Aim: The aim of this study was to determine the influence of gender on chronotropic and hemodynamic response during dobutamine stress echocardiography with early injection of atropine (EA-DSE).
Methods: From January 2000 to June 2003, we retrospectively evaluated patients who underwent EA-DSE for known or suspected coronary artery disease. We studied 494 patients, 243 men and 251 women, who were not under beta-blocker or calcium channel-blocker therapy (Group A) and 326 patients, 157 men and 169 women, using these medications (Group B). Differences on chronotropic and hemodynamic responses during EA-DSE were assessed by gender in the two groups. Predictors of need for higher doses of dobutamine were determined by multivariate analysis.
Results: In Group A, higher proportion of women achieved test end points at the stage of 20 mcg/kg per minute. Dobutamine and atropine doses were lower in women than in men (29 +/- 5 versus 31 +/- 6 mcg/kg per minute; P = 0.001 and 0.61 +/- 0.32 versus 0.78 +/- 0.43 mg; P = 0.006). Cardiac chronotropism and systolic blood pressure response patterns differed by gender. In Group B, there was no difference in the proportion of patients who achieved test end points at each stage of dobutamine. The independent predictors of the need for higher doses of dobutamine in Group A were gender [Odds Ratio (OR) = 1.99, 95% Confidence Interval (CI) = 1.19-3.32; P = 0.008], age (OR = 0.91,CI = 0.89-0.93; P < 0.001), and baseline heart rate (OR = 0.95,CI = 0.93-0.98; P < 0.001). Independent predictors in the total population were age (OR = 0.92,CI = 0.90-0.94; P < 0.001), baseline heart rate (OR = 0.95,CI = 0.93-0.97; P < 0.001), and beta-blocker therapy (OR = 0.42,CI = 0.18-1.51; P = 0.04).
Conclusion: Gender has influence on heart rate and blood pressure response to the EA-DSE in patients without use of drugs with negative chronotropic effects.