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PubMedDate not supplied

[The role of physical training in left ventricular performance and exercise tolerance in patients with chronic myocardial infarct].

UNLABELLED: The aims of the complex rehabilitation of the patients with chronic myocardial infarction are the improvement of the left ventricular performance and the increasing of the exercise capacity. OBJECTIVES: The objectives of the study is the long-term evaluation of some hemodynamic parameters at rest and during the stress test, at patients with chronic myocardial infarction during the physical training. METHODS: We investigated 132 patients with chronic myocardial infarction, mean age 51.4 +/- 8.5 years, during 36.9 +/- 31 months of follow-up. 81 followed a programme of physical training (the study group); 51 did not follow the training. There were determined the following parameters: cardiac rate (CR), blood systolic and diastolic pressures (BSP,BDP), time-pressure index (TPI), the metabolic equivalent (MET), the ejection fraction (EF), by echocardiographic and systolic time intervals methods, at rest and the exercise test, for each step. There have been followed the CR, BSP, BDP during the physical training. RESULTS: At the study group there is a significant reduction of CR at rest (p < 0.05) and during the training (p < 0.001). The exercise testing reveals the following: at the study group, TPI does not modify (GR increases but BSP decrease); at the second group there are significant increases of CR, BP and MET at all the steps of the testing (p < 0.001-0.0001). EF improves significantly (p < 0.05) only at patients with inferior myocardial infarction who followed the training. There is a good correlation between the results of EF measured by echographic and by systolic time intervals methods. CONCLUSIONS: Patients who underwent physical training improved the CR at rest and TPI and MET at each step. There is a slight rise of EP at the study group with inferior myocardial infarction.

Chronic Disease↗
PubMed1997

Effect of venous obstruction of lower extremities on exercise tolerance.

The effect of venous obstruction on effort tolerance is not well appreciated. We studied a patient with severe lower body venous obstruction (with near normal heart and lung function) who had marked exercise intolerance. Peak O2 uptake for leg exercise was reduced, but peak O2 uptake for upper extremities was normal. This difference indicates that severe venous obstruction can lead to exercise limitation.

Arm↗
PubMed1993

Hydralazine and isosorbide dinitrate combination improves exercise tolerance in heart failure. Results from V-HeFT I and V-HeFT II. The V-HeFT VA Cooperative Studies Group.

BACKGROUND: To better define the effects of long-term vasodilator therapy on exercise performance in chronic congestive heart failure, we compared placebo with prazosin and with the combination of hydralazine and isosorbide dinitrate (Hyd-Iso) in 642 men over a 5-year period in V-HeFT I. METHODS AND RESULTS: Patients were randomized (double-blind) to 20 mg of prazosin daily or 300 mg of hydralazine plus 160 mg daily of isosorbide dinitrate or placebo. We compared enalapril (20 mg daily), a converting enzyme inhibitor, with Hyd-Iso in 804 men over another 5-year period in V-HeFT II: Background therapy in both trials consisted of digitalis and diuretics. Serial bicycle ergometric exercise was performed with gas exchange measurements during progressive incremental work rates to a symptom-limited peak end point. Gas exchange anaerobic threshold (ATge) measurement was performed in the second trial. In V-HeFT I, an increase in peak VO2 with Hyd-Iso compared with placebo approached significance at 2 months (p < 0.16) and was significant (p < 0.04) at 1 year. In V-HeFT II, Hyd-Iso significantly increased peak VO2 compared with enalapril (p < 0.01 at 3 months, p < 0.02 at 6 months and 2 years). The changes in ATge measurements were not statistically different between the two treatment groups in V-HeFT II: CONCLUSIONS: Combination therapy with Hyd-Iso was more effective in increasing peak VO2 than placebo, prazosin, or enalapril in patients with mild-to-moderate congestive heart failure. Long-term data were confounded by mortality and other events, which may have led to an underestimate of the benefits of Hyd-Iso over placebo and an underestimate of the long-term benefits of enalapril on exercise performance. Therefore, short-term improvement in exercise performance is a suitable therapeutic end point, but long-term studies should more appropriately assess mortality.

Anaerobic Threshold↗
PubMed2000

[The effect of one-year treatment with captopril on exercise tolerance and myocardial ischemia in patients with myocardial infarction ].

The aim of the study was to assess the effect of 1-year captopril therapy initiated 1-4 days (mean: 21-24 h) after beginning of AMI on exercise performance and myocardial ischemia during cycle ergometer test. 93 pts with first documented Q-wave AMI, aged L 70 years were qualified for the study. 50 of the pts were randomly included to the captopril group, 43 to the control group. In both groups pts with inferior AMI (accordingly 66% and 72%) and normal LV function (EF > or = 40% in ECHO) were prevailed in the study. Captopril therapy was initiated with the dose of 3.125 mg, then every 8 hours the dose of 6.25 mg was administered in Ist and IInd day, 12.5 mg--in III day and 25 mg from IV day on. Exercise cycle ergometer tests (ExT) were performed in every pt at 14 day, and 1, 3, 6 and 12 months after AMI. The ExT began at 25 W of power and was increased at 2-minute intervals by 25 W until fatigue or other typical cause of termination of the test. In the captopril group duration of ExT lengthened significantly in comparison with initial test (on 14 day) after 3 (6.4 +/- 1.47 vs 5.3 +/- 1.54 min; p < 0.01), 6 (6.7 +/- 1.59 vs 5.3 +/- 1.54 min; p < 0.001) and 12 months (7.0 +/- 1.22 vs 5.3 +/- 1.54 min; p < 0.001). In the control group exercise time was longer after 6 and 12 months compared to initial examination (accordingly 6.4 +/- 1.43 and 6.5 +/- 1.26 vs 4.8 +/- 1.47 min; p < 0.001). However, the differences regarding this time between the captopril and control group were not significant on consecutive control stages. The final result of the test (positive, negative, doubtful) did not differ significantly in both groups on consecutive examination stages. Captopril administered during 1-year period after AMI slightly improved physical working capacity (accelerated the improvement) and had no effect on ischemia during estimated cycle ergometer test. These results may depend on inclusion to the study predominantly pts with normal LV function and interior MI.

Aged↗
PubMed1998

Improved exercise tolerance after losartan and enalapril in heart failure: correlation with changes in skeletal muscle myosin heavy chain composition.

BACKGROUND: In congestive heart failure, fatigue-resistant, oxidative, slow type I fibers are decreased in leg skeletal muscle, contributing to exercise capacity (EC) limitation. The mechanisms by which ACE inhibitors and AII antagonists improve EC is still unclear. We tested the hypothesis that improvement in EC is related to changes in skeletal muscle composition toward type I fibers. METHODS AND RESULTS: Eight patients with congestive heart failure, NYHA classes I through IV, were treated for 6 months with enalapril (E) 20 mg/d, and another 8 with losartan (L) 50 mg/d. EC was assessed with maximal cardiopulmonary exercise testing at baseline and after treatment. Myosin heavy chain (MHC) composition of the gastrocnemius was studied after electrophoretic separation of slow MHC1, fast oxidative MHC2a, and fast glycolytic MHC2b isoforms from needle microbiopsies obtained at baseline and after 6 months. EC improved in both groups. Peak V(O2) increased from 21.0+/-4.7 to 27.6+/-4.3 mL . kg-1 . min -1 (P=0.011) in the L group and from 17.5+/-5.0 to 25.0+/-5.5 mL . kg-1 . min -1 (P=0.014) in the E group. Similarly, ventilatory threshold changed from 15.0+/-4.0 to 19.9+/-4.9 mL (P=0. 049) with L and from 12.0+/-1.9 to 15.4+/-3.5 mL (P=0.039) with E. MCH1 increased from 61.2+/-11.2% to 75.4+/-7.6% with L (P=0.012) and from 60.6+/-13.1% to 80.1+/-10.9% (P=0.006) with E. Similarly, MHC2a decreased from 21.20+/-9.5% to 12.9+/-4.4% (P=0.05) with L and from 19.9+/-7.8% to 11.8+/-7.9% (P=0.06) with E. MHC2b changed from 17. 5+/-6.5% to 11.7+/-5.2% (P=0.07) with L and from 19.5+/-6.4% to 8. 1+/-4.6% (P=0.0015) with E. There was a significant correlation between net changes in MHC1 and absolute changes in peak V(O2) (r2=0.29, P=0.029) and a trend to significance for MHC2a and 2b. CONCLUSIONS: Six months' treatment with L and with E produces an improvement in EC of similar magnitude. These changes are accompanied by a reshift of MHCs of leg skeletal muscle toward the slow, more fatigue-resistant isoforms. Magnitude of MHC1 changes correlates with the net peak V(O2) gain, which suggests that improved EC may be caused by favorable biochemical changes occurring in the skeletal muscle.

Angiotensin II↗
PubMed1987

Exercise tolerance in patients with and without ventricular aneurysm.

To assess the role of a left ventricular aneurysm (VA) in affecting cardiac pump function, 36 patients with an echo-proved postmyocardial infarction (MI) VA underwent maximal symptom limited exercise testing. A control group was formed of 36 patients with a previous MI without VA. The two groups were matched for age, sex, and site of MI. No difference was found in maximal work capacity (MWC), heart rate (HR), systolic blood pressure (BP), delta HR/k rho m, delta BP and VO2max/kg during exercise. MWC in patients with VA and anterior MI was lower as compared to patients with VA and inferior MI (2,839.3 +/- 1,340.9 vs. 4,537.5 +/- 1,453.7, p less than 0.05) while no difference was found between anterior and inferior MI without VA. Patients with VA and anterior MI tolerated lower workloads as compared to those with anterior MI without VA (2,839.3 +/- 1,340.9 vs. 3,996.4 +/- 2,347.1, p less than 0.05). No difference was found between patients with inferior MI with or without VA. No major adverse cardiovascular events occurred during or after the tests. Patients were grouped for echo-estimated ejection fraction (EF) less than 30%, 30-50% and greater than 50%. Only 1 patient without VA was found among patients with EF less than 30%. In both groups MWC increased with the increase of EF. Patients with VA, anterior MI and EF less than 30% showed the lowest exercise tolerance (2,216.6 +/- 529.1), and no patient with VA and inferior MI exhibited EF less than 30%. In conclusion, in patients with VA, exercise testing is a safe and useful tool to evaluate the functional capacity of the residual 'non-aneurysmatic' myocardium.

Exercise Test↗
PubMed1999

The effect of specific inspiratory muscle training on the sensation of dyspnea and exercise tolerance in patients with congestive heart failure.

BACKGROUND: It has been previously shown that the inspiratory muscles of patients with congestive heart failure (CHF) are weaker than those of normal persons. This weakness may contribute to the dyspnea and limit exercise capacity in these patients. The respiratory muscles can be trained for both strength and endurance. HYPOTHESIS: The present study was designed to evaluate the effect of specific inspiratory muscle training (SIMT) on inspiratory muscle performance, lung function, dyspnea, and exercise capacity in patients with moderate heart failure. METHODS: Twenty patients with CHF (NYHA functional class II-III) were recruited for the study. The subjects were randomized into two groups: 10 patients were included in the study group and received SIMT and 10 patients were assigned to the control group and received sham training. Subjects in both groups trained daily, 6 times/week, for one-half h, for 3 months. The subjects started breathing at a resistance equal to 15% of their PImax for 1 week and the resistance was then increased incrementally to 60%. Spirometry, inspiratory muscle strength (assessed by measuring the PImax at residual volume), and endurance (expressed by the relationship between PmPeak and PImax), the 12-min walk test, and peak VO2 were performed before the beginning and at the end of the training period. RESULTS: All patients in the training group showed an increase in the inspiratory muscle strength [mean (+/- standard error of the mean) PImax increased from 46.5 +/- 4.7 to 63.6 +/- 4.0 cm H2O, p < 0.005], and endurance (mean PmPeak/PImax from 47.8 +/- 3.6 to 67.7 +/- 1.7%, p < 0.05), while they remained unchanged in the control group. This was associated in the training group with a small but significant increase in forced vital capacity, a significant increase in the distance walked (458 +/- 29 to 562 +/- 32 m, p < 0.01), and an improvement in the dyspnea index score. No statistically significant change in the mean peak VO2 was noted in either group. CONCLUSIONS: Specific inspiratory muscle training resulted in increased inspiratory muscle strength and endurance. This increase was associated with decreased dyspnea, increase in submaximal exercise capacity, and no change in maximal exercise capacity. This training may probe to be a complementary therapy in patients with congestive heart failure.

Aged↗
PubMed2004

Effects of tiotropium on lung hyperinflation, dyspnoea and exercise tolerance in COPD.

The aim of this study was to test the hypothesis that use of tiotropium, a new long-acting anticholinergic bronchodilator, would be associated with sustained reduction in lung hyperinflation and, thereby, would improve exertional dyspnoea and exercise performance in patients with chronic obstructive pulmonary disease. A randomised, double-blind, placebo-controlled, parallel-group study was conducted in 187 patients (forced expiratory volume in one second 44 +/- 13% pred): 96 patients received 18 microg tiotropium and 91 patients received placebo once daily for 42 days. Spirometry, plethysmographic lung volumes, cycle exercise endurance and exertional dyspnoea intensity at 75% of each patient's maximal work capacity were compared. On day 42, the use of tiotropium was associated with the following effects at pre-dose and post-dose measurements as compared to placebo: vital capacity and inspiratory capacity (IC) increased, with inverse decreases in residual volume and functional residual capacity. Tiotropium increased post-dose exercise endurance time by 105 +/- 40 s (21%) as compared to placebo on day 42. At a standardised time near end-exercise (isotime), IC, tidal volume and minute ventilation all increased, whilst dyspnoea decreased by 0.9 +/- 0.3 Borg scale units. In conclusion, the use of tiotropium was associated with sustained reductions of lung hyperinflation at rest and during exercise. Resultant increases in inspiratory capacity permitted greater expansion of tidal volume and contributed to improvements in both exertional dyspnoea and exercise endurance.

Aged↗
PubMed2001

Is exercise tolerance limited by the heart or the lungs?

This 55-year-old man with known rheumatic mitral valve disease is modestly disabled achieving a VO2max of 72% and a maximal power output of 76% of the predicted normal. His capacity to exercise is limited by dyspnea due to a reduction in his capacity to breathe. Ipratropium bromide was initiated to maximize his expiratory flow and improve his ventilatory capacity. A trial of inhaled steroids produced no improvement. He was referred for rehabilitation and smoking cessation. A decision was made to continue surveillance, postponing mitral valve replacement.

Blood↗