Accuracy of the oscillometric method for the measurement of heart rate at rest and during mild exercise.

OBJECTIVE

Whether oscillometric devices provide accurate measurements of heart rate (HR) is not known. Our aim was to determine the accuracy of an oscillometric device for the measurement of HR during rest and exercise.

METHODS

The Microlife WatchBP O3, a monitor previously validated for blood pressure measurement, was tested in 36 individuals from the general population (mean age, 72.9 years; 18 men). HR was measured at rest and during stress testing on a cycle ergometer in order to increase HR by 15% or more. HR was computed from the oscillometric waves recorded during the deflation phase of the blood pressure measurement and was compared with HR measured by pulse palpation by two observers.

RESULTS

At rest, the mean device-observer HR difference was 0.9 ± 2.1 bpm. During exercise, the average HR increase was 20.3% and the mean device-observer difference was 0.6 ± 2.6 bpm. The device-observer HR differences were all included within ±6 bpm both at rest and during exercise. Kappa statistics showed a very good agreement between device and observers both at rest (kappa scores, 0.82-0.88) and during exercise (kappa scores, 0.81 and 0.86). The device-observer HR differences were unrelated to the level of HR or to pulse pressure.

CONCLUSION

The present study shows that the oscillometric technique is able to provide reliable HR measurements during rest and mild exercise. Whether evaluation of HR performance should be included during validation testing of automatic monitors should be established by regulatory bodies.