吸入小剂量一氧化氮降低先天性心脏病肺动脉高压的初步研究

目的：探索吸入小剂量一氧化氮（ＮＯ）对先天性心脏病（先心病）肺动脉高压的治疗作用。方法：先心病合并肺动脉高压〔平均肺动脉压（ＭＰＡＰ）＞６．４ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）〕患者９例，年龄３～２０岁，在自主呼吸下吸入３６±１０ｖｐｍ的ＮＯ，监测并记录ＮＯ吸入前和吸入后１、３、５、１０和１５分钟时的ＭＰＡＰ、平均血压（ＭＢＰ）、心率（ＨＲ）、脉搏氧饱和度（ＳｐＯ２）、混合静脉血氧饱和度（ＳｖＯ２）等参数的变化。结果：基础ＭＰＡＰ为９．５±１．８ｋＰａ，吸入ＮＯ后各时间点ＭＰＡＰ显著降低，波动于８．９～８．１ｋＰａ（Ｐ＜０．０５）；并可明显增高ＳｖＯ２（Ｐ＜０．０５），从０．７６±０．０６升至０．８３±０．０２（Ｐ＜０．０５）；ＭＢＰ、ＨＲ和ＳｐＯ２无明显变化。结论：吸入小剂量ＮＯ确能选择性降低先心病合并肺动脉高压患者的肺动脉压，并增高ＳｖＯ２；吸入小剂量ＮＯ对这类患者围手术期有显著治疗前景。     

一氧化氮吸入治疗心脏术后肺动脉高压的护理

心脏手术患者术后并发肺动脉高压(ＰＨ)与肺血管内皮细胞缺氧时与一氧化氮 (ＮＯ)代谢障碍有关 ,这类患者吸入适量的外源性ＮＯ对降低肺动脉压有一定的作用 ,ＮＯ半衰期极短 (3～ 4ｓ) ,易被血红蛋白迅速灭活 ,因此吸入ＮＯ只扩张肺血管 ,对体循环无影响[1 ] 。现就对我科 1996年10月～ 1998年 4月 12例中至重度肺动脉高压患者术后吸入ＮＯ治疗的护理要点作初步的探讨。1　资料与方法1 1　一般资料　 12例中男 7例 ,女 5例 ,年龄 3～ 5 5岁。心脏瓣膜置换术 3例 ,肺动脉栓塞 1例 ,其余为先天性心脏病心房、室间隔缺损修补患者。1 2　ＮＯ吸…     

一氧化氮吸入疗法对烟雾吸入性损伤犬心脏能量代谢和病理变化的研究

目的：评价烟雾吸入性损伤犬吸入一氧化氮（ＮＯ）后心脏病理改变与心室肌组织能量代谢的变化。方法：２１只犬随机分为３组,烟雾吸入损伤后,对照组（８只）单纯吸氧（ＦｉＯ２＝０．４５）,治疗组（９只）吸氧（ＦｉＯ２＝０．４５）＋０．００４５％ＮＯ,正常组（４只）不致伤,用于病理和组织学对照。实验终点进行心室肌组织学和病理形态学检测。结果：对照组ＡＴＰ含量和能量负荷（ＥＣ）显著低于正常组和治疗组（Ｐ均＜０．０１）,对照组ＡＤＰ和ＡＭＰ含量明显低于正常组（Ｐ均＜０．０１）,但ＡＤＰ明显高于治疗组（Ｐ＜０．０５）;心脏光镜和电镜病理所见,治疗组病理性改变程度较对照组轻。结论：在烟雾吸入性损伤犬模型中,吸入ＮＯ可不同程度改善心肌组织能量代谢,心脏病理形态改变也有一定程度减轻,表明ＮＯ吸入疗法对改善心脏能量代谢和病理改变有益。     

地塞米松对急性颅脑损伤患者血内NOS活性和NO产量的影响

目的 了解地塞米松（ＤＭ）对急性颅脑损伤（ＡＣＩ）患者围术期血内一氧化氮合成酶（ＮＯＳ）活性和一氧化氮（ＮＯ）产量的影响。方法 ２０例ＡＣＩ患者随机分为ＤＭ治疗组（于麻醉诱导前０．４ｍｇ／ｋｇＩＶ）和对照组,用分光光度法测定血清ＮＯＳ活性和ＮＯ产量。结果 术前两组ＮＯＳ、ＮＯ均高于下沉对照组,其中ＮＯＳ有显著性差异（Ｐ〈０．０１）。ＤＭ组自麻醉诱导前至开颅手术后２４小时（Ｔ０～Ｔ５）动态观察发现,ＮＯ、ＮＯＳ自始至终呈降低趋势;而对照组则呈显著性升高（ＮＯＴ１、Ｔ５,ＮＯＳＴ５）,组间比较有显著性差异。结论 ＡＣＩ患者术前存在ＮＯＳ、ＮＯ代谢率乱,开颅手术后其含量进一步升高而加重脑缺血再灌注损伤。麻醉诱导时应用ＤＭ可显著抑制ＡＣＩ患者体内ｉＮＯＳ释放具有脑保护作用。可作为选择性ｉＤＯＳ拮抗剂在临床应用。     

中,重度急性一氧化碳中毒患者血一氧化氮含量的测定

２５例急性一氧化碳（ＣＯ）中毒患者血一氧化氮（ＮＯ）检测结果，报告如下。１病例与方法１．１病例：１９９６年１０月～１９９８年２月在本院ＩＣＵ住院的急性ＣＯ中毒患者２５例，均伴有不同程度的昏迷，按文献〔１〕诊断标准分中度和重度中毒。中度中毒组９例，男５...     

吸入一氧化氮改善烟雾吸入性损伤犬肺通气功能的意义

目的评价吸入一氧化氮（ＮＯ）对犬烟雾吸入性损伤肺通气功能改善的效果。方法烟雾吸入伤后，将１７只犬随机分为２组，对照组（ｎ＝８）单纯吸氧（ＦｉＯ２，０．４５），治疗组（ｎ＝９）吸氧（ＦｉＯ２，０．４５）＋０．００４５％（４５ｐｐｍ）ＮＯ，连续监测１２小时血气变化；并按时相点抽血检测有关指标。数据行多个样本均数间方差分析。结果吸入ＮＯ治疗组ＰａＣＯ２、呼吸指数（ＲＩ）、肺泡死腔率（ＶＤ／ＶＴ）、肺动脉分流率（ＱＳ／ＱＴ）和碳氧血红蛋白（ＨｂＣＯ）含量比对照组均有不同程度的下降（Ｐ＜０．０５～０．０１），而动脉血浆亚硝酸盐（ＮＯ－２）水平则明显高于对照组（Ｐ＜０．０１）。结论吸入ＮＯ能明显改善肺通气功能，作为吸入性损伤的综合治疗，吸入ＮＯ疗法值得进一步研究。     

一氧化氮对吸入性损伤犬肺功能的改善作用及机制

目的：评价吸入一氧化氮（ＮＯ）对烟雾吸入性损伤犬肺功能的改善效果，并验证其作用机制。方法：２１只犬随机分为３组，烟雾吸入后的对照组（８只）给予单纯吸氧（ＦｉＯ２０．４５）；治疗组（９只）吸氧（ＦｉＯ２０．４５）＋０．００４５％ＮＯ，连续监测１２小时血气变化；正常组（４只）不致伤，用于建立组织学对照。数据行多个样本均数间方差分析。结果：治疗组肺氧合功能明显改善（Ｐ均＜０．０５），肺通气功能也明显改善（Ｐ均＜０．０５）；动脉血和肺组织环磷酸鸟苷（ｃＧＭＰ）明显升高（Ｐ均＜０．０１）。结论：吸入ＮＯ能明显改善肺功能，其作用机制为提高平滑肌细胞内ｃＧＭＰ水平。推荐临床应用吸入ＮＯ作为吸入性损伤的综合治疗方法。     

血浆代用品血定安和林格氏液对机体血液动力学影响的比较观察

目的：比较血定安和林格氏液对机体血流动力学的影响。方法：选择２０例硬膜外阻滞下行子宫切除术的患者，在平面固定于Ｔ６－Ｓ后分为血定安组（组１）和林格氏液组（组２）、用无创性连续心排血量监测仪（ＢＯＭＥＤ－ＮＣＣＯＭ－３）测定血流动力学数值。结果：两组患者心排血量（ＣＯ）、心脏指数（ＣＩ）、每搏量（ＳＶ）和每搏指数（ＳＩ）等指标在硬膜外阻滞平面固定后均有明显下降。但在组１快速输注血定安５００ｍｌ后这些     

超声雾化吸入的疗效观察和护理研究

为了研究超声雾化吸入在治疗小儿急性阻塞性呼吸道疾病（ＡＯＰＤ）中的疗效及其护理要点，深入研究达到最佳疗效的护理方法，优选最适宜于超声雾化吸入的抗菌药物，本课题以２岁以内的小儿ＡＯＰＤ为研究对象，共计５７例，分成两组，即立克菌星组（简称Ｎ组）３１例，庆大霉素组（简称Ｇ组）２６例。两组均采用超声雾化吸入，以体温、咳嗽、喘鸣、呼吸困难和罗音的持续时间为参数，作为判断疗效的指标。经统计结果表明，除喘鸣持续时间外，其他４项指标均显示Ｎ组的改善程度比Ｇ组显著（Ｐ＜０．０５），且用药期间无任何毒副反应     

参麦注射液在腹部外伤低血容量性休克致多脏器功能失常综合征中的防治作用

目的：探讨参麦注射液对腹部外伤并发低血容量性休克所致多脏器功能失常综合征（ＭＯＤＳ）的防治作用。方法：腹部外伤低血容量性休克患者６８例，随机分成２组。对照组３２例，采用手术及综合治疗；治疗组３６例，在手术及综合治疗基础上于休克发生后２４小时内加用参麦注射液静滴，每日１次。观察创伤后不同时间ＭＯＤＳ发生数和死亡数。结果：创伤后３日，治疗组ＭＯＤＳ发生数和死亡数与对照组比较无显著性差异（Ｐ＞０．０５），创伤后第５、７、１１、１５日治疗组的ＭＯＤＳ发生数和死亡数与对照组比较均有显著性差异（Ｐ＜０．０５和Ｐ＜０．０１）。结论：参麦注射液有扩张血管、改善微循环和调节免疫功能的作用。创伤发生后早期连续应用参麦注射液对腹部外伤并发低血容量性休克所致的ＭＯＤＳ具有预防作用。     

高血压病左心功能相关性的超声研究

目的 探讨高血压病左心房与左心室功能的相关关系。方法 对照组20例，高血压病左心室心肌质量指数(LVMI)正常组32例，高血压病左心室肥厚组16例，采用声学定量技术，测量左心房助力泵功能(LAEF、AE)、管道功能(CV)和储存器功能(RV)以及左心室舒张功能。结果 左心房助力泵功能与其主动收缩前容量、RV正相关，与CV及左心室舒张功能负相关；左心房管道功能与AE、LAEF、RV和左心房主动收缩前容量显著负相关，与左心室舒张功能正相关；左心房储存器功能与左心房主动收缩前容量、LAEF正相关，与CV负相关，与左心室舒张功能指标无显著相关。结论 高血压病左心室舒张功能减退导致左心房管道功能减低、肺静脉与左心房间压差增大、左心房储存器功能增强、左心室舒张早期充盈增加，而管道功能与储存器功能的改变导致左心房前负荷增加和左心房收缩能力增强、左心房助力泵功能增强、左心室舒张晚期充盈增加。     

Influence of Different Atrioventricular and Interventricular Delays on Cardiac Output During Cardiac Resynchronization Therapy

Restoration of the atrioventricular (AVD) and interventricular (VVD) delays increases the hemodynamic benefit conferred by biventricular (BiV) stimulation. This study compared the effects of different AVD and VVD on cardiac output (CO) during three stimulation modes: BiV-LV = left ventricle (LV) preceding right ventricle (RV) by 4 ms; BiV-RV = RV preceding LV by 4 ms; LVP = single-site LV pacing. We studied 19 patients with chronic heart failure due to ischemic or idiopathic dilated cardiomyopathy, QRS ≥ 150 ms, mean LV end-diastolic diameter = 78 ± 7 mm, and mean LV ejection fraction = 21 ± 3%. CO was estimated by Doppler echocardiographic velocity time integral formula with sample volume placed in the LV outflow tract. Sets of sensed-AVDs (S-AVD) 90–160 ms, paced-AVDs (P-AVD) 120–160 ms, and VVDs 4–20 ms were used. BiV-RV resulted in lower CO than BiV-LV. S-AVD 120 ms and P-AVD 140 ms caused the most significant increase in CO for all three pacing modes. LVP produced a similar increase in CO as BiV stimulation; however, AV sequential pacing was associated with a nonsignificantly higher CO during LVP than with BiV stimulation. CO during BiV stimulation was the highest when LV preceded RV, and VVD ranged between 4 and 12 ms. The most negative effect on CO was observed when RV preceded LV by 4 ms. Hemodynamic improvement during BiV stimulation was dependent both on optimized AVD and VVD. LV preceding RV by 4–12 ms was the most optimal. Advancement of the RV was not beneficial in the majority of patients.     

实时三维超声心动图定量冠心病、扩张型心肌病心房和心室容积及功能的研究

目的应用实时三维超声心动图(RT-3DE)定量评价冠心病、扩张型心肌病患者左心室、左心房、右心室和右心房容积及收缩功能。方法在24例正常人、16例扩张性心肌病和27例心肌梗死患者中,应用实时三维超声心动图获取各房室全容积三维图像,分别应用2、4、8平面方法测量各房室收缩末期容积(ESV)、舒张末期容积(EDV)和射血分数(EF),并与二维超声心动图(2DE)Simpson法和声学定量(AQ)技术测值比较。结果在扩张性心肌病和心肌梗死患者中,2DE、AQ技术和RT-3DE2平面法测量的左、右心房和左、右心室ESV、EDV明显低于RT-3DE4平面法、8平面法测值(P<0.05);各种方法检测的EF值差异无统计学意义(P>0.05)。2DE、AQ技术和RT-3DE检测结果均显示扩张性心肌病、心肌梗死患者各房室ESV、EDV均明显大于正常组(P<0.05),EF明显低于正常组(P<0.05)。结论应用实时三维超声心动图能显示心腔立体结构,测量各心腔容积,评价心脏功能。     

心脏MRI评估肺动脉高压患者的心功能

目的探讨心脏MRI(CMRI)评价肺动脉高压(PH)患者心室功能的临床价值。方法对30例PH患者(PH组)及30名健康志愿者(对照组)进行CMRI,分别计算右心室(RV)与左心室(LV)的舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量(SV)、射血分数(EF)、舒张末期心肌质量(MM)等心功能参数,除EF外均经体表面积(BSA)校正,记为EDVI、ESVI、SVI、MMI。计算心室质量指数(VMI,为舒张末期RV MM与LV MM的比值)。采用两独立样本t检验分析两组参数有无差异。结果 PH组RV EDVI、ESVI及MMI均显著高于对照组(P均<0.01),RV EF显著低于对照组(P<0.01),两组RV SVI的差异无统计学意义(P>0.05)。PH组LV EDVI和SVI显著低于对照组(P均<0.05),而LV ESVI、EF及MMI与对照组的差异均无统计学意义(P均>0.05)。PH组VMI显著高于对照组(P<0.01)。PH组中23例(23/30,76.67%)患者LV舒张早期可见明显变形,其中室间隔变平10例,室间隔向左弓形突出13例。结论CMRI能够无创、准确地提供PH患者RV与LV的功能信息,对于评价PH患者心室功能具有重要价值。     

Relevance of Echocardiographic Evaluation of Right Ventricular Function in Patients Undergoing Cardiac Resynchronization Therapy

Aims: Right ventricular (RV) dysfunction is a marker of poor prognosis in heart failure (HF) patients. It is still unclear whether RV function might influence response to cardiac resynchronization therapy (CRT).
Methods: Forty-four consecutive patients with HF, large QRS, and either intraventricular or interventricular dyssynchrony underwent echocardiographic evaluation before, 1 month after, and 6 months after CRT. Response to CRT was considered in case of significant LV reverse remodeling, defined as the occurrence of LV end-systolic volume (LVESV) reduction ≥15% at 6 months.
Results: All echocardiographic indexes of baseline RV function and dimensions were significantly more impaired in nonresponders versus responders to CRT: tricuspid annular plane systolic excursion (TAPSE 15 ± 4 mm vs 20 ± 5 mm, P = 0.001), RV systolic pulmonary artery pressure (RVSP 39 ± 14 mmHg vs 27 ± 8 mmHg, P = 0.02), RV end-diastolic area (RVEDA 23 ± 6 cm² vs 16 ± 3 cm² P < 0.001), RV end-systolic area (RVESA 16 ± 6 cm² vs 8 ± 2 cm², P = 0.001), and RV fractional area change (30 ± 12% vs 48 ± 8%, P < 0.001). All the indexes of RV function significantly correlated with the percentage of LVESV reduction after CRT. Severe RV dysfunction was defined as TAPSE ≤14 mm and the population was stratified into two groups based on baseline TAPSE ≤ or > 14 mm. As compared to those with high TAPSE (n = 30), patients with low TAPSE (n = 14) were less likely to show LV reverse remodeling after CRT (76% vs 14%, P < 0.001).
Conclusions: Our study suggests that RV function significantly affects response to CRT. Poor LV reverse remodeling occurs after CRT in patients with HF having severe RV dysfunction at baseline.     

Effect of Hypoxemia on Fetal Ventricular Deformation in a Chronically Instrumented Sheep Model

We hypothesized that in near-term sheep fetuses, hypoxemia changes myocardial function as reflected in altered ventricular deformation on speckle-tracking echocardiography. Fetuses in 21 pregnant sheep were instrumented. After 4 d of recovery, fetal cardiac function was assessed by echocardiography at baseline, after 30 and 120 min of induced fetal hypoxemia and after its reversal. Left (LV) and right (RV) ventricular cardiac output and myocardial strain were measured. Baseline mean (standard deviation [SD]) LV and RV global longitudinal strains were ?18.7% (3.8) and ?14.3% (5.3). Baseline RV global longitudinal and circumferential deformations were less compared with those of the left ventricle (p = 0.016 and p < 0.005). LV, but not RV, global longitudinal strain was decreased (p = 0.003) compared with baseline with hypoxemia. Circumferential and radial strains did not exhibit significant changes. In the near-term sheep fetus, LV global longitudinal and circumferential strains are more negative than RV strains. Acute hypoxemia leads to LV rather than RV dysfunction as reflected by decreased deformation.     

Right ventricular pressure overload during acute lung injury: Cardiac mechanics and the pathophysiology of right ventricular systolic dysfunction

Right ventricular (RV) pressure overload (PO) accompanying acute lung injury is associated with a poor prognosis. To determine if RV ischemia (RVI) is responsible for RV failure (RVF) during acute PO induced by an acute lung injury, a group of eight dogs was studied with the pericardia open after instrumentation with RV, left ventricular (LV), and pulmonary artery (PA) Millar catheters, a PA thermodilution catheter, an aortic fluid-filled catheter, and RV and LV septal-free wall segment length crystals. The animals were studied during baseline, and after infusing glass beads into the right atrium sufficient to first double the PA pressure (PAP), then triple the PAP, and finally to produce RVF (decreased cardiac output with increased RV preload). Transmural RV biopsies were obtained at each phase for adenosine triphosphate and creatine phosphate (CP) assays. To determine the mechanism of RVI, a second group of nine dogs was studied (with the pericardia closed) at baseline, after a doubling of PAP and during RVF. Right ventricular myocardial blood flow was determined by a microsphere technique at each phase and was correlated with the determinants of RV myocardial O₂ demand and supply. In the open pericardia group, RVF, but not doubling or tripling of PAP, was associated with a decrease in CP to 50% of baseline conditions, confirming RVI (4.82 ± 3.67 versus 10.39 ± 3.94 μmol/gm wet weight; P < .005). In the closed pericardia group, RV myocardial blood flow increased in response to myocardial O₂ demands (multiple R = .69 for endocardial and .64 for epicardial flow; P < .05), although the ratio for total RV blood flow to myocardial O₂ demand ratio (planimetered area beneath RV pressure tracing) decreased (4.88 ± 2.76 versus 2.08 ± 2.14; P < .05). In both groups of dogs, RVF was associated with a similar decrease in LV end diastolic segment length or preload (17% in open group and 10% in closed group; P = NS between groups) and stroke work. From these observations, we conclude that after an acute lung injury, RVPO induces RVF because RV myocardial O₂ demand outstrips RV myocardial O₂ supply. Coincidentally with RVF, LV function is depressed on a preload-mediated basis independent of the pericardium, suggesting a dominant “series” interaction between both ventricles. These observations suggest that therapy in patients with acute lung injury is better aimed at increasing RV myocardial blood flow and RV function.     

Diffuse fibrosis is common in the left,but not in the right ventricle in patients with transposition of the great arteries late after atrial switch operation

In adult patients with transposition of the great arteries (TGA) late after atrial switch operation (AtSO), each of the ventricles is faced with a profoundly different pressure regimen from the one they are meant to support in normal conditions. The extent of diffuse fibrosis of the right ventricle (RV) and left ventricle (LV) in these patients remains incompletely investigated. Aim of this study was to quantify the degree of fibrosis of the unloaded LV and of the overloaded RV by determining the myocardial extracellular volume (ECV) with non-invasive techniques as T1 mapping. We determined ECV by cardiac magnetic resonance (CMR) in 10 patients (36.8?±?5.3 years old) with TGA late after AtSO, without relevant pulmonary stenosis, by acquiring T1-maps of the myocardium before and 10 min after injection of Gadolinium-based contrast agent. ECV of the inferior wall (36% (33–41%)) and of the lateral wall (37% (35–39%)) of the LV was significantly increased compared to the ECV of the RV (27% (25–29%)), in both comparisons P?<?0.0001. Long-time LV unloading following atrial switch procedures leads to severe myocardial fibrosis of the subpulmonary LV. T1 mapping CMR might be useful for selection of patients with atrial switch operation, in whom reestablishment of the LV as a systemic ventricle by staged arterial switch operation is planned. However larger studies and newer higher resolution methods for T1-mapping are needed to determine the role of ECV in the decision of a surgical intervention in this kind of population.     

Estimation of left ventricular systolic function by single transpulmonary thermodilution

Objective The single-indicator transpulmonary thermodilution technique (PiCCO system) provides two derived indices of cardiac systolic function: the cardiac function index and the global ejection fraction. We used transesophageal echocardiography to compare theses indices with left ventricular fractional area of change only for patients with no isolated right ventricular dysfunction. (The global cardiac systolic function may be decreased despite preserved left ventricular function in this situation.)Design Prospective, open, clinical study.Setting Intensive care unit (ICU) in a university hospital.Patients Thirty-three mechanically ventilated patients.Intervention Left ventricular fractional area of change (LVFAC) was measured using transesophageal echocardiography. The cardiac function index (CFI) and the global ejection fraction (GEF) were determined from transpulmonary thermodilution-derived cardiac output and thoracic volumes.Measurements and main results Transesophageal echocardiography identified 3 patients with isolated right ventricular failure (PiCCO underestimated LVFAC in this situation). Significant correlations were established between LVFAC and CFI (r=0.87, n=30, p<0.0001) or GEF (r=0.82, n=30, p<0.0001). The mean differences between measured LVFAC and LVFAC estimated with CFI or GEF were 0.8±8.5% (range: –17 to 14%) and 0.8±9.0% (range: –21 to 19%), respectively. Area under the receiver operating characteristics curves for the estimation of LVFAC 40% using CFI or GEF was 0.92. CFI >4 and GEF >18% estimated LVFAC 40% with respective sensitivities of 86 and 88% and specificities of 88 and 79%. Significant correlations were established between changes of LVFAC and CFI/GEF over time.Conclusions In mechanically ventilated ICU patients, PiCCO-derived cardiac function index and global ejection fraction provide reliable estimations of LV systolic function but may underestimate it in the cases of isolated right ventricular failure.     

Similar Long-Term Benefits Conferred by Apical Versus Mid-Septal Implantation of the Right Ventricular Lead in Recipients of Cardiac Resynchronization Therapy Systems

Introduction: The benefits conferred by cardiac resynchronization therapy (CRT) are markedly influenced by the left ventricular (LV) lead placement. Little is known regarding the optimal right ventricular (RV) stimulation site.
Study Objective: To compare the long-term outcomes of CRT in patients with RV leads placed in the mid-septal region versus the apex.
Methods and Results: This nonrandomized, observational study included 117 patients with standard indications for CRT. The LV lead was implanted on the postero-lateral or lateral LV wall, while the RV lead was implanted at the apex (n = 82) or in the mid-septum (n = 35). Both groups were similar with respect to baseline clinical, demographic, and echocardiographic characteristics. After 12 months of CRT, the rates of clinical response to CRT were similar in both groups (63% vs. 66%), and similar degrees of reverse LV remodeling and LV resynchronization were observed on echocardiography and color tissue Doppler imaging. A ≥30% relative increase in LV ejection fraction (EF) occurred in 76% of patients in the RV apex group, versus 49% of patients in the RV mid-septum group (P = 0.05). A ≥45% left ventricular ejection fraction (LVEF) was measured at 12 months in 40% of patients in the RV apex group, versus 31% in the RV mid-septum group (ns).
Conclusions: RV mid-septal stimulation was not associated with a higher rate of response to CRT or greater improvement in LV function compared to RV apical stimulation.