运动对血浆心钠素影响的初步探讨

本文通过观察中长跑运动员极限运动下血浆心钠素的变化,探索运动对心脏内分泌的影响。实验结果提示了运动时由于血液动力学和神经生化变化引起血浆心钠素增加,有训练运动员极限运动后心钠素明显增加,与良好的心脏功能和运动能力有关。     

运动对心脏心钠素受体基因表达的影响

为探讨运动对心脏心钠素受体基因表达的影响,建立不同强度运动训练动物模型,采用免疫荧光组织化学法、原位杂交、激光共聚焦扫描和计算机图像分析技术,观察心脏心钠素受体的分布和运动对心脏心钠素受体基因表达的影响,结果表明,心钠素受体主要分布在心内膜、心肌纤维的肌膜、心肌纤维间的结缔组织和冠状动脉分支的血管壁.中等和大强度运动使心脏A型心钠素受体基因表达上调和C型心钠素受体基因表达下调,力竭运动使A型心钠素受体基因表达下调和C型心钠素受体基因表达上调.     

细胞内游离钙在运动心脏重塑中的作用

本文建立了运动心脏的实验动物模型，应用激光扫描共聚焦显微镜与新一代钙荧光指示剂Ｆｌｕｏ－３／ＡＭ的方法，对心肌活细胞内具有生物活性的游离钙的动态变化进行了研究，以期了解运动心脏结构与功能重塑的细胞机制。结果显示：经过１２周耐力训练后，心肌细胞内游离钙浓度静息值无显著性改变，心肌收缩时其游离钙浓度峰值较对照组显著增高１１％（Ｐ＜０．０５）。停止训练８周后，心肌收缩时胞内游离钙浓度峰值较训练时显著降低１４％（Ｐ＜０．０５），恢复到正常对照水平。研究结果提示，运动心脏可保持细胞内钙稳态，心肌收缩时收缩结构钙可获得量增多，是运动心脏心肌收缩性增强的重要机制之一，同时，心肌细胞内游离钙的增多对于运动心脏肥大的发生也起重要的介导作用，而且，运动心肌细胞内游离钙的改变是一种可逆性变化。     

运动心脏内分泌功能可复性的研究

为了进一步探讨运动心脏的可复性及其与病理心脏的本质差异,通过动物实验模拟运动心脏,观察了停止运动训练８周后心脏重量的变化,并对心肌组织与血浆中心钠素和降钙素基因相关肽含量进行了放射免疫测定。结果显示,经过１２周耐力训练后,心脏重量指数显著增高５１％;心房肌组织与血浆中心钠素含量分别显著增高４９％和７９％;心房肌组织与血浆中降钙素基因相关肽含量分别显著增高３６％和１９％。停止训练８周后,心脏重量指数较训练时显著降低２４％,心脏绝对重量和心脏重量指数与其对照组无显著差异;心房肌组织与血浆中心钠素含量分别较训练时显著降低２２％和３３％,基本恢复到正常对照水平;心房、心室肌组织与血浆降钙素基因相关肽含量分别较训练时降低１７％、８％和３％,也恢复到正常对照水平。研究结果表明,运动心脏确有心肌肥大,同时,运动心肌组织,尤其心房组织中心钠素和降钙素基因相关肽的产生与分泌水平增高,对运动性心肌肥大的发生、心肌收缩性的增强及冠脉循环的改善起重要调节作用。停训后运动心肌细胞心钠素和降钙素基因相关肽的改变不仅表明运动心脏内分泌功能改变具有可复性,而且,进一步证实运动心脏与病理心脏有着本质的差别。     

运动训练对内膜下心肌组织的影响

为探讨运动心脏的形态学特征,本文对经过跑台耐力训练的大鼠心室内膜下心肌进行了组织学、酶组织化学及超微病理学研究。结果表明,较大强度的耐力训练可引起实验大鼠内膜下心肌组织、细胞结构的一系列缺氧性改变。提示内膜下心肌是运动心脏的易损部位。     

运动员心电图(医务监督第三讲)

<正> 心电图在运动心脏学和运动医学实践工作中已被广泛应用,不仅用于运动员心脏问题的诊断和运动员心脏的机能评定,也用于预防和治疗运动员心脏异常以及指导训练。心电图是将心肌发生的电激动记录下来,再结合临床其他资料给予解释。身体训练时由于心脏负荷增加,心脏结构,植物神经功能和激素水平发生的适应性变化都将影响心肌的电激动。     

缺锌对运动训练大鼠血清和睾丸睾酮及锌水平的影响

为探讨缺锌对运动能力影响的机制，本研究通过建立大鼠缺锌模型和跑台训练模型，观察缺锌对运动训练大鼠血清和睾丸睾酮及锌水平的影响。结果显示：缺锌引起训练和未训练大鼠体重、身长增长缓慢，身体瘦弱，跑台训练及运动中，主动性差，不愿奔跑，表现出缺锌对运动意识和能力的影响。锌缺乏大鼠血清和睾丸睾酮及锌含量显著下降（Ｐ＜０．０５）。运动训练引起锌缺乏大鼠睾丸重量减少（Ｐ＜０．０５）。７５％ＶＯ＿（２ｍａｘ）强度运动后即刻，锌充足大鼠血清锌水平显著上升，而锌缺乏大鼠血清锌显著下降（Ｐ＜０．０５）。结果表明，缺锌引起机体睾酮水平下降，可能籍此影响运动能力。缺锌状况下训练将加速睾丸的萎缩。运动后血清锌的变化与机体锌营养状况有关。     

心脏康复的运动训练对心力衰竭治疗的研究进展

心脏运动训练是心脏康复的核心，同时还包括康复评估、规律药物治疗、饮食指导及生活习惯，接受健康教育和定期监测生理指标等。研究表明，运动训练对心力衰竭（heart failure，HF）患者神经系统、循环系统、外周血管、呼吸系统和骨骼肌组织等［1-3］有影响。心力衰竭的病理生理机制涉及心肌和骨骼肌细胞的有氧代谢、能量转运、血管内皮功能紊乱、交感神经系统活动和促炎症细胞因子等方面。患者由于心脏结构或功能异常，损害心室充盈及射血功能，进而引起的一种复杂的临床综合征，其主要症状表现为呼吸困难、乏力、体液潴留等。HF在各年龄阶段病死率均高于同期其余心血管病，既往慢性心力衰竭（chronic heart failure，CHF）治疗要求卧床休息，限制患者体力活动以减轻心脏负荷，随着心脏康复的发展，心衰康复领域也有明显的进步，目前各临床指南均推荐运动治疗，强调心脏康复在HF治疗中的重要性和必要性。本文依据心脏康复在治疗心力衰竭的生理病理基础上，结合最新的国内外研究情况进行综述。     

冠状动脉造影、平板运动及心电图对冠心病诊断的对比研究

目的探讨冠心病患者冠状动脉病变与常规静息心电图ST-T改变、平板运动试验的关系。方法对226例行冠状动脉造影的非心肌梗死病人的常规静息心电图、平板运动试验结果进行比较。结果常规静息心电图有ST-T改变的124例患者中,51例(41.13%)冠状动脉造影显示冠状动脉正常;除去心脏结构改变患者,仅有39例(31.45%)心电图ST-T改变是由冠状动脉病变引起。冠状动脉造影证实存在冠状动脉病变的150例患者中,77例(51.33%)常规静息心电图正常,其中75例(97.40%)平板运动试验阳性。结论冠状动脉造影是冠心病的一种有效的筛选方法,临床依据常规静息心电图ST-T改变诊断冠心病应慎重。     

赛艇运动员最大负荷运动后血浆心钠素的变化及其与心血管功能的关系

通过观察赛艇运动员最大负荷运动后血浆心钠素与心血管功能的变化,探讨赛艇运动对心脏内分泌功能的影响。结果提示,最大负荷运动时,血浆心钠素水平有训练者显著高于无训练者,训练水平高者显著高于训练水平低者,且与良好心血管功能和运动应激能力相关。     

中老年“过去的运动员”超声心动图和运动心电图初步观察

用超声心动图和ECG运动实验观察中老年“过去的运动员”左心形态和功能,并通过2年随访,对其中ECG运动试验阳性者作出评价,认为ECG阳性并非由训练直接引起,而与一般冠心病好发因素有关。文章指出,对过去的运动员也应保持适量的健身运动并制定合理的生活制度。     

Cardiac response during various activities in patients with ischemic heart disease evaluated by an ambulatory ventricular monitor (VEST)

To assess the cardiac response to various exercise in ischemic heart disease (IHD), left ventricular function was continuously measured with an ambulatory ventricular monitor (VEST) in 3 normal subjects and 15 IHD patients. Treadmill exercise (early stage (E1), end stage (E2) and recovery standing state (RE], walking (WK) and climbing stairs (CS), was used for exercise. 15 IHD patients were divided into 4 groups by the LVEF response to treadmill exercise. In group 1 (G1), LVEF increased gradually at stage 1 and became plateau from stage 2 to end stage like normal group. In group 2 (G2), LVEF increased at stage 1 and became plateau from stage 2 but decreased from maximal EF more than 5% at end stage. In group 3 (G3), LVEF increased only at stage 1 and decreased immediately after stage 1 to end stage. The decrease of LVEF at end stage from standing was more than 5%. In group 4 (G4), LVEF decreased at stage 1 and became minimum at end stage. This grouping was well related to thallium redistribution (Tl RD) score and coronary arteriography (CAG) score. We could predict the severity of coronary artery disease from this grouping because all group 3 or 4 patients had severe coronary artery disease. VEST was useful for the evaluation for the tolerance to daily activities. Group 1, 2 and 3 tolerated daily activities while group 4 could not always. The degree of the increase in cardiac output during ischemia evaluated by VEST may be one of the useful index of the tolerance to exercise. In conclusion VEST was very useful for evaluating cardiac capacity of ischemic heart disease patients during various exercise.     

Aneurysm-like wall motion abnormality in hibernating myocardium detected by stress thallium scintigraphy]

A 70-year-old female patient presented and ECG with QS patterns and ST elevation in V1-3. Left ventriculography showed severely abnormal wall motion of the anteroseptal similar to a left ventricular aneurysm. Based on previous experience that 201Tl myocardial scintigraphy revealed possible myocardial viability in a patient with left ventricular aneurysm suspected of having apparently no myocardial viability, percutaneous transluminal coronary angioplasty (PTCA) was performed for severe stenosis of the left anterior descending artery. Follow-up images 3 months later showed a remarkable improvement in parietal motility of the left ventricle and recovery of almost normal cardiac function. This case demonstrates that exercise myocardial scintigraphy is useful for diagnosing hibernating myocardium associated with severely abnormal parietal motility, such as left ventricular aneurysm.     

Evaluation of the cardiac performance in patients with coronary artery disease by the pulmonary blood volume change in exercise test

Evaluation of the cardiac performance was studied by the change of the pulmonary blood volume (PBV) during the exercise testing in 17 normal subjects (group N), 18 patients with angina pectoris (group A) and 25 with both old myocardial infarction and angina pectoris (group M). The exercise testing was performed by bicycle ergometer in supine position. Blood pressure, heart rate, cardiac output measured by dye dilution method, left ventricular ejection fraction (EF) by multi-gate method, pulmonary artery pressure by Swan-Ganz catheter and PBV was measured during exercise. PBV was estimated by the radioactivity of the systemically administered Tc-99m labeled RBC in the lung field. ROI was adjusted over the right upper and lower lung field. And also the effect of the nitroglycerin was examined. In the result, (1) EF at the peak exercise increased in group N but decreased in group A and M, (2) Increased pulmonary artery diastolic pressure at the peak exercise (PAd at exercise) was remarkably higher in group A and M than group N. (3) PBV was unchanged in group N, however, increased 9.6% in group A and 10.9% in group M. (4) Increased rate of PBV revealed good correlation with delta EF (r = -0.68, p less than 0.01) and PAd at exercise (r = 0.83, p less than 0.01), and was considered as the pulmonary congestion due to left ventricular dysfunction. (5) After the sublingual administration of nitroglycerin, the increased PAd and PBV at the peak exercise was suppressed. Particularly, it was remarkable in group A. Then it was concluded that the noninvasive measurement of PBV during exercise could suggest the extent of the pulmonary congestion and was very useful for evaluation of the cardiac performance in coronary artery disease.     

Sudden cardiac death due to physical exercise in male competitive athletes. A report of six cases

In the period of 30 years, i.e. from 1973 to 2002, we noticed in Croatia 6 sudden and unexpected cardiac deaths in male athletes during or after training. Two were soccer players, 2 athletic runners, one was a rugby player and one was a basketball player. All of them were without cardiovascular symptoms. At the forensic autopsy, the first athlete, aged 29, had chronic myocarditis and thickened left ventricular wall of 15 mm. The second, aged 21, had an acute myocardial infarction of the posterior wall with normal coronaries and thickened left ventricular wall of 15 mm. The third aged 17, had hypoplastic right coronary artery and narrowed ascending aorta, suppurant tonsillitis and subacute myocarditis. Two athletes, aged 29 and 15, had hypertrophic cardiomyopathy and normal coronaries, and one dilated aorta. The sixth, aged 24, had arrhythmogenic cardiomyopathy of the right ventricle. All the 6 athletes died suddenly, obviously because of malignant ventricular arrhythmias. In Croatia the death rate among athletes reached 0.15/100 000, in others who practice exercise reached 0.74/100,000 and the difference is highly significant (c2=14.487, Poisson rates=3.81, P=0.00014) and in physicians-specialists reached 33.6/100,000. Preventive medical examinations are essential, especially in athletes before physical exercise, as are other investigations in every case suspicious of heart disease, including electrocardiogram (ECG), stress ECG, echocardiography and stress-echocardiography and other findings if indicated. Physical exercise is contraindicated in acute respiratory infection: in 2 of those cases had been a cause of death as a trigger.     

Stress induced right ventricular dysfunction: an indication of reversible right ventricular ischaemia

Stress induced changes in left ventricular ejection fraction are widely used in the detection and assessment of coronary artery disease. This study demonstrates that right ventricular dysfunction may also occur, and assesses its significance in terms of coronary artery anatomy. This study involved 14 normal subjects and 26 with coronary artery disease investigated by equilibrium radionuclide ventriculography, at rest and during maximal dynamic exercise. Mean normal resting right ventricular ejection fraction (RVEF) was 0.40 (SD 0.118), and all normal subjects increased RVEF with stress (mean delta RVEF + 0.13 SD 0.099). Mean delta RVEF in the subjects with coronary artery disease was significantly lower at 0.00 (SD 0.080), but there was overlap between the two groups. The largest falls in RVEF were seen if the right coronary artery was occluded without retrograde filling. In this subgroup with the most severely compromised right ventricular perfusion (nine subjects), RVEF always fell with stress, and mean delta RVEF was -0.08 (SD 0.050). There was no significant correlation between delta LVEF and delta RVEF, implying that the right ventricular dysfunction was due to right ventricular ischaemia, rather than secondary to left ventricular dysfunction. Stress induced right ventricular ischaemia can therefore be detected readily by radionuclide ventriculography.     

Eccentric exercise in coronary patients: central hemodynamic and metabolic responses

PURPOSE: With lengthening (eccentric) muscle contractions, the magnitude of locomotor-muscle mass and strength increase has been demonstrated to be greater compared with shortening (concentric) muscle contractions. In healthy subjects, energy demand and heart rate responses with eccentric exercise are small relative to the amount of muscle force produced. Thus, eccentric exercise may be an attractive alternative to resistance exercise for patients with limited cardiovascular exercise tolerance. METHODS: We tested the cardiovascular tolerance of eccentric exercise in 13 coronary patients (ages 40-66) with preserved and/or mild reduced left ventricular function. Patients were randomly assigned to either an eccentric (ECC; N = 7) or a concentric (CON; N = 6) training group and trained for 8 wk. Training workload was increased progressively (from week 1 to 5) to an intensity equivalent to 60% [OV0312]O(2peak). RESULTS: On average, maximum power output achieved with ECC was fourfold compared with CON (357 +/- 96 W vs 97 +/- 21 W; P < 0.005), whereas measures of oxygen uptake and blood lactate were significantly lower (P < 0.05 each), and ratings of perceived exertion were similar for ECC and CON. During a 20-min session of ECC and CON, central hemodynamics was measured by means of right heart catheterization. During ECC, responses of mean arterial blood pressure, systemic vascular resistance, pulmonary capillary pressure, cardiac index, and stroke work of the left ventricle on average were in the normal range of values and similar to those observed during CON. Compared with baseline, after 8 wk of training, echocardiographic left ventricular function was unchanged. CONCLUSION: The results indicate uncoupling of skeletal muscle load and cardiovascular stress during ECC. For low-risk patients with coronary heart disease without angina, inducible ischemia, or left ventricular dysfunction, ECC can be recommended as a safe new approach to perform high-load muscular exercise training with minimal cardiovascular stress.     

川崎病巨大冠状动脉瘤的外科治疗(附5例报告)

目的探讨终末期川崎病(黏膜皮肤淋巴结综合征)合并冠状动脉瘤的临床特点、外科干预指征及手术方法。方法回顾性分析2006年5月-2007年10月经手术治疗的5例川崎病合并冠状动脉瘤患者的临床资料。患者年龄2～57岁,冠状动脉瘤体直径1·5～2·5cm,其中右冠状动脉多发冠状动脉瘤1例,左冠状动脉主干及前降支冠状动脉瘤2例,左、右冠状动脉瘤2例。术前心电图显示ST改变5例。心脏超声EF值明显减低4例,心衰急诊入院1例。冠状动脉造影右冠状动脉完全闭塞、心室壁运动幅度减低1例。手术方法包括体外循环直视下冠状动脉内膜剥脱、血栓清除、瘤体成形4例,其中1例同期行冠状动脉切口远端支架置入。另1例直接行冠状动脉搭桥术。结果无手术死亡,心脏全部自动复跳。术后ICU病程平稳,4例心电图ST段缺血改善、心脏超声EF值明显提高,1例ST段及EF值改善不显著。结论临床Ⅲ期以上川崎病合并冠状动脉瘤有明显临床症状者应外科干预,采用内膜剥脱、血栓清除、瘤体成形及冠脉搭桥等综合方法,结合术后抗凝及免疫治疗,可有效改善心肌缺血及心脏功能。     

Myocardial diastolic function and exercise

There are several important links between aerobic exercise performance and the diastolic phase of the cardiac cycle. During acute exercise, diastolic function must be augmented in order for left ventricular filling to match increased left ventricular output, i.e., cardiac output. This challenges the myocardium because the shortened duration of diastole during exercise may compromise left ventricular filling, thereby limiting the stroke volume. Additionally, left ventricular filling must be accomplished at relatively low filling pressures, otherwise pulmonary vascular congestion may occur. Left ventricular diastolic function may be impaired in the elderly and/or in individuals with ischemic coronary syndromes. Regular aerobic exercise training appears to enhance left ventricular diastolic function and may benefit patients with clinically relevant "diastolic dysfunction." The purpose of this paper is to discuss the relative importance between diastole and exercise and to review some of the involved putative mechanisms.     

Influence of high-intensity exercise training on the ventilatory response to exercise in patients with reduced ventricular function.

BACKGROUND: Exercise training increases exercise capacity in patients with reduced ventricular function in part through improved skeletal muscle metabolism, but the effect training might have on abnormal ventilatory and gas exchange responses to exercise has not been clearly defined. METHODS: Twenty-five male patients with reduced ventricular function after a myocardial infarction were randomized to either a 2-month high-intensity residential exercise training program or to a control group. Before and after the study period, upright exercise testing was performed with measurements of ventilatory gas exchange, lactate, arterial blood gases, cardiac output, and pulmonary artery and wedge pressures. RESULTS: In the exercise group, peak VO2 and VO2 at the lactate threshold increased 29 and 39%, respectively, whereas no increases were observed among controls. Maximal cardiac output increased only in the exercise group (1.7 L x min(-1), P < 0.05), and no changes in rest or peak exercise pulmonary pressures were observed in either group. At baseline, modest inverse relationships were observed between pulmonary wedge pressure and peak VO2 both at rest (r = -0.56, P < 0.05) and peak exercise (r = -0.43, P < 0.05). Maximal VE/VCO2 was inversely related to maximal cardiac output (r = -0.72, P < 0.001). Training did not have a significant effect on these relationships. Training lowered VE/VO2, heart rate, and blood lactate levels at matched work rates throughout exercise and tended to lower maximal Vd/Vt. The slope of the relationship between VE and VCO2 was reduced after training in the exercise group (0.33 pre vs 0.27 post, P < 0.01), whereas control patients did not differ. CONCLUSIONS: Exercise training among patients with reduced left ventricular function results in a systematic improvement in the ventilatory response to exercise. Training increased maximal cardiac output, tended to lower Vd/Vt, and markedly improved the efficiency of ventilation. Peak VO2 and ventilatory responses to exercise were only modestly related to pulmonary vascular pressures, and training had no effect on the relationships between exercise capacity, ventilatory responses, and pulmonary pressures.