Management of Cardiac Implantable Electrical Devices in the Perioperative Period

344 REGIONAL AND GLOBAL LV ENDOCARDIAL CONDUCTION PATTERNS IN CARDIOMYOPATHY PATIENTS WITH LEFT BUNDLE BRANCH BLOCK AND WITH NARROW QRS: IMPLICATIONS FOR CARDIAC RESYNCHRONIZATION THERAPY H.M. Haqqani, K.C. Roberts-Thomson, R.L. Snowdon, R.N. Balasubramanian, R. Rosso, P.B. Sparks, J.K. Vohra, J.M. Kalman, J.B. Morton Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia Objective: To characterize LV endocardial activation in cardiomyopathy patients with and without left bundle branch block (LBBB). Background: The significant rate of non-response to cardiac resynchronization therapy (CRT) with current selection criteria may be partly due to variations in LV activation. Methods: Electroanatomic isochronal activation mapping of the LV endocardium was performed in 40 patients with severe cardiomyopathy, 22 ischemic and 18 nonischemic. 27 patients (68%) had LBBB (Group 1) and these were compared to 13 patients with cardiomyopathy and normal QRS (Group 2). Results: LBBB patients were older with larger LV dimensions, larger LV volumes, lower mean ejection fractions (24 ± 6.5% vs. 29 ± 6.1%, p = 0.04) and greater low-voltage area. The mean QRS duration with LBBB was 155 ± 23 ms, cf. 105 ± 8 ms in Group 2 with correspondingly longer total endocardial activation 132 ± 24 ms vs. 95 ± 13 ms. Overall 28 patients (70%) had earliest LV activation in the septum. 26 patients (65%) had latest LV activation in the basal lateral wall. The prevalence of non-septal earliest sites and non-lateral latest activation sites was not different between groups. Non-endocardial activation times were longer in Group 1. They also had longer mean transseptal activation times, longer septal to lateral wall delay, and slower global conduction velocity. Conclusion: One third of patients with cardiomyopathy and LBBB have latest endocardial activation at a nonlateral wall site. Patients with severe cardiomyopathy and narrow QRS have similar LV activation heterogeneity but demonstrate significantly less endocardial activation dyssynchrony. These findings have implications for the application of and patient selection for CRT. doi:10.1016/j.hlc.2009.05.346

Abstracts

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345 MANAGEMENT OF CARDIAC IMPLANTABLE ELECTRICAL DEVICES IN THE PERIOPERATIVE PERIOD V. Nadurata, J. Mekel, A. Mortada, N. Sharma, C. McDonald, M. Bell, M. Constatine, E. Riordan Bendigo Health, Bendigo, Australia Patients undergoing surgery with cardiac implantable electrical devices (CIEDs) – pacemakers and ICDs – are increasing. This resulted in increased request to reprogram CIEDs. We believe that current and recent model CIEDs do not always need to have this done. Therefore, we made an algorithm to address the perioperative management and assessed its safety. An algorithm was made based on the following: pacing and sensing polarity, antitachycardia pacing, defibrillator function, response to magnet, rate response sensor, noise reversion, underlying rhythm. From the surgical side, we considered the site and distance of surgery and diathermy pads to the device; polarity of diathermy; duration and type of surgery. All patients with CIEDs undergoing surgery in a 4month period were given recommendation based on the algorithm. Patient and device details were analyzed. A safety review was done in relation to possible device related complications. 31 patients were included in the study—15 patients had either orthopedic, abdominal and ENT surgeries while 5 patients had endoscopy. 21 patients had diathermy, 17 of which was unipolar. 25 patients had a pacemaker and 6 had ICD. 13/31 are pacemaker dependent at the time of surgery, 10 had diathermy of which 5 was reprogrammed to asynchronous mode equating to only 5/31. 5/6 ICD patients had diathermy, with 2 patients needing reprogramming and 3 patients had just magnet applied on device. There we did not document complications. We conclude that it is effective and safe to adapt the algorithm. doi:10.1016/j.hlc.2009.05.347 346 MARKED PERIANNULAR ENDOCARDIAL SUBSTRATE DIFFERENCES IN NON-ISCHEMIC DILATED CARDIOMYOPATHY PATIENTS WITH AND WITHOUT CLINICAL VENTRICULAR TACHYCARDIA H.M. Haqqani, J.M. Kalman, K.C. Roberts-Thomson, R.L. Snowdon, R.N. Balasubramanian, R. Rosso, P.B. Sparks, J.K. Vohra, J.B. Morton Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia Objective: To compare the electrophysiologic substrate in non-ischemic dilated cardiomyopathy (DCM) with and without clinical sustained monomorphic ventricular tachycardia (SMVT). Background: DCM patients with SMVT have a periannular distribution of left ventricular (LV) endocardial low

ABSTRACTS

Heart, Lung and Circulation 2009;18S:S1–S286