Determinants of left atrial local impedance: Relationships with contact force, atrial fibrosis, and rhythm.

INTRODUCTION: The relationships between baseline tissue local impedance (LI), contact force (CF), atrial fibrosis, and atrial rhythm are uninvestigated in a clinical setting. We compared the relationship of LI and CF between atrial fibrillation (AF) and sinus rhythm (SR) accounting for the effects of atrial fibrosis as assessed by bipolar voltage and LI. METHODS: Patients undergoing persistent AF ablation were recruited. LI was recorded referenced to patient blood pool (LIr) and concurrent to changes in CF, with data collected at the same locations in AF and SR. RESULTS: Twenty patients were recruited. 109 locations were sampled obtaining 1903 data points (SR: 966, AF: 937). CF correlated strongly with LI (repeated measures correlation = 0.64). The relationship between CF and LIr was logarithmic. Rhythm and CF had a significant main (both p < .0005) and interaction effect (p = .022) on tissue LI: AF demonstrated higher LIr values than SR for similar CF. Bipolar voltage had no effect on the relationship of CF to LIr in either rhythm. Assessing fibrosis using LIr showed an interaction effect with CF for LIr in SR and AF, (SR: p < .0005, AF: p = .01), with increased fibrosis showing lesser change in LIr per gram of CF. CONCLUSIONS: CF and rhythm significantly affect the measured LIr of LA myocardium. Optimal catheter-tissue coupling may be better achieved with higher levels of CF and in AF rather than SR. Atrial fibrosis, as assessed by LIr but not bipolar voltage, affected the CF-LI relationship.

Role of routine investigations post cardiac devices implants in detecting peri-procedural complications: A retrospective analysis from a tertiary UK center.

BACKGROUND: Peri-procedural complications associated with cardiac implantable electronic devices are not uncommon. European Society of Cardiology guidelines recommend device checks of all devices within 72 h of implant. European Heart Rhythm Association expert practical guide on Cardiac implantable electronic devices (CIEDs) recommend that a chest x-ray (CXR) should be performed within 24 h to rule out pneumothorax and document lead positions. First, the rate of peri-procedural complications associated with CIED implants at our center, as well as patient and/or procedural-related factors that are associated with higher rates of complications, is analyzed. Second, the yield of the guideline-recommended measures in the early detection of peri-procedural complications is examined. MATERIALS AND METHODS: Consecutive de novo transvenous device implants at our center in 2019 were retrospectively analyzed. Patients' demographics, types and indications for device therapy, procedural reports, device checks, and CXRs were obtained from the hospital electronic records. RESULTS: A total of 578 patients (Age 74 ± 16 years, 68% male) were included. All patients had routine post-procedure CXRs and device checks. There were 16 (2.8%) complications; 7 (1.2%) pneumothoraxes, 6 (1%) pericardial effusions, and 3 (0.5%) lead displacements. Procedure time correlated significantly with complications; in uncomplicated cases it was 99 ± 43 min versus 127 ± 50 min in procedures associated with complications (p = .02). CONCLUSIONS: Routine post CIED implantation CXRs can detect early peri-procedural complications, while repeat post mobilization device checks has low yield of detection of complications. The only statistically significant predictor of peri-procedural complications is the duration of the procedure; longer procedures were associated with higher rates of complications.

Is day-case surgical procedure safe for MICRA leadless pacemaker implantation?

BACKGROUND: MICRA implantation is not commonly done as a day-case procedure. Elective leadless pacemakers are implanted routinely in our centre. OBJECTIVE: To assess whether the day-case MICRA procedure is safe. METHODS: We retrospectively collected data from all patients undergoing elective MICRA implantation at our centre between May 2014 and Nov 2022 (n = 81). Two patient groups were stratified: those planned to be discharged on the same day (SD, n = 52) and those planned to be observed overnight after the procedure (ON, n = 29). Patient demographics, size of the sheath used, type of MICRA device, and rate of complications were recorded. In patients with successful implants (n = 80), device function at discharge and first routine follow-up were evaluated. RESULTS: There were 58% males in the SD group and 45% in the ON group. Median age was 49 years in the SD and 67 years in the ON. Among patients who were planned as a day case, 8 patients had to stay in the hospital but for < 48 h: 2 due to minor groin bleeding, 1 due to patient's request despite fit to discharge, 4 due to the procedure carried out later in the day, and 1 for observation due to procedural complexity. MICRA implantation was successful in 80 patients. The rate of the major complications was 2% in the SD group and 7% in the ON group (p = 0.223), and none of the co-morbidities assessed showed an association with any complications. Device parameters at the follow-up were available in 76 patients. The rate of patients with low and stable PCT at follow-up was also 98% in the SD group and 96% in the ON group. CONCLUSIONS: Day case MICRA procedure can be performed safely in an appropriately selected patient population.