Figure 4

Supraventricular premature complex in an inoculated, BSE-negative steer. ECG of an 89 month-old Holstein-Friesian steer (CN1090) intracerebrally inoculated at five months of age with spleen homogenate collected from cattle orally dosed with BSE brainstem homogenate and culled at 10 months post inoculation. A normally shaped QRS complex occurs prematurely (supraventricular premature complex: SPC) and is not preceded by a P wave. There is also sinus arrhythmia present. Mean heart rate 57 beats per minute.