From: Myocardial functional responses do not contribute to maximal exercise performance in the heat
 | Temperate (n = 12) | Heat stress (n = 12) | ||||
---|---|---|---|---|---|---|
Rest | Maximal | Delta | Rest | Maximal | Delta | |
Stroke volume (mL beat−1) | 81 (14) | 116 (20) | 35 (16) | 72 (16) | 111 (24) | 39 (17) |
Stroke index (mL beat−1 m−2) | 40.3 (6.3) | 57.5 (6.2) | 17.2 (6.9) | 35.5 (6.3) | 54.9 (8.7) | 19.4 (8.1) |
Cardiac output (L min−1) | 5.5 (1.1) | 21.3 (3.5) | 15.8 (3.0) | 5.1 (1.3) | 20.4 (4.1) | 15.3 (3.3) |
Cardiac index (L min−1 m−2) | 2.7 (0.4) | 10.6 (1.1) | 7.8 (1.1) | 2.5 (0.5) | 10.1 (1.5) | 7.6 (1.4) |
Aortic velocity (cm s−1) | 102 (10) | 204 (23) | 103 (21) | 95 (10) | 205 (29) | 110 (23) |
Ejection time (s) | 0.247 (0.037) | 0.173 (0.023) | −0.074 (0.025) | 0.242 (0.034) | 0.167 (0.015) | −0.075 (0.029) |
Ejection rate (mL s−1) | 326 (21) | 673 (114) | 347 (107) | 296 (56) | 661 (117) | 365 (85) |
S (cm s−1) | 12 (2) | 26 (3) | 13 (3) | 14 (2) | 25 (3) | 12 (4) |
E (cm s−1) | 69 (15) | 167 (17) | 97 (16) | 71 (14) | 159 (11) | 88 (14) |
E′ (cm s−1) | 16 (3) | 32 (5) | 16 (7) | 15 (3) | 31 (4) | 17 (5) |
E/E′ | 4.4 (1.1) | 5.3 (0.9) | 0.9 (1.4) | 5.0 (1.5) | 5.2 (0.8) | 0.2 (1.8) |