Background Nominal atrioventricular （AV） interval in dual chamber pacemaker （DDD） is not the best AV delay in the majority of patients with atrioventricular block. To find a simple method for optimizing AV delay a...Background Nominal atrioventricular （AV） interval in dual chamber pacemaker （DDD） is not the best AV delay in the majority of patients with atrioventricular block. To find a simple method for optimizing AV delay adjustment, we assessed surface electrocardiography （ECG） for optimizing AV delay during dual chamber pacing. Methods DDD pacemakers were implanted in 46 patients with complete, or almost complete, AV block. Optimal AV delay was achieved by programming an additional delay of 100 ms, to the width of intrinsic P wave or to the interval between pacing spike to the end of P wave on surface ECG. Leit ventricular （LV） end diastolic and end systolic volumes, ejection fraction and diastolic parameters were measured by Doppler echocardiography during both nominal and optimal AV delay pacing.Results Compared to nominal AV delay setting, LV end diastolic volume increased [to （53.2±11.3） ml from （50.2 ± 10.2） ml, P〈0.05], end systolic volume decreased [to （26.1 ± 9.0） ml from （27.9 ± 8.2） ml, P〈0.05] during adjusted AV delay pacing, resulting in an increase in LV ejection fraction [to （68.2±5.3）% from （64.5±4.3）%, P〈0.05]. LV diastolic filling and isovolumic relaxation time were not significantly changed.Conclusion Optimization of AV delay by surface ECG is a simple method to improve LV systolic function during dual chamber pacing.展开更多
Heart failure was a major and increasing public health problem, with an almost ＂epidemic＂ increase in the number of patients. Despite recent advances in pharmacotherapy, the prognosis remains poor. Cardiac resynchro...Heart failure was a major and increasing public health problem, with an almost ＂epidemic＂ increase in the number of patients. Despite recent advances in pharmacotherapy, the prognosis remains poor. Cardiac resynchronization therapy （CRT）, by pacing right and left ventricles, has been proved to improve symptoms and reduce mortality for heart failure patients with cardiac dyssynchrony, However, 20% to 30% of patients did not respond to CRT. The good cardiac synchronicity before CRT and the remaining atrioventficular, inter- and intra-ventricular dyssynchrony after CRT may explain the non-response. New echocardiographic techniques, and in particular tissue Doppler imaging （TDI） analysis, has been proved to be a helpful tool in evaluating cardiac dyssynchrony, as well as in assessing the degree of cardiac resynchronization after biventricular device implantation. So, in this study, we optimized the pacing parameters to determine whether echo-guided optimizing of AV/VV delays would enhance the effect of CRT on cardiac function and synchronicity.展开更多
目的运用组织多普勒成像（TDI）评价DDD双腔起搏病人房室间期（AVD）的变化对其左心室收缩功能的影响。方法对25例植入永久性DDD起搏器病人（其起搏频率为70 min^-1,AVD分别程控在70、150和230ms）和18例正常人,应用组织多普勒测量后间...目的运用组织多普勒成像（TDI）评价DDD双腔起搏病人房室间期（AVD）的变化对其左心室收缩功能的影响。方法对25例植入永久性DDD起搏器病人（其起搏频率为70 min^-1,AVD分别程控在70、150和230ms）和18例正常人,应用组织多普勒测量后间隔、左心室侧壁、左心室前壁、左心室下壁、前间隔和左心室后壁二尖瓣环收缩期运动速度（Sm）,应用脉冲多普勒测量左心室每搏量（LVSV）。结果AVD程控为150 ms DDD起搏组Sm与正常对照组及AVD为70 ms和230 ms DDD起搏组Sm存在显著性差异（F=5.35,q=3.03-6.13,P〈0.05）,并且AVD程控为150 ms DDD起搏组的Sm与LVSV间呈明显正相关（r=0.68,P〈0.01）。结论运用组织多普勒分析房室间期的变化对二尖瓣环收缩期运动速度的影响,可以估测双腔起搏病人左心室收缩功能。展开更多
文摘Background Nominal atrioventricular （AV） interval in dual chamber pacemaker （DDD） is not the best AV delay in the majority of patients with atrioventricular block. To find a simple method for optimizing AV delay adjustment, we assessed surface electrocardiography （ECG） for optimizing AV delay during dual chamber pacing. Methods DDD pacemakers were implanted in 46 patients with complete, or almost complete, AV block. Optimal AV delay was achieved by programming an additional delay of 100 ms, to the width of intrinsic P wave or to the interval between pacing spike to the end of P wave on surface ECG. Leit ventricular （LV） end diastolic and end systolic volumes, ejection fraction and diastolic parameters were measured by Doppler echocardiography during both nominal and optimal AV delay pacing.Results Compared to nominal AV delay setting, LV end diastolic volume increased [to （53.2±11.3） ml from （50.2 ± 10.2） ml, P〈0.05], end systolic volume decreased [to （26.1 ± 9.0） ml from （27.9 ± 8.2） ml, P〈0.05] during adjusted AV delay pacing, resulting in an increase in LV ejection fraction [to （68.2±5.3）% from （64.5±4.3）%, P〈0.05]. LV diastolic filling and isovolumic relaxation time were not significantly changed.Conclusion Optimization of AV delay by surface ECG is a simple method to improve LV systolic function during dual chamber pacing.
文摘Heart failure was a major and increasing public health problem, with an almost ＂epidemic＂ increase in the number of patients. Despite recent advances in pharmacotherapy, the prognosis remains poor. Cardiac resynchronization therapy （CRT）, by pacing right and left ventricles, has been proved to improve symptoms and reduce mortality for heart failure patients with cardiac dyssynchrony, However, 20% to 30% of patients did not respond to CRT. The good cardiac synchronicity before CRT and the remaining atrioventficular, inter- and intra-ventricular dyssynchrony after CRT may explain the non-response. New echocardiographic techniques, and in particular tissue Doppler imaging （TDI） analysis, has been proved to be a helpful tool in evaluating cardiac dyssynchrony, as well as in assessing the degree of cardiac resynchronization after biventricular device implantation. So, in this study, we optimized the pacing parameters to determine whether echo-guided optimizing of AV/VV delays would enhance the effect of CRT on cardiac function and synchronicity.
文摘目的运用组织多普勒成像（TDI）评价DDD双腔起搏病人房室间期（AVD）的变化对其左心室收缩功能的影响。方法对25例植入永久性DDD起搏器病人（其起搏频率为70 min^-1,AVD分别程控在70、150和230ms）和18例正常人,应用组织多普勒测量后间隔、左心室侧壁、左心室前壁、左心室下壁、前间隔和左心室后壁二尖瓣环收缩期运动速度（Sm）,应用脉冲多普勒测量左心室每搏量（LVSV）。结果AVD程控为150 ms DDD起搏组Sm与正常对照组及AVD为70 ms和230 ms DDD起搏组Sm存在显著性差异（F=5.35,q=3.03-6.13,P〈0.05）,并且AVD程控为150 ms DDD起搏组的Sm与LVSV间呈明显正相关（r=0.68,P〈0.01）。结论运用组织多普勒分析房室间期的变化对二尖瓣环收缩期运动速度的影响,可以估测双腔起搏病人左心室收缩功能。
