急性期脑卒中患者心肌酶与QT离散度的变化

目的探讨脑卒中患者急性期心肌酶、QT离散度的变化及意义。方法选择71例脑出血、78例脑梗塞患者和57例健康老年人，分别测定各组心肌酶、QT离散度，并进行比较。结果与对照组相比，脑出血组和脑梗塞组心肌酶显著升高、QT离散度明显延长（p〈0．01）；脑出血组和脑梗塞组比较，天冬氨酸转移酶（AST）、乳酸脱氢酶（LDH）、肌酸磷酸激酶（CK）显著升高（p〈0．01），肌酸磷酸激酶同工酶（CK—MB）、QT离散度（QTd）两组无显著性差异（p〉0．05）。结论脑卒中急性期心肌酶、QT离散度有显著变化，二者的监测有利于脑卒中病情及心脏受累程度的全面评价．对判断患者的预后有重要意义。     

Creatine kinase isoforms as circulating markers of deterioration in idiopathic dilated cardiomyopathy

Background: A proportion of patients with dilated cardiomyopathy (DCM) may have ongoing myocardial damage secondary to viral or immune mediated myocardial inflammation. Hypothesis: The prognostic determinants identify patients with decreased survival but do not provide a measure of myocardial damage. To obtain an objective assessment of myocardial damage in DCM, we measured plasma levels of creatine kinase (CK), its isoenzymes (CK-MM and CK-MB), and separated the isoforms of CK-MM and CK-MB. Methods: The cohort consisted of 77 consecutive patients (61 men, 16 women) with DCM (World Health Organization criteria), aged 49 ± 14 years (range 19–60). Patients had been symptomatic for 29 ± 38 months (range 0.5–200 months) with 48 in New York Heart Association class I/II and 29 in class III/IV at the time of diagnosis. During median follow-up of 27 months from diagnosis (range 0.6–165), 50 patients remained clinically stable and 27 had deteriorated. Results: A significantly higher proportion of patients with DCM had abnormal MB2/MB1 ratio compared with normal volunteers (11,14% vs. 1, 1%, p = 0.003). Patients who deteriorated had higher MB2/MB1 ratio, (1.22 ± 0.62 vs. 0.85 ± 0.56;p = 0.01), and more frequently had abnormal MB2/ MB1 ratio (8,30% vs. 3,6%;p=0.004) and CK and CK-MM activities (5, 19% vs. 2, 4%;p = 0.03) than those who remained stable. Patients with DCM with high CK-MB activity had 3.13-fold increased odds of sudden death or need for cardiac transplantation (95% confidence interval 1.53–6.40, p = 0.008). Thus, CK measurements, in particular CK-MB isoforms, are markers of myocardial damage in a subset of patients with DCM and could be useful in investigating the possibility of persistent myocardial damage in these patients.     

心脏停跳与不停跳先心病矫治术患者围术期cTnⅠ及心肌酶水平变化

目的探讨心脏停跳与不停跳先天性心脏病（先心病）矫治术对心肌的损伤程度,并寻找敏感性评价指标。方法将40例同期拟行先心病矫治术的患者随机分为对照组和观察组各20例,分别于心脏停跳与不停跳下手术,两组麻醉及体外循环（CPB）方法相同。分别于围术期检测血清心肌肌钙蛋白Ⅰ（cTnⅠ）、肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）、肌酸激酶（CK）、AST、α-羟丁酸脱氢酶（HBDH）,同时观察心电图及心脏超声指标改变。结果两组围术期心电图及心脏超声指标均无明显异常,但术中、术后血清cTnⅠ及CK、CK—MB、LDH水平均明显升高,对照组显著高于观察组;其中血清cTnⅠ水平升高出现早、恢复慢（术后72h时仍显著高于术前水平）。结论心脏不停跳先心病矫治术对心肌的损伤小于心脏停跳手术;cTnⅠ是评价心脏手术围术期心肌损伤敏感的特异指标．     

肺心病患者血清hs-CRP与心肌酶的临床观察

目的探讨血清hs-CRP(超敏C反应蛋白)、CK-MB(磷酸肌酸激酶同工酶MB)、CK(磷酸肌酸激酶)、LDH(乳酸脱氢酶)、AST(天门冬酸氨基转移酶)在慢性肺心病患者急性发作期及治疗缓解期的变化情况。方法测定95例确诊为肺心病急性发作期患者治疗前后、60例肺心病治疗缓解期患者及30例正常人血清hs-CRP、心肌酶水平。结果肺心病患者血清hs-CRP、心肌酶明显高于健康人群,且急性发作期明显高于临床缓解期(P<0.05);急性发作期患者治疗前后血清hs-CRP、心肌酶差异显著(P<0.05);死亡组血清hs-CRP、心肌酶明显高于存活组(P<0.05)。结论血清hs-CRP与心肌酶的变化可作为肺心病患者的预后及疗效判断的有效指标。     

Failure of Serial Electrocardiograms to Exclude a Large Anterior Myocardial Infarction and the Role of Transesophageal Echocardiogram in Acute Myocardial Infarction

When patients present with acute onset of chest pain suggestive of myocardial ischemia, immediate clinical decisions regarding thrombolysis, percutaneous transluminal coronary angioplasty, or both are usually based on the history and abnormal electrocardiograms and confirmed by the presence of abnormally elevated cardiac enzymes. However, there are potential limitations of the electrocardiograms and initial cardiac enzymes in the diagnosis and confirmation of acute myocardial infarction. We describe the case of a patient who presented with an acute onset of chest pain and had a normal electrocardiogram and initial cardiac enzymes yet was found by transesophageal echocardiography to have a large myocardial infarction.     

心肌酶在重症肺炎的临床应用

目的研究肺炎患者心肌酶变化情况及心肌酶对重症肺炎的临床应用价值。方法以383例肺炎患者为研究对象,比较重症肺炎与普通肺炎心肌酶水平差异及不同病原体感染引起重症肺炎心肌酶异常率,并研究重症肺炎组中心肌酶异常患者与心肌酶正常患者心电图异常情况、心衰等并发症的发生率及死亡率。结果重症肺炎组、普通肺炎组心肌酶比较均有统计学差异(P<0.05);病毒性肺炎较易引起心肌酶异常;重症肺炎中心肌酶异常组与心肌酶正常组比较,心电图异常率及心衰发生率比较有统计学差异(P<0.05)。结论心肌酶对重症肺炎合并心肌损伤有重要监测作用,对重症肺炎病情评估有重要临床应用价值。     

Ruling out acute myocardial infarction early with two serial creatine kinase-MBmass determinations.

AIMS: We studied the diagnostic value for acute myocardial infarction of serial creatine kinase-MBmass measurements on admission and at 7 h after the onset of symptoms. METHODS AND RESULTS: Patients presenting to our chest pain unit with symptoms of <5-h duration were eligible. Patients were kept under observation at least until 12 h after onset of symptoms. Blood samples were drawn on admission and 7 and 10 h after onset of symptoms. Creatine kinase-MBmass>7.0 microg x 1(-1) (upper reference limit for acute myocardial infarction), or an increase >2.0 microg x 1(-1) (reference change value) between admission and at 7 h was considered abnormal. Of a total of 470 patients, 248 patients had acute myocardial infarction: 100 out of the 248 patients had a single creatine kinase-MBmass>7.0 microg x 1(-1) on admission (sensitivity 40%, 95% CI:34-46%), 234/248 patients at 7 h (sensitivity 94%, 95% CI:91-97%), and 240/248 at 10 h (sensitivity 97%, 95% CI:94-99%). At 7 h, 246/248 patients had either a single creatine kinase-MB >7.0 microg x 1(-1) or a significant increase between admission and 7 h (sensitivity 99%, 95% CI:98-100%). Of 222 patients without acute myocardial infarction, 214 had a normal serial creatine kinase-MBmass (specificity 96%, 95% CI:93-98%). CONCLUSION: In patients with symptoms of <5-h duration, acute myocardial infarction can be ruled out using serial creatine kinase-MBmass taken on admission and at 7 h.     

Voltage gradients in transvenous and subcutaneous defibrillation and their risk of myocardial damage

Introduction

Transvenous implantable cardioverter-defibrillator (ICD) shocks have been associated with cardiac biomarker elevations and are thought in some cases to contribute to adverse clinical outcomes and mortality, possibly from myocardium exposed to excessive shock voltage gradients. Currently, there are only limited data for comparison with subcutaneous ICDs. We sought to compare ventricular myocardium voltage gradients resulting from transvenous (TV) and subcutaneous defibrillator (S-ICD) shocks to assess their risk of myocardial damage.

Methods

A finite element model was derived from thoracic magnetic resonance imaging (MRI). Voltage gradients were modeled for an S-ICD with a left-sided parasternal coil and a left-sided TV-ICD with a mid-cavity, a septal right ventricle (RV) coil, or a dual coil lead (TV mid, TV septal, TV septal + superior vena cava [SVC]). High gradients were defined as > 100 V/cm.

Results

The volumes of ventricular myocardium with high gradients > 100 V/cm were 0.02, 2.4, 7.7, and 0 cc for TV mid, TV septal, TV septal + SVC, and S-ICD, respectively.

Conclusion

Our models suggest that S-ICD shocks produce more uniform gradients in the myocardium, with less exposure to potentially damaging electrical fields, compared to TV-ICDs. Dual coil TV leads yield higher gradients, as does closer proximity of the shock coil to the myocardium.     

The effect of cardiac troponin testing on clinical care in a veterans population

BACKGROUND: Cardiac troponin is more accurate than creatine kinase (CK) testing for detecting myocardial injury in patients with acute coronary syndromes (ACS), but its effects on clinical care compared with CK testing alone is open to question. OBJECTIVE: To test the effects of troponin I on medical decisions for patients undergoing cardiac enzyme testing. DESIGN: Randomized, controlled trial. SETTING: Urban academic Veterans Affairs medical center. PATIENTS: Three hundred ninety-two patients presenting to the emergency department (ED) and outpatient settings with symptoms and/or electrocardiograms suggestive but not diagnostic of ACS. INTERVENTION: Random assignment to linked CK-troponin I (CKTnI) testing or CK testing alone. MEASUREMENTS: ED discharge and cardiac catheterization incidence (primary); ED medication use, inpatient noninvasive testing, revascularization procedures, discharge medications, and 8-week ED visits, hospitalizations, and procedures (secondary). RESULTS: Groups were similar in all variables except history of heart failure (CK 26.8% vs CKTnI 17.0%). ACS comprised 12.2% of the cohort. ED discharge incidence was greater in the CKTnI arm (18% vs 9.6%; relative risk [RR], 1.83; 95% CI, 1.08 to 3.31; P=.02; number needed to test=12.6; 95% CI, 4.5 to 130). Troponin testing had no significant effect on catheterization incidence (18.2% vs 14.5%; RR, 1.19; 95% CI, 0.72 to 1.92; P>.20) or other outcomes except follow-up echocardiography (13.4% vs 7.4%; RR, 2.24; 95% CI, 1.11 to 4.69; P=.02). CONCLUSIONS: In a veterans population undergoing cardiac enzyme testing, CKTnI testing led to more ED discharges than CK testing alone but had no effect on inpatient care and was associated with more echocardiograms in a follow-up period.     

Cerebrospinal fluid creatine kinase isoenzyme BB levels do not predict the clinical outcome in patients unconscious following cardiac resuscitation

It has recently been claimed that an increase in creatine kinase isoenzyme BB(CK-BB) in cerebrospinal fluid (CSF) is well correlated with the cerebral outcome in patients resuscitated after cardiac arrest. Twenty-one such patients consecutively admitted from outside this hospital participated in the study. The patients were divided into two groups: 6 survivors and 15 nonsurvivors. The median CSF-CK-BB value was 5 U/L among nonsurvivors and below detection limit among survivors (NS). However, the predictive value of a positive test is limited, since only 6 of 15 nonsurvivors (40%) had an increase in CSF-CK-BB (predictive value of positive test = 67%). The predictive value of a negative test is limited, since 3 of 6 survivors (50%) showed no rise in CSF-CK-BB (predictive value of negative test = 25%). No relationship between cerebral dysfunction and CSF-CK-BB values was revealed. Thus, CSF-CK-BB does not predict the clinical outcome in patients resuscitated after cardiac arrest.     

Coordinate Regulation of Metabolic Enzyme Encoding Genes During Cardiac Development and Following Carvedilol Therapy in Spontaneously Hypertensive Rats

Fuel substrate utilization is highly regulated during cardiac development and with the onset of cardiac hypertrophy. Glucose and lactate are the predominant fuel substrates utilized during cardiac development. Postnatally, a switch occurs so that fatty acids become the chief energy substrate in the nonfed adult mammalian heart. A reversion back towards fetal energy metabolism occurs with the development of cardiac hypertrophy. To evaluate the role of this substrate preference switch in the development of cardiac hypertrophy, the molecular regulation directing these switches is being explored. Thus, we have begun by defining the temporal expression patterns of genes encoding key rate-controlling enzymes directing major fuel substrate metabolism during cardiac development, with pressure-overload-induced cardiac hypertrophy, and following antihypertensive therapy in spontaneously hypertensive rats. The genes encoding the fatty acid and adult enriched rate-controlling glycolytic enzymes are expressed at low levels in the fetal and neonatal rat heart. The genes encoding these enzymes are significantly and coordinately upregulated ( 70%) in adult rat hearts compared to the fetal expression patterns. A reciprocal and coordinate downregulation ( 40% reduction) of the fatty acid and adult enriched glycolytic enzyme encoding genes are observed with the induction of pressure-overload-induced hypertrophy in spontaneously hypertensive rats compared to Wistar–Furth normotensive control rats. Antihypertensive therapy with carvedilol, a vasodilating -and -adrenoreceptor antagonist, attenuates this reversion of the metabolic gene expression pattern towards fetal levels compared to placebo-treated littermate controls. This coordinate developmental and hypertrophy-induced regulation of genes that encode enzymes controlling both fatty acid and glycolytic catabolic pathways in the heart implicates potential mutual/overlapping regulatory signaling proteins within their gene regulatory programs. These gene regulatory pathways need to be identified and modulated in order to characterize the functional role of fuel substrate metabolism in cardiac development and with the induction of cardiac hypertrophy.     

Beneficial effects of exercise training in heart failure patients with low cardiac output response to exercise – a comparison of two training models

BACKGROUND: Exercise capacity of patients with chronic heart failure (CHF) correlates poorly with estimates of cardiac function. Yet, it has been suggested that only patients without severely impaired cardiac output (CO) benefit from exercise training. Comparisons of different training models have not been made in the same study. AIMS: To evaluate whether the response to different training models diverges according to the cardiac output response to exercise in patients with chronic heart failure. METHODS: Sixteen CHF patients (63 +/- 11 years) with an ejection fraction of 30 +/- 11% underwent a baseline cardiopulmonary exercise test, right heart catheterization and leg muscle biopsy. Cardiac output (CO) response to exercise was defined as the ratio between CO increase and the increase in oxygen uptake (CO response index) during exercise. Patients were randomized into two training regimens, differing with regard to active muscle mass, i.e. whole body and one-legged exercise. RESULTS: Baseline exercise capacity expressed as W kg-1 correlated with the CO response index (r = 0.51, P < 0.05). Exercise capacity on the cycle ergometer increased in both groups but more in the one-legged than in the two-legged training group (P < 0.05). The improvement in exercise capacity did not correlate with base-line exercise capacity. It correlated with CO response index in the one-legged (r = 0.75, P < 0.01) but not in the two-legged training group. CO response index correlated negatively with the pulmonary capillary wedge pressure at peak exercise (r = - 0.60, P < 0.05). The increase in leg muscle citrate synthase activity after training correlated negatively with the baseline CO response index (r = - 0. 50, P < 0.05). CONCLUSIONS: The improvement of exercise capacity after one-legged training correlates with the CO increase in relation to the O2 uptake before training. In patients with low CO response, individualization of the exercise regimen is needed and the benefits of training a limited muscle mass at a time deserve further study.     

Cardiac perforation with tamponade during cardiac catheterization

Among 6,675 adult patients undergoing cardiac catheterization in our institution, three patients developed cardiac perforation and tamponade (incidence 0.04%). Two perforations involved the left atrium, and one the right atrium. Tamponade developed in the three patients. Hemodynamic confirmation of tamponade was available in two patients. Pericardiocentesis was performed in all three patients. Two patients required emergency surgery. All patients recovered.     

The correlation between myocardial resilience after high-intensity exercise and markers of myocardial injury in swimmers

To investigate how high-intensity exercise influences an athlete''s myocardial resilience and the correlation between myocardial resilience and markers of myocardial ischemic injury.Fifteen swimmers participated in high-intensity exercises. Cardiac ultrasound was performed before and after exercise on each subject. Left ventricular general strain, systolic general strain rate, and the differences (▴general strain and ▴ general strain rate, respectively), before and after exercise were analyzed. Blood was collected at the morning of the exercise day and 6 hours after exercise to measure cardiac enzyme indicators.The correlation between myocardial resilience and markers of myocardial injury were evaluated. Most cardiac enzymes concentrations increased after exercise (P < .05). Cardiac troponin I, creatine kinase MB, and cardiac troponin T were all correlated with the degree of ▴ peak strain (differential value of posterior wall basal segment before and after exercise) and ▴ peak strain rate (differential value before and after exercise) (P < .05).After high-intensity exercise, the concentrations of creatine kinase MB and cardiac troponin T in the blood are positively correlated with two-dimensional ultrasound deformation indices, proving the fact that the seindices can be used as a diagnostic basis for myocardial injury, and are more sensitive than general strain. The two-dimensional strain echocardiogram is non-invasive and easily accepted by the patient. It can make up for the shortage of myocardial enzymes in the injury areas, including weak timeliness and the inability to locate injury.     

Cardiac Involvement of Adult T Cell Leukemia/Lymphoma

Adult T-cell leukemia/lymphoma (ATL) is a refractory T-cell lymphoma with variable clinical profiles, commonly exhibiting extra-nodal involvement. The myocardial involvement of ATL is often detected at an autopsy; however, the development of a symptomatic cardiac mass due to ATL is extremely rare. We herein report a 65-year-old man with ATL who developed cardiac symptoms due to a rapidly enlarging left ventricular mass soon after the initiation of systemic chemotherapy. We also summarize previously reported cases of symptomatic ATL with cardiac involvement.     

Morphological observations of tumors in cardiac conduction system

Tumors of the cardiac conduction system(CCS) have rarely been reported. The CCS from 198 cardiac-related deaths(Group Ⅰ) ,and 838 deaths from non-cardiovascular diseases or trauma(Group Ⅱ) ,were studied. Sampling was done of the sinoatrial node(SAN) and atrio-ventricular node(AVN) along their long axis of each node as a single block and the His bundle(HB) perpendicular to its long axis in 2-4 blocks. Five-micron serial sections were made;tissue slices were taken intermittently,every 20th from the SAN,every 10th from the AVN,and every 30th from the HB and bundle branches(BB) ,by continuous slices three times. Tumors in the CCS were found in 12 cases(1.155 %) ,where 10(0.965%) were primary tumors,and 2(0.193%) were metastatic tumors. The primary tumors included 4 fibromata compressing the HB(0.386 %) ,4 hemangiomata(0.386%) ,1 AVN tumor(0.097 %) ,and 1 rhabdomyoma(0.097 %) . In 8 of the 10 cases,the tumors were located in the AVN or HB. The metastatic tumors originated from lymphocytic leukemia and malignant lymphoma(histiocytic type) in lung,and were all found in the SAN. Of the 12 cases,2 were from the group Ⅰ. Tumors in the CCS are the smallest tumors in different parts of the body,which can cause sudden death.     

EDITORIAL: Premature Coronary Heart Disease: Ask about the Family

ABSTRACT To study prospectively the effects of a brief febrile viral infection on parameters of muscle and circulatory function, seven volunteers were inoculated with sandfly fever virus and two control subjects with sterile saline. During but not after fever, decreased isometric and dynamic strength and endurance were recorded in various muscles. Impairment could not be explained by altered activities of relevant muscle enzymes in serum or muscle tissue or by altered muscle ultrastructure, but correlated with the severity of perceived symptoms, including myalgia, as rated by each subject. Compared to baseline, cardiac stroke volume was lower during and after fever. During fever, an increased heart rate maintained cardiac output at pre-inoculation values, whereas cardiac output fell in early convalescence. This decrease in cardiac output correlated significantly with the severity of fever. Thus, in brief viral infections a transient impairment of muscle performance capacity is correlated to subjective symptoms such as myalgia, rather than to fever, whereas a decreased cardiac output following such infections seems to be associated with the fever reaction.