Volume 84, Issue 2, Pages 191-194 (August 1983) Heart Rate Pattern during Sleep in an Infant with Congenital Prolongation of the Q-T Interval (Romano-Ward Syndrome)  Hedi L. Leistner, M.D., Gabriel G. Haddad, M.D., Tze L. Lai, Ph.D., Robert B. Mellins, M.D., F.C.C.P.  CHEST  Volume 84, Issue 2, Pages 191-194 (August 1983) DOI: 10.1016/S0012-3692(15)33494-2 Copyright © 1983 The American College of Chest Physicians Terms and Conditions

FIGURE 1 Family members with documented prolongation of the Q-T index (solid black symbols). Individuals who died suddenly and unexpectedly are also indicated (by slash through symbol), with age at death in parentheses Uncles of this infant have Q-T index at upper limit of normal (half black squares). Other family members have not been examined. CHEST 1983 84, 191-194DOI: (10.1016/S0012-3692(15)33494-2) Copyright © 1983 The American College of Chest Physicians Terms and Conditions

FIGURE 2 Scatter plot of overall variability of heart rate, as measured by interquartile range of R-R interval in this infont (x's) and in normal infonts (dots) at each age and during REM (left) and quiet (right) sleep. Individual values and means (horizontal lines) of normal infants are shown. CHEST 1983 84, 191-194DOI: (10.1016/S0012-3692(15)33494-2) Copyright © 1983 The American College of Chest Physicians Terms and Conditions

FIGURE 3 Scatter plot of beat-to-beat variability, as measured by interquartile range of ΔRR in this infant (x's) and in normal infants (dots) at each age and during REM (left) and quiet (right) sleep. Individual values and means (horizontal lines) of normal infants are shown. CHEST 1983 84, 191-194DOI: (10.1016/S0012-3692(15)33494-2) Copyright © 1983 The American College of Chest Physicians Terms and Conditions