Cardiovascular responses during isokinetic knee extension testing in chronic heart failure patients

Abstract

Abstract . Background: Isokinetictestingimposesseverecardiovascular stresswhichmustbetakenintoconsideration particularlywhen at risk patients are involved. Objective: To assess the effects of isokinetic tests on heart rate (HR) in stable chronic heart failure (CHF) patients. Subjects: Twenty five CHF patients, 23 men, 2 women. Intervention: Aftera10-minwarm-uponacycleergometer, onelowerlimbwastestedisokineticallyusing3successiverepetitionsof knee flexion-extension at 60 and 180 ◦ /s and 20-repetitions at 240 /s. Heart rate was recorded on average over 5 sec and wasanalyzed at the start and end of each exercise. Peak V ˙ O 2 was assessed during maximal incremental test on the ergometer. Results: Maximal values (117.6 ± 22.0 bpm) of HR were obtained during incremental exercise testing which corresponded to97.6 ± 14.0 % of maximal HR noted at peak V ˙ O 2 . Conclusion: Isokinetic muscle strength testing in CHF patients must be performed under the supervision of an experiencedclinician who should judge the value and feasibility of the endurance test.Keywords: Peak torque, heart rate, heart disease