Left Axillary Implantation of Loop Recorder versus the Traditional Left Chest Area: A Prospective Randomized Study.

BACKGROUND: Based upon the results of a previous small pilot study, we present the results of a prospective single-center randomized study comparing the performance of the implantable loop recorder (ILR) at two implanting sites. METHODS: A group of patients whose ILRs were implanted via a left axillary approach were compared with a group who received an ILR in the traditional left site of the chest. Follow-up (FU) was scheduled every 6 months or when symptoms occurred. All patients enrolled in the study had a complete FU from implantation to explantation. R- and P-wave amplitudes were measured at implantation and during FU. Explantation of the device was programmed at the end of service life or when ILR analysis resulted in a complete and exhaustive diagnosis. RESULTS: Sixty-three patients were enrolled (70 ± 12 years, range: 21-92, 59% male): 31 standard and 32 with axillary access. The R-wave amplitude obtained with the new technique was comparable with that obtained with the standard procedure. The diagnostic accuracy of the ILR was comparable in the two groups. The axillary implantation procedure was slightly longer but no complications were observed. CONCLUSION: This long-term randomized study confirmed that axillary access for ILR implantation is feasible, safe, well tolerated, and reliable in terms of device performance. Moreover, it is aesthetically superior to the standard approach and carries the potential of minimizing permanent scarring after ILR extraction.

Left axillary implantation of loop recorder.

BACKGROUND: We compared the clinical course of 10 patients who received an implantable loop recorder (ILR) at a traditional site with 11 patients whose ILRs were implanted via a subpectoral site via a left axillary approach without complications. METHODS AND RESULTS: R-wave amplitude was determined at implantation and during follow-up. Each patient was followed after 7 days to optimize device setting and then at 1 and 3 months. The R-wave amplitude obtained with the new technique was significantly higher and more stable than that obtained with the standard procedure. Our preliminary experience suggests that axillary access for ILR implantation is feasible, safe, well tolerated, and reliable in terms of sensing function and device performance. Moreover, it is superior aesthetically to the standard approach and carries the potential of minimizing permanent scarring after ILR extraction.

VDD pacemaker replacement is safe and reliable independently of the previously implanted lead: a prospective and controlled study.

UNLABELLED: Theoretically, replacement of a VDD device requires using a similar pacemaker to provide the best match between the filtering characteristics of the pacemaker and the atrial dipole of the lead. This study evaluated the performance of newly implanted Vitatron VDD pacemakers connected to dedicated leads and compared the results with those of the same Vitatron pacemakers used as replacement but connected to a variety of nondedicated leads. METHODS: 23 consecutive patients (15 M, 8 F, 78 +/- 6 years) in Group 1 underwent pacemaker replacement with a VDD(R) Saphir 3 (Vitatron BV, Arnhem, The Netherlands) device designed for an 8.6 mm atrial dipole. Atrial dipoles of the previously implanted leads ranged from 5 to 30 mm. Another 22 consecutive patients (14 M, 8 F, 80 +/- 7 years) in Group 2 received a Saphir 3 pacemaker with the related dedicated lead. RESULTS: P-wave amplitude measured by the same Pacing Sensing Analyzer (PSA) at the first implantation was 1.7 +/- 0.8 vs. 1.7 +/- 0.5 mV (P = NS) in groups 1 and 2 respectively. P-wave amplitudes measured at 1 month follow-up after replacement in Group 1 and at 1 month follow-up after implantation in Group 2 were 0.69 +/- 0.5 vs. 0.85 +/- 0.3 mV (P = NS) respectively. The percentage of atrial sensing at the same follow-up was 97 +/- 3 vs. 95 +/- 5% (P = NS) in groups 1 and 2 respectively. CONCLUSIONS: Replacement of VDD pacemakers with the Saphir 3 model designed for a short dipole is safe and reliable when used in combination with previously implanted nondedicated leads.

Heart rate regularisation in patients with permanent atrial fibrillation implanted with a VVI(R) pacemaker.

UNLABELLED: Irregularity of ventricular cycles is a cause of haemodynamic impairment and symptoms in patients with atrial fibrillation (AF). AIM OF THE STUDY: Aim of the study was to determine the optimal pacing rate to stabilise ventricular cycle length at rest in patients with chronic AF, bradycardiac symptoms and VVI pacing. METHODS: The compensatory pause (CP) in AF, as defined by Langendorf, was used as a reference value in pacing the heart. The spontaneous mean heart rate (MHR) was assessed with the PM OFF. The CP was then calculated with the pacing rate programmed at 40 bpm. Four pacing rates were tested: rate of the CP (RCP), RCP + 5 bpm, RCP - 5 bpm and RCP - 10 bpm. RESULTS: RCP provided a good estimate of the MHR (r = 0.92). Pacing percentage (P%) was 24 +/- 15% at the pacing rate of RCP - 10 bpm, 39 +/- 19% at RCP - 5 bpm, 63 +/- 17% at RCP, and 79 +/- 19% at RCP + 5 bpm (p < 0.001). The corresponding HR modestly increased from 65 +/- 13 bpm to 66 +/- 13 bpm (p = NS), 68 +/- 13 bpm (p < 0.001) and 71 +/- 13 bpm (p < 0.001), respectively. CONCLUSION: The RCP estimates, during pacing, what the spontaneous MHR would be. Ventricular stimulation at the RCP causes a high P%, stabilising cardiac cycles with a modest increase in HR.

VDD pacemaker replacement independently of the implanted lead: a prospective study.

BACKGROUND: Single-lead VDD pacing is effective, safe and reliable. The only still open, practical issue is represented by the theoretical need of replacing each device with a similar one compatible with the already implanted lead to guarantee the performance of the system. The aim of our study was to investigate the atrial sensing performance of VDD pacemakers working in combination with non-dedicated chronic leads. METHODS: We enrolled 16 consecutive patients (12 males, 4 females, mean age 78 +/- 7 years) admitted to our institution for end of life of the battery. Atrial dipoles ranged from 5 to 30 mm. All replacements were done with a VDD(R) Saphir 3 (Vitatron) designed for an atrial dipole of 8.6 mm. RESULTS: All pacemakers were found to be performing well without any complaint by the patients imputable to stimulation defects. The P-wave amplitudes measured by the old and new pacemakers are similar and respectively 0.64 +/- 0.40 vs 0.73 +/- 0.53 mV (p = NS). So the old and new devices detect similar P waves. The atrial sensing percentage at 1 month of follow-up with the new pacemaker was even better than that of the old one (97 +/- 4 vs 95 +/- 3% respectively, p = 0.016): this is not imputable to the pacemaker but to the higher programmed atrial sensitivity (0.17 +/- 0.06 vs 0.18 +/- 0.07 mV respectively, p = NS). CONCLUSIONS: Independently of the implanted lead, the replacement of VDD pacemakers with devices designed for a short dipole is feasible, safe and reliable. This possibility overcomes a presumed limitation of this pacing modality.