High-density mapping of Koch's triangle during sinus rhythm and typical atrioventricular nodal re-entrant tachycardia, integrated with direct recording of atrio-ventricular node structure potential.

BACKGROUND: The mechanism of typical slow-fast atrioventricular nodal re-entrant tachycardia (AVNRT) and its anatomical and electrophysiological circuit inside the right atrium (RA) and Koch's Triangle (KT) are not well known. OBJECTIVE: To identify the potentials of the compact AV node and inferior extensions and to perform accurate mapping of the RA and KT in sinus rhythm (SR) and during AVNRT, to define the tachycardia circuit. METHODS: Consecutive patients with typical AVNRT were enrolled in 12 Italian centers and underwent mapping and ablation by means of a basket catheter with small electrode spacing for ultrahigh-density mapping and a modified signal-filtering toolset to record the potentials of the AV nodal structures. RESULTS: Forty-five consecutive cases of successful ablation of typical slow-fast AVNRT were included. The mean SR cycle length (CL) was 784.1 ± 6 ms and the mean tachycardia CL was 361.2 ± 54 ms. The AV node potential had a significantly shorter duration and higher amplitude in sinus rhythm than during tachycardia (60 ± 40 ms vs. 160 ± 40 ms, p < .001 and 0.3 ± 0.2 mV vs. 0.09 ± 0.12 mV, p < .001, respectively). The nodal potential duration extension was 169.4 ± 31 ms, resulting in a time-window coverage of 47.6 ± 9%. The recording of AV nodal structure potentials enabled us to obtain 100% coverage of the tachycardia CL during slow-fast AVNRT. CONCLUSION: Detailed recording of the potentials of nodal structures is possible by means of multipolar catheters for ultrahigh-density mapping, allowing 100% of the AVNRT CL to be covered. These results also have clinical implications for the ablation of right-septal and para-septal arrhythmias.

Integration of a Smartphone HF-Dedicated App in the Remote Monitoring of Heart Failure Patients with Cardiac Implantable Electronic Devices: Patient Access, Acceptance, and Adherence to Use.

(200 w) Introduction. Remote monitoring (RM) of cardiac implantable electronic device (CIED) diagnostics helps to identify patients potentially at risk of worsening heart failure (HF). Additionally, knowledge of patient HF-related symptoms is crucial for decision making. Patient smartphone applications may represent an ideal option to remotely collect this information. PURPOSE: To assess real-world HF patient access, acceptance, and adherence to use of an HF-dedicated smartphone application (HF app). METHODS: In this study, 10 Italian hospitals administered a survey on smartphone/app use to HF patients with CIED. The subgroup who accepted it downloaded the HF app. Mean 1-year adherence of the HF app use was evaluated. RESULTS: A total of 495 patients (67 ± 13 years, 79% males, 26% NYHA III-IV) completed the survey, of which 84% had access to smartphones and 85% were willing to use the HF app. In total, 311/495 (63%) downloaded the HF app. Patients who downloaded the HF app were younger and had higher school qualification. Patients who were ≥60 years old had higher mean 1-year adherence (54.1%) than their younger counterparts (42.7%; p < 0.001). Hospitals with RM-dedicated staff had higher mean 1-year patient adherence (64.0% vs. 33.5%; p < 0.001). Adherence to HF app decreased from 63.3% (weeks_1-13) to 42.2% (weeks_40-52, p < 0.001). CONCLUSIONS: High access and acceptance of smartphones/apps by HF patients with CIED allow HF app use for RM of patient signs/symptoms. Younger patients with higher school qualifications are more likely to accept HF app; however, older patients have higher long-term adherence.

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.

Impact of the Pattern of Atrial Fibrillation on Stroke Risk and Mortality.

Thromboembolism is the most serious complication of AF, and oral anticoagulation is the mainstay therapy. Current guidelines place all AF types together in terms of anticoagulation with the major determinants being associated comorbidities translated into risk marker. Among patients in large clinical trials, those with non-paroxysmal AF appear to be at higher risk of stroke than those with paroxysmal AF. Higher complexity of the AF pattern is also associated with higher risk of mortality. Moreover, continuous monitoring of AF through cardiac implantable devices provided us with the concept of 'AF burden'. Usually, the larger the AF burden, the higher the risk of stroke; however, the relationship is not well characterised with respect to the threshold value above which the risk increases. The picture is more complex than it appears: AF and underlying disorders must act synergically respecting the magnitude of its own characteristics, which are the amount of time a patient stays in AF and the severity of associated comorbidities.

CD14CD16 monocyte subset levels in heart failure patients.

Our aim was to define the distribution of monocyte subsets in a cohort of congestive heart failure (CHF) patients, to verify whether increased severity of CHF is linked to the expansion of specific monocyte subsets, and finally to investigate the relationship between monocyte subset relative frequencies, laboratory parameters of inflammation, and monocyte ACE expression. Thirty consecutive CHF patients and 26 healthy control subjects were evaluated for peripheral blood monocyte expression of CD14, CD16 and CD143 (ACE) by flow-cytometry, and for endothelial-derived soluble CD146 levels by ELISA. CD14++ CD16+ frequency was significantly higher in CHF patients than in Controls (%, median value and IQ) (12.3, 8.7-14.8 vs 5.9, 4.7-6.9, p< 0.05, CHF vs Controls), and it increased depending on how high NYHA class was, on worsening LV ejection fraction and on circulating pro-BNP values. Furthermore, it was associated with increasing creatinine and with decreasing GFR and albumin levels. Monocyte CD143 expression was significantly elevated in CHF patients as compared to Controls, and positively associated with CD14++ CD16+ levels. Frequencies of CD14+ CD16+ monocytes were significantly lower in CHF patients as compared to Controls, and negatively correlated with levels of soluble CD146 (r=-0.529; p 0.048). In conclusion, monocytic CD14++ CD16+ frequency and CD143 levels are increased and reflect disease status and progressive cardiac deterioration in CHF patients. The CD14+ CD16+ subset is depleted in CHF and is linked to endothelial damage in this group of patients. Although the question of whether differences in monocyte CD14CD16 expansion are causal or whether they represent a marker of HF progression which is potentially relevant for risk prediction remains unanswered, we believe that our data represent an important tool for exploring the role of selective inflammatory pathways in CHF progression.