Final answer:
Ventricular fibrillation is an erratic and ineffective heart rhythm that disrupts the normal contraction-relaxation pattern of the heart and prevents it from pumping blood effectively. The treatment, defibrillation, aims to reset the heart's electrical activity.
Step-by-step explanation:
False. In ventricular fibrillation, the ventricles are not in a continuous contraction-relaxation pattern, but rather contracting in a rapid, erratic rhythm, which does not allow the heart to effectively pump blood. The cardiac cycle consists of a phase of contraction called systole and a phase of relaxation called diastole. During ventricular fibrillation, there is no effective systole or diastole, and no coordinated pumping activity.
Defibrillation is the most common treatment for ventricular fibrillation. It aims to stop the erratic electrical activity of the heart to allow a normal rhythm to recommence. Contrary to the chaotic electrical activity in ventricular fibrillation, large currents provided by a defibrillator can help reset the heart's electrical state, analogous to erasing a blackboard before starting afresh.