TABLE 2.

Peak systolic and diastolic LV rotation and strain parameters at rest and during prolonged exercise in the heat

	Exercise time (min)
	Rest	30	60	90	118 ± 1
Systolic component
Basal rotation, degrees
Progressive dehydration	−4.2 ± 1.2	−9.9 ± 2.6	−10.1 ± 2.7	−12.7 ± 2.7	−11.8 ± 2.4
Euhydration control	−3.5 ± 1.0	−11.0 ± 2.4	−10.9 ± 2.1	−10.7 ± 2.5	−9.8 ± 2.5
Apical rotation, degrees
Progressive dehydration	10.2 ± 1.3	17.3 ± 2.9	19.7 ± 2.7	18.6 ± 2.6	19.1 ± 2.9
Euhydration control	10.1 ± 1.5	17.8 ± 2.4	16.0 ± 1.6	16.1 ± 2.1	16.3 ± 2.5
Longitudinal strain, %
Progressive dehydration	−18.9 ± 0.6 †	−22.8 ± 0.8	−21.6 ± 0.8	−22.0 ± 0.8	−21.9 ± 0.6
Euhydration control	−18.1 ± 0.7	−22.2 ± 0.6	−23.5 ± 1.0	−22.3 ± 0.6	−22.9 ± 1.0
Basal radial strain, %
Progressive dehydration	54.7 ± 5.4	39.2 ± 7.2	39.6 ± 8.2	38.0 ± 5.7	38.4 ± 7.0
Euhydration control	50.7 ± 6.0	38.5 ± 8.5	40.4 ± 5.2	39.5 ± 5.5	40.0 ± 6.6
Apical radial strain, %
Progressive dehydration	22.9 ± 5.3	34.6 ± 4.9	36.4 ± 6.0	42.5 ± 6.6	39.8 ± 6.3
Euhydration control	24.4 ± 5.6	41.5 ± 8.7	38.8 ± 4.6	34.0 ± 4.5	43.9 ± 6.5
Basal circumferential strain, %
Progressive dehydration	−18.9 ± 1.4	−18.8 ± 2.1	−18.7 ± 2.0	−18.5 ± 1.6	−18.1 ± 1.7
Euhydration control	−18.0 ± 1.7	−19.4 ± 2.0	−19.2 ± 1.8	−19.5 ± 1.5	−20.3 ± 1.6
Apical circumferential strain, %
Progressive dehydration	−26.2 ± 1.2	−36.3 ± 1.7	−35.4 ± 2.3	−37.1 ± 2.5	−35.3 ± 1.4
Euhydration control	−25.8 ± 1.7	−37.0 ± 2.8	−36.3 ± 2.7	−34.7 ± 2.4	−34.9 ± 1.8
Diastolic component
Basal rotation rate, degrees s−1
Progressive dehydration	61 ± 4 †	123 ± 13	130 ± 20	167 ± 24 †	161 ± 25
Euhydration control	51 ± 4	139 ± 17	137 ± 15	139 ± 18	137 ± 16
Apical rotation rate, degrees s−1
Progressive dehydration	−80 ± 7	−199 ± 21	−220 ± 28	−218 ± 30	−229 ± 31
Euhydration control	−84 ± 11	−227 ± 35	−193 ± 26	−200 ± 32	−183 ± 30

Values are means ± SEM; n = 8 subjects.

^† p < .05 versus euhydration control.