Table 2

ECG and long axis values at rest and peak stress

Controls (n = 17)Patients (n = 27)
Variables Rest Change with stress Rest Change with stress
Heart rate (beats/min)80 (12)+45 (12)*** 81 (10)+42 (15)***
Blood pressure
 Systolic147 (15)+11 (10)** 152 (28)−1 (20)
 Diastolic76 (10)−7 (12)87 (15)†† −10 (15)***
Rate-pressure product115 (16)+86 (24)*** 124 (27)+65 (32)***
ECG intervals
PR interval (ms)160 (22)−36 (18)*** 175 (24)2-151 −50 (28)***
QRS duration (ms)93 (6)−9 (4)*** 95 (12)+16 (18)2-150
QT interval (ms)368 (32)−72 (26)*** 369 (30)−50 (33)***
QTc (ms)432 (13)−25 (16)*** 420 (17)+50 (35)***
QT dispersion82 (28)−12 (48)98 (46)−15 (57)
Long axis
Total excursion (cm)
 Left 1.36 (0.1)+0.27 (0.13)*** 1.2 (0.3)2-151 +0.08 (0.3)
 Septal1.3 (0.15)+0.22 (0.1)*** 1.0 (0.3)†† 2-151 +0.04 (0.24)
Peak lengthening rate (cm/s)
 Left8.7 (1.6)+2.7 (0.9)*** 4.0 (0.4)†† 2-151 −0.01 (1.2)
 Septal7.3 (1.3)+2.2 (1.6)*** 3.5 (2.2)†† 2-151 −0.8 (1.5)2-150
  • Values are means (SD).

  • 2-150 p < 0.01; **p < 0.005; ***p < 0.001, stress vrest (paired t test).

  • 2-151 p < 0.05; ††p < 0.01; †† 2-151p < 0.001, v rest in controls (unpaired t test).