Is Vagal Innervation to the Atrioventricular Node Impaired After Radiofrequency Ablation of the Slow Atrioventricular Nodal Pathway?

To assess the potentially adverse effects of RF catheter ablation (RFCA) of the slow AV nodal pathway on the parasympathetic innervation to the AV node in patients with AV nodal reentrant tachycardia (AVNRT), AV nodal conduction was evaluated following vagal stimulation by means of a phenylephrine bolus injection (200 μg) before and after RFCA in ten patients (mean age, 37 ± 14 years). Nine patients with AV reentrant tachycardia (AVRT) due to a left free wall accessory pathway served as a control group (mean age of 37 ± 12 years). Whereas no prolongation of the AH interval was observed in the AVNRT group following the phenylephrine bolus during sinus rhythm, despite a significant slowing in sinus rate, phenylephrine administration in AVRT patients was associated with both slowing of the sinus rate and prolongation of the AH interval. Following successful RFCA, the same responses were observed. To delineate the indirect effect of heart rate on AV conduction in response to the phenylephrine bolus, the AH interval was also measured during fixed atrial pacing. A marked prolongation of the AH interval occurred in both groups following phenylephrine administration. This prolongation was biphasic in 50% of A VNRT patients before ablation, suggesting a predominant effect of vagal stimulation on the fast AV nodal pathway. RFCA was associated with disappearance of discontinuous AV conduction in all but one patient with AVNRT. Vagal stimulation caused the same amount of AH interval prolongation as before RFCA in both study groups. In conclusion, patients with AVNRT have a preserved modulation of AV nodal conduction in response to vagal stimulation during sinus rhythm. In addition, vagal stimulation seems to exert a predominant effect on the fast A V nodal pathway. RFCA of the slow AV nodal pathway in patients with A VNRT does not cause detectable damage to the vagal innervation to the AV node.     

Prospective Evaluation of Infrahisal Second-Degree AV Block Induced by Atrial Pacing in the Presence of Chronic Bundle Branch Block and Syncope

The value of nonfunctional infrahisal second-degree atrioventricular (AV) block induced by incremental atrial pacing was prospectively examined in 192 patients with chronic bundle branch block (BBB) and syncope. We compared 174 (91 %) patients with normal response to atrial pacing (Group I) to 18 (9%) patients with atrial pacing induced nonfunctional infrahisal second-degree AV block (Group II). Patients in group I had higher incidence of organic heart disease, ventricular tachycardia induction, and retrograde ventriculoatrial conduction (P < 0.001, P < 0.05, P < 0.01, respectively), while patients in group II had higher incidence of primary conduction disease and prolonged H-V intervals (P < 0.001, P < 0.01, and P < 0.001). During mean follow-up period of 65 ± 34 months for group I, and 68 ± 35 months for group II, a development of spontaneous second- or third-degree AV block was higher in group II (14/18 [78%]), than in group I (15/174 [9%]) (P < 0.001). The site of AV block was infrahisal in all patients in group II, and in 10 of 15 patients in group I. Because of the prophylactic pacing in all patients in group II, the incidence of sudden death was similar among the two groups, but patients in group I had higher incidence of cardiac death (P < 0.05). Conclusion: In patients with chronic BBB and syncope, a nonfunctional infrahisal AV block induced by incremental atrial pacing identified patients with particularly high risk of development of spontaneous infrahisal AV block. Therefore, permanent cardiac pacing is absolutely indicated in these patients.     

瑞替普酶并低分子肝素用于急性心肌梗死再灌注治疗的有效性与安全性研究

目的探讨急性心肌梗死(AMI)瑞替普酶静脉溶栓并应用低分子肝素(LMWH)替代普通肝素(UFH)抗凝治疗的安全性与有效性。方法106例AMI患者经瑞替普酶静脉溶栓后,随机分为LMWH组(低分子肝素5000U皮下注射,2次/d)和静脉UFH组(普通肝素静脉泵入24h后改为低分子肝素5000U皮下注射,2次/d),1周后行冠状动脉造影及冠脉介入治疗(PCI)。观察临床再通率、血管开通率、急性期并发症、出血及不良反应的发生率。结果①LMWH组与静脉UFH组相比,临床再通率(82.1%vs78.0%)、血管开通率(78.9%vs75.0%)高,临床再通病例梗死后心绞痛发生率(8.70%vs12.8%)低,但两组之间差异无统计学意义;②LMWH组出血并发症明显低于静脉UFH组(7.14%vs18.0%),差异有统计学意义(P<0.05)。③两组PCI后均予LMWH抗凝治疗,30d内无急性或亚急性支架内血栓形成发生。结论本研究结果提示,瑞替普酶并LMWH用于AMI再灌注治疗是安全、有效、方便的,LMWH用于PCI后抗凝治疗疗效确切。     

Abnormal Atrioventricular Node Conduction and Atrioventricular Nodal Reentrant Tachycardia in Patients Older Versus Younger Than 65 Years of Age

Study Objective: We examined the possible role of atrioventricular node (AVN) conduction abnormalities as a cause of AVN reentrant tachycardia (RT) in patients >65 years of age.
Study Population: Slow pathway radiofrequency catheter ablation (RFCA) was performed in 104 patients. Patients in group 1 (n = 14) were >65 years of age and had AV conduction abnormalities associated with structural heart disease. Patients in group 2 (n = 90) were <65 years of age and had lone AVNRT.
Results: Patients in group 1 versus group 2 (66% vs. 46% men) had a first episode of tachycardia at an older age than in group 2 (68 ± 16.8 vs 32.5 ± 18.8 years, P = 0.007). The history of arrhythmia was shorter in group 1 (5.4 ± 3.8 vs 17.5 ± 14, P = 0.05) and was associated with a higher proportion of patients with underlying heart disease than in group 2 (79% vs 3%, P < 0.001). The electrophysiological measurements were significantly shorter in group 2: atrial-His interval (74 ± 17 vs 144 ± 44 ms, P = 0.005), His-ventricular (HV) interval (41 ± 5 vs 57 ± 7 ms, P = 0.001), Wenckebach cycle length (329 ± 38 vs 436 ± 90 ms, P = 0.001), slow pathway effective refractory period (268 ± 7 vs 344 ± 94 ms, P = 0.005), and tachycardia cycle length (332 ± 53 vs 426 ± 56 ms, P = 0.001). The ventriculoatrial block cycle length was similar in both groups. The immediate procedural success rate was 100% in both groups, and no complication was observed in either group. One patient in group 2 had recurrence of AVNRT. One patient with a 98-ms HV interval underwent permanent VVI pacemaker implantation before RFCA procedure.
Conclusion: In patients undergoing RFCA for AVNRT at >65 years of age had a shorter history of tachycardia-related symptoms than patients with lone AVNRT. The longer AVN conduction intervals and refractory period might explain the late development of AVNRT in group 1.     

Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation

Background

Transcatheter aortic valve implantation (TAVI) has been developed to minimize operative morbidity and mortality in high-risk symptomatic patients unfit for open surgery. With the proximity of the aortic valve annulus to the conduction system there is, however, an unknown risk of conduction disturbances necessitating monitoring and often cardiac pacing.

Materials and methods

We enrolled 50 consecutive patients from January 2007 to 2008 in our prospective evaluation of conduction disturbances measured by surface and intracardiac ECG recordings. Baseline parameters, procedural characteristics as well as twelve-lead surface ECG and intracardiac conduction times were revealed pre-interventionally, after TAVI and at 7-day follow-up.

Results

TAVI was performed successfully in all patients. During 7?days of follow-up the rate for first-degree AV block raised from 14% at baseline to 44% at day 7 (p?p?p?p?p?p?Conclusion Cardiac conduction disturbances were common in the early experience with CoreValve implantation necessitating close surveillance for at least 1?week.     

Procainamide administration during electrophysiology study--utility as a provocative test for intermittent atrioventricular block

The utility of procainamide, up to 10 mg/kg IV, as a provocative test for intermittent high degree atrioventricular (AV) block was evaluated in a total of 89 patients. Forty two patients had resting 1:1 AV conduction but had bifascicular block and a history of syncope. High degree AV block had not been documented in anyone. Before procainamide, the HV interval was greater than 60 ms in 17 of the 42 patients but no patient developed infra-Hisian block with fixed rate atrial pacing or following programmed atrial extrastimuli. Procainamide administration lengthened the mean HV interval by 11.9 ms and in seven (14%) the HV increment was marked, 15-75 ms. Furthermore, four (9.5%) of these 42 patients developed second or third degree infra-Hisian block and in two of these four patients, the HV prior to procainamide administration was normal or only mildly prolonged (less than 60 ms). The findings were compared to those in three "control" groups. Among four patients with bifascicular block, previously documented transient AV block but 1:1 AV conduction at the time of study, three developed high degree AV block following procainamide. Among five patients with bifascicular block but without syncope nor documented high degree AV block, the mean HV interval lengthened by 18.8 ms and in three the HV increment was 24-30 ms. In another 38 patients with neither syncope nor an intraventricular conduction defect, the mean HV interval lengthened by 5.3 ms and in two cases by 20-25 ms. Most importantly, high degree AV block was never observed in the latter two groups. During follow-up of up to 10 years (mean 46 months), three of the seven patients in whom procainamide provoked high degree AV block have subsequently progressed to fixed complete AV block. Although the incidence of provocation of AV block was relatively low, it was concluded that, among patients with possible intermittent AV block, administration of procainamide as a test of distal conduction has limited value but is still useful, and may provide information additional to that obtained from mere assessment of the HV interval.     

Interatrial Conduction During Cardiac Pacing

DDD pacemakers sense and pace right-sided cardiac chambers. The relationship of atrial to ventricular systole on the left side of the heart is of importance for systemic hemodynamics. Effective atrioventricular synchrony is partially determined by interatrial conduction time (IACT). At the time of DDD pacemaker implantation, interatrial conduction was measured using an intraesophageal pill electrode in 25 patients who were on no cardiac medications. Mean interatrial conduction time for all patients prolonged from 95 ± 18 ms during sinus rhythm to 122 ± 30 ms during right atrial pacing (p < 0.001). In 16 patients with P wave duration < 110 ms interatrial conduction prolonged from 85 ± 10 ms during sinus rhythm to 111 ± 9 ms during right atrial pacing (p < 0.01) compared to 114 ± 20 ms prolonging to 111 ± 19 ms (p < 0.01] in 9 patients with P wave duration > 110 ms. In each patient, while atrioventricular conduction prolonged with incremental right atrial pacing, interatrial conduction times did not vary. Interatrial conduction prolongs from baseline during atrial pacing and remains constant at all paced rates from 60–160 heats per minute. In addition to longer interatrial conduction times during sinus rhythm, patients with electrocardiographic P wave prolongation have longer interatrial conduction times during right atrial pacing than do normals (p < 0.0001). Based on interatrial conduction times alone, the AV interval during DDD cardiac pacing should be approximately 25 ms longer during AV pacing as compared to atrial tracking.     

Atrioventricular Wenckebach Point and Progression to Atrioventricular Block in Sinoatrial Disease.

HAYWOOD, G.A., ET AL.: Atrioventricular Wenckebach Point and Progression to Atrioventricular Block in Sinoatrial Disease. The value of measurement of the atrioventricular (AV) Wenckebach point at rest as a predictor of progression to AV block was investigated prospectively. Twenty-four patients with sinoatrial disease without evidence of conduction disturbance on 12-lead ECG or 24-hour ambulatory monitoring were paced with Medtronic Activitrax II, Medtronic Legend, or Telectronics Meta MV systems in AAI or AAIR modes. Patients were monitored for symptoms and evidence of AV block on 24-hour tapes. The mean age of the patients was 67 years (range: 42–88). There were 11 males and 13 females. The mean follow-up time was 10.7 ± 5 months. Four patients required revision of pacing system as a result of development of AV block during follow-up. One other patient manifested intermittent second degree AV block and remains in AAI. The AV Wenckebach points measured at 1 month post implantation in the four patients who developed AV block requiring revision of system were 140, 125, 165, and 60 (mean 123 ± 4). The mean AV Wenckebach point at first assessment in the remaining 20 patients was 153 ± 24. The mean age of those requiring revision of system was 71 ± 7 compared with 67 ± 14 in those who did not. In this small series the frequency of development of significant AV block was 17%. This is markedly higher than in other recently reported series. The study demonstrates that an AV Wenckebach point above 120/min does not confer immunity from progression to AV block.     

Dissociation of Atrioventricular Conduction and Refractoriness Following Application of Radiofrequency Energy to the Canine Atrioventricular Node: Acute and Chronic Observations

The electrophysiology of AV nodal modification induced by radiofrequency energy (n = 5) or a sham procedure (n = 5) was studied in ten dogs. The five dogs that received radiofrequency energy had an AH prolongation > 100% from baseline values and this prolongation persisted throughout the 2-month study. The AV nodal functional refractory period was prolonged only acutely. These data indicate a dissociation between the effects on AV nodal conduction and refractoriness that was induced by this procedure. The five sham treated controls showed no acute or chronic electrophysiological changes. In the dogs that received radiofrequency energy, there was fibrosis of the approaches to the AV node and the region of the A V node itself. It is concluded that chronic modification of AV nodal conduction without concomitant changes in refractoriness can be induced by radiofrequency energy delivered in the proximal portion of the AV node. It would be anticipated that this procedure would not decrease the ventricular response to atrial fibrillation or flutter, but may be effective in preventing AV nodal reentrant tachycardia by interfering with conduction either in the AV node or perinodal region. Since the AV node itself suffers at least moderate pathological damage, there may be an appreciable incidence of the late development of complete heart block after this procedure.     

Incidence and Predictive Factors of Atrial Fibrillation in Paced Patients

We have designed a prospective observational study to analyze the incidence and predictive factors of atrial fibrillation (AF) during a long follow-up, in a large population. Atrial fibrillation episodes were documented by the fallback mode switch (FMS) provided by implanted pacemakers. We have included 377 patients (61% men). The pacing indications were atrioventricular (AV) block (49%), sinus node disease (SND, 16%), bradycardia-tachycardia syndrome (BTS, 5%), AV block + SND (19%), AV block + BTS (6%), and BTS + SND (5%). The mean age at implant was 75 ± 12 (range 28–95). Atrial fibrillation before inclusion was documented in 10% of patients. Drug therapy at first follow-up included beta-adrenergic blockers (17% of the patients), amiodarone (13%), and others (16%). The mean follow-up was 30 ± 24 weeks. At least one AF episode was stored during follow-up in the memory of 169 pacemakers (45%). Among patients without history of AF at implant, 46% had documented FMS during follow-up. Patients with AF received more antiplatelet medications than patients without AF (P = 0.03). In patients with AF, New York Heart Association functional class was slightly higher, amiodarone and sotalol were more often prescribed, and the proportion of hypertension was higher than in patients without AF. However, these trends were not statistically significant. A significant higher incidence of premature atrial beats was observed in patients with AF than patients without AF (P < 0.0002). Patients with AF had a lower atrial percentage of paced events (55%) than patients without AF (63%, P < 0.02). These preliminary results confirm the high incidence of AF in paced patients and suggest a preventive effect of atrial pacing. The effects of other clinical variables may be confirmed with a longer follow-up in a larger population.     

A Direct Midseptal Approach to Slow Atrioventricular Nodal Pathway Ablation

Objectives: The purpose of this study was to describe a midseptal approach to selective slow pathway ablation for the treatment of AV nodal reentrant tachycardia (AVNRT). In addition, predictors of success and recurrence were evaluated. Methods: Selective ablation of the slow AV nodal pathway utilizing radiofrequency (RF) energy and a midseptal approach was attempted in 60 consecutive patients with inducible AVNRT. Results: Successful slow pathway ablation or modification was achieved in 59 of 60 patients (98%) during a single procedure. One patient developed inadvertent complete AV block (1.6%). A mean of 2,7 ±1.4 RF applications were required with mean total procedure, ablation, and fluoroscopic times of 191± 6.3, 22.8 ± 2.3, and 28.2 ±1.8 minutes, respectively. The PR and AH intervals, as well as the antegrade and retrograde AV node block cycle length, were unchanged. However, the fast pathway effective refractory period was significantly shortened following ablation (354± 13 msec vs 298 ± 12 msec; P= 0.008). The A/V ratio at successful ablation sites were no different than those at unsuccessful sites (0.22 ± 0.04 vs 0.23± 0.03). Junctional tachycardia was observed during all successful and 60 of 122 (49%) unsuccessful RF applications (P < 0.0001). A residual AV nodal reentrant echo was present in 15 of 59 (25%) patients, During a mean follow-up of 20.1± 0.6 months (11.5–28 months) there were four recurrences (5%), 4 of 15 (27%) in patients with and none of 44 patients without residual slow pathway conduction (P = 0.002). Conclusions: A direct midseptal approach to selective ablation of the slow pathway is a safe, efficacious, and efficient technique. Junctional tachycardia during RF energy application was a highly sensitive but not specific predictor of success and residual slow pathway conduction was associated with a high rate of recurrence.     

How to Measure AV Nodal Refractoriness in the Presence of Verapamil, Amiodarone, Digoxin, and Diltiazem

On the AV node the negative dromotropic action of verapamil, amiodarone, digoxin, and diltiazem is known to be rate dependent. The effective refractory period of the AV node (AV-ERP) at o short cycle length is related to the AV conduction at that cycle length. We investigated how the numher of stimuli during the conditioning train (S₁) (during measurement of refractoriness at a high pacing rate [cycle length = 180 ms]) might influence the AV-ERP in isolated guinea pig hearts in a Langendorff preparation. Verapamil (10 nM), amiodarone (10 μM), digoxin 10.G nM). and diltiazem (30 nM) caused a comparable prolongation of the AV conduction time (AVCT). All four drugs caused a significant prolongation of the AV-ERP when evaluated by a standard stimulation protocol with a conditioning train of 10 stimuli (10 S₁) at a pacing cycle length of 180 ms followed by the test stimulus (S₂). When the number of stimuli during the conditioning train (SJ was increased (> 10), until the prolongation of AVCT reached steady state, the AV-ERP in the presence of verapamil (132 ± 4 vs 141 ± 3 ms; P < 0.05. mean ± S.E.M.) and diltiazem (143 ± 3 vs 151 ± 3 ms; P < 0.05) was prolonged significantly further. These results indicate that the effect of drugs on AV-ERP should be measured with a modified stimulation protocol, whereby the number of conditioning stimuli is comparable to the time constant characterizing the prolongation of AVCT at fast pacing rates.     

急性心肌梗塞介入治疗患者早期应用β受体阻滞剂对心功能和自主神经功能状态的影响

目的探讨急性心肌梗塞（AMI）介入治疗患者早期应用β受体阻滞剂对心功能和自主神经功能状态的影响。 方法将经介入治疗的122例AMI患者,根据有无早期使用β受体阻滞剂分为对照组（62例）和β阻滞剂治疗组（60例）,比较两组患者的心功能指标、自主神经功能指标和预后情况。 结果首先,相对于对照组,β受体阻滞剂治疗组患者的不良事件发生率和病死率均有所降低,但差异均无统计学意义（33.3% vs. 37.1%、6.7% vs. 8.1%;χ² = 0.189、0.087,P均> 0.05）。治疗28 d时,β阻滞剂治疗组患者的左心室射血分数（LVEF）和窦性心搏R-R间期标准差（SDNN）明显高于对照组,而低频段（LF）/高频段（HF）显著低于对照组,差异均有统计学意义[（53 ± 7）% vs.（49 ± 7）%、（186 ± 49）ms vs.（156 ± 53）ms、（1.2 ± 0.5）vs.（2.1 ± 1.0）;t = 3.440、3.103、5.769,P均< 0.05]。 结论对于AMI介入治疗患者早期应用β受体阻滞剂（美托洛尔）,并根据血浆B型尿钠肽（BNP）水平和病情变化适当调整剂量,能更为有效地促进患者心功能恢复,并促使交感神经活性/迷走神经活性的比值趋于正常水平,可能有助于改善患者的预后。     

Alternating Wenckebach Periods in Acute Inferior Myocardial Infarction: Clinical, Electrocardiographic, and Therapeutic Characterization

We report on twelve patients with alternating Wenckebach periods (AWP) occurring during an acute inferior myocardial infarction (AIMI). There were nine males and three females, with a mean age of 61 years (range, 43 to 75). AWP appeared during the first 48 hours of the AIMI in 10 patients and on the fourth day of hospitalization in two patients. AWP occurred spontaneously in nine patients and following the administration of atropine in the remaining three patients. Mean systolic blood pressure significantly decreased during AWP as compared to the period preceding or following the bradyarrhythmia (93 ± 42 mmHg vs 123 ± 37 mmHg, p < 0.02). Killip functional class was significantly higher during AWP as compared to the period preceding or following the bradyarrhythmia (2.1 ± 1.2 vs 1.5 ± 0.8, p < 0.02). Pacemaker therapy was initiated prophylactically in two patients, because of syncope in six, because of hemodynamic deterioration in two, and for syncope and hemodynamic deterioration in two. Three patients died in cardiogenic shock despite pacemaker therapy. No evidence of right ventricular infarction was seen in the patients.
Atropine administration during AWP significantly increased the sinus rate and significantly decreased the ventricular rates and the systolic blood pressure. In addition, three patients developed long bouts of paroxysmal AV block. Isoproterenol administration improved AV conduction in one patient, caused no change in two patients and induced non-sustained ventricular tachycardia in three patients.
In conclusion, AWP occurring during AIMI is a symptomatic bradyarrhythmia associated with hemodynamic deterioration. Drug therapy for this bradyarrhythmia is usually ineffective and sometimes paradoxical responses are observed. Pacemaker therapy is usually needed to correct symptoms and the worsening hemodynamic status. We recommend prophylactic pacemaker implantation in patients developing AWP during AIMI.     

老年人慢性肺心病伴发急性心肌梗死的临床特点

目的：探讨老年人慢性肺心病伴发急性心肌梗死（ＡＭＩ）的临床特点，方法：对老年慢性肺心病伴发ＡＭＩ４０例（Ａ组）的ＡＭＩ行回顾性分析，以同期收治的老年单纯冠心病ＡＭＩ２８９例（Ｂ组）作对照。结果：Ａ组疼痛发生率（４０．０％）显著低于Ｂ组（７６．８％）Ａ组急性左心衰，心源性休克发生率显著高于Ｂ组，分别为６０．０％与２４．２％，４７．５％与２２．５％，（Ｐ〈０．０１）；Ａ组病死率（４２．５％）显著高于Ｂ     

急性下壁梗死发生房室传导阻滞的时间与预后关系

目的观察急性下壁心梗时，心电图检查和希氏束检查房室传导阻滞发生的时间和对预后的影响。方法患者24例，分为：(1)单纯下壁组；(2)下壁后壁或右室组；(3)下壁合并前、侧壁组。均行心电图及希氏束电图检查。结果三组房室传导阻滞发生率相似，多数房室传导阻滞在急性心肌梗死起病后12h内出现(81．8％)。阿托品和异丙肾上腺素治疗14例，AVB都有不同程度的改善，预后良好。结论急性下壁与合并其他部位心梗的AVB发病率相似，大部分出现时间为12h以内，多数AVB未用起搏治疗获得良好预后。     

血栓弹力图在初发急性心肌梗死患者中的临床应用

目的 探讨血栓弹力图(thromboelastography,TEG)监测与急性心肌梗死患者的冠状动脉病变严重程度是否相关、与住院期间主要心血管不良事件(major adverse cardiac events,MACE)是否相关.方法 选择我院初发急性心肌梗死(acute myocardial infarction,...     

急性心肌梗死并发脑梗死的临床特点

目的：探讨急性心肌梗死并发脑梗死的临床特点。方法：急性心肌梗死住院857例分成并发脑梗死组和无脑梗死组，对其资料进行回顾性分析比较。结果：并发脑梗死组平均肌酸激酶峰值、心尖部梗死、心源性休克、心律失常，均高于无脑梗死组（P＜0．05），并发脑梗死组病死率高于无脑梗死组（P＜0．01）。结论：急性心肌梗死后并发脑梗死与上述因素有关，溶栓及综合防治可减少脑梗死发生率，从而降低急性心肌梗死后病死率。     

急性心肌梗死患者血清生长分化因子15、肌钙蛋白及脑钠肽的表达及其临床意义

目的:探讨血清生长分化因子15(GDF-15)和肌钙蛋白I(cTnI)、脑钠肽(BNP)在急性心肌梗死(AMI)患者中的关系及对其近期预后的预测价值。方法:选择因胸痛(发病时间<12h)入院诊断为AMI患者122例为研究对象,冠状动脉造影正常者40例为对照组。采用ELISA法测定GDF-15及BNP浓度,采用免疫荧光定量技术测定cTnI浓度。记录患者住院和平均随访12个月期间的心血管事件(心血管死亡、心力衰竭、再发心绞痛或再发心肌梗死)的发生情况。结果:AMI组GDF-15与BNP和cTnI浓度呈正相关;发生心血管事件组GDF-15水平高于未发生心血管事件组;多变量logistic逐步回归表明GDF-15是预测近期心血管事件的危险因素(OR=0.79,95%CI:0.67～0.84,P<0.05)。结论:GDF-15与BNP和cTnI浓度呈正相关,GDF-15水平是预测近期心血管事件的有效指标之一。     

Arrhythmic complications of acute coronary syndromes

Cardiac arrhythmias routinely manifest during or following an acute coronary syndrome (ACS). Although the incidence of arrhythmia is directly related to the type of ACS the patient is experiencing, the clinician needs to be cautious with all patients in these categories. As an example, nearly 90% of patients who experience acute myocardial infarction (AMI) develop some cardiac rhythm abnormality and 25% have a cardiac conduction disturbance within 24 hours of infarct onset. In this patient population, the incidence of serious arrhythmias, such as ventricular fibrillation (4.5%) ,is greatest in the first hour of an AMI and declines rapidly thereafter. This article addresses the identification and treatment of arrhythmias and conduction disturbances that complicate the course of patients who have ACS, particularly AMI and thrombolysis. Emphasis is placed on mechanisms and therapeutic strategies.