Prospective evaluation of eligibility for thrombolytic therapy in acute myocardial infarction.

OBJECTIVES--To determine the proportion of patients presenting with acute myocardial infarction who are eligible for thrombolytic therapy. DESIGN--Cohort follow up study. SETTING--The four coronary care units in Auckland, New Zealand. SUBJECTS--All 3014 patients presenting to the units with suspected myocardial infarction in 1993. MAIN OUTCOME MEASURES--Eligibility for reperfusion with thrombolytic therapy (presentation within 12 hours of the onset of ischaemic chest pain with ST elevation > or = 2 mm in leads V1-V3, ST elevation > or = 1 mm in any other two contiguous leads, or new left bundle branch block); proportions of (a) patients eligible for reperfusion and (b) patients with contraindications to thrombolysis; death (including causes); definite myocardial infarction. RESULTS--948 patients had definite myocardial infarction, 124 probable myocardial infarction, and nine ST elevation but no infarction; 1274 patients had unstable angina and 659 chest pain of other causes. Of patients with definite or probable myocardial infarction, 576 (53.3%) were eligible for reperfusion, 39 had definite contraindications to thrombolysis (risk of bleeding). Hence 49.7% of patients (537/1081) were eligible for thrombolysis and 43.5% (470) received this treatment. Hospital mortality among patients eligible for reperfusion was 11.7% (55/470 cases) among those who received thrombolysis and 17.0% (18/106) among those who did not. CONCLUSIONS--On current criteria about half of patients admitted to coronary care units with definite or probable myocardial infarction are eligible for thrombolytic therapy. Few eligible patients have definite contraindications to thrombolytic therapy. Mortality for all community admissions for myocardial infarction remains high.     

A Novel Approach to Standard Techniques in the Assessment and Quantification of the Interventricular Systolic Relationship

A 51-year-old female undergoing an outpatient stress echocardiogram to evaluate atypical chest pain developed acute ST elevation in the anterior precordial leads on electrocardiogram following exercise. Echocardiography revealed a severe rise in pulmonary artery systolic pressure (PASP) with marked right ventricular (RV) enlargement and interventricular septum flattening. Subsequently, cardiac catherization confirmed an exercise-induced elevation in PASP and diagnosed pulmonary arterial hypertension without evidence of coronary artery disease. This case suggests that an acute elevation in pulmonary artery pressure with RV dilation may be a potential cause of acute ST elevation during stress testing.     

A longitudinal study on BIO14.6 hamsters with dilated cardiomyopathy: micro-echocardiographic evaluation

Background

Acute myocarditis may mimic myocardial infarction, since affected patients complain of "typical" chest pain, the ECG changes are identical to those observed in acute coronary syndromes, and serum markers are increased. We describe a case series of presumptive myocarditis with ST segment elevation on admission ECG.

Methods and Results

From 1998 to 2009, 21 patients (20 males; age 17-42 years) were admitted with chest pain, persistent ST segment elevation, serum enzyme and troponine release. All but one patients had fever and flu-like symptoms prior to admission. No abnormal Q wave appeared in any ECG tracing, and angiography did not show significant coronary artery disease. Patients remained asymptomatic at long term follow-up, except 2 who experienced a late relapse, with the same clinical, electrocardiographic and serum findings as in the first clinical presentation.

Conclusion

Presumptive myocarditis of possible viral origin characterized by ST elevation mimicking myocardial infarction, good short term prognosis and some risk for recurrence is relatively frequent in young males and appears as a distinct clinical condition.     

ST segment elevation on electrocardiogram: the electrocardiographic pattern of Brugada syndrome

A 77-year-old white diabetic woman was brought to our emergency department (ED) after becoming lightheaded and hypotensive at home. Her routine tests including a chest radiograph were normal. Her electrocardiogram (ECG) showed significant ST segment elevation in leads V1 to V4. Serial cardiac enzymes and troponin were within normal limits. Her ECG met the criteria for type 1 Brugada syndrome. Brugada syndrome, which is more common in young Asian males, is an arrhythmogenic disease caused in part by mutations in the cardiac sodium channel gene SCN5A. To diagnose the Brugada syndrome, 1 ECG criterion and 1 clinical criterion should exist. Brugada syndrome can be associated with ventricular tachycardia or fibrillation; the only treatment proven to prevent sudden death is placement of an implantable cardioverter defibrillator, which is recommended in symptomatic patients or in those with ventricular tachycardia induced during electrophysiologic studies and a type 1 ECG pattern of Brugada syndrome. It is important to recognize the Brugada ECG pattern and to differentiate it from other etiologies of ST segment elevation on ECG.     

心电图ST段不同改变与急性心肌梗死患者冠脉造影病变特点及生活质量的相关性研究

目的:探讨心电图ST段不同改变与急性心肌梗死患者冠脉造影病变特点及生活质量的相关性。方法:选取选取2015年6月到2017年6月在本院接受治疗的急性心肌梗死患者208例,根据心电图ST段的改变情况将患者分为ST段抬高组(124例)、ST段压低组(64例)、ST段无偏移组(20例),所有患者进行冠脉造影检查和常规治疗,比较治疗前三组患者的冠脉造影情况和冠脉狭窄程度,比较治疗1个月后三组患者的生活质量评分。结果:在ST段抬高组中,共检测出单支血管闭塞病变99例,占79.84%,两支或两支以上血管病变25例,占20.16%,其中侧支循环开放19例,开放率为15.32%。在ST段压低组中,共检测出单支血管非闭塞病变6例,占9.38%,两支或两支以上血管非闭塞病变56例,占87.50%,单支血管闭塞病变2例,占3.13%,其中侧支循环开放34例,开放率为53.13%。在ST段无偏移组中,单支血管闭塞病变15例,占75.00%,单支或多支血管非闭塞病变5例,占25.00%,其中侧支循环开放7例,开放率为35.00%。ST段抬高组、ST段无偏移组患者的冠脉狭窄程度以重度狭窄为主,ST段压低组患者的冠脉狭窄程度以中度狭窄为主,三组患者的轻度狭窄、中度狭窄、重度狭窄整体比较存在统计学差异(P0.05)。三组患者的疼痛评分、躯体受限评分、精神及活动评分整体比较具有统计学差异(P0.05),ST段压低组的上述评分均显著高于ST段抬高组和ST段无偏移组(P0.05)。结论:心电图ST段不同改变与急性心肌梗死患者冠脉造影病变密切相关,且ST段压低患者的预后通常较好。     

心肌透壁缺血时心脏表面心电图ST段位移的仿真研究

利用心肌的双域模型计算机模拟了不同区域心肌透壁缺血时ＳＴ 段位移在心脏表面的分布,发现心脏表面ＳＴ 段位移的分布式样和缺血区域大小有关,一个小面积的透壁缺血在缺血区上出现均匀分布的ＳＴ 段上升, 而在心脏表面的其他部位上几乎没有出现ＳＴ 段下降; 一个大面积的缺血像左降支或左旋支区域的缺血, ＳＴ 段位移在心脏表面的左侧区出现了一个偶极子式的分布,在缺血区为ＳＴ 段上升, 在正常区为ＳＴ 段下降, 并且其幅度随远离缺血边界而减小; 同时发现透壁缺血时的ＳＴ 段下降是缺血电流源的不可分割的一部分。 比较了这些模拟结果和在动物实验中所观察到的ＳＴ 段位移的变化,从而分析了本文得到的结论在临床上定位心肌缺血的指导意义。     

24 Hour ST Segment Analysis in Transient Left Ventricular Apical Ballooning

Objective

The etiologic basis of transient left ventricular apical ballooning, a novel cardiac syndrome, is not clear. Among the proposed pathomechanisms is coronary vasospasm. Long-term ST segment analysis may detect vasospastic episodes but has not been reported.

Methods

30 consecutive patients with transient left ventricular apical ballooning, left ventricular dysfunction and normal or near-normal coronary arteries were investigated. A 24-hour Holter ECG was obtained after emergency admission. ST segment analysis was performed automatically in 2 leads and confirmed by visual inspection. Criteria for an ischemic event were: 1. ST elevation or 2. horizontal or down-sloping ST segments ≥1 min duration and ≥100 µV J+80 point deviation corrected for baseline ST-deviation.

Results

Patients presented with ST segment elevation (n = 19) and/or T wave inversion (n = 20) on admission ECG. Ejection fraction was 50±12%. No transient ST elevations were observed during Holter ECG analysis. In 3 patients, 8 transient episodes of ST depression were recorded. Durations of episodes varied between 75s and 790s (mean 229s). Maximal ST deviation averaged −191±71 µV. Ischemic burden was −1 to −22 mVs (mean −8 mVs). 27 patients showed no ischemic events.

Conclusions

ST segment analysis of 24 h Holter recordings revealed minor ischemic events in only 10% of patients with transient left ventricular apical ballooning. Overall, ST segment changes were not indicative of recurrent coronary spasm playing a major role in the genesis of transient left ventricular apical ballooning.     

Cocaine: its use in otolaryngology

A review of 120 patients who had a discharge diagnosis of intermediate coronary syndrome showed 12 patients with documented transient ST elevation during spontaneous rest pain consistent with Prinzmetal''s angina. Coronary arteriography showed severe proximal occlusive coronary atherosclerosis in nine of the patients, and normal or minimal disease in the other three patients. In two of these three, there was documented coronary arterial spasm with reproduction of symptoms during arteriography. Although a shorter history of chest pain, presence of an old myocardial infarction and a positive finding on electrocardiogram treadmill test tended to predict the patients with severe occlusive coronary artery disease, these methods were inadequate to select candidates for arteriography. All patients responded well to nitroglycerine while in the hospital. Five of the nine patients with coronary artery disease had coronary bypass operations, with two excellent, two fair and one poor result. One of the three patients with normal findings on coronary arteriograms died with refractory ventricular arrhythmia six months after study. The other two have had good-to-moderate relief of symptoms on long-acting vasodilators and propranolol. Current concepts of the syndrome of Prinzmetal''s angina and ST elevation are reviewed. It appears that this syndrome has a wide spectrum of clinical presentations and coronary arteriographic anatomies.     

Acute Myocardial Infarction and Stress Cardiomyopathy following the Christchurch Earthquakes

Background

Christchurch, New Zealand, was struck by 2 major earthquakes at 4:36am on 4 September 2010, magnitude 7.1 and at 12:51pm on 22 February 2011, magnitude 6.3. Both events caused widespread destruction. Christchurch Hospital was the region''s only acute care hospital. It remained functional following both earthquakes. We were able to examine the effects of the 2 earthquakes on acute cardiac presentations.

Methods

Patients admitted under Cardiology in Christchurch Hospital 3 week prior to and 5 weeks following both earthquakes were analysed, with corresponding control periods in September 2009 and February 2010. Patients were categorised based on diagnosis: ST elevation myocardial infarction, Non ST elevation myocardial infarction, stress cardiomyopathy, unstable angina, stable angina, non cardiac chest pain, arrhythmia and others.

Results

There was a significant increase in overall admissions (p<0.003), ST elevation myocardial infarction (p<0.016), and non cardiac chest pain (p<0.022) in the first 2 weeks following the early morning September earthquake. This pattern was not seen after the early afternoon February earthquake. Instead, there was a very large number of stress cardiomyopathy admissions with 21 cases (95% CI 2.6–6.4) in 4 days. There had been 6 stress cardiomyopathy cases after the first earthquake (95% CI 0.44–2.62). Statistical analysis showed this to be a significant difference between the earthquakes (p<0.05).

Conclusion

The early morning September earthquake triggered a large increase in ST elevation myocardial infarction and a few stress cardiomyopathy cases. The early afternoon February earthquake caused significantly more stress cardiomyopathy. Two major earthquakes occurring at different times of day differed in their effect on acute cardiac events.     

Tissue distribution and subcellular localization of a variant form of the human ST2 gene product, ST2V

The human ST2 gene has been known to encode three splice variants; namely, a soluble secreted form of ST2, a transmembrane form of ST2L, and ST2V of undetermined localization. Therefore, analysis of tissue distribution and subcellular localization of ST2V is important to elucidate functional relationships among the three splice variants of the human ST2 gene. RT-PCR procedure revealed that ST2V is predominantly expressed in the stomach, small intestine, and colon. Transfection of ST2V cDNA into COS7 cells in the presence of [(35)S] methionine and cysteine produced radiolabeled 40 kDa protein, which is recognized by specific monoclonal antibody against human ST2. Subcellular fractionation analysis showed that ST2V protein was distributed in the insoluble fraction of the cell lysate. Finally, ST2V protein was detected on the plasma membrane of COS7 cells, which had been transfected with ST2V cDNA, by confocal laser microscopic analysis. These findings taken together, indicate that ST2V protein localizes on the plasma membrane, suggesting its possible role in modification of the ST2L-signaling pathways.     

Are coronary artery spasm and progressive damage to the heart associated with the hyperventilation syndrome?

A case of coronary artery vasospasm was studied in a man with a four year history of angina. He had evidence of symptomatic hyperventilation during a spontaneous episode of chest pain. When asked to hyperventilate the pain in his chest and ST elevation were reproduced in the same leads as occurred during the spontaneous attack. This may be the first reported case of spontaneous hyperventilation producing vasoconstriction, and the patient''s previous admissions to the coronary care unit may have been associated with coronary vasospasm induced by hyperventilation. When patients with variant angina report pains in the chest in association with dizziness and breathlessness hyperventilation should be considered to be a possible cause of the symptoms. As coronary vasospasm is increasingly implicated in angina after myocardial infarction the role of hyperventilation should be considered more often.     

Synthesis of disialyl Lewis a (Le(a)) structure in colon cancer cell lines by a sialyltransferase,ST6GalNAc VI,responsible for the synthesis of alpha-series gangliosides

Biosynthesis of disialyl Lewis a (Lea) was analyzed using previously cloned ST6GalNAc V and ST6GalNAc VI, which were responsible for the synthesis of alpha-series gangliosides. Among lactotetraosylceramide (Lc4), neolactotetraosylceramide, and their sialyl forms, only sialyl Lc4 was sialylated with ST6GalNAc V and ST6GalNAc VI. The products were confirmed to be disialyl Lea in TLC-immunostaining. Compared with the original substrate GM1b, the synthetic rates of disialyl Lea were 22 and 38% with ST6GalNAc V and ST6GalNAc VI, respectively. Since sialyl Lea could not be converted to disialyl Lea, disialyl Lea was produced only from disialyl Lc4. Therefore, it appears that ST6GalNAc V/VI and fucosyltransferase III (FUT-3) compete for sialyl Lc4, their common substrate. The results of either one transfection or co-transfection of two genes into COS1 cells revealed that both ST6GalNAc VI and FUT-3 contributed in the synthesis of disialyl Lea but partly compete with each other. Many colon cancer cell lines expressed the ST6GalNAc VI gene more or less, and some of them actually expressed disialyl Lea. None of them expressed ST6GalNAc V. These results suggested the novel substrate specificity of ST6GalNAc VI, which is responsible for the synthesis of disialyl Lea but not for alpha-series gangliosides in human colon tissues.     

A normal coronary arteriogram in a very young man with Prinzmetal's variant angina: Case report with review of the literature

The case of a very young man with Prinzmetal's variant angina and a normal coronary arteriogram is described. While in the hospital for diagnosis, he experienced severe chest pain accompanied by transient ST segment elevation. After intravenous administration of Ergonovine Maleate (0.4 mg), spastic obstruction of the right coronary artery was observed. He was treated successfully with nifedipine, and during 4 months of follow-up, he has had no symptoms. Because of the diagnostic interest in this type of angina in a young person, the literature on Prinzmetal's angina has also been reviewed.     

Presence and expression of a novel variant form of ST2 gene product in human leukemic cell line UT-7/GM.

A novel variant cDNA from the human ST2 gene other than ST2 or ST2L was identified and tentatively named ST2V. Alternative splicing inserts a new exon which leads to a change in the C-terminal portion of ST2, causing it to gain a hydrophobic tail instead of losing the third immunoglobulin-like domain. ST2V is expressed in human leukemic cell line UT-7 and its sublines UT-7/GM, UT-7/EPO, and UT-7/TPO, in addition to human helper T cell line 5C10. The amount of ST2V mRNA is greatly diminished when UT-7/GM cells are induced to differentiate into either erythroblastic or megakaryoblastic phenotypes. The possible roles of the ST2V in growth and differentiation are intriguing.     

Recurrent myocardial infarction in a patient with Prinzmetal's angina and normal coronary arteries

A 55-year-old man was referred for the evaluation of frequent chest pain and syncope. While in the hospital, he experienced severe chest pain accompanied by transient ST segment elevation and a slight elevation of cardiac enzyme levels. Multiple coronary arteriograms were recorded at various times during an interval of 2 months. On one occasion, the results were normal; on another occasion, they showed total occlusion of the left anterior descending, diagonal, and circumflex coronary arteries. The occlusion was completely relieved with sublingual nitroglycerin. Because the patient's clinical condition deteriorated rapidly, double aortocoronary saphenous vein bypass was performed to the left anterior descending and circumflex coronary arteries. During the induction of anesthesia, ventricular fibrillation occurred, and the patient died from refractory recurrent fibrillation 4 hours after surgery. Postmortem examination revealed normal coronary arteries, patent vein grafts, and multiple focal areas of recent and old myocardial fibrosis. Thus, it appears that coronary spasm, in the presence of otherwise normal coronary arteries, can produce myocardial infarction with necrosis, and that medical management may provide a more successful method of treating such patients.     

Differential antagonism of mu agonists by U50,488H in the rat

Agonist, and antagonist effects of the proposed kappa opioid agonist, U50,488H (U50) have been studied in an experimental model of seizure activity (flurothyl-induced seizure threshold) (ST) and in the central modulation of spontaneous, volume-induced micturition contractions (bladder motility) (BM) in rats. Intracerebroventricular (i.c.v.) administration of U50 (at the doses tested) did not produce any agonist effect in either ST or in BM. In contrast, i.c.v. administration of [D-Ala2, NMPhe4, Gly-ol]enkephalin (DAGO) or etorphine, agonists with activity at mu opioid receptors, produced an elevation of ST and inhibition of BM. The elevation in ST produced by etorphine (0.004 nmol) was prevented by prior treatment with U50. In contrast, the approximately equieffective elevation in ST resulting from DAGO was not affected by U50 pretreatment. Similarly, pretreatment of rats with U50 antagonized the approximately equieffective BM effects of etorphine, but not those of DAGO. As both DAGO and etorphine are thought to exert their effects via the opiate mu receptor, the results may be consistent with the view that subpopulations of mu receptors exist within the central nervous system; these sites may be differentially associated with the kappa receptor.     

Novel Rearrangements in the Staphylococcal Cassette Chromosome Mec Type V Elements of Indian ST772 and ST672 Methicillin Resistant Staphylococcus aureus Strains

Staphylococcus aureus is a commensal gram positive bacteria which causes severe and non severe infections in humans and livestock. In India, ST772 is a dominant and ST672 is an emerging clone of Staphylococcus aureus. Both cause serious human diseases, and carry type V SCCmec elements. The objective of this study was to characterize SCCmec type V elements of ST772 and ST672 because the usual PCR methods did not amplify all primers specific to the type. Whole genome sequencing analysis of seven ST772 and one ST672 S. aureus isolates revealed that the SCCmec elements of six of the ST772 isolates were the smallest of the extant type V elements and in addition have several other novel features. Only one ST772 isolate and the ST672 isolate carried bigger SCCmec cassettes which were composites carrying multiple ccrC genes. These cassettes had some similarities to type V SCCmec element from M013 isolate (ST59) from Taiwan in certain aspects. SCCmec elements of all Indian isolates had an inversion of the mec complex, similar to the bovine SCCmec type X. This study reveals that six out of seven ST772 S. aureus isolates have a novel type V (5C2) SCCmec element while one each of ST772 and ST672 isolates have a composite SCCmec type V element (5C2&5) formed by the integration of type V SCCmec into a MSSA carrying a SCC element, in addition to the mec gene complex inversions and extensive recombinations.     

Association of cytokines with endothelium dependent flow mediated vasodilation (FMD) of systemic arteries in patients with non-ischemic cardiomyopathy

Background

Takotsubo cardiomyopathy is an acute cardiac syndrome characterized by transient LV regional wall motion abnormalities (with peculiar apical ballooning appearance), chest pain or dyspnea, ST-segment elevation and minor elevations of cardiac enzyme levels

Case presentation

A 68-year-old woman was admitted to the Emergency Department because of sudden onset chest pain occurred while transferring her daughter, who had earlier suffered a major seizure, to the hospital. The EKG showed sinus tachycardia with ST-segment elevation in leads V2–V3 and ST-segment depression in leads V5–V6, she was, thus, referred for emergency coronary angiography. A pre-procedural transthoracic echocardiogram revealed regional systolic dysfunction of the LV walls with hypokinesis of the mid-apical segments and hyperkinesis of the basal segments. Coronary angiography showed patent epicardial coronary arteries; LV angiography demonstrated the characteristic morphology of apical ballooning with hyperkinesis of the basal segments and hypokinesis of the mid-apical segments. The post-procedural course was uneventful; on day 5 after admission the echocardiogram revealed full recovery of apical and mid-ventricular regional wall-motion abnormalities.

Conclusion

Takotsubo cardiomyopathy is a relatively rare, unique entity that has only recently been widely appreciated. Acute stress has been indicated as a common trigger for the transient LV apical ballooning syndrome, especially in postmenopausal women. The present report is a typical example of stress-induced takotsubo cardiomyopathy in a Caucasian Italian postmenopausal woman.     

静脉溶栓时机对急性ST段抬高型心肌梗死患者溶栓效果及主要不良心脏事件发生率的影响

目的:探讨静脉溶栓时机对急性ST段抬高型心肌梗死患者溶栓效果及主要不良心脏事件发生率的影响。方法:将2016年1月至2017年12月我院接诊的314例急性ST段抬高型心肌梗死患者纳入本研究,按照溶栓治疗时间不同分为A组(发病至溶栓时间6 h)172例、B组(发病至溶栓时间为6～12 h)102例和C组(发病至溶栓时间12 h)40例,比较三组患者溶栓效果、溶栓后ST段回落情况以及住院期间主要不良心脏事件发生情况。结果:A组患者梗死冠脉溶通率、溶栓后ST段回落幅度高于B组和C组,且B组高于C组,差异均有统计学意义(P0.05)。A组患者治疗后ST段回落最大幅度所需时间、住院期间主要不良心脏事件总发生率低于B组和C组,且B组低于C组,差异均有统计学意义(P0.05)。结论:急性ST段抬高型心肌梗死患者发病后6 h内静脉溶栓治疗梗死冠脉溶通率更高、ST段回落效果更好,可降低住院期间主要不良心脏事件发生风险。     

STEMI or non-STEMI: that is the question

Acute coronary syndromes are usually classified on the basis of the presence or absence of ST elevation on the ECG: ST-elevation myocardial infarction or non-ST-elevation myocardial infarction (NSTEMI)patients with acute myocardial infarction (AMI) need immediate therapy, without unnecessary delay and primary percutaneous coronary intervention (PPCI) should preferably be performed within 90 min after first medical contact. However, in AMI patients without ST-segment elevation (pre) hospital triage for immediate transfer to the catheterisation laboratory may be difficult. Moreover, initial diagnosis and risk stratification take place at busy emergency departments and chest pain units with additional risk of ‘PPCI delay’. Optimal timing of angiography and revascularisation remains a challenge. We describe a patient with NSTEMI who was scheduled for early coronary angiography within 24 h but retrospectively should have been sent to the cath lab immediately because he had a significant amount of myocardium at risk, undetected by non-invasive parameters.