Assessment of hemodynamic responses during some form of exertion or stress during cardiac catheterization is useful among patients suspected of having valvular stenosis who demonstrate normal or borderline valve gradients at rest. Leg raising exercise and drug administration are commonly used for this purpose, but each has inherent limitations. To evaluate the usefulness of dynamic arm raising exercise as a means of altering hemodynamics during cardiac catheterization, 23 such patients were studied. Measurements obtained during arm raising exercise were compared with those at rest. Heart rate rose by 34 +/- 4 beats/min (p less than 0.001), while cardiac output increased by 1.4 +/- 0.2 l/min (p less than 0.001). Stroke volume decreased slightly, although left ventricular filling pressures and pulmonary capillary wedge pressures rose in nearly all subjects. The change in valvular gradients was variable. These data were compared with those obtained in 11 similar patients receiving either dopamine or isoproterenol as an intervention. The changes in heart rate and cardiac output from the resting state were similar between the groups, with fewer side effects occurring during arm exercise. Dynamic arm exercise is a safe and effective maneuver which can be performed during cardiac catheterization in patients undergoing diagnostic evaluation of stenotic valvular disease.