What is the defined abnormal ST/HR index value?

The defined abnormal ST/HR index value is an important marker used to assess cardiovascular responses during exercise. An index value of 1.6 indicates a threshold above which the likelihood of significant cardiovascular abnormalities increases. This value is derived from clinical observations and studies that segment normal exercise responses from potentially pathological conditions, particularly in populations with known cardiovascular issues.

Values below 1.6 typically represent a more favorable or normal response, suggesting that the heart is functioning adequately in relation to the workload and that there is not a significant risk of ischemia or other complications. In contrast, higher values, such as 2.2 or 2.4, can indicate more severe discrepancies in heart function or blood flow, signaling potential risks during exercise. Therefore, an index value of 1.6 serves as a critical cut-off point for clinicians and exercise professionals to monitor and interpret during stress tests.