Pilot Study Assessing the Hemodynamic Impact and Post-Exercise Hypotension Induced by High- Versus Low-Intensity Isometric Handgrip in Patients with Ischemic Heart Disease

Background: Isometric handgrip (IHG) exercise reduces blood pressure (BP) in both normotensive and hypertensive individuals. However, there are few studies specifically addressing its effects in hypertensive patients with ischemic heart disease (IHD). This research aimed to compare acute hemodynamic responses and post-exercise hypotension to single bouts of IHG handgrip performed at two different intensities in patients with IHD. Methods: Fifty-four sedentary patients were enrolled and randomly assigned to one of three groups: (1) high-intensity isometric handgrip performed at 70% of maximal voluntary contraction (MVC) (IHG-70%); (2) low-intensity isometric handgrip performed at 30% of MVC (IHG-30%); (3) control group (no exercise). Heart rate and BP were measured, and transthoracic echocardiography was performed at baseline, during exercise (lasting 3 min), and after 15 min post-exercise. BP was also measured at 30, 45, and 60 min of recovery. Results: No significant changes in systolic BP occurred during the exercise phase between the three study groups. Systolic BP decreased significantly in IHG-70% compared to the control at 30 (-7.7 +/- 1.9; p = 0.035) and 45 min (-8.1 +/- 2.3; p = 0.021) post-exercise, while there were no significant differences between IHG-70% and IHG-30% at different time-points. There were no significant changes in diastolic BP between the two active groups and between IHG-70 and IHG-30 versus control at different time-points (repeated-measures ANOVA p = 0.257). Global work efficiency was unchanged in IHG-70% (-4%) and IHG-30% (+1%) compared to control (ANOVA p = 0.154). Conclusions: High-intensity and low-intensity isometric handgrip exercises did not cause hemodynamic impairment in IHD. High-intensity exercise was more effective than low-intensity in reducing post-exercise systolic BP.