动态优化AV/VV间期心脏再同步治疗慢性心力衰竭的临床观察

目的: 观察动态优化AV/VV间期心脏再同步治疗（cardiac resynchronization therapy,CRT）治疗慢性心力衰竭（CHF）的短中期疗效。方法: 12例CHF晚期患者接受CRT治疗,分别于植入前、植入术后3、6个月在超声心动图指导下优化房室（AV）间期和室室（VV）间期,同时观察心腔结构、二尖瓣返流及心电图、脑钠尿肽（BNP）检查等,评价CRT临床疗效。结果: 最佳优化AV间期120～180（158±19）ms和VV间期4～28（16±7）ms,临床症状改善,六分钟步行距离由(257±23)m增加至(344±21)m,QRS时限由（136±17）ms降至(109±12)ms(P<0.01,P<0.05)。植入后左室舒张末内径（LVEDD）较植入前明显缩小［(71±10) mm vs. (54±4),P<0.05］; 左室射血分数（LVEF）提高［(0.308±0.022) vs. (0.531±0.085),P<0.01］;血浆BNP值由植入前（876±415）ng/L降至(70±28)ng/L(P<0.05)。结论: 动态程控AV/VV间期可以提高CRT对CHF患者短、中期疗效。     

动态优化AV/VV间期心脏再同步化治疗慢性心力衰竭的中远期疗效

目的 观察动态优化AV/VV间期心脏再同步化治疗（CRT）慢性心力衰竭的中远期疗效。方法 19例心衰晚期患者接受CRT治疗,分别于植入前、植入术后1周、3、6及12个月在心脏彩超指导下优化AV/VV间期治疗,同时观察心腔结构、二尖瓣返流、主动脉瓣射血速度时间积分（AVTI）、心电图以及测定血浆脑钠肽（BNP）水平等,评价其血流动力学改变。结果 动态优化下最佳优化AV间期120～180 ms （158.33±19.46 ms）之间和VV间期4～28 ms （15.83±7.12 ms）之间临床症状改善,6分钟步行距离由255.71±21.58 m增加至397.37±11.35 m（P0.001）,QRS时限由138.79±16.06 ms降至105.53±8.80 ms（P<0.05）。植入后左心室舒张期末内径（LVEDD）较植入前明显缩小（73.53±9.41 mm比54.11±3.41;P<0.05）,左心室射血分数（LVEF）较植入前明显提高（31%±3%比58%±6%;P<0.01）;AVTI由14.69±1.48优化后增加至20.52±1.18（P<0.05）,血浆BNP水平由植入前的1069.02±501.85 ng/L降至81.26±31.51 ng/L（P<0.05）。结论 动态优化AV/VV间期可以改善患者的血流动力学,提高CRT对慢性心力衰竭患者中远期疗效。     

心脏再同步化治疗起搏参数优化对心脏同步性及心功能的影响

目的 应用组织多普勒研究心脏再同步化治疗(CRT)术后A-V、V-V间期优化对心脏同步性能及心功能的影响,探索A-V、V-V间期优化在增强CRT临床疗效中的作用.方法 32例慢性心力衰竭患者接受CRT治疗,于术后7天、3个月、6个月进行A-V、V-V间期优化,观察心脏同步性和心功能变化.采用彩色超声诊断仪进行图像采集及下线分析.结果 经观察,术后7天、3个月、6个月的A-V间期需行优化的例数分别为28例、10例、6例,V-V间期需行优化的例数分别为29例、6例、5例.与CRT术前相比:CRT治疗术后未优化时的左室12节段组织速度达峰时间标准差明显改善[(68.8±26.4)ms与(41.6±23.1)ms,P＜0.01],左室射血分数增加[(28±4)%与(31±3)%,P＜0.05],主动脉瓣前向血流速度时间积分增加[(13.6±3.1)cm与(15.5±4.3)cm,P＜0.05],舒张早期跨二尖瓣血流峰速和舒张早期心肌组织运动峰速的比值下降(13.1±5.3与9.3±4.3,P＜0.05),左室舒张充盈时间延长[(313.2±93.6)ms与(368.6±97.1)ms,P＜0.05].与术后未优化时相比:术后7天优化心脏同步性指标进一步改善(P＜0.05),心功能指标无明显改变;术后3个月、6个月优化与术后7天优化相比,心脏同步性指标无明显改变,P＞0.05;术后6个月优化的左室射血分数增加,左室舒张充盈时间延长,P＜0.01.结论 CRT术后7天,A-V、V-V间期优化治疗改善心脏同步指标;术后6个月优化进一步改善心功能.     

具有一键优化功能的起搏器心脏再同步化治疗慢性心力衰竭的临床观察

目的:观察具有一键优化功能的起搏器心脏再同步化(CRT)治疗慢性心力衰竭(CHF)的临床疗效.方法:16例CHF患者接受起搏器CRT治疗,并分别于植入起搏器术后1周、3个月、6个月、12个月行一键优化,同时行超声心动图及组织多普勒检查.评价具有一键优化功能的起搏器CRT治疗的临床疗效.结果:最佳一键优化AV间期在110-180(159.33±19.50)ms之间,最佳VV间期在0～28(15.73 ±7.55)ms之间.16例患者一键优化起搏器植入术后1周、3个月、6个月、12个月行一键优化后QRS时限、室间隔和左心室后壁收缩时间差(SPWMD)、左心室射血前时间与右心室射血前时间差值(TQ-AV-TQ-PV)、二尖瓣反流面积、左心室舒张末内径(植入术后1周除外)、血浆脑钠素均较植入前降低,并且术后随时间延长逐渐降低,差异均有统计学意义(P均<0.05);主动脉前向血流速度时间积分(VTI)、左心室射血分数、6分钟步行距离均较植入前增加,并且术后随时间延长逐渐增加(血浆脑钠素植入术后12个月与6个月比较除外),差异均有统计学意义(P均<0.05).结论:具有一键优化功能的起搏器CRT治疗能改善CHF患者的血流动力学、临床症状,提高其疗效.     

具有一键优化功能的CRT治疗慢性心力衰竭的临床观察

目的观察具有一键优化功能的心脏起搏与不具一键优化功能的心脏再同步化治疗(cardiac resynchronization therapy,CRT)慢性心力衰竭(chronic heart failure,CHF)的临床疗效。方法 19例慢性心力衰竭患者接受CRT治疗,并根据起搏器是否具有"一键优化"功能分为"一键优化"组(n=10)和"超声优化"组(n=9),于术前收集患者的相关资料,术后1周、3个月分别行一键优化及超声优化评价CRT治疗的临床疗效。结果一键优化与超声优化的最佳优化房室(AV)间期(131.00±7.40ms VS 134.00±15.80ms)及最佳优化心室(VV)间期(18.50±9.50ms VS17.00±13.60ms)比较差异无统计学意义。通过定期随访,发现两组起搏器植入术后3个月,6个月经优化后心胸比、左心室舒张末压、左心室射血分数及6分钟步行试验两组间并无统计学差异(除BNP术前及术后3月两组间有统计学差异外)。结论有一键优化功能的CRT治疗慢性心力衰竭的临床疗效不亚于常规超声心动图优化的CRT,且一键优化功能方便、快捷给临床工作带来更多方便性。     

动态优化AV／VV间期的心脏再同步治疗对慢性心力衰竭的疗效评价

目的评价AV／VV间期动态优化的心脏再同步治疗（CRT）对慢性心力衰竭的疗效。方法26例因心力衰竭接受CRT的患者分别于植入术后1周,6个月以及12～18个月在超声指导下行AV／VV间期优化。同时行超声心动图以及组织多普勒、心电图、6min步行距离试验（6MHW）、血浆脑钠肽（BNP）值以及x线胸片（心胸比）检查。结果本文最佳优化AV间期在100～140（120．77±8．91）ms之间,最佳优化VV间期在4～24（12．92±5．34）ms之间。CRT植入后最佳AV间期在±10ms之间波动,最佳VV间期在±4ms之间波动。植入后1周同植入前相比左心室射血分数（LVEF）由0．30±0．04增加至0．31±0．03,舒张期二尖瓣反流速度时间积分（VTImr）由（18．97±3．81）cm降至（16．04±3．64）cm;间隔对后壁的运动延迟（SPWMD）由植入前（125．06±7．47）ms降至（105．06±12．06）ms;QRS时限由植入前（144．35±10．76）ms降歪（129．00±6．65）ms;6MHW由植入前（278．46±12．55）m增加至（324．62±25．49）m;血浆BNP值由植入前（672．79±98．36）pg／ml降至（484．03±106．02）pg／ml。12～18个月AV／VV间期优化后同优化前相比：LVEF值由0．32±0．03增至0．40±0．03,VTImr由（16．04±3．64）cm降至（8．67±1．18）cm;SPWMD由（105．06±12．06）ms降至（101．00±7．56）ms;QRS时限无明显变化;6MHW由（324．62±25．49）m增加至（347．12±15．24）m;血浆BNP值由（484．03±106．02）pg／ml降至（98．41±8．57）pg／ml。左心室舒张末期内径（LVEDD）由（71．73±7．07）mm降至（64．46±4．95）mm;心胸比由（71±5）％降至（63±4）％。结论动态程控AV／VV间期可以提高CRT对慢性心力衰竭的短、中、远期疗效。     

普伐他汀对慢性心力衰竭患者血浆脑钠素水平及心功能的影响

目的探讨普伐他汀对慢性心力衰竭(CHF)患者血浆脑钠素(BNP)水平和心功能的影响.方法将56例CHF患者随机分为普伐他汀组(30例)和对照组(26例),2组均给予常规治疗,普伐他汀组另加普伐他汀10 mg,qn,疗程8周.测定治疗前、后左心室舒张末内径(LVDd)、左心室射血分数(LVEF)、血浆BNP浓度的变化.结果普伐他汀治疗8周后,血浆BNP浓度由(218.6±64.2)ng/L降至(149.4±50.1)ng/L(P＜0.01);LVEF由(34.4±3.4)%升至(45.4±4.9)%(P＜0.05),LVDd由(65.5±5.1)mm降至(45.4±4.9)mm(P＜0.05),与对照组比较均差异有统计学意义;且患者血浆BNP降低值与LVEF增加存在负相关(r=-0.71,P＜0.01),而与LVDd减少呈正相关(r=0.79,P＜0.05).结论普伐他汀能明显改善心功能,抑制血浆BNP增高.     

慢性重度心力衰竭患者血B型利钠肽浓度正常的临床意义探讨

目的 探讨慢性重度心力衰竭(心衰)患者出现血B型利钠肽(B-type natriuretic peptide,BNP)浓度正常的临床意义.方法 采用前瞻性对照研究的方法观察心功能Ⅲ～Ⅳ级的慢性重度心衰患者57例.血BNP浓度正常的13例患者为研究组(A组),血BNP浓度明显升高的44例为对照组(B组),分析两组患者的临床特点,判定血BNP浓度正常对于慢性重度心衰患者的意义.结果 两组患者的基线情况差异无统计学意义.A组的左室舒张末期内径大于B组[(70.56±4.33)mm与(63.73±3.75)mm,P＜0.05];A组的左室射血分数小于B组[(24.16±2.50)%与(28.49±2.63)%,P＜0.05].A组中能耐受美托洛尔的人数比例少于B组[(7/13)与(39/44),P＜0.05],耐受剂量低于B组[(12.5±6.25)mg/d与(24.20±11.22)mg/d,P＜0.05].两组血BNP浓度在稳定期各时间段无明显改变,但在慢性心衰急性发作与缓解后,A组无显著性改变[(74.03±11.18)ng/L与(71.38±11.68)ng/L,P＞0.05],而B组改变明显[(962.73±165.00)ng/L与(876.24±167.70)ng/L,P＜0.05].随访中,A组病死率高于B组(11/13与6/44,P＜0.05).Logistic多因素回归分析显示:血BNP降低为预测重度慢性心衰患者心原性死亡的独立危险因素(OR值45.488,95%可信区间5.322～388.791),P＜0.05.结论 慢性重度心衰患者出现血BNP浓度正常提示BNP分泌机制的耗竭和心脏功能的进一步恶化.     

单左室起搏通过频率适应性房室延迟实现双心室再同步

目的探讨单左室起搏通过频率适应性房室延迟(RAAV)算法跟踪生理性房室延迟(AVD)实现双心室再同步的可行性及治疗慢性充血性心力衰竭(CHF)的效果。方法入选符合心脏再同步化治疗(CRT)Ⅰ类适应证并植入带RAAV功能的三腔或双腔起搏器的CHF患者64例,其中RAAV单左室起搏(LUVP)组(单左室组)32例,以标准双室起搏(BVP)组(标准双室组)32例为对照组。两组给予标准心脏超声优化,比较主动脉前向血流速度时间积分(AVI),左室射血分数(LVEF)、十二节段达峰时间标准差(TS-SD12)、主肺动脉射血前时间差(IVMD)、二尖瓣返流面积(MRA)、EA峰间距(E/A pd)、QRS波时限、年平均治疗费用、NYHA分级、6min步行试验(6MWT)等指标。结果与标准双室组比较,单左室组电池寿命更长[(7.8±0.3)年vs(4.5±0.2)年,P0.001],QRS波时限短[(136±10)ms vs(142±11)ms,P0.05],优化耗时较短[(20±4)min vs(52±8)min,P0.001],MRA更少[(3.1±1.1)cm~2 vs(3.7±1.2)cm2,P0.05],IVMD缩短[(64.2±12.8)ms vs(72.3±13.6)ms,P0.05],年均治疗费用低[(1.3±0.1)万元vs(2.2±0.2)万元,P0.001];AVI增加[(21.8±2.3)cm vs(20.6±2.1)cm,P0.05],余指标两组比较均无统计学意义(P0.05)。结论 RAAV单左室起搏可实现双室再同步,疗效不劣于标准BVP,且更符合生理性并降低治疗费用。     

新活素治疗顽固性心力衰竭临床疗效观察

目的观察新活素对顽固性心力衰竭的临床治疗疗效。方法入选2009年4月~2013年6月在陕西省宝鸡市第六人民医院入院治疗的顽固性心力衰竭患者72例,根据患者入组顺序分为观察组(n=36)和对照组(n=36),观察比较两组患者用药前及用药后72 h血压、血清氨基末端脑钠肽前体(NT-pro BNP)水平、左室射血分数(LVEF)、心率、左室舒张末期内径(LVEDd)变化以及药物的不良反应。结果观察组用药72 h后改善顽固性心力衰竭的有效率明显高于对照组(86.1%vs.52.8%,P0.05)。与治疗前相比,治疗后两组心率均明显下降,观察组[(84.7±4.3)次/min vs.(80.8±2.7)次/min,P0.05];对照组[(85.5±3.0)次/min vs.(80.6±1.8)次/min]。治疗后观察组[(2843.4±611.3)ng/L vs.(1675.5±446.8)ng/L,P0.05]与对照组[(2782.0±688.3)ng/L vs.(1955.1±404.4)ng/L]NT-pro BNP水平均明显下降(P0.05),观察组下降大于对照组(P0.05)。治疗后观察组[(37.6±7.9)%vs.(49.8±7.9)%]与对照组[(36.9±10.2)%vs.(45.0±9.0)%]LVEF均明显增加(P0.05),且观察组LEVF升高大于对照组(P0.05)。两组在低血压发生率上无统计学差异(P0.05)。结论新活素治疗顽固性心力衰竭具有较好的疗效,能明显改善患者的血流动力学参数,且无明显不良反应。     

心脏再同步化治疗术后采用超声心动图指导与QuickOpt功能进行间期优化的相关分析

目的探讨在超声心动图指导下(超声法)和利用QuickOpt功能(IEGM法)优化心脏再同步化治疗(CRT)患者感知房室延迟(SAV间期)、起搏房室延迟(PAV间期)和室间延迟(VV间期)对患者急性血流动力学影响的一致性。方法 19例植入具有QuickOpt功能的CRT(D)的患者,采用超声法获得最大主动脉血流速度积分(aVTI)及其相应的SAV、PAV、VV间期;利用IEGM法获得优化SAV、PAV、VV间期并测定相应aVTI。结果两种方法获得的最佳SAV、PAV、VV间期所对应的aVTI的一致相关系数(CCC)分别为95.95%,97.29%,92.45%(P0.01)。超声法与IEGM法获得的优化SAV间期(131.67±22.30 ms vs 121.11±13.24 ms,P=0.117)、PAV间期(178.42±21.86 ms vs 171.05±12.87 ms,P=0.114)与VV间期(15.79±15.75 ms vs 16.32±20.20 ms,P=0.871)均无显著差异。IEGM法进行间期优化花费时间比超声法大大减少(1.28±0.45 min vs 43.60±11.07 min,P0.01)。结论利用QuickOpt功能对CRT患者进行术后间期优化,可以获得与心脏超声优化一致的急性血流动力学影响效果,并且大大减少优化花费时间。     

Optimization of cardiac resynchronization therapy in non-responders

BackgroundCardiac resynchronization therapy plays important role in treatment of heart failure patients with low left ventricular ejection fraction. However, a significant number of patients do not improve after implantation. Optimization of atrioventricular and interventricular delay could improve clinical status of these patients.ObjectivesThe purpose of this study was to compare optimization of atrioventricular (AV) and interventricular (VV) delays with aortic velocity-time integral (VTI) and with maximal value of the first derivative of a left ventricular pressure signal (LVdP/dt_max).MethodsFifteen non-responders were optimized with aortic VTI method and QuickOpt. After 3 months the follow up echocardiography and clinical evaluation were done. Ten non-responders were optimized with LVdP/dt_max and QuickOpt. After 3 month follow up echocardiography and clinical evaluation were done.ResultsIn the first group of patients (age 74.3 years (65.3, 84.3), 83.4% male, etiology 66% ischemic heart disease, NYHA class before optimization III 66.7%, III-IV 33.3%, LVEF 23.0% (15.0; 32.0)), no correlation between AV and VV delays setting obtained from aortic VTI and QuickOpt was found. Optimization generated shorter QRS complex. After 3 months of follow up, there was no change in echo parameters or NYHA class. In the second group of patients (age 76.7 years (66.6, 82.4), 90% male, etiology 60% ischemic heart disease, NYHA class before optimization III 50%, III-IV 50%, LVEF 29.5% (10.0; 35.0)), no correlation between AV and VV delays setting obtained from LVdP/dt_max and QuickOpt was found. Optimization in this group of patients also generated shorter QRS complex. After 3 months, increase in LVEF was observed, but other echo parameters and NYHA class remained unchanged.ConclusionUsing aortic VTI guided optimization in CRT devices did not bring any profit for non-responder patients. Echocardiography parameters and NYHA status did not changed in 3 months follow up. Using invasive LVdP/dt_max leads to a change in left ventricular ejection fraction, but NYHA class remains unchanged.     

Cardiac resynchronization therapy: variations in echo-guided optimized atrioventricular and interventricular delays during follow-up

BACKGROUND: Relatively few data are available on long-term echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay programming in cardiac resynchronization therapy (CRT). We assessed variations in optimized AV and VV delays during long-term follow-up. METHODS: Thirty-seven consecutive heart failure patients received Doppler echocardiographic optimization of AV and VV delay within 48 hours from CRT device implantation, at 6 months and at 12 months (the last for the first enrolled 14 patients). RESULTS: After implantation, median optimized AV delay was 100 ms (range, 45 ms); VV optimization led to simultaneous biventricular activation in 4 patients, left ventricular preactivation in 17 patients and right ventricular preactivation in 16 patients. At 12 months median AV delay decreased to 85 ms (23 ms) (P < 0.05 vs. baseline). With respect to previous assessment, VV delay variations > or =40 ms were observed in 41% of the patients at 6 months and in 57% of the tested patients at 12 months. A nonconcordance (by Kappa test) of optimized VV delays was found between each new assessment and the previous one. VV delay optimization was associated with significant (P < 0.001) increases in aortic velocity time integral both at baseline and during follow-up. CONCLUSIONS: Echocardiographic optimization of AV and VV delay is associated with broad intraindividual variability during follow-up. A new assessment of optimized VV delays during long-term follow-up reveals a nonconcordance with previous values and provides increases in forward stroke volume.     

心脏再同步治疗难治性心力衰竭的临床应用

目的评价心脏再同步治疗（CRT）难治性心力衰竭的临床疗效。方法21例难治性心力衰竭患者接受CRT治疗;左心室导线采用经心脏静脉血管径路植入或开胸直接缝合左心室心外膜导线。植入术后定期随访,分析患者心功能、活动耐量、生活质量评分、QRS时限、左心室射血分数（LVEF）、左心室舒张末内径（LVEDD）等指标的变化,评价CRT的临床疗效,测试起搏参数并在超声心动图指导下优化AV间期和VV间期。结果21例患者成功植入CRT,其中3例患者因心脏静脉血管畸形而采用开胸植入左心室心外膜导线。平均随访（9．8±9．5）个月,死亡3例;2例患者因心力衰竭症状复发再住院;其余患者心功能分级、生活质量评分、活动耐量较植入术前有显著改善;植入术后1个月LVEF明显提高（0．31±0．06对0．37±0．05,P〈0．01）;二尖瓣反流程度[（2．24±0．89）级对（1．43±0．75）级,P〈0．01];LVEDD植入术后6个月明显减小（（71．91±8．38）mm对（68．82±10．80）mm,P〈0．05];QRS时限分析显示CRT治疗有效组术后明显变窄（（162．50±24．08）ms对（142．50±19．15）ms,P〈0．05],无效组变化不明显[（148．00±10．95）ms对（138．00±4．47）ms,P〉0．05]。1例患者左心室导线脱位。右心房和右心室起搏导线的阈值、感知灵敏度及阻抗均在正常范围,左心室导线各参数,除1例患者阈值升高外余均正常。3例开胸植入心外膜导线患者除1例于植入术后第5个月心脏性猝死,余2例分别随访18个月和26个月,左心室导线阈值分别为0．5V／0．4ms和1．0V／0．4ms。CRT治疗的总临床有效率为76．2％。结论CRT治疗难治性心力衰竭有效,能恢复患者心脏电活动和机械活动的同步性,显著改善心功能。QRS时限变窄是CRT疗效的重要预测指标。     

Long-term clinical effect of hemodynamically optimized cardiac resynchronization therapy in patients with heart failure and ventricular conduction delay

OBJECTIVES: We sought to compare the short- and long-term clinical effects of atrial synchronous pre-excitation of one (univentricular) or both ventricles (biventricular), that provide cardiac resynchronization therapy (CRT). BACKGROUND: In patients with heart failure (HF) who have a ventricular conduction delay, CRT improves systolic hemodynamic function. The clinical benefit of CRT is still being investigated. METHODS: Forty-one patients were randomized to four weeks of first treatment with biventricular or univentricular stimulation, followed by four weeks without treatment, and then four weeks of a second treatment with the opposite stimulation. The best CRT stimulation was continued for nine months. Cardiac resynchronization therapy was optimized by hemodynamic testing at implantation. The primary end points were exercise capacity measures. Data were analyzed by two-way repeated-measures analysis of variance. RESULTS: The left ventricle was selected for univentricular pacing in 36 patients. The clinical effects of univentricular and biventricular CRT were not significantly different. The results of each method were pooled to assess sequential treatment effects. Oxygen uptake during bicycle exercise increased from 9.48 to 10.4 ml/kg/min at the anaerobic threshold (p = 0.03) and from 12.5 to 14.3 ml/kg/min at peak exercise (p < 0.001) with the first treatment, and from 10.0 to 10.7 ml/kg/min at the anaerobic threshold (p = 0.2) and from 13.4 to 15.2 ml/kg/min at peak exercise (p = 0.002) with the second treatment. The 6-min walk distance increased from 342 m at baseline to 386 m after the first treatment (p < 0.001) and to 416 m after the second treatment (p = 0.03). All improvements persisted after 12 months of therapy. CONCLUSIONS: Cardiac resynchronization therapy produces a long-term improvement in the clinical symptoms of patients with HF who have a ventricular conduction delay. The differences between optimized biventricular and univentricular therapy appear to be small for short-term treatment.     

心脏再同步化起搏治疗随访

目的探讨心脏再同步化起搏治疗(CRT)随访的相关技术细节。方法22例难治性充血性心力衰竭(简称心衰)患者(男14例、女8例),年龄59.5±7.8(47~74)岁,其中扩张型心肌病16例、高血压性心脏病6例。按常规方法置入双室起搏器后,按一定程序对起搏系统及患者的临床综合反应随访观察,根据患者反应及时对起搏系统参数进行优化。结果随访22±13.01(1~48)个月,双室起搏辅以优化的起搏参数及药物治疗。心衰临床症状改善,心功能提高,运动耐量增加,生活质量提高,心脏重塑进程延缓,因心衰住院事件减少。结论CRT必须从置入起搏器的即刻开始进行动态随访、优化起搏参数。     

Prospective comparison of echocardiographic atrioventricular delay optimization methods for cardiac resynchronization therapy

BACKGROUND: Atrioventricular (AV) delay optimization can be an important determinant of the response to cardiac resynchronization therapy (CRT) in patients with medically refractory heart failure and a ventricular conduction delay. OBJECTIVES: The purpose of this study was to compare two Doppler echocardiographic methods of AV delay optimization after CRT. METHODS: Forty consecutive patients (age 59 +/- 12 years) with severe heart failure, New York Heart Association class 3.1 +/- 0.4, QRS duration 177 +/- 23 ms, and left ventricular ejection fraction 26% +/- 6% referred for CRT were studied using two-dimensional Doppler echocardiography. In each patient, the acute improvement in stroke volume with CRT in response to two methods of AV delay optimization was compared. In the first method, the AV delay that produced the largest increase in the aortic velocity time integral (VTI) derived from continuous-wave Doppler (aortic VTI method) was measured. In the second method, the AV delay that optimized the timing of mitral valve closure to occur simultaneously with the onset of left ventricular systole was calculated from pulsed Doppler mitral waveforms at a short and long AV delay interval (mitral inflow method). RESULTS: The optimized AV delay determined by the aortic VTI method resulted in an increase in aortic VTI of 19% +/- 13% compared with an increase of 12% +/- 12% by the mitral inflow method (P <.001). The optimized AV delay by the aortic VTI method was significantly longer than the optimized AV delay calculated from the mitral inflow method (119 +/- 34 ms vs 95 +/- 24 ms, P <.001). There was no correlation in the AV delay determined by the two methods (r = 0.03). CONCLUSION: AV delay optimization by Doppler echocardiography for patients with severe heart failure treated with a CRT device yields a greater systolic improvement when guided by the aortic VTI method compared with the mitral inflow method.