Time courses of voluntary running activity and causes of death in DCM mice.

<p><b><i>A.</i></b> Typical time courses of running activity in three mice that maintained high activity (>5 km/day) and died suddenly. <b><i>B.</i></b> Instances of three mice that decreased running activity to <1 km/day and died. <b><i>C.</i></b> Instances of two mice that gradually lost running activity to between 1 and 5 km/day and died. Different symbols indicate different individual mice. <b><i>D</i></b> and <b><i>E</i></b><b>.</b> LW/BW (<i>D</i>) and HW/BW (<i>E</i>) ratios in mice found dead in their cage. HD: mice with running activities of >5 km/day before death (<i>n</i> = 15). MD: mice that showed last running activity between 1 and 5 km (<i>n</i> = 2). LD: mice with activity of <1 km/day before death (<i>n</i> = 12). Bars are mean±SD. *P<0.05, **P<0.01, ***P<0.001. <b><i>F.</i></b> Typical ventricular arrhythmia recorded with telemetry ECG system from a 2.5-month-old mouse with high wheel running activity. Inset: ECG record with expanded time scale. Ventricular tachycardia (VT) repetitively occurred for 15 min in this mouse.