A 66-year-old woman with a history of typical atrial flutter and atrial fibrillation was referred to our institution for radiofrequency ablation. In 1997, her atrial flutter was successfully ablated. During the next 4 years, she remained free of both arrhythmias. In 2001, the patient presented again with atrial fibrillation. During the subsequent electrophysiological study, the index arrhythmia was an incessant atrial tachycardia (AT), 170 bpm (Figure 1, left). A 3-dimensional electroanatomic map (CARTO; Biosense Webster, Inc) of the right atrium (RA) during tachycardia clearly demonstrated a tachycardia originating in the left atrium (LA) (Figure 2). Mapping of the LA through a transseptal puncture revealed an AT arising from a posterolateral LA focus, between the left superior pulmonary vein ostium and the atrioventricular groove (Figure 2). Endocardial recordings during AT from this region showed a discrete electrical potential (Marshall potential) preceding the atrial electrogram (Figure 1, right). Radiofrequency ablation targeting this area of early activation was successfully performed. The patient remains free of atrial arrhythmias at 3-month follow-up. This case indicates that in this particular patient, 2 triggers for atrial fibrillation were documented: an isthmus-dependent atrial flutter and an AT originating from the Marshall ligament.

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Left ventricular dyssynchrony is an independent predictor for adverse cardiac events. Resynchronization therapy improves inter-and intraventricular dyssynchrony in patients with dilated hearts and intraventricular conduction delays.Tissue doppler imaging (TDI) is the only method able to detect regional myocardial asynchrony. Our purpose is to assess the impact of biventricular pacing on inter-and intraventricular asynchrony. Methods: Fourteen patients with advanced heart failure (NYHA class >= III), EF< 35%,QRS 165±15 msec, were studied before and 24 hours after implantation of a CRT system. Heart rate(HR),QRSduration,electromechanical coupling time for the left(Qaorta) and right ventricle(Qpulm) and their difference (Qpulm-Qaort) were calculated before and the day after implantation of a biventricular pacemaker.Tissue doppler velocities and timings (from the onset of the QRS complex to peak systole) were measured in 2 basal and 2 middle segments for longitudinal function(4C apical view).We calculated and compared the changes for both modalities(off and CRT-on). Results: Statistical analysis was performed with the Wilcoxon Matched Pairs Test. ON OFF P VALUE QRS duration(msecs) 176± 35 163± 15 0.59 Heart Rate (bpm) 72.8 ±5 75 ±5 0.71 Q pulm (msecs) 161± 10 110± 7 0.005 Qaorta (msecs) 195 ±15 178± 9 0.18 Q pulm-Qaorta 34 ±10 67± 6 0.021 TDI basal (msecs) 120 ±26 162 ±33 0.18 TDI mid (msecs) 150 ±35 195± 43 0.38Conclusion:CRT improves inter-and intraventricular asynchrony. Tissue velocity imaging revealed significant restoration of synchronous contraction in the basal parts of the left ventricle after CRT Cardiac resynchronization therapy (CRT) improves synchronization of LV segmental contraction.Our puprose is to investigate the acute impact of CRT on mitral regurgitation using validated quantitative echocardiographic methods. Methods: Fourteen patients presenting with severely impaired LV systolic function (NYHA class >= III, EF< 35%,QRS 165±15 msec), were studied before and 24 hours after implantation of a CRT system. EF(%) and stroke volume (SV) are calculated by m-Mode and Simpson's method.The severety of MR was quantified according to (1) the volumetric method, (2) the flow-convergence method with a hemispherical assumption.