首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
QT离散度对心衰患者心脏事件的预测价值   总被引:3,自引:3,他引:0  
目的探讨QT离散度(QTd)、校正QT离散度(QTcd)及心率校正QT间期(QTc)对心衰患者心脏事件的预测价值。方法回顾性研究了106例充血性心力衰竭(CHF)患者QTd、QTcd、及QTc的资料。结果心脏事件发生组CHF病人(Ⅰ组)QTd、QTcd、QTc、QTcd/QTc与无心脏事件发生组(Ⅱ组)比较有显著的统计学差异(P<0.05、<0.01、<0.05、<0.001)。结论QTd、QTcd、QTc、QTcd/QTc是心衰病人心脏事件独立预测因子,QTcd/QTc准确性最高。  相似文献   

2.
OBJECTIVE: Cardiac arrhythmias commonly occur in hemodialysis patients. QT dispersion (QTd=QTmax-QTmin) reflects heterogeneity of cardiac repolarization, and increased QTd is known to predispose the heart to ventricular arrhythmias and sudden cardiac death. The aim of our study was to assess the association of iron stores, reflected by transferrin saturation (TSAT) and ferritin, with the dispersion of corrected QT intervals (QTc) in patients undergoing hemodialysis. METHODS: This cross-sectional, case-controlled study included 40 patients (23 men and 17 women) with renal failure undergoing hemodialysis (Patient group) and 27 subjects (10 men and 17 women) with normal renal function (Control group). In all patients and control subjects, QT intervals were measured on electrocardiogram, and QTc intervals and QTc dispersion were calculated. Electrolyte, hemoglobin and serum TSAT and ferritin levels were also determined. RESULTS: Hemodialysis patients had significantly greater QTc dispersion compared to that of control subjects (61.7+/-23.0 msec vs. 46.0+/-15.7 msec; p=0.001). Though serum iron levels were significantly associated with greater QTc dispersion (r=0.324, p=0.042), other electrolyte levels, duration of dialysis, TSAT and serum ferritin levels were not. CONCLUSION: Although hemodialysis patients have greater QTc dispersion than control subjects, their levels of iron stores as reflected by TSAT and ferritin levels, does not correlate with the degree of QT dispersion.  相似文献   

3.
In previous studies, it has been shown that QT interval prolongation is related to an increased mortality rate in chronic liver disease (CLD). But QT dispersion (QTd) and its clinical significance in CLD has not been well studied. The objectives of this study were to investigate the relation between QTd and severity of the disease and determine its prognostic value in cirrhotic patients. Thirty-three consecutive patients with cirrhosis and 35 sex- and age-matched healthy subjects were studied. QT intervals and QT dispersions were measured on admission, and all intervals were corrected for heart rate according to Bazett's formula. The authors analyzed the potential relationship between QT parameters and the disease severity according to Child-Pugh classification and compared these values between survivors and nonsurvivors after a 3-year follow-up. Child-Pugh classification is used to assess liver function in cirrhosis. Corrected QT (QTc) prolongations were found in 32% of patients with cirrhosis and 5.7% of the healthy controls (p <0.001). The prevalence of increased (>70 ms) corrected QT dispersion (QTcd) was 45% in patients with cirrhosis. According to Child-Pugh criteria: QTd, maximum QT interval (QTmax), corrected QTmax (QTcmax), and QTcd in class C were significantly higher than those of class A and B (p <0.05, for all comparison). But there was no significant difference between class A and B in QTmax, QTcmax, QTd, and QTcd. There were 10 (30%) deaths from all causes during 3-year follow-up in the study group. Cox regression analysis showed that QTd and QTcd were better mortality indicators than QTmax and QTcmax, and Child's classification was the best predictor for mortality among all variables. In conclusion, QT dispersion and corrected QT dispersion parameters were better mortality indicators than other QT interval parameters and also may give additional prognostic information in patients with chronic liver disease.  相似文献   

4.
急性心肌梗死恢复期PTCA及支架置入术对QT离散度的影响   总被引:9,自引:0,他引:9  
目的 观察急性心肌梗死 (AMI)恢复期 (2~ 4周 )行经皮冠状动脉腔内成形术 (PTCA)及支架置入术对QT离散度 (QTd)的影响。方法 选择 5 7例AMI恢复期的患者 ,分别记录PTCA及支架置入术前 1d ,术后 1h的 12导联同步心电图 ,测量QTd及校正的QTd(QTcd) ,并与 86例同期行冠状动脉造影结果正常者进行对照。结果 AMI组行PTCA及支架置入术前最大QT间期 (QTmax) ,最小QT间期 (QTmin) ,QTd及QTcd均较对照组明显增大 ,差异有显著性。前壁与下壁AMI之间上述指标差异无显著性。成功的PTCA及支架置入术后QTmax,QTmin,QTd及QTcd比术前明显缩短 ,两者相比差异有显著性。而单纯行冠状动脉造影对QT离散度无明显影响。结论 AMI患者QTd及QTcd显著高于正常人 ,而AMI恢复期成功的PTCA及支架置入术可使增加的QTd及QTcd显著缩短 ,从而减低AMI后恶性心律失常和心源性猝死的发生率 ,改善患者的远期预后。  相似文献   

5.
BACKGROUND: There has not been a longitudinal investigation of the influence of angiotensin-converting enzyme (ACE) insertion/deletion and angiotensinogen (AGT) M235T gene polymorphisms on repolarization parameters, such as QT dispersion (QTd) and the peak and the end of the T-wave interval (Tpe). METHODS AND RESULTS: Electrocardiographys were recorded from 106 elderly Chinese at baseline, and 2nd and 4th year follow-up. The corrected QT (QTc), QTd, QTc dispersion (QTcd) and Tpe were manually calculated. Average age was 72.7+/-4.1 years (range 62-81). QTd, QTcd and Tpe were significantly prolonged (all p<0.001 at the 2nd and 4th year). At the 4th year the magnitude of the QTd prolongation, but not Tpe, was significantly higher in subjects carrying the ACE D allele than non-D-allele carriers (p=0.001), as was QTcd (p=0.002). This association was still significant in the multivariate analyses (p<0.001 and p=0.001 for QTc and QTcd, respectively). No significant correlation was found between repolarization parameters and AGT genotype. CONCLUSIONS: This longitudinal study shows that the ageing process is associated with prolongation of QTd, QTcd and Tpe after 4 years follow-up. The elderly Chinese subjects with the ACE D-allele had greater prolongation QTd and QTcd.  相似文献   

6.
目的对高龄冠心病患者行经皮冠状动脉介入治疗(PCI)和冠状动脉搭桥术(CABG)术前、后的QT间期离散度(QTd)、校正QT间期离散度(QTcd)、JT间期离散度(JTd)的变化及与心功能相关性的研究。方法利用标准同步12导联心电图和二维彩色多普勒超声心动图对51例行PCI和CABG手术前后的高龄冠心病患者的QTd、QTcd和JTd离散度和心功能进行检测。结果高龄冠脉闭塞患者PCI与CABG术后的QTd、QTcd及JTd较手术前均显著缩短(P<0.01),高龄冠脉闭塞患者PCI与CABG术后的心功能指数(LVEF,E)明显增加(P<0.01)。高龄冠脉闭塞患者PCI与CABG术后的QTd及JTd的显著缩短与LVEF的增加呈正相关。结论对于高龄患者严重狭窄或完全闭塞的冠状动脉由于尚有存活心肌,再通后部分存活心肌可恢复电、机械功能,这对挽救这些存活心肌具有重要意义。  相似文献   

7.
为探讨经皮冠状动脉介入治疗对急性心肌梗死患者心电图QT离散度的影响及其临床意义 ,将我院资料较完整的 138例患者 ,分心肌梗死发病 6h内 (72例 )和 6h以上 (6 6例 )两组 ,测算术前和术后第 1天心电图QT间期、QT离散度、心率校正QT间期和心率校正QT离散度。结果发现 ,两组QT间期和心率校正QT间期术后与术前相比均无显著性差异 ;但术后QT离散度和心率校正QT离散度较术前显著减小 (P <0 .0 1) ,且发病 6h以内组显著小于 6h以上组 (P <0 .0 5 ) ;两组住院期间死亡率分别为 4 .2 %和 7.6 % (P =0 .394 )。结果提示 ,成功的介入治疗能显著减小心肌梗死患者的QT离散度 ,介入治疗施行得越早则减小QT离散度的效果越好。  相似文献   

8.
目的观察安体舒通对慢性充血性心力衰竭患者QT离散度(QTd)的影响,探讨其临床应用价值。方法采用随机、对照方法,设立安体舒通干预组及常规治疗组,测定两组用药前及用药1月后的QTd、校正QT离散度(QTcd)、血钾、血镁、血钠和肌酐。同时测定正常对照者的QTd及QTcd。结果心力衰竭组QTd、QTcd较对照组明显延长,差异有显著性(p<0.01);安体舒通干预组治疗后QTd、QTcd较治疗前显著下降(p<0.01):安体舒通干预组血清钾、镁治疗后较治疗前明显升高(p<0.01),肌酐轻度减低但差异无显著性(p>0.05)。结论安体舒通可降低心衰患者的QTd、QTcd。  相似文献   

9.
2型糖尿病伴高血压患者QT离散度的影响因素   总被引:1,自引:0,他引:1  
目的 探讨2型糖尿病伴高血压患者QT离散度(QTcd)的影响因素。方法 对60例2型糖尿病伴高血压患者,包括左心室肥厚(LVH)21例,非左心室肥厚(NLVH)39例,分别测量QTcd等,并与38例单纯2型糖尿病及60例正常组进行对照。应用相关分析及多因素逐步回归方法进行分析。结果 2型糖尿病各组的QTcd、QTd均较对照组明显延长,其中LVH组较NLVH组和单纯2型糖尿病组的QTcd、QTd的延长更为显著(P<0.001)。相关分析表明,QTcd与左心室重量指数(LVMI)、糖尿病病程及空腹胰岛素水平显著正相关。逐步回归分析表明,QTcd主要决定于LVMI、糖尿病病程和空腹胰岛素水平。结论 影响2型糖尿病伴高血压患者QTcd的主要因素为左心室肥厚、糖尿病病程及空腹胰岛素水平。  相似文献   

10.
QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies have showed that QT interval dispersion changes during episodes of myocardial ischemia. Slow coronary flow (SCF) in epicardial coronary arteries is a rare and unique angiographic finding. Whether this pattern of flow is associated with electrocardiographic abnormalities is unknown. Therefore, this study was designed to investigate whether SCF results in electrocardiographic (ECG) changes compared to normal coronary flow. For this aim 24 patients with angiographically proven SCF who had no obstructive coronary lesion (group I) and 25 patients without coronary artery disease (group II) were included in the study. Both groups underwent a routine standard 12-lead surface electrocardiogram recorded at 50 mm/s during rest. QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated. Distributions of sex, age, body mass index (BMI), and cardiac risk factors were similar in the 2 groups. Mean heart rate was similar in the 2 groups (74 +/-8 vs 77 +/- 7 p > 0.05). Mean QRS interval durations were similar in the groups (92 +/-7 vs 90 +/-6 ms p > 0.005). In group I, QTd, QTcd, and QTc, were significantly higher than in group II (QTd: 73 +/-14 vs 40 +/-14; QTcd: 71 +/-15 vs 42 +/-9; QTc: 414 +/-14 vs 388 +/-13, respectively p <0.05). In conclusion, SCF was found to be associated with prolonged QT interval and increased QT dispersion. Ischemia in microvascular level and/or altered autonomic regulation of the heart may be responsible mechanisms.  相似文献   

11.
QT离散度昼夜的变化与心率变异性的联系   总被引:4,自引:0,他引:4  
目的 探讨QT离散度的昼夜改变与心率变异性的关系。方法 测量计算20例正常人24小时动态心电图的QT、QTc、QT与QTc离散度及心率变异参数。结果 发现QT、QTd、QTcd、RR间期、RMSSD、HF、LH/HF存在昼夜的明显差异。QTd、QTcd与RR间期、RMSSD、HF呈现明显的负性相关,与LF/HF呈明显的正性相关。结论 QT离散度的增加与交感神经活动的增加和迷走神经活动的减弱密切相关。  相似文献   

12.
Isolated coronary ectatic but otherwise normal epicardial coronary arteries are an infrequent angiographic finding. We sought to determine whether coronary artery ectasia (CAE) may alter QT-interval duration and dispersion. The study population consisted of 24 patients with isolated CAE and otherwise normal epicardial coronary arteries (group 1) and sex- and age-matched subjects with atypical chest pain and otherwise normal coronary flow (group 2). Both groups underwent a routine standard 12-lead surface electrocardiogram recorded at 50 mm/s during rest. QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated. Distribution of sex, age, body mass index, and cardiac risk factors were similar in the 2 groups. Mean heart rate was similar in the 2 groups (74 ± 10 vs 70 ± 7, P > .05). In group 1, QTd, QTcd, and QTc were significantly higher than those of group 2 (QTd, 40 ± 17 vs 29 ± 10 milliseconds [P < .05]; QTcd, 43 ± 19 vs 30 ± 10 milliseconds [P < .05]; QTc, 410 ± 21 vs 397 ± 19 milliseconds [P < .05]). In conclusion, CAE was found to be associated with prolonged QT interval and increased QTd. Microvascular dysfunction and/or ischemia may be responsible mechanisms.  相似文献   

13.
目的 探讨冠状动脉旁路移植术 (Coronary artery bypass graftings,CABG)对冠心病患者 QT间期离散度(QTd)、QTc离散度 (QTcd)及 JT离散度 (JTd)的影响。方法 测定 33例 CABG术前和术后的 QTd为 CABG组 ,并以 33例确诊为冠心病行冠状动脉造影 ,而暂未行 CABG手术和装支架的病人作对照组。结果  1CABG前和对照组比较 QTd无显著增大 (P>0 .0 5 )。 2 CABG组术后病人的 QTd、QTcd及 JTd显著减小 (P<0 .0 5 )。 3对照组冠状动脉造影术后 QTd、QTcd及 JTd与术前比较 ,无明显改变 (P>0 .0 5 )。结论  CABG能使 QTd、QTcd及 JTd减小  相似文献   

14.
Glyburide (glibenclamide) is a specific blocker of the adenosine triphosphate (ATP) sensitive potassium (K+) channel. It has been reported to result in prolongation of the QT interval. QT interval dispersion (QTd) is a potentially sensitive marker for increased risk of arrhythmia and sudden cardiac death. The aim of the present study was to evaluate the effect of glyburide on QTd and compare it with that of metformin, a hypoglycemic agent that does not block the adenosine triphosphate sensitive K+ channel. Thirty patients with type 2 diabetes were randomized to glyburide and metformin groups. A 12-lead electrocardiogram was obtained before and at 2 months after being on glyburide or metformin. Therapy with QT and QTd were measured and QT corrected for rate (QTc). There was no significant difference between the glyburide and metformin groups in age (62 +/- 9 vs 59 +/- 10 years), baseline RR interval (819 +/- 86 vs 753 +/- 100 ms), QT (387 +/- 28 vs 383 +/- 27 ms), and QTc (433 +/- 25 vs 444 +/- 15 ms). Glyburide was associated with a significant increase in QTc (433 +/- 24 to 467 +/- 24 ms, p <0.001), QTd (24 +/- 16 to 60 +/- 22 ms, p <0.001), and QTc dispersion (QTcd) (35 +/- 18 to 68 +/- 21 ms, p <0.001). In contrast, metformin was associated with a decrease in QTc (444 +/- 15 to 432 +/- 15 ms, p <0.01) and did not affect QTd (14 +/- 5 to 12 +/- 6 ms, p = NS) and QTcd (23 +/- 9 to 22 +/- 10 ms, p = NS). Glyburide, unlike metformin, causes an increase in QT dispersion. Increased dispersion may be a factor underlying an increased risk of arrhythmias and sudden cardiac death.  相似文献   

15.
心率对QT离散度的影响   总被引:3,自引:0,他引:3  
目的 探讨心率对QT离散度(QTd)的影响以及心率对QTd进行校正的必要性。方法 采用食道心房调搏法改变心率,同时记录每种心率的12导联同步心电图以计算相应的QTd,采用Bazett公式对QTd进行校正(QTcd)。结果 QTd、QTcd均与心率呈负相关(r分别为-0.544和-0.664,P均小于0.001);QTd与QTcd呈显著正相关(r=0.98,P<0.001)。结论 QTd、QTcd与心率呈负相关,QTd与QTcd呈高度正相关,故不必用Bazett公正校正QT间期。  相似文献   

16.
AimTo study correlation between QT interval parameters (QTc interval & QT dispersion) and disease activity (SLEDAI) in patients with systemic lupus erythematosus (SLE).MethodsThe study was done on 100 newly diagnosed patients with SLE and 100 age matched controls from January 2012 to December 2013. A standard 12 lead Electrocardiogram was obtained. QT interval was calculated from beginning of ‘q’ wave to end of T wave in lead II or lateral leads (V5, V6). QT dispersion was measured as the difference between maximum and minimum QT intervals. SLE disease activity was measured SLEDAI.ResultsEighty four patients had high disease activity. QTc was >440 msec in 51 patients and 6 controls. QTd was prolonged in 6 patients and 6 controls. The mean QTc interval among patients (463.30 ± 27.43 msec) was higher than in controls (397.24 ± 31.85 msec; p < 0.001). However the mean QTd among patients (44.40 + 20.61 msec) was similar to that in controls (39.2 + 17.7 msec). Difference of QTc values during severe flare from baseline QTc values was statistically significant (r = 0.863; Pearson's correlation coefficient).ConclusionsPatients with high disease activity have higher prevalence of QTc prolongation, QTc interval may be used as a surrogate marker for assessing disease activity in SLE.  相似文献   

17.
AIMS: To compare QT dispersion measurements in diabetic patients to control subjects and assess any associations between QT dispersion and diabetic clinical characteristics. METHODS: A total of 512 diabetics and 50 age and gender matched controls were studied. QT interval was measured manually in 12-lead conventional electrocardiograms, and QT dispersion (QTd), heart rate-corrected QT dispersion (QTcd), number of leads-adjusted QT dispersion (adjuQTd) and adjacent QT dispersion (adjaQTd) were calculated. Demographic, clinical, laboratory and electrocardiographic data were recorded. RESULTS: Diabetics showed increased QT dispersion compared to controls (QTd: P<0.001, QTcd: P<0.001, adjuQTd: P<0.001), even those with recent diagnosis (less than 2 years) and without arterial hypertension, ECG abnormalities or chronic degenerative complications (QTd: P=0.01, QTcd: P<0.001, adjuQTd: P=0.04). Left ventricular hypertrophy (QTd: P<0.001, QTcd: P<0.001, adjuQTd: P<0.001, adjaQTd: P<0.001) and conduction disturbances (QTd: P=0.002, QTcd: P=0.003, adjuQTd: P=0.003) were the electrocardiographic findings associated with increased QT dispersion in bivariate analysis. Clinical variables were the presence of arterial hypertension (QTd: P=0.004, QTcd: P=0.01, adjuQTd: P<0.001), even without left ventricular hypertrophy (QTd: P=0.01, QTcd: P=0.03, adjuQTd: P=0.003), and the presence of diabetic cardiovascular complications (QTd: P=0.02, QTcd: P=0.01, adjuQTd: P=0.008, adjaQTd: P=0.03). No association between QT dispersion and the presence of diabetic microvascular complications, glycaemic control, age and gender, or cardiovascular drugs was observed. Multivariate regressive statistical analysis confirmed the associations noted in bivariate analysis. CONCLUSIONS: Diabetic patients have increased QT dispersion compared to non-diabetics even those without arterial hypertension and cardiovascular complications and with recent diagnosis. The presence of arterial hypertension, diabetic cardiovascular complications and electrocardiographic abnormalities of left ventricular hypertrophy and conduction disturbances were associated to increased QT dispersion in diabetes mellitus.  相似文献   

18.
老年冠心病患者QT离散度变化及其临床意义   总被引:1,自引:0,他引:1  
目的探讨老年冠心病患者QT离散度(QTd)和心率校正的QT离散度(QTcd)与致命性室性心律失常(FVA)及心衰(HF)之间的关系。方法测定了84例老年冠心病患者的QTd及QTcd,其中心原性猝死(CSD)9例,FVA23例,非FVA61例。有HF47例,无HF37例。结果CSD组QTd、QTcd显著大于FVA及非FVA组(P<0.05;P<0.01),FVA组QTd、QTcd大于非FVA组(P<0.01),HF组QTd、QTcd显著长于无HF组(P<0.01)。本文QTd和QTcd呈显著正相关(r=0.9720,P<0.01)。结论作者认为QTd和(或)QTcd可作为评估老年冠心病患者发生FVA和(或)HF预后的重要参考指标。  相似文献   

19.
Acute coronary ischemia augments inhomogeneity in ventricular repolarization, which significantly correlates with ventricular fibrillation. The effects of glycoprotein IIb/IIIa receptor inhibition on QT interval dispersion (QTd), and the effects of QTd changes on in-hospital, 30 day, and long-term cardiac events in patients with unstable angina (UA) and non-Q-wave myocardial infarction (MI) have not been investigated previously. Eighty-three patients presenting with Braunwald class IIIB UA or non-Q-wave MI were randomized to standard therapy (aspirin and unfractionated heparin, 42 patients) or tirofiban therapy: addition to standard therapy (41 patients). QT interval dispersion (QTd) and corrected QTd (QTcd) were measured prior to therapy, and 6, 24, 48, 72, and 96 hours after the initiation of the treatment. In both groups QTd and QTcd were higher than normal limits during the admission, prior to therapy. The first QTd and QTcd were not different between two groups; the remaining values were significantly lower in tirofiban group except the first and last QTd (p values for QTd at 6, 24, 48, 72, and 96 hours are 0.057, 0.045, 0.0006, 0.04, and NS, respectively, and for QTcd, they are 0.017, 0.046, 0.0004, 0.012, and 0.01, respectively). When the first QTd and QTcd compared to the following measurements in each group, the first significant decrease occurred at 6th hour (p = 0.004 for QTd, and 0.004 for QTcd) in tirofiban group, whereas in standard therapy group it was occurred at 48th hour (p = 0.02) for QTd, and 72nd hour (p = 0.019) for QTcd. While the incidence of in-hospital acute MI, recurrent refractory angina, and total major cardiac events were significantly lower in the tirofiban group (p = 0.03, 0.04, and 0.01, respectively) that early QTd recovery observed, the 30 day and long-term incidence of major cardiac events were not different between the two groups. GP IIb/IIIa receptor inhibition in addition to heparin treatment causes a faster recovery of increased QT dispersion, and the early recovery of QTd is associated with a reduction in in-hospital major cardiac events.  相似文献   

20.
The risk of sudden cardiac death is higher in patients with obesity, particularly in the upper body obesity. The most common cause of cardiac events are serious ventricular arrhythmias. Delayed cardiac repolarization leading to the prolongation of the QT interval is a well characterised precursor of arrhythmias. The QT interval dispersion reflects inhomogeneity of repolarization. The aim of this study was to assess QT interval dispersion (QTd) in obese women and to establish the relationship between obesity and QTd. 62 patients with obesity (group 1) and 15 apparently healthy women (group 2) were included in our study. Obese subjects were distinguished in accordance to the waist to hip ratio (WHR) into three subgroups: 1a--obese women with upper body obesity; 1b--obese women with WHR: 0.75-0.85; 1c--obese women with lower body obesity. A standard 12-lead ECG was performed in each subjects and QTd, QTdc (QT correlated interval dispersion), QTdR (QTd ratio) were calculated. The left ventricular mass (LVM) and left ventricular mass index (LVMI) were obtained from echocardiograms. We found QTd, QTdc, QTdR and LVM, LVMI to be significantly higher in obese women as well as positive correlation between BMI and both LVM, LVMI. QTdR was significantly higher in subgroup 1a compared with subgroup 1c. CONCLUSIONS: 1) QT interval dispersion was increased in obese women compared with healthy subjects, 2) supposedly increased QTd was associated with the type of obesity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号