1 Trimetazidine has a direct anti-ischaemic effect on the myocardium without altering the rate x pressure product or coronary blood flow. 2 The effects of trimetazidine (20 mg three times daily) were compared with those of propranolol (40 mg three times daily) in a double-blind parallel group multicentre study in 149 men with stable angina. 3 Reproducibility of exercise performance was verified during a 3 week run-in placebo washout period. All patients had > 1 mm ST-depression on exercise test. 4 After 3 months, similar anti-anginal efficacy was observed between the trimetazidine (n = 71) and propranolol (n = 78) groups. No significant differences were observed between trimetazidine and propranolol as regards anginal attack rate per week (mean difference P -TMZ: -2; 95% CI: -4.4, 0.5) and exercise duration (mean difference P -TMZ: 0 s; 95% CI: -33, 34) or time to 1 mm ST segment depression (mean difference P -TMZ: 13 s; 95% CI: -24, 51). Heart rate and rate x pressure product at rest and at peak exercise remained unchanged in the trimetazidine group but significantly decreased with propranolol (P < 0.001 in all cases). With both drugs there was a trend to decreased ischaemic episodes in the 46% patients who experienced ambulatory ischaemia on Holter monitoring. Six patients stopped trimetazidine and 12 propranolol. Of these, five in each group were withdrawn because of deterioration in cardiovascular status. 5 The results suggest that trimetazidine and propranolol at the doses studied have similar efficacy in patients with stable angina pectoris. The unchanged rate x pressure product suggests that the mechanism of action of trimetazidine is not primarily reduction in energy demand.

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Many exercise protocols are in use in clinical cardiology, but no single test is applicable to the wide range of patients' exercise capacity. A new protocol was devised that starts at a low workload and increases by 15% of the previous workload every minute. This is the first protocol to be based on exponential rather than linear increments in workload. The new protocol (standardised exponential exercise protocol, STEEP) is suitable for use on either a treadmill or a bicycle ergometer. This protocol was compared with standard protocols in 30 healthy male volunteers, each of whom performed four exercise tests: the STEEP treadmill and bicycle protocols, a modified Bruce treadmill protocol, and a 20 W/min bicycle protocol. During the two STEEP tests the subjects' oxygen consumption rose gradually and exponentially and there was close agreement between the bicycle and the treadmill protocols. A higher proportion of subjects completed the treadmill than the bicycle protocol. Submaximal heart rates were slightly higher during the bicycle test. The STEEP protocol took less time than the modified Bruce treadmill protocol, which tended to produce plateaux in oxygen consumption during the early stages. The 20 W/min bicycle protocol does not take account of subjects' body weight and consequently produced large intersubject variability in oxygen consumption. The STEEP protocol can be used on either a treadmill or a bicycle ergometer and it should be suitable for a wide range of patients.

We have studied a standardized exercise protocol suitable for use with a treadmill or bicycle (STEEP protocol) and compared it with a modified Bruce treadmill protocol in a group of patients with chronic cardiac failure. The STEEP protocol has been previously validated in normal subjects. Exercise time (6.79 +/- 2.42 vs 5.34 +/- 1.95 min, P < 0.05) and peak VO2 (16.66 +/- 4.09 vs 15.01 +/- 3.72 ml.min-1.kg-1, P < 0.05) were greater with the STEEP treadmill compared with the bicycle protocol, but VO2 was very similar at equal exercise stages in both modalities. Heart rate and respiratory exchange ratio tended to be greater during bicycle exercise at equal stages. Exercise time was greater with the modified Bruce protocol (9.00 +/- 3.02 min, P < 0.05) than with either STEEP protocol, but peak VO2 (17.13 +/- 4.52 ml.min-1.kg-1) was similar to that obtained with the STEEP treadmill test. We conclude that the STEEP protocol may be used to test patients with chronic cardiac failure, and that exercise times relate well in both treadmill and bicycle. The protocol should prove useful in studies involving a wide range of exercise capacities or both bicycle and treadmill exercise.

Serum total creatine kinase (CK) and the lactate dehydrogenase (LDH) isoenzymes were studied in 38 sedentary middle-aged men (aged 35-50 yrs) during a 30 week marathon training programme. Basal CK activity rose by 33% after 15 weeks but a significant rise (27%) in LDH activity took 30 weeks to occur. Post-exercise (maximum test on a bicycle ergometer) CK and LDH activities were higher than pre-exercise levels but the increment in enzyme activity following exercise did not change. LDH1 and LDH2 isoenzyme activity increased by 2.5% and 4% of total LDH respectively while LDH3 and LDH5 decreased by 3.9% and 2.4% respectively over 30 weeks. Post marathon total CK did not correlate with finishing time at 30 mins or 30 hrs post race. The range of CK MB isoenzyme activity at 30 mins post race was 1.8-9.8% of total CK with 11 subjects having a value above 6%. The training programme appears not to have affected muscle CK and LDH release during exercise but isoenzyme distribution changes reflect the adaptations known to occur in muscle during endurance training. Unfortunately only 16 subjects were available for all the investigations, and it is these upon whom most of the data were obtained.