Perioperative Sensor and Algorithm Programming in Patients with Implanted ICDs and Pacemakers for Cardiac Resynchronization Therapy.

BACKGROUND: ICDs and pacemakers for cardiac resynchronization therapy (CRT) are complex devices with different sensors and automatic algorithms implanted in patients with advanced cardiac diseases. Data on the perioperative management and outcome of CRT carriers undergoing surgery unrelated to the device are scarce. METHODS: Data from 198 CRT device carriers (100 with active rate responsive sensor) were evaluated regarding perioperative adverse (device-related) events (A(D)E) and lead parameter changes. RESULTS: Thirty-nine adverse observations were documented in 180 patients during preoperative interrogation, which were most often related to the left-ventricular lead and requiring intervention/reprogramming in 22 cases (12%). Anesthesia-related events occurred in 69 patients. There was no ADE for non-cardiac surgery and in pacemaker-dependent patients not programmed to an asynchronous pacing mode. Post-operative device interrogation showed significant lead parameter changes in 64/179 patients (36%) requiring reprogramming in 29 cases (16%). CONCLUSION: The left-ventricular pacing lead represents the most vulnerable system component. Comprehensive pre and post-interventional device interrogation is mandatory to ensure proper system function. The type of ICD function suspension has no impact on each patient's outcome. Precautionary activity sensor deactivation is not required for non-cardiac interventions. Routine prophylactic device reprogramming to asynchronous pacing appears inessential. Most of the CRT pacemakers do not require surgery-related reprogramming.

Atrial distribution of connexin 40 and 43 in patients with intermittent, persistent, and postoperative atrial fibrillation.

BACKGROUND: Sustained atrial fibrillation (AF) causes alterations in atrial electrical and structural properties. Conflicting data regarding the structural remodeling of the gap junction proteins connexin (Cx) 40 and 43 in human and animal studies exists. We investigated the amount and distribution of Cx40 and Cx43 in three subtypes of AF. METHODS: In 50 patients undergoing coronary artery bypass graft and/or mitral or aortic valve surgery, right atrial appendages were taken and examined with immunoconfocal microscopy. Retrospectively, four groups were built: (1) sinus rhythm pre- and postoperative (SR, n=20), (2) intermittent AF, but SR prior to surgery (intAF, n=6), (3) postoperative AF (popAF, n=12), and (4) persistent AF, at least 3 month prior to surgery (persAF, n=12). We analyzed the amount of Cx40 and Cx43 and the degree of fibrosis in three randomly selected areas of each sample. RESULTS: As compared with SR, the amount of Cx40 was significantly reduced by 53% in persAF. The distribution pattern of Cx40 was heterogeneous in patients with SR, intAF, and popAF, whereas patients with persAF showed similar densities of Cx40 in the three examined areas. We found no significant difference in the amount of Cx43 between the four groups. The distribution pattern of Cx43 was heterogeneous in all four groups. The Cx40/Cx43 ratio was significantly reduced in patients with popAF and persAF by 51% and 53%, respectively. No difference was seen in the degree of fibrosis between the four groups. CONCLUSIONS: In this study, sustained AF leads to a reduction in the amount of Cx40. Together with a specific Cx40/Cx43 ratio, this may contribute to localized conduction abnormalities, facilitating the self-perpetuation of re-entry pathways in AF. In the time course of structural atrial remodeling these changes seem to be earlier than a concomitantly developing fibrosis.