P1-76

P1-76

S132 Heart Rhythm, Vol 3, No 5, May Supplement 2006 D-HBP P-HBP RVAP Base vs. D-HBP Baseline After pacing Baseline After pacing Base Base vs...

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S132

Heart Rhythm, Vol 3, No 5, May Supplement 2006

D-HBP

P-HBP

RVAP

Base vs. D-HBP

Baseline

After pacing

Baseline

After pacing

Base Base vs. vs. P-HBP RVAP Baseline

After pacing

p

QRS 90 ⫾ 12 92 ⫾ 14 88 ⫾ 15 129 ⫾ 22 89 ⫾ 13 156 ⫾ 18 NS ms Intra-LVd 27 ⫾ 10 24 ⫾ 12 34 ⫾ 15 43 ⫾ 11 30 ⫾ 12 54 ⫾ 23 NS ms Yu 14 ⫾ 7 13 ⫾ 10 13 ⫾ 6 17 ⫾ 8 14 ⫾ 7 23 ⫾ 11 NS index ms EML 164 ⫾ 25 176 ⫾ 32 171 ⫾ 35 225 ⫾ 41 167 ⫾ 30 227 ⫾ 43 NS ms

P

p

⬍0.05 ⬍0.05 NS

⬍0.05

NS

⬍0.05

⬍0.05 ⬍0.05

P1-74 EVALUATION OF LEFT VENTRICLE PRESSURE DERIVATIVE ENHANCED BY MULTI SITE PACING IN PATIENTS WITH HEART FAILURE Keiji Inoue, MD, Naoto Inoue, MD, Hiroshi Fujita, MD, Tetsuya Tanaka, MD, Akiko Matsuo, MD, Yoshiharu Nishibori, MD, Kenji Suzuki, MD, Norikazu Takechi, MD and Yumi Otsuki, MD. Kyoto 2nd Red Cross Hospital, Kyoto, Japan. Background: One of the essential point of cardiac resynchronization therapy is improvement of left ventricle (LV) pressure derivative (dP/dt). However, evaluation of dP/dt augmented by pacing multi site is not well-established. We assessed the LV pressure derivative maximum (LV⫹dP/dt) and minimum (LV-dP/dt) under various pacing modes including biventricular pacing, right ventricle (RV) bifocal pacing and trisite stimulation in heart failure cases. Methods: Thirty cardiac failure patients were studied by cardiac catheterization. LV⫹dP/dt and LV-dP/dt were measured during atrial pacing as control atrial-ventricular sequential stimulation at a rate of 80 beats/min. Atrial-ventricular delay was fixed at 100 msec. The measurements of dP/dt during atrial-ventricular sequential stimulation at same rate were made under the following stimulation mode: RV apex, RV outflow, LV lateral, RV bifocal (RV apex ⫹ RV outflow), biventricular1 (RV apex ⫹ LV lateral), biventricular2 (RV outflow ⫹ LV lateral), trisite (RV apex ⫹ RV outflow ⫹ LV lateral). Results: The average of baseline LV⫹dP/dt and LV⫺dP/dt were 748mmHg/sec and ⫺781mmHg/sec. RV apex pacing decreased LV⫹dP/dt by 25% significantly(p⬍0.05). LV⫹dP/dt during RV outflow pacing showed no change compared with control. LV lateral, RV bifocal, biventricular1, biventricular2 and trisite pacing increased LV⫹dP/dt by 32%, 24%, 35%, 36% and 34%, respectively (p⬍0.05). Biventricular1, biventricular2 and trisite pacing increased absolute value of LV-dP/dt by 20%, 19% and 27%, respectively (p⬍0.05) while other pacing mode decreased these data. Trisite pacing increased absolute value of LV-dP/dt more than biventricular pacing. There was no remarkable difference of data between biventricular1 pacing and biventricular2 acing. Conclusions: RV apex stimulation impaired LV function, whereas RV outflow pacing preserved LV function. RV bifocal pacing provided a modest but favorable effect. LV lateral, biventricular and trisite pacing showed better performance in systolic phase than the control equally. Trisite pacing demonstrated additional effect on diastolic function.

P1-75 CARDIAC RESYNCHRONISATION AS A RESCUE THERAPY IN UNSTABLE OVERT HEART FAILURE DEPENDENT OF INTRAVENOUS VASOPRESSIVE AGENTS Paul Milliez, MD, PhD, Olivier Thomas, MD, Abdeddayem Haggui, MD, Alexandre Mebazaa, MD, PhD, Patrick Schurando, MD, Fabrice Extramiana, MD, PhD, Philippe Beaufils, MD and Antoine Leenhardt, MD. Lariboisie`re University Hospital, Paris, France and Ambroise Pare Clinic, Neuilly sur Seine, France.

Introduction: Cardiac resynchronisation therapy (CRT) is a validated treatment for overt heart failure (HF) in class III-IV of the NYHA patients despite an optimal medical therapy. CRT has demonstrated a significant reduction of overall mortality, hospitalisations for heart failure and a deep improvement of various functional parameters. We aimed to assess in patients with unstable overt heart failure on vasopressive agents the beneficial effects of CRT. Methods and Paients: Among 188 implanted patients within 4 years with a CRT device (22 with an ICD-CRT), 14 has been carried out in unstable overt HF despite vasopressive agents (dobutamine or adrenaline or both). All procedures were performed under local anesthesia and with constant arterial monitoring under the supervision of an anesthesiologist. Patients were predominantly male (12/14) with a mean age of 69 ⫾ 15 yrs, with ischemic cardiomyopathy in 5 and non-ischemic in 9 with mean LVEF of 20 ⫾ 10%. Dependence to vasopressive agents was defined as the inability to stop or reduce the drugs without occurrence of hypotension, oligoanuria (⬍20ml per hour), and hypoxemia. Results: All patients underwent successful implantation. There were no complications related to the procedure. All patients were subsequently monitored during 72 hours in intensive care unit. All vasopressive agents were withdrawn within 72 hours. One patient with a CRT died 24 hour after the procedure from a ventricular tachyarrhythmia. During the mean follow-up of 3 years (6 months to 4 years), one patient died of HF. Hence, 12 from 14 patients (85%) were alive with improvement of their NYHA class (at least 1 class) and LVEF (mean of ⫹5%). Conclusion: This preliminary study shows that CRT is a feasible, safe and reliable option as a rescue therapy in the setting of an unstable overt HF. CRT could be considered as an additional therapy in patients in end-stage HF ineligible for ventricular assist devices.

P1-76 PACING-INDUCED DYSSYNCHRONY PRECONDITIONS RABBIT MYOCARDIUM AGAINST ISCHEMIA/REPERFUSION INJURY Ward Y. R. Vanagt, MD, Richard N. M. Cornelussen, PhD, Erik Blaauw, MS, Tammo Delhaas, MD, PhD and Frits W. Prinzen, PhD. Maastricht University, Maastricht, The Netherlands. Background: Because increased mechanical load induces preconditioning (PC) and dyssynchrony increases loading in late-activated regions we investigated whether dyssynchrony induced by ventricular pacing (VP) at normal heart rate leads to cardioprotection. Methods: Isolated working rabbit hearts were subjected to 35 min global ischemia and 2h of reperfusion, while keeping preload and afterload constant. Seven hearts underwent VPPC (3 periods of 5 min VP at the posterior left ventricular (LV) wall), 7 hearts underwent ischemic preconditioning (IPC, 3 periods of 5 min global ischemia) and 9 hearts served as control (C). LV pressure and sonomicrometry were used to assess hemodynamics and segment work (SW) in anterior and posterior LV myocardium. Myocardial release of lactate, phosphorylation of ERK and expression of proBNP mRNA were determined to gain insight in the molecular processes involved in VPPC. * ⫽ p⬍0.05. Results: Infarct size (TTC staining) was 18.3⫾13.0% in group C, and was uniformly reduced in the VPPC and IPC groups (1.8⫾0.8%*, and 3.5⫾3.1%*, respectively, N.S. between VPPC and IPC). During LV pacing (VPPC group) SW increased to 335⫾207%* in anterior and decreased to negative values (⫺23⫾63%*) in posterior myocardium. LV pacing did not significantly affect lactate release and coronary flow. Immediately after the 3rd LV pacing cycle (VPPC3) ERK phosphorylation was increased in anterior LV myocardium. Ten min later, proBNP mRNA expression was increased 3-4 fold in both anterior and posterior myocardium (Figure). Conclusion: Intermittent dyssynchrony is equally cardioprotective as “classical” IPC. Dyssynchrony-induced protection is not induced by ischemia but may be mediated by stretch-induced ERK phosphorylation and proBNP mRNA upregulation.

Poster 1

S133

P1-78 FEASIBILITY OF A FORCE-BASED EP CATHETER ADVANCING CONTROL IN A TELEROBOTIC SYSTEM Gianni Plicchi, PhD, Emanuela Marcelli, PhD, Laura Cercenelli, PhD and Mario Parlapiano, MD. Bologna University, Bologna, Italy.

P1-77 INITIAL EXPERIENCE WITH A TELEROBOTIC SYSTEM TO REMOTELY NAVIGATE AND AUTOMATICALLY RE-POSITION EP CATHETERS Emanuela Marcelli, PhD, Gianni Plicchi, PhD and Laura Cercenelli, PhD. Bologna University, Bologna, Italy. Background: The insertion and maneuvering in the human body of EP catheters is currently carried out manually under fluoroscopy guidance, resulting in operator fatigue and prolonged ⫻-ray exposure. We report initial experience with a novel Telerobotic System (TS) to remotely navigate and control the re-positioning of standard steerable EP catheters within the heart. Materials and Methods: The TS is composed of a driving unit to transmit longitudinal, rotational and steering movements to the catheter, a user interface and an electrically powered controller implemented with an automatic re-positioning algorithm to guide the catheter come-back to previously explored endocardial sites. The algorithm was designed optimizing the sequence of catheter movements to provide a quick and safe catheter re-positioning. The TS, implemented for a specific steerable EP catheter (Rf Enhancr, Medtronic), was evaluated in 3 sheep. The catheter was firstly manually advanced to the right atrium, then remotely moved to the desire locations using the TS. The automatic catheter re-positioning was verified by fluoroscopic monitoring on four different endocardial sites previously explored and recorded. Results: Preliminary in vitro results showed a good accuracy for the repositioning algorithm (0.2⫾0.1 mm, 2.5⫾1.1 mm, 2.7⫾1.9 mm for longitudinal, rotational and steering movements, respectively), confirmed by fluoroscopic evidence during in vivo evaluation. The use of the TS reduced the time needed for catheter navigation compared to conventional manual procedure (18.5⫾8.2 vs. 25.3⫾18.6 sec) and significantly decreased the time for precise catheter re-positioning (5.3⫾3.6 vs. 15.5⫾11.4 sec). Conclusions: The TS proved to be a promising tool for remote navigation reducing significantly the time for re-positioning of EP catheters during interventional procedures.

Background: The use of robotically controlled EP catheters was recently proposed but the issue of determining during the automatic catheter maneuvering the risk of cardiac tissue perforation remains unsolved. We in vivo evaluated the feasibility of equipping a novel Telerobotic System (TS) for EP catheters manipulation with a force sensor for a controlled catheter advancing to prevent cardiac tissue damages. Materials and Methods: In 3 sheep an EP catheter (RF Enhancr, Medtronic) was first manually advanced to the right atrium. Then the TS was used to remotely navigate the catheter from a reference “non contact” position (0) to selected “contact” endocardial sites (A, B), under fluoroscopic guidance. For each catheter advancing/withdrawing movement force signals were continuously acquired. Simultaneously impedance (Z) values, measured between catheter electrodes (tip-ring), were recorded using a custom impedance transducing instrument. Results: From reference “non-contact” catheter position (0) to each “contact” catheter position and repeated re-positioning to the same sites (R01, R02, R03, RA1, RA2, RB1, RB2, RB3), a marked variation of force signals resulted (max ⌬F⫽194%). The impedance measurements were less sensitive to distinguish a ‘contact‘ from a ‘non contact‘ catheter position (max ⌬Z⫽4%). Conclusions: The TS for EP catheter manipulation with an on-board force sensor showed to be a feasible tool to provide a controlled catheter advancing, preventing the risk of cardiac tissue damages. Further studies will be needed to develop a force-based feedback control able to automatically stop catheter advancing to avoid the risk of perforation.

P1-79 CARDIAC RESYNCHRONIZATION THERAPY IN ATRIAL FIBRILLATION: AN INSYNC ITALIAN REGISTRY LONG-TERM FOLLOW-UP