Atrial fibrillatory wave amplitude revisited: A predictor of recurrence after catheter ablation independent of the degree of left atrial structural remodeling

Background: The fibrillatory wave amplitude (FWA) during atrial fibrillation (AF) is thought to reflect structural atrial remodeling, but it remains unclear what determines the FWA. Methods: 114 consecutive patients were prospectively studied who underwent catheter ablation of AF. The mean FWA was computed by automated surface ECG analyses. The extent of the left atrial (LA) voltage-defined atrial fibrosis and conduction properties were estimated by a three-dimensional high-density electroanatomical mapping system. The LA size was evaluated by transthoracic echocardiography. The study patients were divided into 2 groups according to an FWA in lead V1 above the median value of 46 µV (high FWA group, n=57) or below 46 µV (low FWA group, n=57). Results: There were no differences in the age, gender, CHADS2 score, prevalence of paroxysmal AF, medications, ablation strategy, and LA volume index between the two groups. The LA low voltage areas in the low FWA group were not different from those in the high FWA group. The total LA activation time and local LA conduction velocity did not differ between the two groups. During a median follow-up of 710 days, the recurrence rate after ablation was significantly higher in patients with a low FWA than a high FWA (log-rank P=0.02). In a multivariate analysis, non-paroxysmal AF, the LA volume index, and FWA were independent predictors of recurrence after　ablation. Conclusions: The FWA was not correlated with the markers of atrial structural remodeling. Nevertheless, the FWA could still provide information for predicting the clinical outcome after AF ablation

744-3 Inhibition of Nitric Oxide Synthesis does not Increase Cardiac Contractile Response but Reduces Coronary Blood Flow Response to β-Adrenergic Stimulation in Normal Dogs

Although the induction of nitric oxide (NO) synthesis has been implicated as a cause of cytokine-induced depression of cardiac β-adrenergic responsiveness. whether the NO system constitutively present in the normal myocardium plays a role in its physiologic response to β-adrenergic stimulation in vivoremains controversial. Accordingly, we examined the effects of low and high doses of NW-nitro-L-arginine methyl ester (L-NAME)(10 and 100 μg/kg/min for 10 min), an NO synthase inhibitor, administered into left circumflex coronary artery (LCX) on responses of peak left ventricular (LV) dP/dt, regional wall thickening in LCX region and LCX blood flow to graded intracoronary (IC) doses of isoproterenol (ISO:0.002 to 0.016 μg/kg/min) in 7 anesthetized dogs. IC L-NAME was associated with dose-related reductions in IC acetylcholine-induced coronary vasodilation. Effects of L-NAME on ISO-induced changes are shown:baselineISO:0.0020.0040.008.0016Peak LV dP/dt (mmHg/sec) (n=7)control2029±1362586±1922820±2003309±2554120±419*low L-NAME2171±1492566±1762894±2063214±2233707±250*high L-NAME2114±1662326±1932560±1523014±1403354±171*Wall thickening (%) (n=2)control22±725±629±533±735±9low L-NAME25±1125±1528±1931±1836±21high L-NAME28±1725±1525±1531±1934±15LCX blood flow (ml/min)(n=7)control33±648±752±661±870±9*low L-NAME36±741±844±947±852±9*high L-NAME33±736±838±740±748±8*mean ± SEM*p<0.05Thus, inhibition of NO synthesis by L-NAME did not change baseline contractility nor did it increase its response to ISO. It also did not alter baseline blood flow, but reduced significantly its response to ISO. These data strongly suggest that the NO system in the normal myocardium does not modulate contractility, but NO formation in the vasculature contributes to the β-adrenergic coronary vasodilation

Observation of Large CP Violation in the Neutral B Meson System

We present a measurement of the Standard Model CP violation parameter sin 2phi_1 based on a 29.1 fb^{-1} data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. One neutral B meson is fully reconstructed as a J/psi Ks, psi(2S) Ks, chi_c1 Ks, eta_c Ks, J/psi K_L or J/psi K^{*0} decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin 2phi_1 = 0.99 +- 0.14(stat) +- 0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.Comment: 4 figures, to appear in Phys. Rev. Letter

Measurement of B0d - B0d-bar mixing rate from the time evolution of dilepton events at the Upsilon(4S)

We report a determination of the B0d - B0d-bar mixing parameter Delta-m_d based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 /fb data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Delta-m_d as a free parameter. Using both muons and electrons, we obtain Delta-m_d = 0.463 +- 0.008(stat.) +- 0.016(sys.) ps^{-1} This is the first determination of Delta-m_d from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.Comment: 12 pages, 2 figure

Measurement of the CP Violation Parameter sin(2phi_1) in B^0_d Meson Decays

We present a measurement of the Standard Model CP violation parameter sin(2phi_1) based on a 10.5 fb^{-1} data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider. One neutral B meson is reconstructed in the J/psi K_S, psi(2S) K_S, chi_{c1} K_S, eta_c K_S, J/psi K_L or J/psi pi^0 CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine sin(2phi_1) = 0.58 +0.32-0.34 (stat) +0.09-0.10 (syst).Comment: LaTex, 13 pages, 3 figures, submitted to P.R.

A Measurement of the Branching Fraction for the Inclusive B --> X(s) gamma Decays with the Belle Detector

We have measured the branching fraction of the inclusive radiative B meson decay B --> X(s) gamma to be Br(B->X(s)gamma)=(3.36 +/- 0.53(stat) +/- 0.42(sys) +0.50-0.54(th)) x 10^{-4}. The result is based on a sample of 6.07 x 10^6 BBbar events collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e^+e^- storage ring.Comment: 14 pages, 6 Postsript figures, uses elsart.cl

Measurement of Inclusive Production of Neutral Pions from Upsilon(4S) Decays

Using the Belle detector operating at the KEKB e+e- storage ring, we have measured the mean multiplicity and the momentum spectrum of neutral pions from the decays of the Upsilon(4S) resonance. We measure a mean of 4.70 +/- 0.04 +/- 0.22 neutral pions per Upsilon(4S) decay.Comment: 15 pages, 4 figs. Submitted to Phys.Rev.

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C