Optimized radiofrequency lesions through local impedance guidance for effective CTI ablation in right atrial flutter.

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.

Comment to "Chronic disease management in heart failure: focus on telemedicine and remote monitoring".

No abstract present.

Catheter Ablation for Atrial Fibrillation in Structural Heart Disease: A Review.

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Patients with structural heart disease (SHD) are at an increased risk of developing this arrhythmia and are particularly susceptible to the deleterious hemodynamic effects it carries. In the last two decades, catheter ablation (CA) has emerged as a valuable strategy for rhythm control and is currently part of the standard care for symptomatic relief in patients with AF. Growing evidence suggests that CA of AF may have potential benefits that extend beyond symptoms. In this review, we summarize the current knowledge of this intervention on SHD patients.

Physical Activity in Patients With Heart Failure During and After COVID-19 Lockdown: Single-Center Observational Retrospective Study.

BACKGROUND: The COVID-19 pandemic forced several European governments to impose severe lockdown measures. The reduction of physical activity during the lockdown could have been deleterious. OBJECTIVE: The aim of this observational, retrospective study was to investigate the effect of the lockdown strategy on the physical activity burden and subsequent reassessment in a group of patients with heart failure who were followed by means of remote monitoring. METHODS: We analyzed remote monitoring transmissions during the 3-month period immediately preceding the lockdown, 69 days of lockdown, and 3-month period after the first lockdown in a cohort of patients with heart failure from a general hospital in Lombardy, Italy. We compared variation of daily physical activity measured by cardiac implantable electrical devices with clinical variables collected in a hospital database. RESULTS: We enrolled 41 patients with heart failure that sent 176 transmissions. Physical activity decreased during the lockdown period (mean 3.4, SD 1.9 vs mean 2.9, SD 1.8 hours/day; P<.001) but no significant difference was found when comparing the period preceding and following the lockdown (-0.0007 hours/day; P=.99). We found a significant correlation between physical activity reduction during and after the lockdown (R2=0.45, P<.001). The only significant predictor of exercise variation in the postlockdown period was the lockdown to prelockdown physical activity ratio. CONCLUSIONS: An excessive reduction of exercise in patients with heart failure decreased the tolerance to exercise, especially in patients with more comorbidities. Remote monitoring demonstrated exercise reduction, suggesting its potential utility to encourage patients to maintain their usual physical activity levels.

Correlation between pulmonary artery pressure and thoracic impedance: Insights from daily monitoring through an implanted device in chronic heart failure.

BACKGROUND: Thoracic impedance (TI) decrease and pulmonary artery pressure (PAP) elevation precede acute decompensation in congestive heart failure (HF). However, the relationship between TI and PAP has been studied only in the context of acute decompensation. METHODS: This prospective, observational study enrolled subjects with reduced ejection fraction HF, previously implanted with an ICD capable of measuring TI. Patients underwent implantation of a sensor for direct measurement of PAP (CardioMEMs™). Both TI and PAP were remotely monitored daily during follow up. Investigators were blinded to PAP values during the first three months, then PAP was used as a guide to therapy. RESULTS: Ten patients were followed up for 405±141days (3720 patient-days). During hemodynamic guided therapy, diastolic PAP (dPAP) decreased from 27.8±10.2mmHg to 24.0±8.0mmHg (p<0.001); non-significant variations of TI were observed. A significant negative correlation was found between the variations of TI and PAP vs. baseline (p<0.001). Episodes of sustained increase of PAP preceded subsequent periods of TI decrease by 5.6±3.9days, but the former were poor predictors of the latter (sensitivity 0.37). CONCLUSIONS: Our study confirms the strict correlation that exists between left ventricular filling pressures and lung water content, estimated by dPAP and TI, respectively. However, dPAP acute variation analysis showed a limited value in predicting subsequent episodes of TI decrease.