Exercise Body Surface Potential Mapping in Single and Multiple Coronary Artery Disease: Results (Part 2)
The group mean ST isointegral maps of the four CAD groups and the control subjects are illustrated in Figure 4. As can be seen, the spatial changes in ST patterns from rest to peak exercise were similar in all four patient groups, namely the development of absolute negative ST integral values over the left lateral chest, with minima located over the precordium (Fig 4). This common reduction in ST integrals, the BSPM equivalent of ST depression was confirmed by the temporal subtraction (cessation minus rest) maps (Fig 4). Note, as well, that the subtraction map of the normal group also revealed a relative decrease of ST integral values over the same torso area as the patient groups (cessation minus rest; Fig 5).
Quantitatively, the degree of exercise ST integral change was much greater in CAD groups 2 and 3, than in any of the other study groups (Tables 2 and 3). The sum of ST integral decrease from rest to immediate cessation of exercise averaged —5,700 ± 2,353mV*s in group 2 and —7,282 ±2,746 mV*s in group 3 (NS); these values were significantly (p<0.05) more negative than CAD group 1 (- 3,447 ± 2,011 mV-s), CAD group 4 (-3,152 ± 1,337 mV*s) (Table 2) and the normal group 5 subjects (-2,323 ± 1,809mV*s) (Table 3). There were no differences in the body surface sum of exercise ST integral decrease among CAD patient groups 1 and 4 (Table 2) and the normal control subjects (group 5; Table 3). buy prednisone
The group mean 5-min recovery maps and the recovery minus rest subtraction maps confirmed that, on average, substantial ST integral ischemic changes persisted, although significantly lessened, at 5-min postexercise in all four CAD groups (Fig 4; Table 2). The equivalent maps of the normal subjects indicated, in contrast, a return to near rest status by 5 min postexercise (Fig 4).