Left Ventricular Hypertrophy

The electrocardiogram or vectorcardiogram often indicates features compatible with left ventricular hypertrophy in persons who do not have the condition. Increased QRS voltage, increased QRS duration, and ST-T changes in an isolated electrocardiogram or vectorcardiogram may mislead the physician, but serial records noting progressive changes appreciably improve the accuracy of diagnosis.     

Ventricular Activation Onset-Triggered Left Ventricular Pacing:

Ventricular activation onset-triggered (VAOT) left ventricular pacing modalities synchronize left ventricular paced activation with existing intrinsic ventricular activation, in patients with complete LBBB and adequate rate. The purpose of this study was to evaluate the safety and feasibility of VAOT pacing with one left ventricular pacing lead, during temporary pacing in the postoperative period following open heart surgery. VAOT pacing was studied in five patients with LBBB and two patients with previously implanted right ventricular pacemakers. The VAOT pacing system used was assembled by modifying the function of existing equipment and its programming is described in detail. Comparative ECGs are reported, documenting the changes in ventricular activation produced by VAOT pacing. Stability of surface ECG acquisition was found to be essential to the success of temporary VAOT pacing and inappropriate pacing due to ECG instability is described. Patients were studied at rest and none experienced congestive heart failure. In the comparison of cardiac output, with and without VAOT pacing, no significant differences were found in LBBB patients or those with right ventricular pacemakers. In the comparison of arterial pressure, with and without VAOT pacing, no significant differences were found in six patients, however, in one LBBB patient with intrinsic predominant ventricular trigeminy, VAOT pacing was observed to have an antiarrhythmic effect resulting in suppression of ventricular ectopy and stabilization of arterial pressure. All patients survived VAOT pacing and the postoperative period without complications requiring additional intervention or treatment. (PACE 2004; 27[Pt. I]:730–739)     

左室舒张功能不全

左室舒张功能不全吴向明综述陆凤翔审校（安徽省明光市人民医院明光２３９４００）ＬｅｆｔＶｅｎｔｒｉｃｕｌａｒＤｉａｓｔｏｌｉｃＤｙｓｆｕｎｃｔｉｏｎＷｕＸｉａｎｇｍｉｎｇ（Ｐｅｏｐｌｅ’ｓＨｏｓｐｉｔａｌｏｆＭｉｎｇｇｕａｎｇＭｕｎｉｃｉｐａｌｉｔｙ，...     

等容舒张期左室平均压力变化率评价左室舒张功能的价值

目的：探讨等容舒张期左室平均压力变化率评价左室舒张功能的价值。方法： 采用多普勒超声及计算机技术测量５０ 例二尖瓣返流患者左室舒张功能的指标。结果： 等容舒张期左室平均压力变化率（－ ｄｐ／ｄｔｍ ｅａｎ） 与左室压力最大下降速率（－ ｄｐ／ｄｔｍ ａｘ）显著相关（ｒ＝ ０．８７）,与左室心肌松弛时间常数中度相关（ｒ＝ ０．５６）;以－ ｄｐ／ｄｔｍ ａｘ＜ １５００ｍｍ Ｈｇ／ｓ定为左室舒张功能异常,－ ｄｐ／ｄｔｍ ｅａｎ＜ １２００ｍ ｍ Ｈｇ／ｓ判断左室舒张功能异常的敏感性为８５％ ,特异性为１００％ 。结论： － ｄｐ／ｄｔｍ ｅａｎ 可准确、无创性评价左室舒张功能。     

健康人左室质量与舒张功能的关系

目的：探讨健康人左室质量与左室舒张功能的关系。方法：随机选取健康教师320名，行彩色多普勒超声心动图检查，结果：相关分析显示：伴随左室质量的增加E波的峰值速度下降，A波的峰值增加，二者比值下降，等容松驰时间延长，肺静脉收缩波峰值与舒峰值之比增加，但多元回归显示年龄增长、心率加快、体重指数大、血压高和男性是舒张功能减退的独立因素，左室质量指数进入多元回归方程，结论：决定健康人左室舒张功能的因素是年龄、心率、体重指数，血压和性别而不是左室质量。     

多普勒超声获取左室射血时间与二尖瓣返流持续时间比值评价左室收缩功能

本文探讨应用多普勒获取左室射血时间与二尖瓣返流持续时间比值评价左室收缩功能。４７例接受彩色多普勒检查存在返流者，根据返流大小分为轻、重度返流者。结果表明：应用多普勒获取校正ＬＶＥＴ／ＭＲ－ｄ比值与超声心动图双平面面积－长度Ｓｉｍｐｓｏｎ法估测ＬＶＥＦ在全部受检者及轻、重度返流组分别存在较好相关性（ｒ＝０．６５、ＳＥＥ１７％；ｒ＝０．８０ＳＥＥ９％；ｒ＝０．６８ＳＥＥ１９％），同时根据校正ＬＶＥＴ／ＭＲ－ｄ比值估测左室收缩功能障碍存在较高的敏感性、特异性及准确率。因此用校正ＬＶＥＴ／ＭＲ－ｄ比值可用于评价左室收缩功能。     

原发性高血压不同左室构型对左室功能的影响

目的　探讨原发性高血压不同左室构型对左室功能的影响。方法　根据Ganau’s分类法将 72例原发性高血压患者分为正常左室构型组 ,向心性重构组 ,向心性肥厚组、离心性肥大组。运用超声心动图和彩色多普勒技术检测各组LVEF、CO、CI、SV ;二尖瓣口E、A峰 ,E、A峰流速积分 (EVI、AVI)及E/A、EVI/AVI和IVRT ,并与正常组对照。结果　①向心性重构组CI、SV值降低、离心性肥大组LVEF值降低 ,高血压各组E/A、EVI/AVI、A峰、AVI、IVRT有改变 ,与对照组比较有显著性差异 ;②高血压各组间多无显著性差异。③向心性肥厚和离心性肥大组可有E/A <1、12 .0三种模式 ,其中 1相似文献   

Adenosine Sensitive Left Ventricular Tachycardia

Presented here is a 39-year-old male patient with no structural heart disease but a ventricular tachycardia with right bundle branch block morphology and right axis deviation, which is responsive to adenosine. The ventricular tachycardia was initiated by ventricular pacing, shown to originate from the mid-anterior free wall region of the left ventricle and terminated by adenosine. Radiofrequency current application at a site where presumed P potentials were recorded eliminated the tachycardia, a finding that suggests that the origin of the tachycardia may be closely related to the anterior fascicle.     

Asystole Following Left Ventricular Pacing

During biventricular ICD implantation, pacing the epicardial inferior posterior-lateral surface of the left ventricle via the coronary sinus produced asystole. The proposed mechanism is a Bezold-Jarisch reflex manifested by a drop in heart rate and blood pressure through direct C fiber stimulation. (PACE 2004; 27[Pt. I]:815–817)     

Carbamazepine-Associated Severe Left Ventricular Dysfunction

Introduction: The cardiovascular effects of carbamazepine are well-known but left ventricular dysfunction is rarely reported. Case Report: We describe 2 cases of severe carbamazepine-associated left ventricular dysfunction during massive self intoxications in young patients without preexistent cardiac disease. We compare our cases to the available literature and discuss the mechanisms implied in the development of left ventricular dysfunction following carbamazepine overdose. Bedside echocardiography was useful in both diagnosis and treatment.     

左室舒张早期血流传播时间与左室松弛时间常数的相关性分析

目的：探讨舒张早期二尖瓣血流Ｅ波流速相地于空间点和时间点的变化及其与左室舒张的关系,寻找估测左室舒张功能的新指标。方法;在犬实验中应用心导管法测量左室松驰时间常数（Ｔ）,应用脉冲波多普勒测量二法瓣瓣肖及瓣下１ｃｍ及２ｃｍ三个取样点的Ｅ波流速拉下各与瓣尖Ｅ波流速比值,各点心电图Ｒ波顶峰至Ｅ波顶峰的时间（Ｒ－Ｅ）、瓣下各点与瓣尖Ｒ－Ｅ０时间幽会测定对照状态和结扎冠状动脉后各项指标的变化,并分析脉冲多普     

左室中层缩短率与高血压者左室构型和左室重量关系的研究

目的 探讨左室中层缩短率与高血压患者左室构型及左室重量的关系.方法 收集2008年10月～2008年12月的51例患者入高血压病组,47名健康体检者作为正常对照组.分析临床特点,同时行超声心动图,采用常规M型测定左室舒张末内径、收缩未内径、左室舒张末和收缩末容量,软件计算射血分数、缩短分数、左室中层缩短率以及相对室壁厚度和左室重量.根据相对室壁厚度和左室重量将高血压患者分为4个亚组:正常结构组、向心性蕈构组、向心性肥厚组和离心性肥厚组.分析各组的收缩功能指标,观察左室中层缩短率与左室相对室壁厚度和左室重量的相关性.结果 ①高血压组与对照组比较:高血压组室间隔舒张末内径显著增加(1.18±0.28 vs 0.95±0.13,P<0.001)、后壁舒张末内径明显增加(1.01±0.17 vs 0.89±0.17,P<0.01)、左室中层缩短率明显降低(18.0±4.9 vs 22.3±5.9,P<0.01).②高血压不同构型亚组的收缩功能和左室构型的比较:左室舒张期室间隔厚度、相对窜壁厚度、左室重量差异有统计学意义,而舒张末左室内径、射血分数以及缩短分数差异无统计学意义,左室中层缩短率有统计学差异(P<0.05).③高血压组左室收缩功能与相对室壁厚度和左室重量的相关性:左室中层缩短率与相对室壁厚度相关(r=-0.42,P<0.05)、左室中层缩短率与左室重量指数显著相关(r=0.67,P<0.01)、而射血分数、缩短分数与左室重量、相对室壁厚度之间无相关关系.结论 左室壁内缩短分数可以更有效的评价早期高血压患者的收缩功能,并与其相对室壁厚度和左室重量有相关关系.     

Epicardial Macroreentrant Ventricular Tachycardia Associated with a Left Ventricular Aneurysm

A 62‐year‐old man with severe coronary artery disease and a left ventricular aneurysm underwent catheter ablation of ventricular tachycardia (VT) with right bundle branch block QRS morphology. Endocardial bipolar voltage mapping with standard threshold settings demonstrated no low‐voltage areas within the aneurysm. Catheter ablation of the epicardial surface of the aneurysm eliminated the VT. Endocardial bipolar voltage mapping with any other settings could not predict the site of the epicardial arrhythmogenic substrate whereas endocardial unipolar voltage mapping could. Endocardial unipolar voltage mapping may be helpful for predicting epicardial arrhythmogenic substrates. (PACE 2012; 35:e13–e16)     

斑点追踪技术对高血压并左室肥厚患者左室扭转及解旋运动的研究

目的 应用斑点追踪技术(STI)评价高血压合并左室肥厚(LVH)患者左室的扭转及解旋运动.方法 采集29例正常人和50例原发性高血压伴轻度左室肥厚(LVH)及中-重度LVH患者左室短轴心尖和心底水平二维图像,用EchoPAC工作站脱机分析.计算扭转角度峰值(Ptw)、收缩末期扭转角度(AVCtw)、等容舒张末期扭转角度(MVOtw)、解旋率(UntwR)、扭转速度峰值(PTV)、扭转速度达峰时间(TPTV)、解旋速度峰值(PUV)和解旋速度达峰时间(TPUV).结果 高血压轻度LVH及中-重度LVH组Ptw、AVCtw、MVOtw较正常组明显增加(P<0.05).UntwR在三组间两两比较,差异均有显著性(P<0.05).与正常组及轻度LVH组比较,中-重度LVH组TPUV明显延长(P<0.05).结论 STI技术可准确评价高血压LVH引起的左室功能的改变;UntwR可能成为一个评价左室舒张功能的新指标.