Exercise testing: improving performance with a ramped Bruce protocol

The standard Bruce protocol was compared with a ramped Bruce protocol in stress testing of a general population of patients.

We examined hemodynamic responses, test duration, and patient comfort with each exercise protocol. Twenty-three patients completed the study, 14 men and 9 women with a mean age of 51 +/- 12 years. Each patient completed the 2 treadmill protocols in a random manner.

Mean peak heart rate, systolic blood pressure, and rating of perceived exertion according to the revised Borg scale were equivalent in both protocols, measuring 157 +/- 15 beats/min, 170 +/- 22 mm Hg, and 8 +/- 1 for the Bruce and 158 +/- 17 beats/min, 175 +/- 20 mm Hg, and 8 +/- 1 for the ramp protocol (P = NS). Duration of test and metabolic equivalents (METs) were greater with the ramp than with the Bruce protocol. For the Bruce duration and METs were 8:25 +/- 3:00 min and 9.6 +/- 3.1, and for the ramp 10:01 +/- 2:32 min and 11.4 +/- 2.7 (P <.0001 for both). Subjective rating of difficulty was assessed on a scale of 1 to 5, 1 being the most difficult and 5 being the easiest. Rating for the Bruce protocol was 2.5 +/- 0.9 and for the ramp 4.1 +/- 0.9 (P <.0001).

We propose that a ramped modification of the Bruce protocol achieves equivalent hemodynamic goals but with better duration. Patients preferred the ramp with respect to comfort, and exercise data can be correlated easily with standard protocols.