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

Abstract

Background: Isokinetic testing imposes severe cardiovascular stress which must be taken into consideration particularly when 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: After a 10-min warm-up on a cycle ergometer, one lower limb was tested isokinetically using 3 successive repetitions of knee flexion-extension at 60 and 180°/s and 20-repetitions at 240°/s. Heart rate was recorded on average over 5 sec and was analyzed at the start and end of each exercise. Peak ˙VO $_{2}$ 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 to 97.6 ± 14.0% of maximal HR noted at peak ˙VO $_{2}$ .

Conclusion: Isokinetic muscle strength testing in CHF patients must be performed under the supervision of an experienced clinician who should judge the value and feasibility of the endurance test.