[Efficacy of oral nitroglycerin in the therapy of exertion angina]

A sample of 14 patients suffering from stable effort angina has been examined by means of exercise ECG test, in order to evaluate the efficacy, the onset of action and duration of effect of buccal nitroglycerin in the treatment of effort angina. The optimal dose of buccal NTG was predetermined for each patient through the analysis of heart rate changes (increase of at least 10 beats/min) and/or of blood pressure modifications (decrease of at least 10 mmHg). By applying a randomized double-blind design, the variations observed during exercise ECG tests after 20 minutes and 4 hours from the administration of buccal NTG (at the given dosage) or of placebo, have been evaluated. The following variables have been analyzed: heart rate, blood pressure, double product, time of onset of angina and/or of ST depression, amount of ST depression, duration of exercise test and maximum work-load. No significant changes have been observed for heart rate, blood pressure and double product both at the maximum effort and at the same level of effort as in the basal test. For each of the remaining variables a significant difference has been shown in favour of buccal NTG as compared to placebo, both after 20 min. and 4 hs. More in detail, the duration of the exercise test has been 6.14 +/- 2.77 mins on buccal NTG and 4.42 +/- 2.08 mins on placebo (+ 38%; p less than 0.05) after 20 mins and 6.40 +/- 3.19 on buccal NTG and 5.15 +/- 2.73 on placebo, after 4hs (+ 24%; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)