Resting and Postexercise Apexcardiogram Correlated with Maximal Treadmill Stress Test in Normal Subjects

Ninety-eight normal subjects, mean age 51 years, who had a maximal treadmill stress test had a satisfactory apexcardiogram at rest and after a double Master's test. The mean resting a-wave ratio was 11.6% in 13 normal subjects with an abnormal maximal treadmill test and 7.8% in 85 normal subjects with a normal treadmill test (P < 0.001). The mean postexercise a-wave ratio was 19.7% in 13 normal subjects with an abnormal treadmill test and 12.8% in 85 normal subjects with a normal treadmill test (P < 0.001). Four of 13 normal subjects (31%) with an abnormal treadmill test had a resting a-wave ratio of ≥15% compared with two of 85 normal subjects (2%) who had a normal treadmill test (P < 0.001). Seven of 13 normal subjects (54%) with an abnormal treadmill test had a postexercise a-wave ratio of ≥20% compared with eight of 85 normal subjects (9%) who had a normal treadmill test (P < 0.001).