Abnormal recovery systolic blood pressure response for detecting coronary artery disease in men and women investigated by upright bicycle exercise.

We investigated the clinical significance of recovery systolic blood pressure (SBP) ratio, obtained dividing the recovery SBP at 1st (R1/A) or 3rd min (R3/A) by the peak exercise SBP (before stopping), during upright bicycle exercise in 530 subjects (ranging from 17 to 73 years). Our results may be summarized as follows: 1) we found a higher value of R1/A in control subjects with exercise induced ST depression; 2) the normal range in women was higher than in men; 3) the use of recovery SBP ratios gives a lower sensitivity and a higher specificity than ST segment analysis in detection of CAD; 4) this pattern may be useful particularly in patients with previous myocardial infarction and not detectable ST segment analysis during exercise.

Recovery systolic blood pressure response after treadmill exercise procedures. Evidence against its usefulness in detecting coronary artery disease.

We compared the response of the systolic blood pressure (SBP) recovery ratio (obtained by dividing the SBP recovery values by the peak exercise values) during a treadmill exercise test in patients with chest pain and an angiographically normal coronary tree (n = 18) (C group), one or more greater than or equal to 70% stenosed major coronary vessel and normal resting ejection fraction (n = 26) (CAD group) or depressed left ventricular function (ejection fraction less than 40%) (n = 15) (CAD DYS group). The mean values of SBP recovery ratios were, in the three groups: 0.93 +/- 0.07, 0.97 +/- 0.07, 0.95 +/- 0.09, respectively, at the 1st min and 0.83 +/- 0.08, 0.88 +/- 0.09, 0.86 +/- 0.08, at the 3rd min. There are no significant differences in the CAD or CAD DYS group versus the C group, because of large overlapping of points in the plot. The post-exercise SBP response during treadmill procedures cannot provide the opportunity for differentiation of CAD patients with or without left ventricular dysfunction at rest from subjects with chest pain and normal coronary tree, while upright bicycle exercise, as we previously observed, can.

Exercise time: a possible source of misleading results during long-term pharmacological studies by multiple stress testings in coronary artery disease.

The assessment of chronic pharmacological treatment of stable angina requires serial exercise stress testings. It is well known that exercise tolerance can be improved by the training effect of performing repeated testings. Our study investigated the values of heart rate, systolic blood pressure, rate-pressure product, and duration of exercise at 0.1 mV ST depression during exercise and the same parameters plus the maximal ST-segment depression at peak exercise, collected from three different tests. The first and second were performed at one-week intervals before, and the third (75 days after the first), was performed after a double-blind study with a drug versus placebo. We found a significant increase of exercise duration at 0.1 mV ST depression and at peak exercise, while 6 of 12 patients increased exercise duration from the second to the third test. Individual variability of exercise duration showed increasing values, ranging from 0 to 71% (first vs. third test). In contrast, the ratio of heart rate and systolic blood pressure did not differ between the tests. Our data criticized the use of mean values of exercise time for pharmacological studies; moreover, individual variability could affect results independently of drug or placebo administration. These findings should be taken into account in order to exclude misleading results.

Heart rate, PR, and QT intervals in normal children: a 24-hour Holter monitoring study.

A dynamic electrocardiographic Holter monitoring study was performed in 32 healthy children (20 males and 12 females, age range 6-11 years old), without heart disease, according to clinical and noninvasive instrumental examination. We evaluated atrioventricular conduction time (PR), heart rate (HR), and QT interval patterns defining the range of normality of these electrocardiographic parameters. The PR interval ranged from 154 +/- 10 ms (mean +/- SD) for HR less than or equal to 60 to 102 +/- 12 ms for HR greater than or equal to 120 (range 85-180). The absolute mean HR was 87 +/- 10 beats/min (range 72-104), the minimum observed HR being 61 +/- 10 (range 51-79), the maximum 160 +/- 20 beats/min (range 129-186). Daytime mean HR gave a mean value of 93 +/- 10 (range 71-148), while during night hours it was 74 +/- 11 (range 54-98). The minimum QT interval averaged 261 +/- 10 ms for HR greater than 120 and the maximum 389 +/- 9 ms for HR less than or equal to 60; the corresponding mean value of QTc (i.e., QT corrected for HR) ranged from 388 +/- 8 for HR less than or equal to 60 beats/min to 403 +/- 14 ms for HR greater than 120 beats/min. The results of the present study provide data of normal children which can be readily compared against those of subjects in whom cardiac abnormalities are suspect or patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Atenolol and/or nifedipine in effort angina: which is the treatment of choice for exercise coronary protection?

The authors performed a long-term, double-blind, crossover, randomized study on the effects of two drugs (atenolol, 100 mg/day, or nifedipine, 10 mg t.i.d.) when administered alone or in combination on the exercise tolerance in 10 patients with stable angina on effort (mean age 52 +/- 4 years, 8 males and 2 females) and documented significant (greater than or equal to 70%) obstructive coronary lesions at angiography. None of the drug treatments improved exercise duration or maximal sustained work load. Atenolol decreased significantly ST segment depression to -1 +/- 0.8 from -1.91 +/- 0.7, baseline and -2.05 +/- 0.5, placebo. Nifedipine was not better than placebo. The atenolol plus nifedipine treatment was better than placebo (p less than 0.001) or nifedipine alone (p less than 0.05) but was not more significantly efficacious than atenolol alone. Long-term management of exertional angina can be usefully performed using atenolol. The use of nifedipine at the present dose of 10 mg, although well tolerated, did not improve the ST signs of ischemia.