy. Clinical trial registration Catheter Ablation of Arrhythmias with a High‐Density Mapping System in Real‐World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998.

Objectives: To evaluate the effects of cardiac resynchronization therapy (CRTd) in patients with type 2 diabetes mellitus (T2DM) optimized via automatic vs. echocardiographic guided approach. Background: Suboptimal optimization of atrio-ventricular (AV) and inter-ventricular (VV) timings reduces CRTd response. Thus, we hypothesize that automatic CRTd optimization could ameliorate clinical outcomes in T2DM patients.Methods: We designed a prospective, multicenter study to recruit, from October 2016 to June 2019, 191 patients with T2DM and heart failure (HF) candidate to receive a CRTd. Study outcomes were CRTd responders rate, hospitalizations for HF worsening, cardiac deaths and all cause of deaths in T2DM patients treated with a CRTd and randomly optimized via automatic (n 93) vs. echocardiographic (n 98) guided approach at 12 months of follow-up.Results: We had a significant difference in CRTd responders rate (68 (73.1%) vs. 58 (59.2%), p 0.038), and hospitalization for HF worsening (12 (16.1%) vs. 22 (22.4%), p 0.030) in automatic vs. echo-guided group of patients. At multivariate Cox regression analysis, automatic guided approach (3.636 [1.271-10.399], CI 95%, p 0.016) and baseline highest values of atrium pressure (automatic SonR values, 2.863 [1.537-6.231], CI 95%, p 0.006) predicted CRTd responders rate. In automatic group, we had significant difference in SonR values comparing CRTd responders vs. non responders (1.24 ± 0.72 g vs. 0.58 ± 0.46 g (follow-up), p 0.001), hospital admission for HF worsening events (0.48 ± 0.29 g vs. 1.18 ± 0.43 g, p 0.001), and cardiac deaths ( 1.13 ± 0.72 g vs. 0.65 ± 0.69 g, p 0.047).Conclusions: automatic optimization increased CRTd responders rate, and reduced hospitalizations for HF worsening. Intriguingly, automatic CRTd and highest baseline values of SonR could predict the outcome of CRTd responders. Notably, there is a significant difference in SonR values for CRTd responders vs. non responders, hospitalizations for HF worsening and cardiac deaths. Clinical trial: ClinicalTrials.gov Identifier NCT04547244;

In the present article we report the case of a patient at high risk of infection wearing a subcutaneous ICD (S‐ICD) due to previous system extractions, hospitalized for symptomatic BBR VT and underwent radiofrequency catheter (RF) ablation. Afterwards, to prevent the possible progression of the infra‐His conduction disease to a complete block, it was decided to implant a pacemaker system. Since the high infectious risk, and the patient's firm refusal to implant another transvenous system given the previous extractions he underwent in the past, it was decided to implant a leadless pacemaker with atrioventricular synchrony.