高血压心脏病左心房收缩功能的超声心动图评价

目的应用超声心动图技术分析高血压病人的左心房收缩功能。方法60例高血压患者、20例健康对照者。根据左室质量指数将高血压病人分为左室构型正常组及左室肥厚组，取组织多普勒的速度模式，将取样容积放在二尖瓣瓣环处，测量心房收缩期的组织运动速度(A’)、衡量其与传统的评价左心房功能的参数如左房射血力、左房动能等的相关性。结果伴随高血压病情的加重，A’、心房收缩期血流峰值速度(A)、LAEF、LASV、左房射血力、左房动能明显增加，高血压组、左室肥厚组、左室构型正常组与健康对照组差异有显著性意义(P＜O．01)；A’与LAEF(r=O．81，P＜O．01)，LASV(r=O．73，P＜O．01，左房射血力(r=O．84，P＜O．01)，左房动能(r=O．81，P＜O．01)呈高度正相关。结论QTVI技术测定的A’是评价高血压病左心房收缩功能有意义的指标。     

Usefulness of low-dose dobutamine echocardiography in idiopathic dilated cardiomyopathy.

INTRODUCTION: Low-dose dobutamine stress echocardiography is a common and useful technique to assess myocardial viability in patients with ischemic cardiomyopathy. OBJECTIVE: To evaluate the use of low-dose dobutamine stress echocardiography in determining the functional status of patients with idiopathic dilated cardiomyopathy (IDCM). METHODS: Prospective study of 28 patients with IDCM by transthoracic echocardiography (2D), low-dose dobutamine stress echocardiography, cardiopulmonary exercise testing (CPET) and measurement of pro-BNP. RESULTS: The mean age of the population was 50.3 +/- 11.5 years, 9 female and 19 male. Mean ejection fraction was 32.1 +/- 9.8%. All were in sinus rhythm. The following parameters were analyzed in 2D echocardiography and after dobutamine: dimensions of left atrium (LA) and of left ventricle in diastole and systole, shortening fraction (%), left ventricular end-diastolic (EDV) and end-systolic volumes (ESV), ejection fraction (EF), and mitral inflow (E, A, E/A ratio and deceleration time). In CPET, we considered the following parameters: peak VO2 and % maximal peak VO2 attained. We compared echo results with CPET. There was a correlation between age and peak VO2 (r = -0.38 with p = 0.049). In 2D echo, there was a correlation between baseline EF and LA dimensions and peak VO2 (r = 0.45 / p = 0.004 and r = -0.49 / p = 0.014, respectively). After dobutamine echo, there was a correlation between some echo parameters and peak VO2: EF - r = 0.59 / p = 0.001, LA dimensions - r = 0.56 / p = 0.007, and ESV - r = -0.45 / p = 0.026. Percentage maximal peak VO2 attained correlated with LA dimensions measured in 2D echo and after dobutamine (r = -0.398 / p = 0.036 and r = -0.674 / p = 0.02 respectively) and EF after dobutamine (r = -0.389 / p = 0.04). The value of pro-BNP correlated with LA dimensions and baseline EF (r = 0.44 / p = 0.02 and r = -0.57 / p = 0.002, respectively), and the correlation was maintained after inotropic stimulation with dobutamine (r = 0.57 / p = 0.001 and r = -0.55 / p = 0.0039). CONCLUSION: Low-dose dobutamine stress echocardiography showed stronger correlations with cardiopulmonary exercise testing than the parameters evaluated by conventional echocardiography and could be used to determine the functional status of patients with dilated cardiomyopathy; patients with greater ejection fraction after inotropic stimulation had better cardiopulmonary tests.     

Impact of patient's age and disease duration on cardiac performance in acromegaly: a radionuclide angiography study.

The aim of this study was to evaluate the impact of age and disease duration on cardiac performance in acromegaly. To address these issues, the left ventricular function at rest and during physical exercise was assessed by equilibrium radionuclide angiography in 40 rigorously selected patients with active acromegaly but without evidence of other complications able to affect heart function and in 32 healthy controls. Patients and controls were divided in two groups, on the basis of age below and above 40 yr. Circulating GH and insulin-like growth factor-I levels were significantly increased in patients, compared with controls, but were similar in the two groups of patients. At peak exercise, the systolic blood pressure was significantly higher in elderly patients (P < 0.001), whereas diastolic blood pressure was significantly higher in young patients than in age-matched controls (P < 0.01). Heart rate at peak exercise was significantly higher in young than in elderly patients and controls (P < 0.01), without any evidence of arrhythmia in both groups. The left ventricular ejection fraction at rest was normal (>50%) in all but 2 patients and in all controls. The left ventricular ejection fraction at peak exercise was significantly decreased in elderly, compared with young, patients (P < 0.01) and in age-matched controls (P < 0.001). A normal response of the left ventricular ejection fraction to exercise was found in 12 of 40 patients (30%) and in 28 of 32 controls (87.5%) (chi2, 5.764; P < 0.01). Exercise-induced changes in left ventricular ejection fraction were significantly decreased in young (+5.2 +/- 4.4% vs. +21.3 +/- 3.4%, P < 0.005) and elderly patients (-10.2 +/- 2.8% vs. +13.7 +/- 2.7%, P < 0.0001), as compared with age-matched controls. The peak rate of left ventricular filling was significantly higher in young, than in elderly, patients whether peak filling rate was normalized to end-diastolic volume (P < 0.001), or stroke volume (P < 0.0001), or expressed as the ratio of peak filling rate to peak ejection rate (P < 0.001). The peak rate of left ventricular filling was significantly decreased in elderly patients, compared with young patients and age-matched controls, whether peak filling rate was normalized to end-diastolic volume (P < 0.01), or stroke volume (P < 0.005), or expressed as the ratio of peak filling rate to peak ejection rate (P < 0.001). In the patient group, the left ventricular ejection fraction at peak exercise was significantly correlated with age (r = -0.33, P < 0.05), estimated disease duration (r = -0.34, P < 0.05), exercise-induced changes of the left ventricular ejection fraction (r = 0.34, P < 0.05), and the peak rate of left ventricular filling, whether peak filling rate was normalized to end-diastolic volume (r = 0.33, P < 0.05). Age and estimated disease duration were both significantly correlated with the peak rate of left ventricular filling, whether peak filling rate was normalized to end-diastolic volume (r = 0.55, P < 0.001 and r = -0.49, P < 0.001, respectively), or stroke volume (r = 0.5, P < 0.001 and r = -0.57, P < 0.001, respectively), or expressed as the ratio of peak filling rate to peak ejection rate (r = 0.56, P < 0.0001 and r = -0.52, P < 0.001, respectively). In the control group, the left ventricular ejection fraction at peak exercise was significantly correlated with the left ventricular ejection fraction at rest (r = 0.54, P < 0.01), exercise-induced changes of the left ventricular ejection fraction (r = 0.57, P < 0.001), but neither with age nor peak rate of left ventricular filling at all measurements. In conclusion, left ventricular performance is more frequently preserved in young patients with a short disease duration, although the left ventricular response to exercise was already reduced, as compared with controls. (ABSTRACT TRUNCATED)     

实时三维斑点追踪成像技术评价老年缺血性二尖瓣反流患者左心房功能的研究

目的应用实时三维斑点追踪成像(RT3D-STI)技术检测老年缺血性二尖瓣反流患者的左心房心肌运动及容积变化,评价左心房功能。方法选取86例老年慢性冠心病患者,根据有无继发于冠状动脉病变的二尖瓣反流分为单纯冠心病(CHD)组(32例)及缺血性二尖瓣反流(IMR)组(54例,其中20例轻度反流、18例中度反流、16例重度反流),对照组为32例老年健康志愿者。应用RT3D-STI技术测量左心房心肌整体纵向、圆周、径向应变及左心房最大容积、最小容积、主动收缩前容积,并计算左心房总体(LAEF)、被动(LApEF)及主动射血分数(LAaEF),分析左心房容积变化及心肌应变与左心房功能的关系。结果CHD组与IMR组左心室射血分数(LVEF)、LAEF均较对照组降低,且IMR组低于CHD组;与对照组比较,IMR组左心房最小容积(LAVmin)增大、LAaEF降低(均P<0.05)。IMR组及CHD组左心房整体纵向应变(GLS)、左心房整体圆周应变(GCS)、左心房整体径向应变(GRS)与对照组比较均降低,且IMR组低于CHD组,随反流程度增加,GLS、GCS、GRS均不同程度减低;与对照组比较,IMR组左心房整体纵向应变达峰时间标准差(TLS-SD)、左心房整体圆周应变达峰时间标准差(TCS-SD)、左心房整体径向应变达峰时间标准差(TRS-SD)均增大(均P<0.05)。CHD组及IMR组GLS、GCS、GRS与LAEF呈较强相关性(CHD组r=-0.745、-0.718、0.627,P=0.006、0.007、0.009;IMR组r=-0.785、-0.781、0.643,P=0.006、0.007、0.008)。TLS-SD、TCS-SD、TRS-SD评价左心房功能改变的ROC曲线分析结果显示,曲线下面积分别为0.903、0.890、0.872,其灵敏度与特异度分别为89.7%、81.8%,78.6%、84.8%,85.7%、72.1%。结论通过测量IMR患者左心房容积变化及追踪描记心肌运动,RT3D-STI技术可较准确、客观地评价老年IMR患者左心房功能的改变。     

海水浴体疗对高血压患者左房收缩功能的康复作用

目的:应用超声心动图技术评价海水浴体疗运动对高血压患者左房收缩功能的康复作用。方法:160例高血压病人,按自愿分为海水浴组和对照组,根据左室质量指数(LVMI)高血压患者被分为左室正常构型和左室肥厚型。应用超声心动图技术分析被观察者疗养前、后的左房收缩功能各指标,并进行比较。结果:治疗前,与左室构型正常组比较,左室肥厚组的左房灌注分数(LAT)、左房射血分数(LAEF)、左房搏出量(LASV)、左房射血力、左房动能明显增加(P<0．05-<0．01);两组同型左房收缩功能各指标无明显差异(P>0．05)。经过4周的疗养后,海水浴组左房收缩功能各指标与疗养前及对照组比较,左室正常构型组的显著下降(P<0．05),左室肥厚型组的极显著下降(P<0．05-<0．01),而对照组于疗养前、后无明显差异(P>0．05)。结论:海水浴体疗运动是项综合性的全身有氧运动;能降低高血压病患者的心肌耗氧量,减轻心脏负荷,改善左房收缩功能。     

Does the age of onset of growth hormone deficiency affect cardiac performance? A radionuclide angiography study

BACKGROUND: GH and IGF-I seem to play a relevant role in cardiac development and performance. Long-standing GH deficiency (GHD) causes several abnormalities in cardiac structure and performance which ultimately determine an increased cardiovascular morbidity and mortality. OBJECTIVE: To investigate whether the age of onset of GHD plays a role in determining the negative effects on the heart. DESIGN: Open cross-sectional PATIENTS: 55 patients with adulthood-onset GHD and 36 healthy sex- and age-matched controls. Patients and controls were divided into 2 groups in line with age: 32 patients and 16 controls, were aged 相似文献   

Left atrial volumes, function and work before and after mitral valve repair in chronic mitral regurgitation

BACKGROUND AND AIM OF THE STUDY: Despite the effect of mitral valve repair in left ventricular (LV) function having been extensively studied, investigations of left atrial (LA) performance indices are minimal. This prospective study was undertaken to analyze LA volumes, function and work in patients with chronic mitral valve regurgitation (MR) who underwent mitral valve repair; the analyses were conducted both before and six months after surgery. METHODS: Twenty patients (15 males, five females; mean age 51.4 +/- 12.5 years) with severe MR (grade IV) due to floppy mitral valve/mitral valve prolapse (FMV/MVP; anterior, posterior or both) underwent mitral valve repair. LA volumes, maximal at mitral valve opening (LAmax); minimal at valve closure (LAmin); and at onset of atrial systole (P-wave on ECG, LAP); and transmitral Doppler A-wave velocity were measured before and six months after surgery. LA stroke volume (LASV) = LAP - LAmin; LA ejection fraction (LAEF) = LASV/LAP; LA kinetic energy (LAKE) = 1/2 x LASV x 1.06 (specific gravity of blood) x A2 (dyne x cm x 10(3)); LA and LV dimensions and functions were assessed at the same time. RESULTS: NYHA functional class was improved postoperatively by at least one grade. LV systolic and diastolic dimensions were reduced significantly in all patients (p <0.001). LA volumes (LAmax, LAmin and LAP) were decreased significantly in all patients (p <0.001); LASV remained unchanged. LAEF and LAKE were increased significantly (both p <0.001). The A-wave was also increased (p <0.001). CONCLUSION: Increased LA work (LAKE) after mitral valve repair, despite a decrease in LA volumes, suggests that LA muscle dysfunction was present before surgery. LA involvement may precede LV involvement. The determination of LA performance and work will help to optimize the timing of surgery in patients with FMV/MVP and MVR.     

Relation of exercise capacity to left ventricular systolic function and diastolic filling in idiopathic or ischemic dilated cardiomyopathy

Although exercise intolerance is a cardinal symptom of patients with dilated cardiomyopathy (DC) and heart failure, the factors that limit exercise capacity in these patients remain a matter of debate. To assess the contribution of left ventricular (LV) diastolic filling to the variable exercise capacity of patients with DC, we studied 47 patients (60 +/- 12 years) with DC in stable mild-to-moderate heart failure with a mean LV ejection fraction of 28%. Exercise capacity was measured as total body peak oxygen consumption (VO2) during symptom-limited bicycle (10 W/min) and treadmill (modified Bruce protocol) exercise. LV systolic function and diastolic filling were assessed at rest before each exercise by M-mode, Doppler echocardiography, and radionuclide ventriculography. As expected, treadmill exercise always yielded higher peak VO2 than bicycle exercise (21 +/- 6 vs 18 +/- 5 ml/kg/min, range 12 to 35 and 7 to 30 ml/kg/min, respectively, p <0.001). Both of these VO2 measurements were highly reproducible (R = 0.98). With univariate analysis, close correlations were found between peak VO2 (with either exercise modalities) and Doppler indexes of LV diastolic filling, as well as with the radionuclide LV ejection fraction. Stepwise multiple regression analysis identified 3 nonexercise variables as independent correlates of peak VO2, of which the most powerful was the E/A ratio (multiple r2 = 0.38, p <0.0001), followed by peak A velocity (r2 = 0.54, p <0.0001) and mitral regurgitation grade (r2 = 0.58, p = 0.024). In conclusion, our data indicate that in patients with DC, peak VO2 is better correlated to diastolic filling rather than systolic LV function.     

Relationship between exercise intolerance and levels of neurohormonal factors and proinflammatory cytokines in patients with stable chronic heart failure

We investigated the correlations between exercise intolerance and the plasma levels of neurohormonal factors and proinflammatory cytokines in chronic heart failure (CHF) patients. Sixty-two CHF patients who underwent cardiopulmonary exercise testing (CPX) were enrolled in this study. Peak oxygen uptake (peak VO2) and the plasma concentrations of noradrenaline (NA), brain natriuretic peptide (BNP), and soluble tumor necrosis factor receptors I and II (TNFR-I and -II) were all measured during the CPX. The patients were divided into three groups according to their peak VO2; a severe exercise intolerance group (severe group; peak VO2 < 18 mL/min/kg), moderate exercise intolerance group (moderate group; 18 24). There were no significant differences in left ventricular ejection fraction (EF) among the three groups. NA and BNP both increased gradually in parallel with the worsening of exercise intolerance (NA, 211.5 +/- 75.7 pg/mL, 331.8 +/- 163.7, 441.9 +/- 202.9, respectively; BNP, 37.9 +/- 25.4 pg/mL, 148.9 +/- 117.1, 247.9 +/- 150.0, respectively). TNFR-I and II were significantly higher in the severe group than in the moderate group (1746.1 +/- 950.7 versus 1085.2 +/- 370.5 pg/mL and 2855.3 +/- 1550.9 versus 2047.7 +/- 648.7 pg/mL, respectively), while the values in the moderate group were not significantly different from those in the mild group. EF showed no significant correlations with NA, BNP, TNFR-I, or TNFR-II, whereas peak VO2 exhibited significant negative correlations with NA (r = -0.50, P < 0.0001), BNP (r = -0.53, P < 0.0001), TNFR-I (r = -0.50, P < 0.0001), and TNFR-II (r = -0.45, P < 0.0001). It is concluded that NA and BNP rise in parallel with the degree of exercise intolerance, while TNFR-I and -II rise only when exercise intolerance reaches severe levels.     

二维多普勒超声对高血压患者左房血流动力学变化的分析研究

本文应用二维多普勒超声技术对66例高血压病患者及46例正常人从左房功能、心脏形态结构及血流动力学方面进行分析研究。结果显示：高血压病组LAD、LAV、LAP、LAT、LAET、LASV、LAEF及A峰增加，而E峰、E／A比值、LAPEP，LAPEP／LAET及PFR降低；与正常对照组比较均有显著性差异（P＜0．01或P＜0．001）。结论认为：高血压患者左房收缩前，左室充盈减少，左房代偿性收缩力增强，作功增加，以维持恒定的左房室间的压差，弥补左室充盈不足，为保持正常的心搏量起重要作用。     

The effect of left ventricular systolic function on maximal aerobic exercise capacity in asymptomatic patients with coronary artery disease

The purpose of this study was to examine the relationship between maximal O2 uptake (VO2max) and left ventricular systolic function in patients with coronary artery disease. We studied 27 patients, age 50 +/- 10 years (mean +/- SD), who were asymptomatic and able to attain true VO2max. VO2max was defined by the leveling-off criterion and/or a respiratory exchange ratio of 1.15 or greater. Left ventricular ejection fraction was determined by gated cardiac blood pool imaging. In patients whose ejection fraction decreased with exercise, VO2max was 21 +/- 4 vs 27 +/- 4 ml/kg/min in those whose ejection fraction increased (p less than .001). Systolic blood pressure/end-systolic volume relation was shifted upward and to the right in the former group in response to peak exercise. In contrast, the pressure-volume relation was shifted upward and to the left in patients whose ejection fraction increased with exercise. Ejection fraction at rest did not correlate with VO2max. There was a significant but weak correlation between peak exercise ejection fraction and VO2max (r = .43, p less than .025). Left ventricular exercise reserve, i.e., the change in ejection fraction from rest to exercise, correlated with VO2max (r = .77, p less than .0002), maximal O2 pulse (r = .50, p less than .005), and maximal heart rate during treadmill exercise (r = .61, p less than .001). Maximal heart rate during treadmill exercise correlated with VO2max (r = .70, p less than .0002).(ABSTRACT TRUNCATED AT 250 WORDS)     

Determinants of left ventricular function in isolated rheumatic mitral stenosis

Left ventricular end-diastolic volume (preload), peak systolic wall stress (afterload), instant Emax (contractility index = peak systolic left ventricular pressure/end-systolic volume), left ventricular mass, left ventricular ejection fraction (LVEF) alone and normalised for mass index, were studied in 30 patients with isolated rheumatic mitral stenosis (group 1) and compared with 24 normal individuals (group II) who served as control. Preload was not different in the two groups (p = NS), afterload was increased in group I (p = 0.01), while LVEF, Emax, left ventricular mass and mass normalised LVEF were reduced in mitral stenosis as compared to normal control (p less than 0.01- less than 0.001). Comparison of patients with reduced ejection performance (LVEF less than 50%, n = 9, group IA) with those having normal LVEF (n = 21 group IB) revealed increased left ventricular end-diastolic volume and reduced left ventricular mass, mass normalised ejection fraction and Emax (in IA p less than 0.05). Peak systolic wall stress was comparable in these two subgroups. This study shows that the major determinant of left ventricular dysfunction in isolated rheumatic mitral stenosis is impaired contractility and not the loading factors.     

心房颤动患者复律前后左心房功能变化的超声研究

目的　探讨心房颤动 ( AF )复律后左心房功能变化的特点。方法　选择 AF病人 96例 ,按心脏节律转复的方式分为自发性复律 ( A)组 2 4例 ,药物复律 ( B)组 40例及直流电复律 ( C)组 3 2例 ;分别应用超声心动图测定其左心房内径和容积 ,计算左心房主动和被动排空容积 ,并评价左心房功能。结果　AF时所有病人的左心房扩大 ,而恢复窦性心律后 A、B及 C组左心房内径降低者分别为 10 0 %、74%及 5 2 %。 62例左心房机械功能正常患者与 3 4例左心房功能降低患者比较有更强的左心房射血力 ( LAEF ) ,这与复律后左心房内径降低有关。左心房功能异常( L AEF<7达因 )患者左心房内径和容积分别与左心房射血力呈负相关 ( r=-0 .72和 -0 .76,P<0 .0 0 1)。左心房主动排空分数降低而管道容积却增加。结论　心房颤动复律后 ,左心房机械功能的延迟恢复与持续存在的的左心房扩大有关     

Relationship between ventilatory expired gas and cardiac parameters during symptom-limited exercise testing in patients with heart failure.

PURPOSE: This study investigates the relationship between ventilatory expired gas and cardiac parameters measured during exercise testing in patients with heart failure. METHODS: Twenty-five subjects (12 male, 13 female) diagnosed with compensated heart failure underwent symptom-limited exercise testing with ventilatory expired gas analysis. Metabolic and cardiac measures of interest were collected during testing. RESULTS: Mean peak oxygen consumption (VO2), minute ventilation/carbon dioxide production (VE/VCO2) slope, percentage of age predicted maximal heart rate achieved during exercise testing (%APMHR), and peak respiratory exchange ratio were 14.7 +/- 4.7 mL O2/kg/min-1, 33.8 +/- 9.8, 76% +/- 15%, and 1.1 +/- 0.11, respectively. The VE/VCO2 slope was significantly correlated with the following: %APMHR (r = -0.81, P < 0.001), peak VO2 (r = -0.83, P < 0.001), VO2 at ventilatory threshold (r = -0.70, P < 0.001), and the dead space to tidal volume ratio (VD/Vt) (r = 0.65, P < 0.001). The ability of peak VO2 and %APMHR to predict the VE/VCO2 slope was significant (r = 0.86, r2 = 0.72, P < 0.0001). CONCLUSION: This study demonstrates the importance of analyzing multiple exercise test parameters, including metabolic measures, in patients with heart failure.     

Early and long-term results of coronary artery bypass grafting with severely depressed left ventricular performance

The effects of coronary artery bypass grafting (CABG) on ventricular performance and long-term clinical status were studied in 18 consecutive patients with disabling angina pectoris and severely depressed left ventricular (LV) performance (ejection fraction [EF] 27 +/- 9%). All patients survived CABG, although 1 patient had a perioperative myocardial infarction. There was no change in LVEF at rest, 29 +/- 12%, in the other 17 patients. However, LVEF during peak exercise increased from 22 +/- 7% to 27 +/- 14% (p less than 0.05). The 17 patients were separated into 2 groups: those who increased their peak exercise LVEF by at least 10% (group A, 8 patients) and those who increased it by less than 10% (group B, 9 patients). Preoperatively, patients in group A had a higher LVEF at rest (p less than 0.001) and smaller end-systolic and end-diastolic volumes at rest (p less than 0.001) and during exercise (p less than 0.005). Preoperatively, the LVEF in group A decreased with exercise, from 36 +/- 4% to 27 +/- 5% (p less than 0.01), but was unchanged in group B (19 +/- 3% vs 17 +/- 4%, difference not significant). After CABG, patients in group A had a smaller increase in end-systolic volume with exercise than those in group B (13 +/- 7 vs 34 +/- 22 ml/m2, p less than 0.05), but the changes in end-diastolic volume with exercise were not significantly different. At 27 +/- 5 months after CABG, 5 of 8 patients in group A were asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)     

Complementary roles of simple variables, NYHA and N-BNP, in indicating aerobic capacity and severity of heart failure

AIMS: The extent of exercise intolerance in patients with chronic heart failure (CHF) is dependent on and representative of the severity of heart failure. However, few primary care physicians have direct access to facilities for formal exercise testing. We have therefore explored whether information readily obtainable in the community can reliably predict the functional capacity of patients. METHODS AND RESULTS: Ninety-six subjects with a wide range of cardiac function (10 healthy controls and 86 CHF patients with NYHA classes I-IV, LVEF 36.9+/-15.2%) were recruited into the study and had resting plasma N-BNP and cardiopulmonary exercise testing to measure peak oxygen consumption (VO2). Significantly higher N-BNP levels were found in the CHF group (299.3 [704.8] fmol/ml, median [IQR]) compared with the healthy control group (7.2 [51.2] fmol/ml), p<0.0001. There were significant correlations between peak VO2 and N-BNP levels (R=0.64, P<0.001), peak VO2 and NYHA class (R=0.76, P=0.001), but no significant correlation was seen between peak VO2 and LVEF (R=0.0788, P=0.33). Multivariate analysis identified plasma N-BNP (P<0.0001) and NYHA class (P<0.0001) as significant independent predictors of peak VO2. Logistic modelling with NYHA class and log N-BNP to predict peak VO2<20 ml/kg/min showed that the area under the curve of receiver-operating-characteristic (ROC) curve was 0.906 (95% CI 0.844-0.968). A nomogram based on the data has been constructed to allow clinicians to estimate the likelihood of peak VO2 to be <20 ml/kg/min for given values of plasma N-BNP and NYHA class. CONCLUSIONS: By combining information from a simple objective blood test (N-BNP) and a simple scoring of functional status (NYHA), a clinician can deduce the aerobic exercise capacity and indirectly the extent of cardiac dysfunction of patients with CHF.     

Physical training in patients with chronic heart failure of ischemic origin: effect on exercise capacity and left ventricular remodeling.

BACKGROUND: Physical training is a well-known complementary treatment for chronic heart failure (CHF); however, many aspects require further studies. One of them is the impact on remodeling of the left ventricle (LV). The purpose of this study was to evaluate the effect of 6 months of training on LV, exercise capacity and safety issues in patients with ischemic CHF. METHODS: Fifty patients (mean age 60.1+/-9.2 years) with ischemic CHF, New York Heart Association (NYHA) classification class II and III and left ventricular ejection fraction (LVEF) 相似文献   

Early recovery of oxygen kinetics after submaximal exercise test predicts functional capacity in patients with chronic heart failure.

BACKGROUND: Oxygen (O2) uptake at peak exercise (VO2 peak) is an objective measurement of functional capacity in patients with chronic heart failure (CHF). The significance of recovery O2 kinetics parameters in predicting exercise capacity, and the parameters of submaximal exercise testing have not been thoroughly examined. METHODS AND RESULTS: Thirty-six patients (mean age = 48+/-14 years) with CHF and New York Heart Association functional class I, II, or III, and eight healthy volunteers (mean age = 39+/-13 years) were studied with maximal and submaximal cardiopulmonary exercise testing (CPET). The first degree slope of O2 uptake decay during early recovery from maximal (VO2/t-slope), and submaximal exercise (VO2/t-slope)(sub), were calculated, along with VO2 half-time (T(1/2)VO2). Patients with CHF had a longer recovery of O2 uptake after exercise than healthy volunteers, expressed by a lower VO2/t-slope (0.616+/-0.317 vs. 0.956+/-0.347 l min(-1) min(-1), P=0.029) and greater T(1/2)VO2 (1.28+/-0.30 vs. 1.05+/-0.15 min, P = 0.005). VO2/t-slope correlated with the VO2 peak (r = 0.84, P<0.001), anaerobic threshold (r = 0.79, P<0.001), and T(1/2)VO2, a previously established estimate of recovery O2 kinetics (r = -0.59, P<0.001). (VO2/t-slope)(sub) was highly correlated with VO2/t-slope after maximal exercise (r=0.87, P<0.001), with the VO2 peak (r=0.87, P<0.001) and with T(1/2)VO2 after maximal exercise (r=-0.62, P<0.001). VO2/t-slope after maximal and submaximal exercise was reduced in patients with severe exercise intolerance (F=9.3, P<0.001 and F=12.8, P<0.001, respectively). CONCLUSIONS: Early recovery O2 kinetics parameters after maximal and submaximal exercise correlate closely with established indices of exercise capacity in patients with CHF and in healthy volunteers. These findings support the use of early recovery O2 kinetics after submaximal exercise testing as an index of functional capacity in patients with CHF.     

Relationship between the force of left atrial ejection to left ventricular function in arterial hypertension]

The left atrial ejection force (LAEF), defined as that force exerted by the left atrium (LA) to accelerate the blood into the left ventricle during atrial systole, is well accepted for the evaluation of LA systolic function. The aim of this study is to determine whether LAEF is a precursor of the impairement of LV systolic function in patients with arterial hypertension (HTN). For that purpose we studied LAEF in 36 patients with HTN (av. age 58 +/- 8 years) with LV hypertrophy (Lvmi > 134 g/m2 for men and > 110 g/m2 for women). LV systolic function estimated by the fractional shortening (FSh) was 35 +/- 4% (28 to 44); 32 normal subjects (NS) were also analyzed. All subjects were submitted to echo and doppler examinations. METHODS: LAEF was obtained by the formula: 1/3 x MVA x (A-vel)2, where MVA is mitral valve area measured by 2D echo while A-vel. is the late diastolic (atrial) mitral velocity. RESULTS: 1. LAEF increased significantly with age in NS (r = 0.78) p < 0.05). Age corrected LEAF was calculated as % LEAF = (actual LAEF/normal LAEF x 100. 2. Compared to NS. % LAEF was lower in HTN (78 + 25%). 3. There was a significant inverse correlation between LAEF and LV wall thickness (r = -0.46) (p < 0.05). 4. % LAEF was 66 +/- 31% in patients with FSh < 33% and 79 +/- 25% in those with FSh > 33% (p < 0.05). 5. In HTN with the duration > 15 years, % LAEF was lower than in patients with < 15 years (62 +/- 25 vs 76 +/- 24) (p < 0.05). CONCLUSIONS: 1. LAEF is decreased in more advance stages of HTN. 2. This impairment is related to LV hypertrophy and to the duration of the disease. 3. LAEF is a sensitive precursor for LV systolic deterioration in patients with hypertension.     

A comparison of 16 weeks of continuous vs intermittent exercise training in chronic heart failure patients

The authors compared the effects of continuous (CON) and intermittent (INT) exercise training programs on functional capacity, quality of life (QOL), and cardiac function in 23 congestive heart failure patients. Patients were randomized to CON exercise training (n=13; aged 66±7 years; peak oxygen consumption [VO(2)], 12.4±2.5 mL/kg/min; weight, 83±12 kg; left ventricular ejection fraction [LVEF], 29.5%±7.2%) or INT exercise training (n=10; aged 59±11 years; VO(2), 12.2±6.5 mL/kg/min; weight, 87±24 kg; LVEF 27%±7.9%). These groups completed 16 weeks of stationary cycling at 70% VO(2) thrice weekly for 30 minutes continuously or 60 minutes (60 seconds work:60 seconds rest) intermittently; both groups completed the same absolute volume of work. Three QOL questionnaire responses, VO(2), LVEF, and regional tissue Doppler were quantified. After exercise training, VO(2) increased by 13% in the CON group (P=.12) and significantly by 21% in the INT group (P=.03), although not significantly between the groups (P=.72). In the CON group, Minnesota Living With Heart Failure score improved at 16 weeks (P=.02), while in the INT group, Hare-Davis scores improved (P=.02). Cardiac volumes, resting and peak LVEF, contractile reserve, and tissue velocities were all unchanged from baseline. Intermittent exercise may improve functional capacity to a greater extent than continuous exercise. QOL changes were variable between groups.