N-端心房利钠肽与N-端脑利钠肽对预测左室收缩功能障碍的价值

目的比较N-端心房利钠肽(心钠素NT-proANP)和N-端脑钠肽(NT-proBNP)对左室收缩功能障碍(LVSD)预测效率,依据二者特性确定适用范围并界定最佳下限(cut-off)值。方法入选心血管病患者380例(病例组),依据左室射血分数(LVEF)将患者划分为LVSD组(LVEF≤40%,n=90)及非LVSD组(LVEF40%,n=290)。另选136名健康体检者作为对照组。超声心动图测定LVEF;ELISA法测定血浆NT-proANP和NT-proB-NP浓度。描记NT-proANP和NT-proBNP预测左室收缩功能障碍受试者工作特征(ROC)曲线。依据年龄(以65岁为分界)、性别及原发心血管疾病种类划分亚组,分别描记各组患者NT-proANP和NT-proBNP预测左室收缩功能障碍ROC曲线;确定最佳cut-off值。结果病例组血浆NT-proANP和NT-proBNP浓度均显著高于对照组log(NT-proANP):(3.30±0.41)vs(2.98±0.16),P0.01;log(NT-proBNP):(2.71±0.30)vs(2.49±0.13),P0.01。NT-proANP和NT-proBNP对不同程度LVSD(LVEF≤40%或LVEF≤30%)患者诊断ROC曲线下面积(AUC)均大于0.73(P0.01);对LVEF≤40%的患者,NT-proANPAUC大于NT-proBNP(0.820vs0.738);对LVEF≤30%的患者,NT-proANPAUC明显小于NT-proBNP(0.853vs0.877)。根据各亚组ROC曲线确定cut-off值,NT-proANP为1676.92pmol/L时对各组LVSD预测敏感度88.9%～100%;特异度14.0%～58.7%;阳性预测值9.04%～30.04%;阴性预测值96.96%～98.77%。NT-proBNP为417.37pmol/L时,敏感度77.8%～94.4%;特异度10.0%～55.8%;阳性预测值7.07%～48.88%;阴性预测值94.46%～98.87%。结论 NT-proBNP与NT-proANP均能够反映心力衰竭高危人群心脏功能状态,可作为LVSD的诊断指标,对于LVEF≤40%的预测,NT-proANP效果优于NT-proBNP,有助于早期发现LVSD患者。     

Value of B-type natriuretic peptide in diagnosing left ventricular dysfunction in dialysis-dependent patients

Background: B‐type natriuretic peptide (BNP) is elevated in patients with end‐stage renal failure. The reported accuracy of BNP in diagnosing left ventricular dysfunction in these patients has been inconsistent. Aim: To investigate the diagnostic values of BNP for left ventricular dysfunction in patients undergoing haemodialysis for chronic renal failure. Methods: We measured plasma BNP before and at 10 min and 3, 6 and 24 h after haemodialysis in 56 patients. Results: The average plasma BNP before haemodialysis was 284 ± 369 pg/mL, which was higher than that of healthy subjects (37 ± 37 pg/mL; n = 32, P < 0.01). The average plasma BNP in patients with left ventricular dysfunction (n = 21) was substantially higher than that in those with normal ventricular function before and at 10 min and 3, 6 and 24 h after haemodialysis (P < 0.001). The area under the receiver operating characteristic curves was greater than 0.895 before and at the four time points after haemodialysis (P < 0.01). Using 152 pg/mL as a cut‐off value, predialysis BNP has 81% sensitivity and 83% specificity in diagnosing left ventricular dysfunction in these patients. Conclusion: We concluded that plasma BNP offers a good sensitivity and specificity in diagnosing left ventricular dysfunction in patients with dialysis‐dependent renal failure.     

左室功能不全患者血清脑钠尿肽的水平及诊断价值

目的 :探讨左室功能不全 （LVD）患者血清脑钠尿肽 （BNP）水平和诊断价值。方法 :用ELISA法测定单纯左室舒张功能不全 （LVDD）患者 30例、左室收缩功能不全 （LVSD伴或不伴舒张功能不全 ）患者 15例、心功能正常者 （健康对照组 ）血清BNP浓度 2 0例 ,并按诊断试验的评价方法计算真实性指标。结果 :LVDD组BNP水平明显高于健康组 （2 10± 134ng/Lvs 72± 32ng/L ,P <0 .0 5 ） ,但明显低于LVSD组 （2 10± 134ng/Lvs 10 86± 5 19ng/L ,P <0 .0 5 ）。以BNP≥ 12 0ng/L为截断点 ,诊断LVD的灵敏度和特异度分别为 91%和 95 % ,准确度为 92 % ;判断单纯LVDD灵敏度为 87% ,特异度为 95 %。结论 :LVD患者血清BNP浓度明显升高 ,是较好的诊断指标 ,但单纯LVDD患者升高程度不如LVSD患者 ;若左室收缩功能正常 ,BNP水平≥ 12 0ng/L高度提示LVDD存在的可能。     

Risk Factors for Heart Failure: A Population-Based Case-Control Study

Background

The relative contribution of risk factors to the development of heart failure remains controversial. Further, whether these contributions have changed over time or differ by sex is unclear. Few population-based studies have been performed. We aimed to estimate the population attributable risk (PAR) associated with key risk factors for heart failure in the community.

Methods

Between 1979 and 2002, 962 incident heart failure cases in Olmsted County were age and sex-matched to population-based controls using Rochester Epidemiology Project resources. We determined the frequency of risk factors (coronary heart disease, hypertension, diabetes mellitus, obesity, and smoking), odds ratios, and PAR of each risk factor for heart failure.

Results

The mean number of risk factors for heart failure per case was 1.9 ± 1.1 and increased over time (P <.001). Hypertension was the most common (66%), followed by smoking (51%). The prevalence of hypertension, obesity, and smoking increased over time. The risk of heart failure was particularly high for coronary disease and diabetes with odds ratios (95% confidence intervals) of 3.05 (2.36-3.95) and 2.65 (1.98-3.54), respectively. However, the PAR was highest for coronary disease and hypertension; each accounted for 20% of heart failure cases in the population, although coronary disease accounted for the greatest proportion of cases in men (PAR 23%) and hypertension was of greatest importance in women (PAR 28%).

Conclusion

Preventing coronary disease and hypertension will have the greatest population impact in preventing heart failure. Sex-targeted prevention strategies might confer additional benefit. However, these relationships can change, underscoring the importance of continued surveillance of heart failure.     

The left ventricular dysfunction questionnaire (LVD-36): reliability, validity, and responsiveness

OBJECTIVE—To examine the reliability, validity, and responsiveness of a new health status measure (LVD-36) for patients with left ventricular dysfunction which was designed with emphasis on content validity, clarity, brevity, and ease of use.
DESIGN—At baseline, patients completed the LVD-36 and a range of measures reflecting general health and disease severity. The LVD-36 was repeated after one week. After six months, it was repeated again, along with a transition question to measure global changes in health.
SETTING—Patients were recruited from the cardiology and general medical clinics at a south west London hospital.
PATIENTS—60 patients with chronic left ventricular dysfunction.
INTERVENTIONS—None.
MAIN OUTCOME MEASURES—Short form 36 questionnaire (SF-36), Minnesota living with heart failure questionnaire (LIhFE), New York Heart Association criteria, and exercise performance and echocardiographic tests.
RESULTS—The LVD-36 showed good internal consistency (κ = 0.95) and repeatability (r_i = 0.95). Its scores were significantly associated with SF-36 mental and physical component scores (r = −0.48 and −0.75; p < 0.0001), with exercise capacity (r = −0.52; p < 0.0001), and with systolic shortening fraction (r = −0.27; p < 0.05). Change in the LVD-36 over six months was associated with change in overall health (F = 5.7; p < 0.001). In tests of validity and responsiveness, the LVD-36 performed similarly to or marginally better than the LIhFE.
CONCLUSIONS—The LVD-36 showed a high level of reliability and validity, and appears to measure changes in health. It provides a short, simple, valid, and reliable measure of health status in patients with left ventricular dysfunction.


Keywords: health status; quality of life; heart failure; left ventricular dysfunction     

Cross sectional study estimating prevalence of heart failure and left ventricular systolic dysfunction in community patients at risk

OBJECTIVE—To examine a general practice population to measure the prevalence of signs and symptoms of heart failure (SSHF) and left ventricular systolic dysfunction (LVSD).
DESIGN—Cross sectional screening study in three general practices followed by echocardiography.
SETTING AND PATIENTS—All patients  50 years in two general practices and  40 years in one general practice were screened by case record reviews and questionnaires (n = 2158), to identify subjects with some evidence of heart disease. Among these, subjects were sought who had SSHF (n = 115). Of 357 subjects with evidence of heart disease, 252 were eligible for examination, and 126 underwent further cardiological assessment, including 43 with SSHF.
MAIN OUTCOME MEASURES—Prevalence of SSHF as defined by a modified Boston index, LVSD defined as an indirectly measured left ventricular ejection fraction  0.45, and numbers of subjects needing an echocardiogram to detect one case with LVSD.
RESULTS—SSHF afflicted 0.5% of quadragenarians and rose to 11.7% of octogenarians. Two thirds were handled in primary care only. At  50 years of age 6.4% had SSHF, 2.9% had LVSD, and 1.9% (95% confidence interval 1.3% to 2.5%) had both. To detect one case with LVSD in primary care, 14 patients with evidence of heart disease without SSHF and 5.5 patients with SSHF had to be examined.
CONCLUSION—SSHF is extremely prevalent in the community, especially in primary care, but more than two thirds do not have LVSD. The number of subjects with some evidence of heart disease needing an echocardiogram to detect one case of LVSD is 14.


Keywords: heart failure; left ventricular systolic dysfunction     

QRS prolongation on surface ECG and brain natriuretic peptide as indicators of left ventricular systolic dysfunction

OBJECTIVE: To determine whether the combination of prolonged QRS duration and brain natriuretic peptide (BNP) levels predicts left ventricular systolic dysfunction (LVSD) with a higher accuracy compared with QRS duration or BNP alone. SETTING: University hospital. METHODS: We studied 128 consecutive patients with suspected cardiac disease. At rest the QRS duration on 12-lead ECG and BNP levels were determined. A left ventricular ejection fraction (LVEF) <50% at echocardiography was defined as LVSD. RESULTS: QRS duration in the LVSD group (n = 66, LVEF 30 +/- 8%) was longer than in the group without LVSD (n = 62, LVEF 60 +/- 5%; QRS 129 +/- 34 vs. 96 +/- 20 ms, P < 0.001). BNP was higher in the LVSD group compared with controls (467 +/- 397 vs. 169 +/- 242 pg mL(-1), P < 0.001). A QRS duration of >0.1, >0.11 or >0.12 s was highly specific (63, 90 and 98%) but less sensitive (84, 81 and 75%) for the prediction of LVSD. A QRS cut-off value of 106 ms was moderately sensitive (65%) but very specific (87%) for the prediction of LVSD, whereas a BNP cut-off value of >84 pg mL(-1) was highly sensitive (89%) but only modestly specific (58%). The positive likelihood ratio for LVSD of abnormal BNP (2.0) and QRS prolongation >0.1 s (2.3) was improved by the combination of both criteria (5.1). In multivariate analysis, BNP and QRS duration were independent predictors of LVSD. CONCLUSIONS: The combination of abnormal BNP and QRS prolongation yields a higher positive likelihood ratio for the detection of LVSD compared with the two criteria alone.     

Prevalence of heart failure and left ventricular dysfunction in the general population; The Rotterdam Study.

AIMS: To determine the prevalence of heart failure and symptomatic as well as asymptomatic left ventricular systolic dysfunction in the general population. METHODS AND RESULTS: In 5540 participants of the Rotterdam Study (age 68.9+/-8.7 years, 2251 men) aged 55-95 years, the presence of heart failure was determined by assessment of symptoms and signs (shortness of breath. ankle oedema and pulmonary crepitations) and use of heart failure medication. In 2267 subjects (age 65.7+/-7.4 years, 1028 men) fractional shortening was measured. The overall prevalence of heart failure was 3.9% (95% CI 3.0+/-4.7) and did not differ between men and women. The prevalence increased with age, with the exception of the highest age group in men. Fractional shortening was higher in women and did not decrease appreciably with age. The prevalence of left ventricular systolic dysfunction (fractional shortening <=25%) was approximately 2.5 times higher in men (5.5%, 95% CI 4.1-7.0) than in women (2.2%, 95% CI 1.4-3.2). Sixty percent of persons with left ventricular systolic dysfunction had no symptoms or signs of heart failure at all. CONCLUSIONS: The prevalence of heart failure is appreciable and does not differ between men and women. The majority of persons with left ventricular systolic dysfunction can be regarded as having asymptomatic left ventricular systolic dysfunction.     

Plasma pro-B-type natriuretic peptide in the general population: screening for left ventricular hypertrophy and systolic dysfunction.

AIMS: B-type natriuretic peptide (BNP) measurement in screening for left ventricular hypertrophy (LVH) and left ventricular systolic dysfunction (LVSD) has been evaluated in the general population, but corresponding information on proBNP and the N-terminal proBNP fragment is still limited. We therefore examined whether proBNP measurement is useful for LVH and LVSD screening in the general population. METHODS AND RESULTS: In the 4th Copenhagen City Heart Study, 3497 participants underwent echocardiography with assessment of left ventricular ejection fraction (LVEF) and mass. The impact of gender and age was determined and the diagnostic performance of the plasma proBNP concentration was evaluated using receiver operating characteristic (ROC) curves. Of 1502 men and 1995 women, 4.1 and 2.6% had LVSD defined as an LVEF<60% whereas only 0.4% displayed LVEF<40%. The proBNP concentration was 1.7-fold higher in women compared with men (P<0.0001) and related to age in both genders. The mean proBNP plasma concentration was two-fold higher in subjects with LVSD than without LVSD (P<0.0001). Likewise, LVH imposed a 1.9-fold increase in the proBNP concentration (P<0.0001): Both differences persisted after adjusting for ischaemic heart disease, hypertension, diabetes, gender, and age. The diagnostic performance of proBNP in detecting LVEF<40% was high with an area under the ROC curves of 0.92 (95% CI 0.79-1.00) in women and 0.85 (95% CI 0.74-0.96) in men. CONCLUSION: We have established the impact of age and gender on the proBNP concentration in a large, community-based cohort. The diagnostic performance for proBNP measurement in screening for LVH and LVSD in the general population parallels the reported data for BNP.     

Augmented response in plasma brain natriuretic peptide to dynamic exercise in patients with left ventricular dysfunction and congestive heart failure

OBJECTIVES: We have previously demonstrated that patients with symptomatic congestive heart failure (CHF), but not with asymptomatic left ventricular dysfunction (LVD), have augmented plasma atrial natriuretic peptide (ANP) response to exercise. Plasma brain natriuretic peptide (BNP) response to exercise is less extensively studied. The aim of this study was to determine whether responses of plasma BNP during exercise normalized for exercise workload are altered in patients with LVD and CHF. SUBJECTS AND METHODS: Twenty-nine patients with LVD, 32 patients with CHF (NYHA classes II-III) and 27 age-matched control subjects were studied. Ventilatory, plasma ANP and BNP responses were assessed during symptom-limited cardiopulmonary exercise testing. Plasma natriuretic peptide levels were measured at rest and immediately after peak exercise. The increment in plasma BNP was divided by the increment in oxygen uptake (VO2) from rest to peak exercise, and this ratio [BNP exercise ratio: (peak BNP - rest BNP)/(peak VO2 - rest VO2)] was compared amongst the three groups. RESULTS: Peak VO2 (Control, LVD and CHF: 28.2 +/- 1.7, 21.1 +/- 1.8, 16.2 +/- 0.6 ml, min(-1) kg(-1), respectively), anaerobic threshold and peak workload became smaller as heart failure worsened. Resting and peak plasma ANP levels were significantly higher only in CHF, whilst resting and peak plasma BNP levels displayed a significant and continuous increase from normal subjects to LVD and CHF. The ANP exercise ratio (1.25 +/- 0.36, 2.61 +/- 0.57, 7.72 +/- 1.65, ANOVA P = 0.0002) was significantly higher only in patients with CHF, whilst the BNP exercise ratio (0.35 +/- 0.10, 2.60 +/- 0.69, 4.98 +/- 0.97, ANOVA P = 0.0001) was significantly higher in patients with LVD and became progressively higher in patients with CHF. CONCLUSIONS: These data showed that the BNP exercise ratio, an exercise plasma BNP response normalized with exercise workload, was augmented in patients with LVD, and became progressively higher in CHF, suggesting that an augmented exercise BNP ratio exists early in the course of developing CHF.     

Differences between patients with a preserved and a depressed left ventricular function: a report from the EuroHeart Failure Survey.

AIMS: Due to a lack of clinical trials, scientific evidence regarding the management of patients with chronic heart failure and preserved left ventricular function (PLVF) is scarce. The EuroHeart Failure Survey provided information on the characteristics, treatment and outcomes of patients with PLVF as compared to patients with a left ventricular systolic dysfunction (LVSD). METHODS AND RESULTS: We performed a secondary analysis using data from the EuroHeart Failure Survey, only including patients with a measurement of LV function (n = 6806). We selected two groups: patients with LVSD (54%) and patients with a PLVF (46%). Patients with a PLVF were, on average, 4 years older and more often women (55% vs. 29%, respectively, p < 0.001) as compared to LVSD patients, and were more likely to have hypertension (59% vs. 50%, p < 0.001) and atrial fibrillation (25% vs. 23%, p = 0.01). PLVF patients received less cardiovascular medication compared to PLVF patients, with the exception of calcium antagonists. Multivariate analysis revealed that LVSD was an independent predictor for mortality, while no differences in treatment effect on mortality between the two groups was observed. A sensitivity analysis, using different thresholds to separate patients with and without LVSD revealed comparable findings. CONCLUSIONS: In the EuroHeart Failure Survey, a high percentage of heart failure patients had PLVF. Although major clinical differences were seen between the groups, morbidity and mortality was high in both groups.     

左室舒张性心功能障碍超声左心形态、功能及运动耐量的改变50例分析

对核素心血池扫描证实的５０例左室舒张性心功能障碍（ＬＶＤＤ）病例、２６例左室收缩性心功能障碍（ＬＶＳＨＦ）病例进行Ｍ型、二维、多普勒超声心动图及活动平板运动试验检测，并以２０例正常人为对照组（ＣＧ）。结果表明：（１）左心形态学改变：与ＬＶＳＨＦ组比较，ＬＶＤＤ组左房内径（ＬＡＤ）、左室内径（ＬＶＤ）无明显增加，室间隔厚度（ＩＶＳＴ）、左室后壁厚度（ＰＷＴ）增加。与ＣＧ组比较，ＬＶＤＤ组ＬＡＤ、ＩＶＳＴ、ＰＷＴ增加，但ＬＶＤ差异无显著性。（２）ＬＶＤＤ组收缩功能指标：左室射血分数（ＬＶＥＦ）、心脏指数（ＣＩ）与ＣＧ组比较差异无显著性，ＬＶＳＨＦ组与ＣＧ组比较，ＬＶＳＨＦ组ＬＶＥＦ、ＣＩ减低。与ＣＧ组比较，ＬＶＤＤ组左室舒张功能指标：二尖瓣舒张早期流速峰值（ＥＰＦＶ）、二尖瓣舒张早、晚期流速峰值比（Ｅ／Ａ）、舒张早期减速度（ＤＣ）比ＣＧ组减低，二尖瓣舒张晚期流速峰值（ＡＰＦＶ）、等容舒张时间（ＩＲＴ）较ＣＧ组增高。ＬＶＤＤ组各左室舒张功能指标与ＬＶＳＨＦ组差异无显著性。（３）ＬＶＤＤ组运动时间、运动当量显著低于ＣＧ组，但高于ＬＶＳＨＦ组。     

Influence of hypertension, left ventricular hypertrophy, and left ventricular systolic dysfunction on plasma N terminal proBNP

OBJECTIVES: To examine the relation between plasma concentration of the N terminal of the precursor of brain natriuretic peptide (NT proBNP), left ventricular hypertrophy (LVH), and left ventricular systolic dysfunction (LVSD) in patients with a history of hypertension. DESIGN: Prospective study. SETTING: Teaching hospital based study. PATIENTS: NT proBNP concentrations were determined in five groups of individuals. Group 1: 15 echocardiographic normal controls; group 2: 22 patients with hypertension, normal left ventricular systolic function, and no LVH; group 3: 24 patients with hypertension, normal left ventricular systolic function, and LVH; group 4: 13 patients with history of hypertension, no history of ischaemic heart disease, and left ventricular wall motion index (WMI) between 1.9-1.3; and group 5:17 patients with a history of hypertension, no history of ischaemic heart disease, and WMI < 1.2. RESULTS: Median (range) NT proBNP concentrations (in fmol/ml) for groups 1-5, respectively, were: 129.4 (53.6-159.7), 147.4 (54.3-730. 5), 137.1 (35.8-403.9), 356.7 (124.4-934.4), and 493.5 (248.9-909). Mean log NT proBNP differed among all five groups (p < 0.0001), and between groups 4 and 5 versus groups 1-3 (p < 0.0001), and group 4 versus group 5 (p = 0.02) only. CONCLUSIONS: The results suggest that the presence of hypertension with or without LVH (and normal left ventricular systolic function) does not affect NT proBNP concentrations. Moreover, there is a significant rise in NT proBNP only when LVSD develops in hypertension. Thus, NT proBNP remains a useful diagnostic aid for LVSD, even in hypertensive patients.     

Transient left ventricular dysfunction (tako-tsubo phenomenon): Findings and potential pathophysiological mechanisms

Tako-tsubo-like left ventricular dysfunction phenomenon (TTP) is characterized by transient left ventricular apical ballooning associated with symptoms, electrocardiographic changes and minimal cardiac enzyme release in the absence of coronary artery disease. Initially described in Japan, TTP occurs worldwide, predominantly in women and frequently after emotional or physical stress. Symptoms include anginal chest pain, dyspnea and syncope. Electrocardiographic ST elevations may be present only for several hours, and are followed by negative T waves that persist for months. Arterial hypertension is found in up to 76% of TTP patients, hyperlipidemia in up to 57% and diabetes mellitus in up to 12%. Potential pathophysiological mechanisms for TTP include catecholamine-induced myocardial stunning or hyperkinesis of the basal left ventricular segments, coronary vasospasm, plaque rupture, myocarditis and genetic factors. TTP patients should be monitored similarly to myocardial infarction patients because organ failure, cardiogenic shock, ventricular fibrillation or rupture may occur. Beta-blockers are indicated, whereas catecholamines and nitrates should be avoided. The long-term prognosis is unknown.     

Assessment of heart failure and left ventricular systolic dysfunction after cardiac pacing in patients with preserved left ventricular systolic function

BACKGROUND: There is an accumulating data suggesting the deleterious effects of right ventricular pacing on left ventricular performance. Such pacing mimics left bundle branch block resulting in a prolonged QRS duration and causes ventricular asynchrony. AIMS: The purpose of this study is to assess heart failure and left ventricular systolic function after cardiac pacemaker implantation in patients with atrioventricular block and preserved systolic left ventricular function. Secondly, we sought to search for predictive factors of developing left ventricular dysfunction after pacing. METHODS: In this prospective study, we included patients who had been implanted for at least six months. They underwent medical history and examination, 12 leads electrocardiogram and echocardiography before pacemaker implantation and when attending to routine pacemaker follow up. RESULTS: Forty-three patients (22 men and 21 women, age 71+/-12 years) were included in this study. Twenty-nine patients had DDD pacing and 14 VVI pacing. The ventricular lead was implanted in the apex in all patients. After a median follow up of 18+/-11 months, 11 patients (25%) developed signs of congestive heart failure. NYHA was higher after implantation (1.64+/-0.7 versus 2.27+/-0.8, p>0.00001). Left ventricular ejection fraction decreased significantly during follow up (60+/-6% versus 51+/-13%, p=0.0002). Eleven (25%) patients developed left ventricular dysfunction. We compared patients who had left ventricular ejection fraction (LV EF) less or equal to 40% (group A) and patients having LV EF greater than 40% (group B) after implantation. Patients in group A had a paced QRS width significantly larger than group B (181+/-32 ms versus 151+/-26 ms, p=0.002), a significantly prolonged intra left ventricular electromechanical delay (115+/-59 ms versus 45+/-35 ms, p<0.0001) and interventricular delay (44+/-29 ms versus 27+/-18 ms, p=0.02). Age, sex, diabetes hypertension, pacing mode and percentage of ventricular pacing were similar in both groups. A paced QRS width of 180 ms had the best sensitivity and specificity for detecting left ventricular dysfunction: sensitivity=54% and specificity=93%, p=0.01, area under the curve=0.75. CONCLUSION: Patients with atrioventricular block and preserved left ventricular systolic function at baseline decrease significantly left ventricular ejection fraction after pacing. Induced ventricular asynchronism plays a major role in the deterioration of left ventricular function. Prolonged paced QRS width is a good predictor of left ventricular dysfunction after pacing. Larger prospective studies are needed to confirm these data.     

组织多普勒成像联合血浆N末端B型钠尿肽原评价左心室舒张功能

目的应用组织多普勒成像技术结合血浆N末端B型钠尿肽原（NT—proBNP）共同评价左心室舒张功能。方法随机选择120例左心室舒张性心力衰竭患者为研究组,120例心功能rF常且无心力衰竭症状和依据的患者为对照组。分别测取患者血浆NT—proBNP水平、左心室射血分数（排除收缩性心力衰竭患者）,二尖瓣血流频谱舒张早期速度（E）和二尖瓣血流频谱舒张晚期速度（A）并计算其比值E／A,二尖瓣环室间隔舒张早期峰值速度（Esep）和左心室游离壁舒张早期峰值速度（Elat）,两者的均值作为二尖瓣环舒张早期速度（Em）,并计算二尖瓣血流频谱舒张早期速度E和二尖瓣环舒张早期速度Em的比值E／Era,综合评价左心室舒张功能。结果研究组与对照组比较,平均血浆NT—proBNP水平增高（P〈0．01）,E／Era增大（P〈0．01）,E／A减小（P〈0．01）。研究组、对照组患者的平均血浆NT—proBNP水平与E／Era呈正相关。利用E／Em检出左心率舒张性心力衰竭阳性率高于E／A,联合NT—proBNP和E／Em诊断左心室舒张性心力衰竭阳性预测值为94％,阴性预测值为83％。结论血浆NT—proBNP水平与组织多普勒成像左心室舒张功能参数E／Em之间存在明显的相关性,联合NT—proBNP和E／Em较E／A能更好的诊断左心室舒张忡心力衰竭。