Margaret Tynan

Antibiotic prophylaxis in permanent pacemaker implantation: a prospective randomised trial.

BACKGROUND--Pacemaker pocket infection is a potentially serious problem after permanent pacemaker implantation. Antibiotic prophylaxis is commonly prescribed to reduce the incidence of this complication, but current trial evidence of its efficacy is conflicting. A large prospective randomised trial was therefore performed of antibiotic prophylaxis in permanent pacemaker implantation. The intention was firstly to determine whether antibiotic prophylaxis is efficacious in these patients and secondly to identify which patients are at the highest risk of infection. METHODS--A prospective randomised open trial of flucloxacillin (clindamycin if the patient was allergic to penicillin) v no antibiotic was performed in a cohort of patients undergoing first implantation of a permanent pacing system over a 17 month period. Intravenous antibiotics were started at the time of implantation and continued for 48 hours. The trial endpoint was a repeat operation for an infective complication. RESULTS--473 patients were entered into a randomised trial. 224 received antibiotic prophylaxis and 249 received no antibiotics. A further 183 patients were not randomised but were treated according to the operators preference (64 antibiotics, 119 no antibiotics); these patients are included only in the analysis of predictors of infection. Patients were followed up for a mean (SD) of 19(5) months. Among the patients in the randomised group there were nine infections requiring a repeat operation, all in the group not receiving antibiotic (P = 0.003). In the total patient cohort there were 13 infections, all but one in the non-antibiotic group (P = 0.006). Nine of the infections presented as erosion of the pulse generator or electrode, three as septicaemia secondary to Staphylococcus aureus, and one as a pocket abscess secondary to Staphylococcus epidermidis. Infections were significantly more common when the operator was inexperienced (< or = 100 previous patients), the operation was prolonged, or after a repeat operation for non-infective complications (principally lead displacement). Infection was not significantly more common in patients identified preoperatively as being at high risk (for example patients with diabetes mellitus, patients receiving long term steroid treatment), although there was a trend in this direction. CONCLUSIONS--Antibiotic prophylaxis significantly reduced the incidence of infective complications requiring a repeat operation after permanent pacemaker implantation. It is suggested that antibiotics should be used routinely.

Comparison of Sprint Fidelis and Riata defibrillator lead failure rates

BACKGROUND/OBJECTIVES Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. METHODS Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. RESULTS 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). CONCLUSIONS Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort.

Time to manual activation of implantable loop recorders—implications for programming recording period: a 10-year single-centre experience

AIM A new generation of commercially available implantable loop recorders (ILRs) has improved arrhythmia detection algorithms but reduced manually activated ECG storage duration. We investigated the effect that this would have had on symptom-arrhythmia correlation in a retrospective patient cohort. METHOD AND RESULTS Retrospective review of all patients receiving a Medtronic Reveal 9525/9526 for the investigation of unexplained syncope or pre-syncope in our centre between 1998 and 2008. All ILRs were programmed for a single manual activation with 40 min retrospective ECG recording. We identified all patients who subsequently underwent permanent pacemaker implantation and analysed the time delay between bradycardia onset and manual ILR activation. Five hundred and sixty-four patients underwent implantation of an ILR during the study period. Of these, 57 (10%) subsequently underwent the implantation of a pacemaker (31 male, median age 66 years, range 9-86 years). In this group, 35 of 57 (61%) bradycardia diagnoses were made in patients (18 male, median age 65 years, range 9-86 years) after manual activation of the ILR. The median time from bradycardia onset to ILR activation was 136 s (0-488 s). Nineteen recordings showed high-grade atrio-ventricular block and 16 sinus node disease. CONCLUSION Ten-year experience with the ILR confirms its utility in establishing a pacemaker indication as the cause for syncope or pre-syncope in 6% (34 of 564) of recipients following manual activation. This requires a recording loop of sufficient duration to reliably include both symptoms and activation.

Long‐Term Thresholds of Nonsteroidal Permanent Pacing Leads: A 5‐Year Study

The present commercial market supports many nonsteroidal endocardial pacing leads of differing construction. In order to compare the performance of these configurations, we studied the long‐term pacing properties of three representative lead types by randomized clinical trial in 99 patients undergoing a first elective VVl implant. Thirty‐one patients received sintered platinum leads, 36 activated pyrolytic carbon leads, and 32 vitreous carbon leads. All received generators capable of noninvasive threshold testing. Acute sensing parameters were R wave amplitude and ST segment elevation measured from the endocardial electrogram. Noninvasive voltage thresholds were measured at implantation, 2 days, 1, 3, and 6 months, and yearly thereafter for 5 years. There were no significant differences between leads in pacing or sensing capabilities at implantation. All three demonstrated similar increases in thresholds, peaking at 1 month, then falling to a plateau by 6 months and did not vary significantly thereafter. There were no significant differences in thresholds between leads during 5 years of follow‐up. The lowest mean threshold at 5 years was 0.93 V at 0.5 ms. This study suggests that: (1) although these lead types all perform well, none offers any particular clinical advantage over another; (2) the degree of early threshold peaking precludes immediate postimplant output reduction, but later thresholds are sufficiently low to enable reductions in pacing output; (3) safe low energy pacing requires greater attention to the lead‐generator combinations; (4) data obtained at subsequent annual follow‐up provided no additional useful clinical information to that obtained at 1 year, and (5) in the absence of other differences, cost can be the deciding factor in lead selection.

Pacing to Restore Right Ventricular Contraction After Surgical Disconnection for Arrhythmia Control in Right Ventricular Cardiomyopathy

Ventricular tachycardia in ARVC (arrhythmogenic right ventricular cardiomyopathy) is typically managed by ICD implantation, with a limited role of catheter ablation. Surgical disconnection of the right ventricular (RV) has been used to control ventricular tachycardia (VT) in ARVC, but it often led to refractory RV failure due to loss of RV contraction after surgery. We report multisite pacing to recruit the disconnected RV to prevent ventricular failure.