Ebook Cardiac resynchronization therapy: Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Cardiac resynchronization therapy: Part 2
Ebook Cardiac resynchronization therapy: Part 2
12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and Ben Ebook Cardiac resynchronization therapy: Part 2ngt HerwegProgrammability of the interventricular Interval • Pathophysiologic basis for programming the v-v interval • Clinical studies of v-v interval programming • General considerations • Effect of v-v timing on the ECG of biventricular pacemakers • Automatic device-based optimization of the v-v Ebook Cardiac resynchronization therapy: Part 2delayPROGRAMMABILITY OF THEINTERVENTRICULAR INTERVALThe methods for atrioventricular (AV) optimization in patients receiving cardiac resynchronizationEbook Cardiac resynchronization therapy: Part 2
therapy (CRT) are almost universally used for programming the optimal interventricular (V-V) delay.1-6 Conventional M-mode echocardiography for the m12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and Ben Ebook Cardiac resynchronization therapy: Part 2n of the extent of residual LV dyssynchrony after V-V programming requires more sophisticated echocardiographic techniques such as tissue Doppler techniques (peak velocity time difference, delayed longitudinal contraction score, etc.), three-dimensional (3D) echocardiography, and automatic endocardi Ebook Cardiac resynchronization therapy: Part 2al border detection.8-12Contemporary biventricular devices permit programming of the V-V interval usually in steps from +80 ms (LV first) to -80 ms (rEbook Cardiac resynchronization therapy: Part 2
ight ventricle (RV) first) to optimize LV hemodynamics. This design was the result of cogent pathophysiologic considerations that simultaneous activat12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and Ben Ebook Cardiac resynchronization therapy: Part 2st mechanical efficiency in CRT is not necessarily achieved by simultaneous pacing of the two ventricles (hence the importance of programmability of the V-V interval) (Figure 12.1):1In normal hearts, activation of the two ventricles does not occur simultaneously, i.e., epicardial RV depolarization s Ebook Cardiac resynchronization therapy: Part 2tarts a few milliseconds earlier than LV depolarisation.14152In CRT, epicardial LV pacing delays transmission of activation that is normally supposedEbook Cardiac resynchronization therapy: Part 2
to reach the subendocardial conduction system before it spreads to the remaining ventricle.3In advanced cardiomyopathy, RV-to-LV interactions can be d12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and Ben Ebook Cardiac resynchronization therapy: Part 2sturbances. The baseline ventricular conduction defect differs considerably from case to case, especially in patients with a QRS duration >150 ms.16 Theoretically, slow conduction in166 CARDIAC RESYNCHRONIZATION THERAPYLVpi — D«lay»dI conduction1 i—I .4-. Normal conductionRVp 1SIMULTANEOUS PACINGI v Ebook Cardiac resynchronization therapy: Part 2^<-.__Delayedconduction-----ị.------Jjj|— TimaA NormalJ conductioni X ProgrammableRVp • v-v delaySEQUENTIALPACINGFigure 12.1 Diagrammatic representatiEbook Cardiac resynchronization therapy: Part 2
on of left ventricular (LV) conduction delay interfering with synchronous activation of the two ventricles at the broken horizontal line. Programmabil12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and Ben Ebook Cardiac resynchronization therapy: Part 2e activated synchronously at the broken horizontal line. LVp. LV pacing event: RVp. right ventricular pacing event.the presence of scar tissue in ischemic cardiomyopathy would necessitate more LV pre-excitation. Conduction delay may be caused not only by isolated left bundle branch block (LBBB), but Ebook Cardiac resynchronization therapy: Part 2 also by more global anisotropic disturbances of the conduction system and/or myocardial scars, latency of LV stimulation, and delayed global depolariEbook Cardiac resynchronization therapy: Part 2
zation.’7_2Ơ Despite similar QRS morphology, congestive heart failure (CHF) patients with LBBB, and LV dyssynchrony exhibit different locations and pa12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and Ben Ebook Cardiac resynchronization therapy: Part 2he operator's choice and coronary sinus anatomy, producing paced ventricular activation patterns that differ from patient to patient. V-V programmability may compensate for less than optimal LV lead position by tailoring ventricular timing to correct for individual heterogeneous ventricular activati Ebook Cardiac resynchronization therapy: Part 2on patterns commonly found in patients with LV dysfunction and CHF.6The presence and varying degree of fusion with the spontaneous QRS complex andpossEbook Cardiac resynchronization therapy: Part 2
ibly with right bundle branch activation alter QRS configuration and hemodynamics.12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and Ben12Optimization of the interventricular (V-V) interval during cardiac resynchronization therapys Serge Barold, Arzu llercil, Stephane Garrigue, and BenGọi ngay
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