Efficacy of transdermal nitroglycerin patches evaluated by dipyridamole-induced myocardial ischemia in patients with coronary artery disease. Comparison between continuous and intermittent schedule

Nitrate tolerance remains a problem despite an enormous number of studies on this phenomenon. The aim of the present study was to compare the efficacy of nitroglycerin transdermal patches intermittently or continuously administered to patients with myocardial ischemia evaluated by the echocardiography dipyridamole stress test. We prospectively studied 34 coronary patients with stable myocardial ischemia. A double-blind, randomized, crossover study technique was used. After a run-in period (1 week) they underwent a dipyridamole stress test to evaluate nitrate responsiveness and then were randomized to 1 week of transdermal nitroglycerine 20 mg/24 h (two patches of 10 mg/24) administered either intermittently or continuously for 1 week. During the following week all patients were given placebo. In the final week, therapy was crossed over the alternate regimen. No significant changes in heart rate, systolic and diastolic blood pressure and rate-pressure product were observed at basal conditions and at peak of dipyridamole infusion among patients after placebo run-in period, after acute, 1 week of intermittent and 1 week of continuous nitroglycerine administration. At peak of dipyridamole infusion after acute administration of nitrate we observed a significant decrease in wall motion score index with respect to placebo. This pattern was similar during intermittent, but not continuous, patch therapy (p < 0.001). Our results suggest that transdermal nitroglycerin patches are an effective anti-ischemic medication, in reducing transient myocardial ischemia induced by dipyridamole. This anti-ischemic effect is lost when an overnight nitrate free dose interval is not used. Moreover the dipyridamole echocardiographic stress test, besides evaluating myocardial ischemia-induced wall motion abnormalities, is adequate to assess both the efficacy and the tolerance of transdermal nitrate therapy.     

Influence of residual ischaemia on heart rate variability after myocardial infarction

Despite the growing evidence for the positive predictive valueof depressed baroreflex sensitivity and/or reduced heart ratevariability after myocardial infarction, the mechanisms involvedin these autonomic alterations are not fully understood. Specifically,the possible influence of residual ischaemia has not been assessed. To address this problem we studied the spectral analysis ofheart rate variability in 21 patients with a first myocardialinfarction in whom the only clinical correlate was the presenceof residual ischaemia, as documented by the positive responseto both an exercise stress test and an echocardiographic stresstest. Data from these patients were compared with those obtainedin a group of postmyocardial infarction patients similar forseveral risk factors, age, site of myocardial infarction, butwithout residual ischaemia. Patients positive for residual ischaemiahad lower power in the whole spectrum (1146±158 vs 1631±159ms², P=0—032) as well as in the low and high frequencybands of heart rate variability. A nocturnal increase in highfrequency was observed in those without residual ischaemia (from167 ± 35 to 242 ± 51 ms², +45%, P0·034),but not in those with residual ischaemia (from 111 ±19 to 141 ± 29 ms², +27%, ns). Thus, residual ischaemia reduces heart rate variability aftermyocardial infarction. The autonomic effects of residual ischaemiaprobably contribute to its negative prognostic value after myocardialinfarction.     

Wavelet transform analysis of heart rate variability to assess the autonomic changes associated with spontaneous coronary spasm of variant angina

We used Wavelet transform (WT) to investigate whether variation in autonomic tone was associated with spontaneous coronary spasm in patients with variant angina by analysis of heart rate variability (HRV). Twenty-one episodes preceding ST-segment elevation were selected under Holter monitoring in 12 men and 3 women with variant angina. HRV indices were calculated at 10 second intervals with the continuous WT, and analyzed within 30 minutes preceding ST-segment elevation. High frequency (HF; 0.15 approximately 2.00 Hz) increased significantly during the 4 minutes prior to ST-segment elevation, low frequency (LF; 0.04 approximately 0.15 Hz) decreased significantly during the period from 10 to 5 minutes and increased significantly during the 2 minutes prior to ST-segment elevation, the LF/HF ratio decreased significantly during the period from 10 to 3 minutes and increased significantly during the 2 minutes prior to ST-segment elevation. The RR interval decreased significantly during the 2 minutes prior to ST-segment elevation. These results suggest that the acute variation in autonomic tone was associated with spontaneous coronary spasm in patients with variant angina. A reduction in sympathetic activity, then enhancement of vagal activity may play a key role in triggering the spontaneous coronary spasm, and the secondary activation of sympathetic activity may worsen the coronary spasm resulting in the attack.     

Protective effect of beta-blockade on dipyridamole-induced myocardial ischaemia: Role of heart rate

This study was designed to investigate the effect of heart ratechanges on dipyridamole echocardiographic tests in patientswith coronary artery disease treated with propranolol. We prospectively studied 12 patients (8 men and 4 women; meanage 56.5 ± 8.7 years) selected by: (a) angiographic evidenceof significant coronary artery disease; (b) adequate echocardiographicwindow; (c) positive dipyridamole echocardiography test resultsin baseline conditions (step I); (d) test reproducibility inthe absence of treatment; (e) negative dipyridamole echocardiographytest results after 7 days of treatment with propranolol (120mg. day^–1) in twice divided doses daily (step II). In all patients treated with propranolol, dipyridamole echocardiographictesting was repeated 24 h after the last negative test. In thesepatients, transoesophageal atrial pacing was performed at peakdipyridamole infusion to increase heart rate to values similarto those observed at baseline (step III). At baseline, heartrate and rate-pressure product were significantly lower in patientstreated with propranolol (–20.3% and –22.5% in groupII, P<0–001 vs step I; –24.3% and –26.4%in group III, P<0.05 vs step I), but the different treatmentsdid not produce significant differences in systolic and diastolicblood pressure. At peak dipyridamole infusion, heart rate andrate-pressure product increased with either placebo or propranololtreatments with respect to baseline, while remaining significantlylower with propranolol as compared to placebo ( –29.6%and –29.5% in step II, P<0001). During treatment withpropranolol plus transoesophageal pacing to maintain heart rateat values attained with placebo, the rate-pressure product didnot change significantly with respect to placebo, nor did systolicblood pressure. Transoesophageal atrial pacing performed duringpropranolol treatment to restore heart rate to baseline valuesdid not affect the dipyridamole echocardiographic test in eightpatients (group I), and induced transient wall abnormalitiesin four patients (group II) (P=ns). Our data suggest that the anti-ischaemic effect of propranololin man is not correlated only to reduction of heart rate.     

Clinical and angiographic implications of a depressed echocardiographic ejection fraction in coronary artery disease

To evaluate the clinical and angiographic implications of a depressed echocardiographic ejection fraction (EF) in coronary artery disease, 45 patients with an echocardiographic EF < 0.50 were studied with complete cardiac catheterizations. Most of the patients had clinical evidence of a prior myocardial infarction, cardiomegaly, and/or congestive heart failure. All had coronary arteriographic evidence of multivessel disease and either reduced cardiac output, elevated left ventricular end-diastolic pressure, or both. Reduction in percentage of echocardiographic dimensional shortening closely paralleled reduction in echocardiographic EF. Forty of the 45 patients (89%) had an angiographic EF less than 0.50. There was considerable scatter of angiographic EF's with echocardiographic EF's between 0.40 and 0.50, limiting the usefulness of these latter values. However, 23 of the 24 patients (96%) with an echocardiographic EF less than 0.40 had an angiographic EF less than 0.40, and there was a linear relationship between these echocardiographic and angiographic values with a correlation coefficient (r) = 0.54 (SEE = ±0.15, p<0.05). All of the 12 patients with both reduced septal and reduced posterior wall excursion on the echocardiogram had both abnormal echocardiographic and angiographic ejection fractions, and 10 of the 12 had EF < 0.40 by both techniques. Our study suggests that coronary artery disease patients with extensive left ventricular dysfunction can be identified noninvasively, and the echocardiographic EF may be useful in deciding whether such patients may require special cardiac catheterization procedures to evaluate contractile reserve if cardiac surgery is being considered.     

Update on intravenous dipyridamole cardiac imaging in the assessment of ischemic heart disease

Intravenous dipyridamole is a relative selective coronary vasodilator which, when combined with thallium-201, provides a useful technique to assess myocardial perfusion. The intravenous dipyridamole is administered as an infusion at a rate of 0.14 mg/kg/min for 4 minutes. In the presence of significant coronary artery disease the increase of coronary blood flow is disproportionate between vessels with and without significant coronary lesions, providing the basis for detecting regional differences in flow using thallium-201. The test can be used alone or combined with low level exercise to increase test sensitivity. The test is safe when performed under medical supervision and when patient selection is done appropriately. Most of the side effects induced by dipyridamole infusion are well tolerated by patients and readily reversed with intravenous aminophylline and sublingual nitroglycerin. The average sensitivity and specificity of the dipyridamole thallium scintigraphy test from the major studies are 76% and 70%, respectively. The test is very useful in providing prognostic information in patients who are unable to exercise. A reversible thallium defect after dipyridamole infusion has been shown to be associated with significant mortality and morbidity in patients with documented or suspected coronary artery disease. The use of intravenous dipyridamole has been extended into other modalities of imaging, including 2-dimensional and Doppler echocardiography, to study functional changes in the left ventricular induced by the infusion of intravenous dipyridamole.(ABSTRACT TRUNCATED AT 250 WORDS)     

冠心病心率变异性及其诊断价值

本文应用２４ｈ动态心电图对健康人（对照组）和冠心病心绞痛、心肌梗死患者进行心率变异性研究。结果发现:心绞痛组和前壁心梗组的正常ＲＲ间期总体标准差（ＳＤＮＮ）、每连续５ｍｉｎ时段正常ＲＲ间期均值的标准差（ＳＤＡＮＮ）及其平均值（ＳＤＮＮｉｎｄｅｘ）、心率总功率（ＴＰ）、极低频功率（ＶＬＦ）、低频功率（ＬＦ）和高频功率（ＨＦ）等均低于对照组（均Ｐ＜０．０１）；下壁心梗组的ＳＤＮＮ，ＳＤＮＮｉｎｄｅｘ和ＬＦ低于对照组（均Ｐ＜０．０５）；前壁心梗组的ＳＤＮＮ，ＳＤＡＮＮ和ＬＦ低于心绞痛组（均Ｐ＜０．０５）。心率变异诊断冠心病的阳性标准取低于对照组上述任一项指标９５％区间下限值，则其特异性为９３．９％，心绞痛组敏感性为５１．２％，心梗组为７１．４％。提示心率变异下降对冠心病的诊断有一定的参考价值。     

左心导管与超声心动图检查对比评价冠状动脉病变对左心室舒张功能的影响

目的探讨冠心病患者冠状动脉病变程度对左心室舒张功能的影响。方法应用心导管及超声心动图检查,对75例经选择性冠状动脉造影确诊的冠心病患者进行了研究。根据冠状动脉造影结果 ,将冠心病患者按病变狭窄所累及的动脉支数分为4组:轻度狭窄组、单支病变组、双支病变组及三支病变组。应用导管法测定主动脉内的收缩压、舒张压、心率、左心室舒张末期压(LVEDP),收缩期及舒张期左室压力最大变化率(dp/dtmax,dp/dtmin)及等容舒张期压力衰减时间常数。比较不同的冠状动脉狭窄程度与心室舒张功能的关系。应用心导管法与超声心动图检查分析左心房内径(LAD)、左心室舒张末期容积(EDV)、收缩末期容积(ESV)、舒张期前1/3充盈量(1/3V)及舒张早期充盈分数(1/3FF),并计算左心室射血分数。应用超声应变率显像分别测量左心室各壁不同节段收缩期、快速充盈期及舒张晚期的峰值应变率,对各峰值应变率与导管法所测的相应指标进行相关性分析。结果常规超声心动图指标比较,在不同冠状动脉狭窄病变组,仅LAD在三支病变组〔(38.74±4.57)mm〕较轻度冠脉病变组〔(33.87±3.80)mm〕及单支血管病变组〔(33.77±3.94)mm〕显著增加。左心导管测定的LVEDP、dp/dtmax、dp/dtmin、EDV、ESV各组比较均无显著的统计学差异。而轻度冠脉病变组的等容舒张期压力衰减时间常数〔(30.31±6.50)ms〕低于其他各组。舒张早期充盈的1/3V及1/3FF在冠状动脉显著狭窄组低于轻度冠脉病变组。结论不同程度的冠状动脉病变对心室的舒张功能具有一定的影响,而且随着病变程度的加重影响增大。超声应变率显像技术可以准确判断冠心病患者的心室舒张功能。     

增龄及冠心病对运动的反应和心率变异性的影响

目的　研究 70岁以上冠心病及非冠心病老人心血管系统对运动负荷的反应 ,探讨其运动负荷特征与心率变异各能谱范围的关系。方法　经活动平板运动试验、动态心电图心率变异能谱分析、并行冠状动脉造影患者 2 16例。 70岁以上老人 96例为老年组 (Ⅰ组 ) ,70岁以下 12 0例为对照组 (Ⅱ组 ) ,两组各分两个亚组 ,冠心病患者分别为Ⅰa、Ⅱa组、非冠心病患者各为Ⅰb组、Ⅱb组。比较各组患者运动前后各生理指标的变化。结果　 (1)Ⅰ组运动峰值心率低于次极量心率 (极量心率 85 % )或 <12 0次 min者多于Ⅱ组 (Ⅰa组 35 .14 %vsⅡa组 15 .5 5 % ,P <0 .0 1,Ⅰb组 16 .95 %vsⅡb组 5 .33% ,P <0 .0 5 ) ;ⅠaⅠb组运动后 1min心率恢复值均 <12次 min ;心率变异高能谱范围呈现增龄性改变 (Ⅰa组vsⅡa组 ,P <0 .0 5 ;Ⅰb组vsⅡb组 ,P <0 .0 5 )。 (2 )Ⅰa组心肌缺血多发生于较低运动负荷时 [ST压低 1mm时的代谢当量 (METs)Ⅰa组 4 .4 8vsⅡa组 5 .4 8,P <0 .0 5 ];Ⅰa组心率变异各能谱范围多呈有意义降低 ,心率变时性损害Ⅰa组高于其他 3个组。结论　 (1)老年人尤其老年冠心病患者存在运动后心血管系统反应迟钝现象 ,心率变异高能谱范围呈现增龄性改变。 (2 )老年冠心病患者心率变异各能谱均有异常。 (3)老年冠心病患?     

2型糖尿病合并缺血性心脏病患者的心率变异性研究

目的探讨2型糖尿病和2型糖尿病合并缺血性心脏病患者对心血管自主神经活动的影响。方法用24h动态心电图检测2型糖尿病患者48例，2型糖尿病合并心肌缺血患者35例及对照组43例健康人的心率变异性（HRV）指标。结果2型糖尿病患者心率变异性指标比正常人明显减低，合并心肌缺血比没有合并心肌缺血的2型糖尿病患者，心率变异性指标仅rMSSD、PNN50减低。结论2型糖尿病患者存在植物神经损害，心率变异性减低，心率变异性减低程度与心脏损害程度有关。合并心肌缺血患者对心血管自主神经损害较没有合并心肌缺血者重。     

经皮冠状动脉介入治疗对急性心肌梗死患者窦性心率震荡及心率变异性的影响

目的探讨经皮冠状动脉介入术（PCI）治疗急性心肌梗死（AMI）后对窦性心率震荡（HRT）和心率变异性（HRV）的影响。方法将150例急性心肌梗死患者分为直接PCI组、延迟PCI组和药物治疗组各50例,分别予直接PC、I延迟PC I和药物治疗。AMI后2~3周各组行动态心电图检查分析其HRT参数：震荡初始（TO）和震荡斜率（TS）,同时获取HRV指标：24 h时平均R-R间距的标准差（SDNN）,每5 min时间段R-R间距平均值的标准差（SDANN）。结果直接PCI组TO明显低于,TS、SDNN、SDANN明显高于延迟PC I组及药物治疗组（P均〈0.01）;延迟PCI组TO明显低于,TS、SDNN、SDANN明显高于药物治疗组（P均〈0.05）。结论直接或延迟PC I可有效地改善AMI心肌缺血,有利于防止恶性心律失常和心性猝死的发生;直接PC I效果更优。     

Improvement in identification of multivessel disease after acute myocardial infarction following stress-recovery analysis of ST depression in the heart rate domain during exercise

The demonstration of extensive coronary artery disease (CAD)after acute myocardial infarction (AMI) has important prognosticimplications. Exercise-induced ST segment depression is commonlyused for detecting the presence of CAD and evaluating its extension.However, even though there have been many attempts to increaseits diagnostic yield, the accuracy of the electrocardiographicsignal for identifying multivessel disease (MVD) is relativelylow, particularly in post-MI patients. The aim of this study was to evaluate the ability of a simpleindex, combining information on the amount and kinetics of STdepression in the heart rate domain during exercise and recovery,to identify MVD after AMI. Seventy patients (mean age 53.4 years) underwent a bicycle,symptom-limited exercise stress test and coronary angiography2–3 weeks and 6 weeks respectively, after uncomplicatedAMI while cardioactive therapy was discontinued. After obtaininga computer-derived measurement of ST levels based on incrementalaveraging of normal complexes, the area subtended to baselineand limited by the ST trend against heart rate during both exercise(Al) and recovery (A2) was calculated The difference (A1-A2)was defined as the ‘Stress-Recovery Index’ (SRI)and dichotomized, by means of receiver-operating characteristicscurve analysis, at 5 mm x beats. min^–1 to define an increasedrisk of MVD. The SRI of patients with MVD was significantly lower than thatof patients with single vessel disease. The sensitivity of SRI< –5 mm x beats. min^–1 (65%) for predicting MVDwas significantly higher than that obtained by other conventionalparameters, without appreciable loss of specificity (81%). Thesensitivity and specificity of SRI for three-vessel diseasewere 79% (P<0.01 vs other parameters) and 78% respectively. SRI may improve the identification of MVD in patients with recentAMI, in whom the accuracy of standard electrocardiographic criteriais usually unsatisfactory.     

老年冠心病患者心率变异性减低与心血管事件的关系

目的　评价一般老年冠心病 (CAD)患者心率变异性 (HRV)减低与心血管事件的关系。方法　回顾性分析我院干部查体中有CAD者 2 4h动态心电图 (DCG)HRV资料与心血管事件的关系 ,共 2 38例。HRV分析包括时域分析和频域分析。比较查体者有和无心血管事件组各时域和频域参数有无差别。结果　有 2 7例老年人发生心血管事件 (有心血管事件组 ) ,2 11例未发生心血管事件 (无心血管事件组 ) ,有心血管事件组与无心血管事件组比较 ,HRV各参数均明显降低 (P <0 .0 1)。结论　一般老年CAD患者如HRV明显降低 ,则易于发生心血管事件。     

Comparisons of angiographic core laboratory analyses of phantom and clinical images: Interlaboratory variability

Centralized, quantitative coronary analysis (QCA) has become the standard for determining change in coronary anatomy in clinical investigations. QCA systems and laboratory methods, however, vary among core facilities, and analysis variability among angiographic core laboratories (ACL) has not be studied. We evaluated QCA accuracy and variability among active ACL, using differing QCA systems by comparing analyses of phantom and clinical cinefilm images. Automated, unedited analyses were performed on images of 11 plexiglass phantom lumens (0.67–5.05 mm) acquired under varying radiographic conditions. Analysis differences from actual luminal diameters ranged widely (+0.42–−0.45 mm) among ACL. Measurement of diameters <1.0 mm were overestimated and diameters >3.0 mm were underestimated. Measurements of midrange diameters (>1.0 mm and <3.0 mm) were most comparable among ACL (93% within ±0.2 mm). Clinical image analysis was performed using differing QCA systems and laboratory methodology on 11 randomly selected study films. Comparative analyses revealed significant variability between laboratories in the assessment of minimal lumen diameter (0.22 ± 0.38 mm P < 0.05). These data describe analysis variability among ACL and demonstrate a need for establishing ACL performance standards. © 1996 Wiley-Liss, Inc.     

Relationship between heart rate turbulence and heart rate, heart rate variability, and number of ventricular premature beats in coronary patients

INTRODUCTION: Heart rate variability (HRV) illustrates regulation of the heart by the autonomic nervous system whereas heart rate turbulence (HRT) is believed to reflect baroreflex sensitivity. The aim of this study was to determine the association between HRT and HRV parameters and the relationship between HRT parameters and heart rate and number of ventricular premature beats (VPBs) used to calculate HRT parameters. METHODS AND RESULTS: In 146 patients (117 males and 29 females; mean age 62 years) with coronary artery disease, a 24-hour ECG Holter monitoring was performed to calculate mean heart rate (RR interval), number of VPBs, time- and frequency-domain HRV parameters and two HRT parameters: turbulence onset (TO) and turbulence slope (TS). Univariate and multivariate regression analyses were performed to evaluate the association between tested parameters. Significant correlation between TS and mean RR interval was observed (r = 0.42; p < 0.001), while no association for TO vs. RR interval was found. TS values were significantly higher in patients with less than 10 VPBs/24 hours than in patients with more frequent VPBs. Significant associations between HRT and HRV parameters were found with TS showing stronger correlation with HRV parameters than TO (r value ranging from 0.35 to 0.62 for TS vs. -0.16 to -0.38 for TO). CONCLUSION: HRT parameters correlate strongly with HRV parameters indicating that HRT should be considered as a reflection of both baroreceptors response and overall autonomic tone. Heart rate dependence of turbulence slope indicates the need to adjust this parameter for heart rate.     

2型糖尿病患者无症状心肌缺血心率变异性的研究

目的冠心病是2型糖尿病主要心血管并发症,且经常表现为无症状心肌缺血（SMI）,本研究观察2型糖尿病患者SMI发作与心率变异性的相关性。方法在我院行运动负荷心肌灌注显像检查的患者中,选取1个月内做过动态心电图监测的157名无冠心病临床症状的2型糖尿病患者,其中34例为SMI患者;123例为无心肌缺血发作患者,并在其中随机选37例为对照组。结果SMI的发生率为21．6％;SMI组除24小时平均心率高于无心肌缺血组外。心率变异性各参数中：总体标准差、均值标准差、标准差均值、差值的均方根和差值〉50ms的百分比与无心肌缺血组相比较均明显下降。结论心率变异性减低与2型糖尿病合并SMI明显相关,而心率变异性减低作为评价心脏神经自主病变的早期信号,说明2型糖尿病合并SMI的发病与心脏自主神经病变密切相关,心率变异性或可作为无症状的2型糖尿病患者SMI筛查的指标之一。     

Successful delivery following myocardial ischemia during the second trimester of pregnancy

Acute myocardial infarction during pregnancy is considered to be associated with approximately 50% mortality of both mother and fetus. However, there are not enough data regarding the role of acute myocardial ischemia. We present a 36-year-old, pregnant, white female who was admitted twice at 18 and 20 weeks of gestation with acute myocardial ischemia. Cardiac catheterization revealed 70–80% stenosis of the mid left anterior descending artery (LAD) with normal antegrade flow and very good retrograde filling of the LAD from distal collaterals of the right coronary artery. Therefore, due to angiographic suggestion of protected LAD territory, we recommended medical therapy and scheduled a vaginal delivery that was successfully completed without cardiovascular complications. A stress thallium test performed 6 months later was normal, supporting our clinical judgment. In conclusion, every case of a pregnant woman with coronary insufficiency should be treated according to individual coronary anatomy and blood supply to the territory of the diseased artery, and should not be based on the old data in the literature. The decision for revascularization prior to delivery versus medical therapy, or Caesarean section versus natural delivery, should be made by a team of a cardiologist and an obstetrician.     

Thallium-201 perfusion imaging with atrial pacing or dipyridamole stress testing for evaluation of cardiac risk prior to nonvascular surgery

Preoperative assessment of cardiac risk using thallium-201 scintigraphy and atrial pacing (n=42) or dipyridamole stress testing (n=35) was performed in 77 patients (mean age 65±7 years), who subsequently underwent elective nonvascular surgery. All patients were at low cardiac risk by clinical criteria; none could perform exercise stress testing due to physical limitations. ST depression consistent with ischemia occurred in 11 patients during atrial pacing and in 1 patient during dipyridamole stress testing (p<0.01). Nine patients had reversible perfusion defects with atrial pacing, and 10 patients with dipyridamole stress testing; fixed defects were present in 15 and 8 patients, respectively. Only one patient (fixed perfusion defect with atrial pacing, left main disease on coronary angiography) underwent preoperative coronary revascularization. Two patients subsequently had postoperative cardiac events. One patient (reversible perfusion defect with dipyridamole stress testing) experienced sudden death after a nonvascular procedure, while a second patient (normal thallium images with dipyridamole testing) had a nonfatal myocardial infarction. In patients having atrial pacing or dipyridamole stress testing, thallium-201 scans that are normal or show only a fixed perfusion defect confirm a low risk of cardiac complications following nonvascular surgery. The presence of a reversible perfusion defect does not preclude a postoperative course free of cardiac complications in patients at low cardiac risk by clinical criteria.     

冠心病患者窦性心率震荡与心率变异性和室性早搏关系的探讨

目的探讨冠心病患者的窦性心率震荡(HRT)及其与心率变异性(HRV)和室性早搏之间的关系。方法86例冠心病患者行24h动态心电图检查,计算机自动测定HRT的两个参数震荡初始(TO)和震荡斜率(TS)、HRV时域和频域指标及室性早搏数目。结果冠心病患者的HRT减弱,HRV降低,且TO与时域指标SDNN和SDANN及频域指标LF和LF/HF明显相关(p<0.05),TS与时域指标SDNN和RMSSD及频域指标HF和LF/HF及室性早搏数目明显相关(p<0.05)。结论冠心病患者的HRT现象减弱,且HRT与HRV及室性早搏数目明显相关。HRT应当是一种较HRV更好预测高危冠心病患者的无创性检查方法。     

脉搏波传导速度与冠状动脉病变严重程度的相关性：324例老年病例分析

目的探讨脉搏波传导速度（PWV）与冠状动脉粥样硬化程度的相关性。方法2008年1月至2010年1月因胸痛入住解放军总医院老年心血管病研究所行冠状动脉造影检查的患者324例,其中男性213例,女性111例,年龄（61±12）岁。根据冠状动脉造影结果分为两组：冠心病组和正常组。冠心病组为冠状动脉造影显示至少有一支以上血管狭窄程度≥50％。同时根据冠状动脉血管病变的支数分为单支病变、双支病变、严重病变[三支病变或（和）左主干病变]组。采用全自动动脉硬化测定仪同步记录左右侧肱动脉一踝动脉脉搏波传导速度（baPWV）作为反映大动脉弹性的指标。结果对324例患者影响冠心病发生的多元logistic逐步回归分析表明,性别、吸烟、PWV是冠心病独立的危险因素。PWV与冠状动脉病变支数的Spearman等级相关分析显示,PWV与冠心病病变支数成正相关（r=0．307,P=0．005）,在校正多种危险因素后相关性消失。多元回归分析表明,PWV≥1600cm／s的患者发生严重病变的危险度是Pwv〈1600cm／s者的5．736倍。结论动脉弹性减退与冠心病有关,冠心病严重病变者较轻度病变者动脉弹性减退更为明显。