What systolic blood pressure response is an absolute indication to stop a maximal exercise test when accompanied by ischemia?

• A. A rise in systolic BP with workload.
• B. SBP remains elevated but stable with no ischemia.
• C. A drop in systolic blood pressure >10 mmHg despite increasing workload, when accompanied by other evidence of ischaemia, requires test cessation.
• D. A decrease in diastolic BP.

Answer: (C)

During a maximal exercise test, the systolic blood pressure should normally rise as workload increases because cardiac output needs to match the higher demand. An absolute stop criterion is reached when the systolic blood pressure falls by more than 10 mmHg from the value at the previous workload step, despite continuing to increase the workload, and there are accompanying signs of ischemia. This combination shows the heart can’t sustain the higher demand and myocardial ischemia or severe dysfunction is occurring, making it unsafe to continue.

Other patterns aren’t as concerning on their own: a rise in systolic pressure with increasing work is expected; systolic pressure that stays elevated and stable without ischemia isn’t by itself an indication to stop; a drop in diastolic pressure alone isn’t a standard stop criterion. The key is the SBP drop >10 mmHg with ongoing workload and clear evidence of ischemia.