Response to upright exercise after myocardial infarction

The left ventricular response to upright bicycle exercise was studied in 39 unselected, non-beta blocked patients (mean(SEM) age 54.2(1.7)yr) (mean(SEM) resting ejection fraction 41.9(2.3)%) 8-10 weeks after myocardial infarction. Nine healthy, age matched, sedentary adult men were studied for comparison (mean(SEM) age 49.8(0.9)yr). The stroke volume and cardiac output were measured by impedance cardiography at rest and after each 3 min workload until symptom limited maximum. The patients were separated into three groups based on stroke volume response to graded exercise. Group 1 (n = 14) had a normal stroke volume response to increasing heart rate. In group 2 (n = 13) stroke volume increased initially then decreased by greater than 15% at a heart rate greater than 100-105 beats.min-1. In group 3 (n = 12) stroke volume failed to increase during exercise. In group 1 cardiac output and mean arterial pressure increased whereas vascular resistance decreased during exercise in a normal fashion. Group 2 had an increased mean arterial pressure and systemic vascular resistance throughout exercise while heart rate increased in a similar fashion to group 1 until work of greater than 70 W was undertaken, at which time heart rate increased in a curvilinear fashion and cardiac output was attenuated. Group 3 had an attenuated cardiac output and a higher heart rate during exercise. In this group of patients systemic vascular resistance failed to decrease normally during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early exercise test after myocardial infarction

Exercise tests of coronary function at the tenth day of an uncomplicated myocardial infarction offer objective evaluation of short-term benefits of an early accelerated physical retraining program. They also allow better individual adaptation of exercises prescribed at the start of convalescence at home. Exercise test results show significant correlation with clinical data and bicycle ergometer tests carried out two months after infarction, with respect to physical aptitude, reasons for discontinuation of test and lethality risk two months after infarction. This suggests that exercise tests performed after the acute phase of myocardial infarction are of diagnostic and prognostic value.     

Central hemodynamics during long-term physical training of patients after myocardial infarction

Left-ventricular function under the effect of regular exercise was examined in post-infarction patients. Ultrasonic B-scanning technique was used to investigate 49 patients doing regular exercise and 34 control patients. The duration of an exercise course was 9-9.5 months. It was demonstrated that long-term physical training resulted in favourable changes in terms of left-ventricular propulsive capacity, whereas control patients showed deterioration of their pumping and contractile functions. The results are vet another evidence that the effect of exercise is necessarily mediated by the heart as the central link of circulation.     

康复运动有助于心肌梗塞患者的恢复

目的:探讨早期康复运动对急性心肌梗塞患者的疗效。方法:将2002年8月到2004年10月在我院循环内科住院并符合入选标准的80例急性心肌梗塞患者,按自愿原则,分成两组,治疗组早期进行常规药物治疗,并早期实行严格合理的运动疗法,对照组绝对卧床,只进行常规药物治疗,不进行康复训练。采用Barthel指数评定患者的日常生活能力,并对比两组的平均住院天数,住院期间的平均花费,心律失常的发生率及生活自理能力,两组患者两年后心肌梗塞的再发率。结果:治疗组平均住院天数、平均花费较对照组减少(P<0.05),日常生活能力较对照组有显著改善(P<0.05),心律失常的发生率两组之间无显著性差异,治疗组的生活自理能力优于对照组(P<0.05)。两年后,治疗组心肌梗塞的再发率均低于对照组(P<0.05)。结论:康复运动有助于心肌梗塞患者的恢复。     

Test for the determination of physical fitness 3 weeks after myocardial infarction]

In a consecutive group of 125 patients three weeks after myocardial infarction an ergometer bicycle test was performed in order to obtain an objective assesment of the physical fitness. The patients were exercised on 3 different workloads during a total time of six minutes. It was attempted to reach the training heart rate which was calculated from the resting heart rate plus 60% of the maximum increase, the maximal heart rate being "215-age in years". The Physical Work Capacity (PWC) was compared with the fitness of on age correlated control group. We could show that the PWC at hospital discharge, i.e. 3 weeks after myocardial infarction, was 79.6 +/- 23% of the normal value. Three weeks later it had improved by another 9%. A positive correlation with the CPJ of Norris and with the degree of physical activity prior to the acute illness could be demonstrated.     

Newly developed stenocardia: fibrinolysis and hemostasis at rest and during physical exercise after myocardial infarction

Postmyocardial infarction patients with angina of new onset showed increased blood levels of fibrinogens, soluble fibrin and fibrinogen-fibrin degradation products one month after the acute onset of MI, while their baseline fibrinolysis had been normal. A variety of fibrinolytic disorders were revealed in response to physical stress.     

Impact of exercise test on signal-averaged ECG in patients with myocardial infarction]

To examine the impact of exercise test (bicycle ergometry) and exercise-induced transient ischemic changes in ST segment on signal-averaged ECG parameters, the authors studied a homogeneous group including 65 patients (62 males and 3 females) with a 2-3-week history of primary myocardial infarction. The findings showed that induced myocardial ischemia caused no significant changes in signal-averaged ECG and late potentials, exercise might induce late potentials without clear-cut ECG signs of myocardial ischemia. It was also indicated that exercise-labile late potentials were significantly more frequently associated with the development of ventricular arrhythmias than steady late potentials.     

The role of aerobic exercise following myocardial infarction]

Aerobic exercise training has an important role within the cardiac rehabilitation program. An exercise test performed in the early period after myocardial infarction (MI) allows determining early the functional status and the risk factors of the patients and can accelerate their return to their occupational life. Patients can get back faster and safely to their active lifestyle following MI with exercises carried out at least 3 days per week, for 20 to 60 minutes and at intensities between 40% to 85% of VO2max. These exercises may concern the lower extremity like walking or running, upper extremity like arm cycle ergometer or combinations of these like rowing or swimming. Regular aerobic exercises increase the functional capacity and parasympathetic tone, and these together lead to an improvement in cardiovascular autonomic control. As a result, frequency of coronary artery disease and other cardiovascular diseases declines to an important extent. Studies conducted in humans and animals have shown contradictory outcomes about left ventricular remodelling. General opinion is that aerobic exercise has no favourable effect on ventricular remodelling.     

Tactical characteristics of physical rehabilitation of patients after myocardial infarct]

A study of the dynamics of the electrocardiographic, hemodynamic and cardiodynamic indices in patients who survived myocardial infarction showed that a specially compiled programme of physical rehabilitation for such patients corresponded in terms of the tempo of load increase to the normalization of these parameters. The leading tactical principle of this programme, that consists in an early activization of the patient in bed and a relatively unhastened transit to active movements in an upright position, may be recommended for a wide practical implementation as the most physiologically grounded.     

Acute myocardial infarction after anaphylactic reaction to amoxicillin]

A 62-year-old man was admitted to the hospital in a state of shock with electrocardiographic signs of inferior-wall acute myocardial infarction. He was initially diagnosed of cardiogenic shock. An urgent coronary angiography showed an irregular stenosis of 90% in the right coronary artery. Coronary angioplasty was performed, and a stent was placed in this lesion. In-depth questioning of the family revealed that the patient had taken an oral dose of amoxicillin 15 minutes before the onset of the symptoms. Further tests proved that he was allergic to amoxicillin, and was diagnosed of anaphylactic shock, complicated with acute myocardial infarction. There are several reports of myocardial infarction as a complication of anaphylactic reaction. We have found very few cases related to antibiotics, and none associated with amoxicillin. The most frequently quoted mechanism in these cases is coronary artery spasm due to the mediators of anaphylaxis. In the case reported herein, the irregular lesion suggests that disruption of an atherosclerotic plaque and platelet aggregation have occurred.     

Transient ischaemia after acute myocardial infarction: relationship to exercise ischaemia

To study the implications of transient myocardial ischaemia following acute myocardial infarction we compared ambulatory ST segment monitoring with exercise treadmill testing in 170 patients (mean age 58 years) at 4-8 weeks after admission. Ambulatory monitoring detected transient ischaemia (265 episodes; 249 (94%) silent) in 53/170 patients (31%) which was less frequent than ischaemia during exercise testing (90 patients; 53%) (P less than 0.0001). However, patients displaying transient ambulatory ischaemia (i) achieved less total exercise (248.7 +/- 17.2 vs 318.7 +/- 14.1 s; means +/- SEM) (P less than 0.006), (ii) developed exercise ST deviation earlier (172.4 +/- 14.3 vs 244.8 +/- 16.2 s) (P less than 0.0004) and (iii) had more widespread exercise ischaemia (3.8 +/- 0.3 vs 2.5 +/- 0.2 ECG leads) (P less than 0.005). Positive ambulatory ST segment monitoring was infrequently found (12/80 patients; 15%) in the presence of a negative exercise test but did identify the majority of patients (9/11 patients; 82%) with easily provoked exercise ischaemia and hence strongly positive exercise tests. These data suggest a limited role for routine 24 h ambulatory monitoring after myocardial infarction for the diagnosis of ongoing ischaemia but raise the possibility of an important place for this test in prognosis and risk stratification.