A perioperative management algorithm for cardiac rhythm management devices: the PACED-OP protocol.

BACKGROUND: Limited data are available regarding the perioperative management of cardiac rhythm management devices (CRMDs) exposed to intraoperative electromagnetic interference. We postulated that implementation of a simple, standardized approach to CRMD management using our own institution's Pacing And Cardioverting Electronic Devices peri-Operative Protocol (the PACED-OP protocol) would be associated with a reduction in the amount of device reprogramming without an increase in CRMD-related complications. METHODS: Records of patients with CRMDs undergoing 497 consecutive surgical procedures were analyzed retrospectively. Roughly half (51%, n = 254) of these procedures occurred before implementation of the PACED-OP protocol, when patients were generally treated according to the American Society of Anesthesiologists' 2005 guidelines. These cases were compared to the remaining surgeries that occurred after implementation of the PACED-OP protocol. Records were screened for evidence of intraoperative CRMD malfunction that was directly associated with the use of electrocautery. Postoperative complications that could be indirectly or possibly linked to electrocautery-mediated CRMD malfunction were also identified. RESULTS: Implementation of the PACED-OP protocol was associated with a significant reduction in the odds of device reprogramming (adjusted odds ratio [aOR] 0.19, P < 0.001). There was no direct evidence of CRMD malfunction in either cohort. The rate of postoperative complications that could be indirectly or possibly linked with electrocautery-mediated CRMD damage did not differ significantly between cohorts (aOR = 1.37, 95% confidence interval 0.56-3.3, P = 0.49). CONCLUSION: The PACED-OP protocol implementation was associated with a significant reduction in the odds of device reprogramming without a significant difference in the odds of CRMD-related complications.

An algorithm for pacing and cardioverting electronic devices undergoing magnetic resonance imaging: The PACED-MRI protocol.

OBJECTIVE: Cardiac implantable electronic devices (CIEDs) have traditionally been a contraindication for magnetic resonance imaging (MRI). However, there is an increasing amount of literature to suggest that MRI can be safely performed in select patients with pacemakers and implantable cardioverter defibrillators by following a standardized protocol. We created an institutional protocol, made accessible as an online form, that is primarily technologist-driven and does not require direct electrophysiologist supervision. The purpose of this study was to evaluate the PACEDMRI protocol for screening and completing MRI in patients with MR conditional CIEDs. SUBJECTS AND METHODS: After the implementation of our standardized PACED-MRI protocol, patients with MR conditional CIEDs who were referred for MRI were included in the study. On the day of the MRI, the device company representative utilized our protocol accessed through PACEDMRI.com. If all parameters and criteria within the protocol were met, the examination proceeded. The device representative programed the CIED to the appropriate mode for MRI as instructed by the PACED-MRI protocol. CIED interrogation was performed immediately before and after MRI. The on-call electrophysiology nurse practitioner was notified only if the protocol instructed the team to not proceed with MRI. CIED programming changes, malfunctions, and intraprocedural events were documented. Additionally, any adverse outcomes were recorded including peri-MRI symptom onset, arrhythmia, and death. RESULTS: One hundred thirty-eight MRI examinations were performed on patients with MR conditional CIEDs (100 pacemakers: 38 implantable cardiac defibrillators). There was no incidence of symptom onset requiring early termination of the MRI, death, or arrhythmic events during or after MRI. No significant changes in lead parameters, including sensing amplitudes, lead thresholds, or lead impedances were noted on post-MRI device interrogation. Out of the 138 completed MRIs, the on-call electrophysiology provider was notified on one, non-urgent occasion. CONCLUSION: The implementation of the standardized, technologists-driven PACED-MRI protocol allowed for a multidisciplinary approach to MRI for patients with MR conditional CIEDs. This study demonstrates that the PACED-MRI protocol can be used for patients with MR conditional CIEDs undergoing MRI without the need for direct electrophysiologist supervision.

Electrocardiographic features and prevalence of bilateral bundle-branch delay.

BACKGROUND: Definitive diagnosis of bilateral bundle-branch delay/block may be made when catheter-induced right bundle-branch block (RBBB) develops in patients with baseline left bundle-branch (LBB) block. We hypothesized that a RBBB pattern with absent S waves in leads I and aVL will identify bilateral bundle-branch delay/block. METHODS AND RESULTS: Fifty patients developing transient RBBB pattern in lead V1 during right heart catheterization were studied. Patients were grouped according to whether the baseline ECG demonstrated a normal QRS, left fascicular blocks, or LBB block pattern. The RBBB morphologies in each group were compared. The prevalence of bilateral bundle-branch delay/block pattern was examined in our hospital ECG database. All patients with baseline normal QRS complexes (n=30) or left fascicular blocks (4 anterior, 5 posterior) developed a typical RBBB pattern. Among the 11 patients with a baseline LBB block pattern, 7 developed an atypical RBBB pattern with absent S waves in leads I and aVL and the remaining 4 demonstrated a typical RBBB. The absence of S waves in leads I and aVL during RBBB was 100% specific and 64% sensitive for the presence of pre-existing LBB block. Among the consecutive 2253 hospitalized patients with RBBB, 34 (1.5%) had the bilateral bundle-branch delay/block pattern. CONCLUSIONS: An ECG pattern of RBBB in lead V1 with absent S wave in leads I and aVL indicates concomitant LBB delay. Pure RBBB and bifascicular blocks are associated with S waves in leads I and aVL.