Q-T and JT dispersion in the elderly with urban hypothermia

Twenty elderly patients (12 females and 8 males, aged 65-88 years) were tre ated because of hypothermia: 11 suffered from moderate (35-32 degreesC) and nine from severe hypothermia (< 32 degreesC). The control group consisted of 20 age and sex-matched healthy elderly persons. Twelve-channel electroca rdiograms were recorded on admission and during hospitalization. In patient s with moderate hypothermia Osborn wave was present in eight of 11, and min imal Osborn wave in three of 11; in severe hypothermia Osborn wave was seen in seven of nine, and minimal in two of nine. The corrected Q-T interval ( Q-Tc) was analyzed according to the formula of Bazett: measured Q-T(s)/root R-R(s). The JT and the corrected JT interval (JTc) were measured according to the formula: JT=Q-T-QRS. The Q-T interval index (Q-TI) was measured acco rding to the formula: (Q-TI:656)X(HR+100); and the JT interval index JTI:(J T:518)X(HR divided by 100). The dispersion of the Q-Tc (JTc) was defined as the difference between maximum and minimum measured Q-Tc interval (JTc). T he Q-Tc interval in the group with hypothermia was 651.41 +/- 130.06 ms, wh ile in the control group it was 398.14 +/- 76.21 ms (P < 0.001). The Q-Tc d ispersion in the group with hypothermia was 91.39 +/- 51.98, and in the con trol group 33.21 +/- 10.25 ms (P < 0.001). The Q-TcI in the group with hypo thermia was 89.91 +/- 21.44, and in the control group 39.56 +/- 9.41 ms ((P < 0.001). The JTc in the group with hypothermia was 542.66 +/- 132.74, in the control group: 328.06 +/- 76.92 (P < 0.001). The JTc dispersion in the group with hypothermia was 79.35 +/- 46.22, and in the control group 28.53 +/- 7.99 (P < 0.0001). The JTcI in the group with hypothermia was 93.06 +/- 17.38, in the control group it was 40.23 +/- 7.59 (P < 0.001). The mean va lues of the Q-TcI were greater than Q-TI, and the mean values of the JTcI w ere greater than JTI, but the difference was not significant (P > 0.10). Th e mean values of the JTcI were greater than Q-TcI, but the difference was n ot significant as well (P > 0.05). There was no correlation between rectal temperature and dispersion of Q-T, Q-Tc, JT, JTc, and Osborn wave. The maxi mum Osborn wave and the maximum Q-T interval were registered in anterosepta l leads (V-2-V-3). The dispersion of the Q-Tc and of the JTc lasted more th an Osborn wave. There was no correlation between rectal temperature and PR interval, RR interval and QRS duration. The prolonged dispersion of the Q-T c (and JTc) last 24-48 h longer than Osborn wave. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.