Final answer:
Cardiac arrhythmia, specifically ventricular fibrillation, is a condition where the heart beats in an uncoordinated manner, making it useless as a pump; defibrillation is the immediate treatment.
Step-by-step explanation:
The condition where the heart becomes uncoordinated and ineffective as a pump is known as cardiac arrhythmia or heart arrhythmia. In ventricular fibrillation, a type of arrhythmia, the heart's electrical activity is severely disrupted, leading to an uncoordinated, rapid, and ineffective heartbeat, preventing the heart from pumping blood effectively. Ventricular fibrillation is a medical emergency and is considered a 'code blue' in hospital settings.
Immediate treatment often involves defibrillation, using paddles to deliver an electrical shock aimed at restoring normal heart rhythm. Untreated, this condition can lead to brain death in a matter of minutes due to insufficient blood flow to vital organs, indicating the severity and the urgency for medical intervention.