射频消融和DDD起搏器治疗典型心房扑动伴缓慢心室率五例

目的探讨典型心房扑动(简称房扑)伴缓慢心室率的介入治疗。方法5例房扑伴缓慢心室率患者,房扑频率240～260次/分,房室传导比例5:1～6:1。1例患者已置入VVI起搏器,但仍有症状。对房扑采用解剖学影像定位法消融下腔静脉与三尖瓣环的峡部。对缓慢心室率采取DDD起搏器治疗(1例VVI改换DDD)。结果消融中房扑终止,峡部达双相阻滞,房扑终止后1例为Ⅱ度Ⅱ型房室传导阻滞,4例为Ⅲ度房室传导阻滞。均成功置入DDD起搏器。随访7～37个月,房扑未见复发,起搏器工作良好,患者症状消失。结论射频消融和DDD起搏器联合治疗典型房扑伴缓慢心室率患者有效而且安全。     

频率适应性起搏器对病态窦房结综合征患者运动贮量的影响

目的：探讨频率适应性起搏器对老年病态窦房结综合征患者生活质量的影响。方法：经临床，动态心电图和运动试验心电图确诊的病态窦房结综合征患者植入永久房室全能型起搏器（DDD），于起搏器植入术后即刻以及一年后分别程控为非频率适应性起搏器模式和频率适应性起搏器模式（DDDR）。两种模式下起搏器各工作一年，动态心电图检测24h活动时心率变化，限制性活动平板运动试验观察动持续时间，最大起搏频率；超声心动图测定最大运动负荷时每搏量、心排出量。结果DDDR模式下。运动持续时间和最大心排出量较DDD模式明显增加．[（87．32±68．877）s：（275．21±57．99）S，P〈0．001；（167．31±18．28）ml／s：（106．13±14．28）ml／s，P〈0．0013。结论：频率适应性起搏器显著改善老年病态窦房结综合征患者的运动耐量。     

Walk test at increased levels of heart rate in patients with dual-chamber pacemaker and with normal or depressed left ventricular function.

BACKGROUND: This study focuses the role of heart rate on cardiac output (CO) at rest and during walk test in patients with dual-chamber pacemaker and depressed or normal left ventricular (LV) function. METHODS AND RESULTS: In nine patients with ejection fraction (EF) <50% (group A) and in seven with EF 50% (group B) haemodynamics were assessed at rest and during three randomized 6-min walk tests at fixed rate of 70, 90, and 110beats.min(-1). All patients had dual-chamber pacemaker implanted for complete heart block. Left ventricular function was monitored by a radionuclide system. In group A, with increasing pacing-rate from 70 to 110beats.min(-1), CO did not change both at rest and during walk, whereas end-systolic volume (ESV) increased (P<0.05) and stroke volume (SV) decreased from 68+/-6 to 47+/-9ml at rest (P<0.0001) and from 112+/-21 to 76+/-17ml during walk (P<0.005). In group B, with increasing pacing-rate, CO rose from 6.4+/-0.7 to 9.1+/-1.6l.min(-1)at rest (P<0.001) and from 10+/-1.5 to 14.1+/-2.2l.min(-1)during walk (P<0.0001), with no change in ESV and SV. CONCLUSIONS: Increasing heart rate in presence of ventricular asynchrony induced by dual-chamber pacing has negative effect on cardiac contractility and does not improve CO at rest or during physical activity in patients with depressed LV function as occurs in those with normal function.     

Cardiopulmonary function and exercise capacity in patients with morbid obesity

INTRODUCTION AND OBJECTIVES: The effect of obesity on cardiac function is still under discussion. The objective of this study was to assess cardiopulmonary capacity in morbidly obese patients.Patients and method. A symptom-limited cardiopulmonary exercise stress test was carried out in 31 morbidly obese patients (BMI 50 9 kg/m2) and 30 normal controls (BMI 24 2 kg/m2. Cardiovascular function was evaluated using the oxygen pulse (oxygen uptake/heart rate). RESULTS: There were no differences in age, sex and height between both groups. During the effort the obese subjects presented greater oxygen uptake, heart rate, systolic arterial pressure and minute ventilation and shorter test duration than control group (14 3 vs 27 4 min; p < 0.001). Oxygen pulse values were higher in obese patients. However, after oxygen uptake indexation by fat free mass, these differences disappeared, suggesting a similar cardiovascular function. At the end of the exercise, the control group reached 96% of their age-predicted maximal heart rate and their respiratory exchange ratio was 1 0.2. Obese patients only reached 86% and 0.87 0.2, respectively. CONCLUSIONS: Due to their need of more energy output to move total body mass morbidly obese patients have a reduced exercise capacity. They finish the test having done a submaximal exercise. However, during this effort they show a normal cardiopulmonar capacity.     

Defining the optimum upper heart rate limit during exercise: a study in pacemaker patients with heart failure.

AIMS: There is no non-invasive method to determine the individual optimum of maximum exercise heart rate. Knowledge of this value is of particular interest in patients with structural heart disease who are prone to tachycardia intolerance. The purpose of this study was to define the optimal maximum heart rate using cardiopulmonary exercise testing and exercise Doppler echocardiography and to compare the results of both approaches. METHODS AND RESULTS: In 49 pacemaker patients with chronotropic incompetence, the optimum upper heart rate limit was determined using cardiopulmonary exercise testing and exercise Doppler echocardiography. The optimum upper rate limit was given by the highest pacing rate which still produced an increase in oxygen consumption, or by that pacing rate which was linked to the lowest value for the Doppler-derived myocardial performance index. In patients with normal left ventricular ejection fraction (>or=55%) the optimum upper rate limit was 86% of age-predicted maximum heart rate, in patients with left ventriuclar dysfunction (ejection fraction 相似文献   

Comparison of exercise capacity evaluated by cardiopulmonary exercise test and hemodynamic parameters in patients with atrial septal defect]

We evaluated the maximal exercise tolerance using cardiopulmonary exercise testing, and investigated the relation of the hemodynamic parameters such as mean pulmonary artery pressure (PAm) and pulmonic-to-systemic flow ratio (Qp/Qs) to exercise tolerance in 18 adult patients consecutively. All the patients had atrial septal defect (ASD). Maximal oxygen uptake (VO2 max) averaged only 21.6 +/- 5.6 ml/min/kg and 63.5 +/- 16.2% of the predicted values (VO2max). And anaerobic threshold averaged 12.5 +/- 2.3 ml/min/kg and 56.7 +/- 12.4% of the predicted values. There were 2 patients who had marked pulmonary hypertension (PH, PAm more than 44 mmHg). Maximal exercise tolerance of these patients was severely impaired, and %VO2max was only 45.9% and 46.2% respectively. In patients without PH (PAm less than 20 mmHg), however %VO2 max ranged widely from 100.3 to 44.7% and PAm correlated with %VO2max weakly (r = -0.53, p less than 0.05). But there was a significant inverse relationship between Qp/Qs and %VO2max(r = -0.85, p less than 0.01). In 16 patients without PH, maximal O2-pulse during exercise was also inversely correlated with Qp/Qs (r = -0.76, p less than 0.01). The relation between PAm and %VO2max suggests that afterload on the right ventricle may be an important determinant of exercise capacity in patients with PH. And the relation between Qp/Qs and %VO2max or Qp/Qs and % maximal O2-pulse suggests that Qp/Qs may also be a very important determinant factor of exercise capacity in patients without PH.     

Effect of programming different AV intervals on mitral insufficiency in patients with DDD pacemaker]

OBJECTIVE: To study the effect of programming three different atrioventricular intervals (AVI) on mitral insufficiency (MI) in patients with permanent pacemaker due to complete atrioventricular block. METHODS: We included 9 patients (mean age 62 +/- 11 years; 6 men), with permanent DDD pacemaker, isolated MI and normal ventricular function. We evaluated MI (in a quantitative way) and cardiac output (CO) through echocardiographic examination with three different AVI (100, 150 and 200 ms). RESULTS: We observed a reduction in the severity of MI with the reduction of the AVI (best results obtained with AVI of 100 ms). We also observed an increase in the CO in 4 patients (those with MI of greater degree) with AVI of 100 ms. CONCLUSIONS: We observed a correlation of longer AVI with greater degree of MI; our results point to the possibility of increasing the CO of patients with greater degrees of MI with shortening of the AVI (probably due to a partial recovery of the regurgitant volume).     

Right ventricular and tricuspid valve function in patients with two ventricular pacemaker leads

Existing data on the effect of retained pacemaker leads on right ventricular (RV) and tricuspid valve function is limited. OBJECTIVE: In this echocardiographic study we investigated the long-term effect of retained ventricular leads on RV and tricuspid valve function in patients with permanent pacemakers. Forty patients, 18 with two (group I) and 22 with one (group II) ventricular lead were assessed echocardiographically at an average of 39 months after the second lead implantation in group I and 80 months after the lead implantation in group II. The sum of the lead body diameter in group I was significantly greater than the body diameter in group II (P < 0.000). There was no significant difference between the groups with respect to chamber diameters and ventricular or valvular functions. The distributions of the different tricuspid regurgitation (TR) grades were similar, with the majority of patients in both groups having mild TR. Retained second pacemaker leads do not have an additional negative effect on right ventricular and tricuspid valve function.     

Cardiovascular response to exercise in pacemaker implanted patients with fixed heart rate

Cardiovascular response to supine exercise was studied in 11 patients with chronic ventricular pacing for complete atrioventricular block whose heart rate was fixed during exercise, and compared with 11 age- and sex-matched normal subjects. Oxygen uptake increased linearly with increasing work rate, and attained maximum values of 15.7 +/- 0.7 and 29.5 +/- 1.1 ml/min.kg, respectively. In both groups, cardiac output increased in association with oxygen uptake, although the maximum value in the patients was less than one half that in the controls (6.8 +/- 0.5 and 15.1 +/- 0.3 l/min). Stroke volume, however, could change in patients, as in the controls under similarly increased afterloads (maximum values were 96 +/- 7 and 93 +/- 3 ml/beat, respectively). During exercise, the systolic arterial pressure elevated to a similar extent in both groups (221 +/- 14 and 235 +/- 12 mmHg, respectively). The increase in stroke volume in the patients was achieved by complete systolic emptying and the Frank-Starling mechanism. It is considered that in patients with ventricular pacing, exercise can produce an increase in stroke volume when myocardial function is not impaired.     

二维斑点追踪技术评价双腔起搏器患者左心室旋转与扭转运动

目的 应用二维斑点追踪技术研究双腔起搏器患者左心室旋转与扭转运动的特征,以探讨左心室心肌收缩功能.方法 40例安置起搏器术后7d的病态窦房结综合征患者(起搏器组)和40例健康体检人群(对照组),获取左心室短轴心底水平、心尖水平二维图像,测量左心室短轴二水平收缩期峰值旋转角度,计算峰值扭转角度.结果 收缩期峰值旋转及扭转角度比较:起搏器组心底水平左心室前室间隔(-1.3°±2.4°.)、侧壁(-8.3°±2.2°)、后室间隔(-7.0°±2.5°),心肌峰值旋转角度较正常对照组减低[(-7.1°±2.9°)、(-12.0°±2.5°)、(-11.7°±2.5°)](均为P＜0.05),心尖水平前室间隔(11.1 °±3.2°)、下壁(10.4°±2.7°)、后室间隔(10.0°±3.3°).心肌峰值旋转角度较正常对照组[(6.5°±2.7°)、(7.3°±2.8°)、(7.0°±2.1°)]增强(均为P＜0.05).心底部峰值旋转角度减低,心尖部心肌峰值旋转角度增强(均为P＜0.05),左心室扭转角度无明显差异.结论 起搏器术后左心室存在局部心肌收缩功能变化,超声斑点追踪技术对于旋转与扭转运动的研究,为临床心功能的变化提供依据.     

Relief of right ventricular angina and increased exercise capacity with long-term oxygen therapy.

Long-term low-flow oxygen therapy can lead to improved exercise capacity and improved hemodynamics in selected patients with pulmonary hypertension. We report a patient who presented with severe exercise limitation and anginal chest pain that appeared to result from pulmonary hypertension and predominantly right ventricular ischemia. Acute oxygen therapy led to relief of pain but no change in exercise capacity or of pulmonary hypertension. After eight months of oxygen therapy, the patient's pulmonary hypertension was unchanged, but right ventricular hypertrophy and marked increases in exercise cardiac output and exercise capacity developed. Thus, oxygen can relieve right ventricular angina and facilitate the development of compensatory hypertrophy.     

Isolation right ventricular hypoplasia: report of two cases

Two cases of the hypoplastic right ventricle are reported. Patient 1: A five-year-old boy underwent cardiac catheterization 13 days after birth which revealed that the end-diastolic volume in the right ventricle was 2 ml. It was 20 ml at the age of two years and 40 ml at five years. Thus, the right ventricular hypoplasia lessened with increasing age. Neither pulmonary nor tricuspid valvular malformation was present. Patient 2: A four-month-old boy received two-dimensional echocardiographic examination at the age of two days which revealed: 1) a small right ventricle in the apical four-chamber view, 2) a half-moon-shaped right ventricle in the subxyphoid short-axis view at the level of the great arteries, and 3) normal positioning of the septal leaflet of the tricuspid valve. Pulsed Doppler echocardiography revealed normal blood flow patterns, immediately above the pulmonary valve and below the tricuspid valve. Cardiac catheterization at the age of three months indicated isolated right ventricular hypoplasia, a diverticulum of the right ventricle, and dilated cardiomyopathy. The patient died of congestive heart failure at the age of four months. Autopsy confirmed the above diagnoses.     

心室频率应答式起搏对老年人运动能力影响的评价

目的评价体动感知心室频率应答式起搏对老年患者运动能力的影响。方法１８例老年患者分别在具频率应答（ＶＶＩＲ）与无频率应答（ＶＶＩ）状态下做８００米快速行走及症状记分和半卧位踏车运动评价。结果８００米快速行走时ＶＶＩＲ所用时间明显短于ＶＶＩ（Ｐ＜０．０５），同时症状记分显示ＶＶＩＲ时症状减轻（Ｐ＜０．０５），尤以乏力改善明显（Ｐ＜０．０１）。踏车运动试验显示ＶＶＩＲ时患者运动时间、做功量增加（均为Ｐ＜０．０５），而症状记分不变（Ｐ＞０．０５）。结论体动感知心室频率应答式起搏可改善老年人运动能力。     

Orthostatic purpura: report of two cases]

Two patients with orthostatic purpura were reported. Case 1: A 47-year-old man was admitted to our institution because of multiple purpuric eruptions over the legs after the long periods of sitting or standing. Bleeding time was 4.0 min. Platelet aggregation induced by ADP was disaggregated and no aggregation was observed when induced by collagen and epinephrine. He was diagnosed as having release abnormality of the platelets caused by glutathione administered for treatment of liver damage for several years. Purpura, however, appeared even though platelet function became normal after discontinuing glutathione. Purpura proved to be induced by the long periods of sitting or standing. Case 2: A 37-year-old woman was admitted to our hospital because of purpuric eruptions over the legs for three years. Bleeding time was 2.0 min. Platelet aggregation induced by ADP, epinephrine, collagen and ristocetin was normal. Purpura was caused by long periods of standing without movement. Wearing elastic pantyhose showed reduced appearance of the purpura. Biopsy specimens from both patients revealed no abnormal findings. Both patients had no abnormal results in coagulation studies. Purpura seemed to be caused by the increased capillary pressure after the prolonged periods of standing. No case report concerning orthostatic purpura or mechanical purpura has been published.     

Left ventricular function and exercise capacity in patients with slow coronary flow

Background: Endothelial and microvascular dysfunction have been implicated in slow coronary flow (SCF). How and to what extent do these etiological factors affect left ventricular (LV) function and exercise capacity? Aim: The aim of the study was to evaluate LV systolic and diastolic function by pulsed tissue Doppler imaging (TDI) in SCF patients and their effects on exercise capacity. Subjects and methods: Sixty SCF patients and 20 control subjects were included in the study. Echocardiographic examination, treadmill exercise test, and TDI were performed. Isovolumic myocardial acceleration (IVA) and myocardial performance index (MPI) were measured. Results: TDI mean parameters for systolic and diastolic LV function were significantly impaired in SCF group with decreased Sa, IVA, Ea/Aa, and increased MPI (0.31 ± 0.06 vs. 0.26 ± 0.04, P < 0.01) compared to control. There was significant correlation between thrombolysis in myocardial infarction (TIMI) frame count and TDI mean parameters for LV systolic function (Sa & IVA, r =?0.53, P < 0.01 & r =?0.36, P < 0.05, respectively). Mean TIMI frame count was correlated with MPI and E/Ea. SCF patients had poorer peak exercise capacity than the controls (9.9 ± 1.9 METs vs. 12.7 ± 2.3, P < 0.01) with significant negative correlation with mean TIMI frame count (r =?0.46, P < 0.01). Conclusion: There is impairment of LV systolic and diastolic function in SCF patients with clinical impact on exercise capacity which emphasizes the importance of close follow‐up of these patients for risk stratification. (Echocardiography 2012;29:158‐164)     

26例心房颤动患者心律转复前后心肺运动试验分析

目的探讨心房颤动对心脏功能的影响及心房颤动患者转复心律前后摄氧量等运动参数的改变。方法采用美国MedGraphics公司心肺运动仪和活动平板,在Bruce改良方案的基础上,对26例心房颤动患者分别进行心律转复前后心肺运动试验。结果26例心房颤动患者心律转复后,静息心率(HRrest)平均由109次min减慢到83次min(P<0001),最大运动时心率(HRmax)平均由182次min减慢到141次min(P<0001);最大每搏摄氧量(VO2maxHR)平均由788mL提高到109mL(P<0001);运动总时间(TET)平均由81min增加到88min(P<0001);最大运动速度(Speed)平均由30mph增加到33mph(P<001);斜度(Elevation)由1315%提高到1385%(P<001),试验过程中无并发症发生。结论心房颤动患者转复窦性心律后,心率明显减慢,最大每搏摄氧量增加,运动时间延长,运动耐力提高,心功能得到改善。