Electrical Alternans of the ST Segment in Non-PrinzmetaPs Angina

Elevated electrical alternans of the elevated ST segment (STEA) was documented in a patient with non-Prinzmetal's or classical angina and severe atherosclerotic coronary artery disease. STEA was precipitated during graded exercise testing. The disappearance of this phenomenon after aortocoronary bypass surgery suggests that the coronary obstructions were the etiologic factors. These findings emphasize that the STEA may occur in myocardial ischemia caused by conditions other than Prinzmetal's angina.     

Propranolol Induced Electrical and Mechanical Alternans in Orthodromic Reciprocating Tachycardia

During an electrophysiological study in a patient with a concealed accessory connection, there was no evidence of eiectrical or mechanical alfernans during tachycardia until propranolol was adminislered, but both forms of alternans developed with tachycardia of a slower rate following propranolol. Echocardiographic. arterial pressure, and electrocardiographic data obtained prior to and following propranolol administration are presented.     

ST segment and T wave alternans in a patient with Brugada syndrome

We describe a patient with Brugada syndrome in whom J point and ST-segment elevation in leads V1 and V2 were augmented by atrial pacing and intravenous administration of propranolol or cibenzoline. Significant T wave alternans with a 2:1 appearance of terminal negative T wave was observed in the absence and presence of atrial pacing after the administration of cibenzoline. The cellular mechanism responsible for T wave alternans, beat-to-beat appearance of terminal negative T wave and augmented J point and ST-segment elevation is discussed.     

Pilsicainide-Induced ST Segment Elevation and ST Segment Depression in Two Patients with Variant Forms of Brugada-Type Electrocardiographic Abnormalities

In two patients with variant forms of Brugada electrocardiographic abnormalities, ST segment elevation, and reciprocal ST segment depression developed during intravenous administration of pilsicainide. In one patient, pilsicainide accentuated the ST segment elevation in leads I, aV_L, and V₁–V₃ and caused ST segment depression in leads II, III, and aV_F. Coronary angiograms at the time of ST segment elevation were normal. In the other patient, pilsicainide accentuated the coved-type ST segment elevation in leads II, III, and aV_F and caused ST segment depression in leads I, aV_L, and V₂–V₅. Frequent premature ventricular complexes (PVCs) with two different left bundle branch block patterns developed during ST segment elevation. Intravenous isoproterenol returned the ST segment to baseline in both patients and suppressed the PVCs in the second patient. We hypothesize that a wide area of epicardial myocardium with large I_to current might explain the reciprocal ST segment depression observed at the time of accentuated ST segment elevation.     

Prevalence of T Wave Alternans in Healthy Subjects

WEBER, S., et al .: Prevalence of T Wave Alternans in Healthy Subjects. Beat-to-beat variations in the amplitude of the T wave (T wave alternans [TWA]) have been associated with malignant ventricular arrhythmias in patients with structural heart disease. TWA has also been observed sporadically in healthy persons during strenuous exercise. Therefore, it was the aim of this study to investigate the prevalence of TWA in healthy subjects at rest and during exercise. TWA was assessed in 48 healthy volunteers with a mean age of 30 ± 8 years (21–53 years) using the CH2000 system for measurement of microvolt level TWA. TWA was not observed in any individual at rest. Short transient intervals of TWA were observed during exercise in five (10.4%) subjects. Sustained TWA was observed in two (4.2%) individuals. In one of these two individuals sustained TWA was recorded at heart rates >110 beats/min. In the other TWA was observed at an onset heart rate of <110 beats/min, and therefore, was considered alternans positive. The prevalence of exercise related sustained TWA in healthy, young individuals is low (2.1%). Short transient intervals of TWA were observed in about 10% of healthy volunteers. These transient episodes of TWA had no clinical impact with respect to a higher vulnerability to ventricular arrhythmias. (PACE 2003; 26[Pt. I]:49–52)     

急性ST段抬高型心肌梗死自发再灌注患者的临床及造影特点分析

目的探讨罪犯血管发生自发再灌注的急性ST段抬高型心肌梗死(STEMI)的临床及造影特点。方法将2006年1月至2009年12月在安贞医院28病房行直接经皮冠脉介入治疗(PCI)的STEMI患者519例,根据直接PCI术前罪犯血管TIMI血流分级,把患者分为自发再灌注组(TIMI血流Ⅲ级)和无自发再灌注组(TIMI血流0～Ⅱ级)。通过冠脉造影观察直接PCI前罪犯血管自发再灌注的发生率,并对其临床相关因素及造影病变特点进行分析。结果两组患者在年龄、CTnI峰值、≥2支血管病变高血栓负荷以及罪犯病变位于LAD部位方面的差异均有统计学意义(其P值分别为0.000、0.000、0.002、0.000和0.003)。而在性别、高血压、糖尿病、吸烟、高脂血症、既往心绞痛、罪犯血管分布、罪犯病变在LCX和RCA分布以及侧枝循环建立方面,其差异均无统计学意义(P值均>0.05)。结论与未发生自发再灌注的患者相比,自发再灌注的STEMI患者年龄较小,CTnI峰值较低,血栓负荷较重,罪犯病变多位于LAD远段。     

Assessment of Time Domain and Spectral Components of Heart Rate Variability Immediately Before Ischemic ST Segment Depression Episodes

In an attempt to study autonomic function during the 5-minute period preceding ischemic ST segment depression (↓ST) episodes, we selected 138 ↓ST episodes, without preceding ↓ST during the last 15 minutes before each episode, from the Holler tapes of 35 patients with multivessel coronary artery disease. For the 5-minute period preceding each ↓ST episode, we calculated the following heart rate variability (HRV) indices; the mean RR interval (RR5), the standard deviation of all RR intervals (SD Index5), the corresponding coefficient of variation (CV5), and the natural log (Ln) of the spectral components, total power at 0.000 to 0.400 Hz (TP5), low frequency power at 0.040 to 0.150 Hz (LF5), high frequency power at 0.150 to 0.400 Hz (HF5), and the ratio of the low to high frequency power (LF5/HF5). As HRV indices of the 24-hour period, we calculated the respective RR, SD Index, CV, LnTP, LnLF, LnHF, and Ln LF/HF. RR5, SD Index5, CV5, and LnTP5 were all significantly lower than RR (t =−5.343, p = 3.7 × 10⁻⁷), SD Index (t =−19.091, p = 1.99 × 10⁻⁴⁰), CV(t -15.780, p = 1.28 × 10⁻³²), and LnTP (t =−3.210, p = 0.0016), respectively. LnHF5 was inversely correlated with the magnitude of the ↓ST; r =−0.174, P < 0.05, and CV5 was inversely correlated with the natural log (Ln) of the ischemic event duration; r =−0.183, P < 0.05. Analogous results were obtained for both the painful and silent ↓ST episodes. It is concluded that HRV is decreased during the 5-minute period preceding ↓ST episodes, and is inversely related with the magnitude and the duration of the ↓ST.     

急性心肌梗死再灌注治疗后24小时 ST段回落程度的预后意义

目的　观察急性心肌梗死溶栓治疗后 3h、2 4h心电图ST段回落程度和出院前超声心动图心功能指标 ,探讨2 4hST段回落程度的预后意义。方法　 12 3例首次急性心肌梗死近期 (3周 )存活病例 ,测量急性期心电图ST段抬高最明显的导联在溶栓治疗开始后 3h、2 4h回落程度 (% ) ,各分为ST段回落≥ 5 0 %组和 <5 0 %组 ,比较各组在第三周超声心动图测量的心功能参数 (t检验 ) ,并以心功能参数为因变量、以急性期与再灌注有关的数据为自变量做多元逐步回归分析。结果　 3h、2 4hST段回落≥ 5 0 %组心功能参数LVEF、LVFS分别明显高于ST段回落 <5 0 %组 (P <0 .0 0 1)。逐步回归分析提示 :3h和 2 4hST段回落程度是心功能参数的独立预报因子。结论　溶栓 3h和 2 4hST段回落是重要的近期预后指标 ;2 4hST段回落有特殊的心功能预后意义 ;3～ 2 4h之间ST段继续回落可能仍有积极的意义。     

最大ST/HR斜率法用于老年冠心病临床诊断的价值探讨

目的:探讨最大ST/HR斜率对老年冠心病临床诊断的价值。方法:用踏车运动试验测定30例老年冠心病和30例正常老年对照的最大ST/HR斜率及ST段压低值。结果:老年冠心病组的最大ST/HR斜率值明显高于对照组(分别为3.04±1.3及0.91±0.9uV/bpm,P<0.01),最大ST/HR斜率的敏感性和特异性高于ST段压低标准(分别为90％,86.6％和60％,73.3％;P<0.05)。随冠脉病变数目增多其最大ST/HR斜率值呈增大趋势。结论:最大ST/HR斜率法对老年冠心病的临床诊断有较高的敏感性和特异性,优于单纯ST段压低法,并对预测冠脉病变数目有一定的价值。     

妊娠贫血对心电图ST段改变的影响

目的 探讨妊娠妇女贫血对心电图ST段改变的影响.方法 随机选择104例门诊行孕期检查的妊娠妇女,根据血常规检查血红蛋白水平分为贫血组和正常组,分析两组心电图ST段改变的导联.结果 贫血组较正常组心电图Ⅱ、Ⅲ、avF、V4、V5、V6导联ST段下移病例与正常组相比明显增多,差异有统计学意义(P<0.05).结论 妊娠妇女贫血是引起心电图ST段改变的因素之一.     

运动引起心电图R波幅和ST段变化的观察

经冠状动脉造影比较对２３例胸痛患得和２０名正常人运动引起的心电图Ｒ波幅和ＳＴ段变化进行了评价。结果：Ｒ波幅变化的敏感性为８１．８１％，特异性为６６．６７％；ＳＴ段压低的敏感性为６３．６４％，特异性为８３．３３％。Ｒ波幅变化的敏感性较ＳＴ段压低高，但特异性低。Ｒ波幅变化受到运动终止时心率影响。终止心率低于１３０次／分没有意义，终止心率１５０次／分，有非常显著意义（Ｐ＜０．０１）。将Ｒ波幅与Ｔ段结合进     

心动过缓伴ST段压低在病窦综合征诊断中的价值

目的：对心动过缓伴ST段压低的现象进行讨论，评估其在病窦综合征诊断中的价值。方法：31例患者行窦房结功能评估、踏车试验、冠状动脉造影和药物试验。结果：26例完成全部研究，其中，11例判定为病窦综合征，15例窦房结功能正常。两组踏车试验中均有部分患者出现心率反应不良，其冠状动脉造影特征为病变均涉及右冠和／或回旋支，而心率反应正常者多为单纯前降支病变；后者进入药物试验，均观察到慢频率依赖性sT段压低。结论：心动过缓与ST段压低可互为因果，并对窦房结功能是否可逆、病因是否属缺血性有诊断价值。     

冠脉造影分析急性下壁心肌梗死前侧壁导联ST段压低

目的　应用冠状动脉造影 ,分析急性下壁心肌梗死患者心电图前壁或侧壁导联上ST段压低的临床义意。方法　 31例患者发病后第 1天标准 12导联心电图记录 ,前壁导联范围为V1 ～V4 ,侧壁导联范围为I、AVL、V5、V6 。患者均进行冠脉造影 ,2 5例 (80 % )自发病后 1个月内接受检查 ,6例于发病后2个月内接受冠脉造影 ,冠脉狭窄≥ 5 0 %被视为异常。结果　冠脉双支或双支以上病变者 ,特别是左旋支存在病变者 ,易发生侧壁导联ST段压低 ,P <0 0 5。前壁导联ST段低压者中 ,也以双支或双支以上病变为多。结论急性下壁心肌梗死时 ,出现前侧壁导联的ST段压低 ,为心肌缺血扩展的标志     

急性下壁心肌梗死胸前导联ST段改变的临床意义

目的分析急性下壁心肌梗死伴胸前导联ST段压低的临床意义。方法选择38例急性下壁心肌梗死患者常规心电图及24h动态心电图进行对照分析。结果急性下壁心肌梗死伴胸前导联ST段压低多于不伴胸前导联ST段压低(P<0.01);下壁伴正后壁心肌梗死伴胸前导联ST段压低多于不伴胸前导联ST段压低(P<0.01);下壁伴右心室心肌梗死与胸前导联ST段压低无明显关联(P<0.01);急性下壁心肌梗死伴胸前导联ST段压低者严重室性心律失常与房室传导阻滞的发生率较不伴胸前导联ST段压低者高(P<0.01)。结论急性下壁心肌梗死伴胸前导联ST段压低往往提示梗死范围大或同时存在心肌缺血、冠脉病变广泛、心功能损害较严重,并且严重室性心律失常与房室传导阻滞的发生率明显增高,心肌酶峰值明显增高临床预后较差。     

Diagnostic performance and partition values of exercise electrocardiographic variables in the detection of coronary artery disease – improved accuracy by using ST/HR hysteresis

Exercise electrocardiography is widely used for initial identification of patients with coronary artery disease (CAD). This study compares the measurements of ST‐segment changes during exercise and during early postexercise recovery in terms of diagnostic discrimination capacity and optimal partition values. Data from 1876 patients undergoing a routine bicycle exercise test were analysed. CAD was angiographically verified in 668 patients, and excluded by angiography (n = 119), myocardial scintigraphy (n = 250), and on clinical grounds (n = 839) in 1208 patients. Postexercise ST/HR hysteresis was calculated as normalized for heart rate (HR) ST/HR loop area during the first 3 min of recovery. ST/HR index was obtained by dividing the overall ST amplitude change during exercise by exercise‐induced HR change, and ST/HR slope was calculated using linear regression analysis of ST/HR data pairs during exercise. ST‐segment depression was measured during, and for 3 min after the exercise. Discriminating capacity of the methods was evaluated in terms of receiver operating characteristic areas and optimal partition values providing the combination of the best sensitivity and specificity were established. The best diagnostic discrimination was provided by ST/HR hysteresis at optimal partition value of ?15 μV, followed by postexercise ST amplitude measurements at gender‐specific partition values of ?10 to ?90 μV, ST/HR slope [partition value 2·4 μV (beats/min)^?1], ST/HR index [partition value 1·6 μV (beats/min)^?1], and ST‐segment depression during exercise (partition value 70 μV in men and 90 μV in women). The results demonstrate that analysis of postexercise ST/HR hysteresis offers the most accurate and gender indifferent identification of patients with CAD.     

aVR导联ST段抬高对窄QRS波心动过速的鉴别及旁道定位作用

目的:观察aVR导联ST段抬高对窄QRS波心动过速的鉴别及旁道定位作用。方法:120例窄QRS波心动过速均经心内电生理和射频消融证实,分析其心动过速发作时体表12导联心电图aVR导联ST段抬高程度及持续时间。结果:120例窄QRS波心动过速中有58例房室折返性心动过速(AVRT),62例房室结折返性心动过速(AVNRT)。aVR导联ST段抬高在AVRT发生率为67.2%,AVNRT为16.1%(P<0.05),诊断AVRT的敏感性、特异性和准确性分别是67.2%、83.9%和75.8%。在39例aVR导联ST段抬高的AVRT中,有28例位于左旁道,7例位于右旁道,3例位于后间隔,1例位于前间隔。aVR导联ST段抬高定位左侧旁道的敏感性、特异性、阳性预测值和准确性分别是77.8%、50.0%、71.8%和76.5%。结论:aVR导联ST段抬高有助于鉴别窄QRS波心动过速及旁道定位。     

急性心肌梗塞早期和持续的心电图ST段对应改变的意义及与心功能的关系

分析104例急性心肌梗塞患者胸痛发作24h内心电图ST段对应性变化及与心功能的关系。发现:44/66例单一部位、8/29例复合部位梗塞和1/9例梗塞原位扩展者心电图有对应ST段改变;有或无对应改变者之间心功能无显著差异,而单一和复合梗塞者之间心功能变化有显著差异;33/51例无对应ST段改变者可找出使ST向量无变化的原因;26例急性下壁梗塞其前壁ST段压低可延伸至V(5～6)导联且发病72h后仍不回复至基线;单纯下壁梗塞者V_(1～4)ST段下降总和与下壁加正后壁者V_(1～4)ST段下降总和之间有显著差异。作者认为:急性心肌梗塞时ST段对应改变系心电向量力变化所致。唯一影响心功能因素是梗塞面积。动态监测ST段对应改变的过程对估计病情和判断预后均极有意义。     

急性ST段抬高型心肌梗死合并血糖代谢异常患者预后分析

目的:总结急性ST段抬高型心肌梗死(STEMI)合并血糖代谢异常(2型糖尿病或就诊血糖升高)患者的预后。方法:回顾性分析2010年1月-2013年9月我科确诊STEMI患者413例的临床资料,比较血糖正常组(A组)与就诊血糖升高组(B组)、2型糖尿病组(C组)的预后。结果:(B+C)组住院期间死亡率明显高于A组(24.7%vs.9.4%,P0.05),C组住院期间再发心肌梗死率明显高于B组和A组(3.9%vs.0%vs.0.7%,P0.05),C组、B组与A组比较,再发心绞痛率(23.4%vs.31.0%vs.14.7%,P0.05)、住院期间心力衰竭率(41.6%vs.50.0%vs.22.1%,P0.05)、住院期间MACE(58.4%vs.65.5%vs.33.4%,P0.05)及一年全因死亡率(34.2%vs.31.4%vs.16.7%,P0.05)发生率更高。结论 :STEMI合并血糖代谢异常的预后差于血糖正常组。     

急性心肌梗死再灌注治疗后ST段下降程度与心功能恢复的关系

目的：探讨急性心肌梗死再灌注治疗后ST段下降程度与慢性期左心功能的关系。方法：将再灌注治疗后30分钟的ST段高度持续下降超过或等于再灌注治疗前最大ST段高度50％的病例作为ST段下降组（31例），未达到50％的病例作为ST段抬高组（30例），根据左室造影对两组间急性期和慢性期梗死局部室壁运动，左室舒张末期容积及左室射血分数（LVEF）进行比较，结果：两组再灌注治疗前ST段高度，侧支循环形成及梗死前有无心绞痛未见明显差异。发病到开始再灌注治疗的时间ST段下降组明显短于ST段抬高组，梗死局部室壁运动指数（SD／chord)在急性期和慢性期有明显改善（P＜0．01），左室舒张末期容积急性期与慢性期比较无扩大，左室射血分数急性期与慢性期比较明显增加（P＜0．01），ST段抬高组，SD/chord在急性期和慢性期未见明显改善，左室舒张末期容积急性期与慢性期比较，呈现显著扩大（P＜0．01），左室射血分数急性期与慢性期比较，无明显改善，CK最高值，ST段抬高组明显高于ST 段下降组（P＜0．01），再灌注治疗过程中ST段再度抬高的出现率，ST段抬高组明显高于ST段下降组（P＜0．05），结论：急性心肌梗死再灌注治疗后ST段下降程度可以作为判断晚期功能改善的指标。