Predicting Long-Term Ventricular Arrhythmia Risk in Children with Acute Lymphoblastic Leukemia Using Normal Values of Ventricular Repolarization Markers Established from Japanese Cohort Study

Figures

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  Figure 1. Flowchart of enrollment of school-aged children in the present study.

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  Figure 2. Box plots of the Tpe interval from each precordial lead. (a) 1st graders. (b) 7th graders. The shaded box shows the interquartile range, the mid-line in the box shows the median of the measured value, the whiskers show the range of the measured value, and the dots show outlier. V1 of the precordial lead is shown in light blue, V2, V3, V4, V5, and V6 are shown in orange, gray, yellow, dark blue, and green, respectively.

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  Figure 3. Chronological changes of the Tpe/QT ratio in 17 pediatric ALL patients. The horizontal dotted line indicates the upper level of the Tpe/QT (0.25, mean + 2SD) based on the present study. In the intensive phase of treatment for ALL, the Tpe/QT ratio of three patients treated with high-risk protocol exceeded the normal range. Among them, one patient, who is indicated by dark blue squares and a thick line (blue arrow), suffered from acute heart failure during the intensive phase of treatment for acute lymphoblastic leukemia (as shown in Figure 4). The Tpe/QT ratio of other patients converged within the normal range over a long period of time.

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  Figure 4. Change in the Tpe/QT ratio in a pediatric ALL patient with acute heart failure. (a) All follow-up terms. The horizontal dotted line indicates the upper level of Tpe/QT (0.25, mean + 2SD) based on the present study. A male patient of 2 years and 11 months of age suffered from acute heart failure (AHF) 4 months after starting treatment for ALL during the intensive phase. (b) First two years. The red arrow indicates the occurrence of AHF. The Tpe/QT ratio was already elevated before AHF. The high Tpe/QT ratio temporarily continued and then fell to a normal level.