Blood pressure measurement during aerobic exercise: subsidies for cardiac rehabilitation.

Background: Institutional documents recommend that hemodynamic variables--heart rate (HR) and systolic (SAP) and diastolic arterial pressure (DAP)--be routinely controlled at the aerobic part of supervised exercise sessions for coronary disease patients.

Objective: a) to determine the pattern and reproducibility of the blood pressure (BP) throughout 15 minutes of physical exercise at constant and moderate intensity; and b) to compare the BP measurement obtained with digital and conventional device during the exercise.

Methods: Thirty adult individuals of both sexes (65+/-11 yrs) were assessed for 15 minutes during lower-limb cycle ergometry and the BP was measured every 2 minutes, between the 3rd and the 13th minutes, using a Tango digital sphygmomanometer (Suntech, USA) and in the 14th minute, using a mercury column sphygmomanometer. Seven days later, at similar time of the day, six individuals had the test repeated to evaluate reproducibility.

Results: Whereas the DAP did not vary throughout the exercise (p > 0.05), SAP increased from the 3rd to 7th minute (146+/-4.1 versus 158+/-4.5 mmHg, p<0.05) and thereafter remained practically constant. The digital and conventional measurements showed a strong correlation - r = 0.83 for SAP and 0.84 for DAP - with no differences for SAP (163+/-4.5 versus 162+/-4.3 mmHg; p >0.05) and a small difference for DAP (72+/-2.4 versus 78+/-2.3 mmHg; p<0.05).

Conclusion: For exercises of moderate and constant intensity in a cycle ergometer with a 15-minute duration, BP measurements must be carried out from the 7th minute on. The digital measurements with the Tango equipment and those obtained with the conventional mercury-column sphygmomanometer were, for clinical purposes, very similar and reproducible.