Final answer:
The recommended energy for biphasic cardioversion of unstable monomorphic VT usually ranges from 100 to 200 joules, but actual levels may vary based on the defibrillator and patient needs.
Step-by-step explanation:
The energy level for biphasic cardioversion of unstable monomorphic ventricular tachycardia (VT) varies depending on the defibrillator model and patient-specific factors. However, initial energy levels recommended typically range from 100 to 200 joules. The goal is to deliver adequate energy to revert the heart back to a normal rhythm without causing damage to the heart muscle. The actual circuitry of heart defibrillators is designed to compensate for magnetic and alternating current (AC) effects, ensuring brief but intense current for effective cardioversion. During open heart surgery, however, much smaller amounts of energy are sufficient for defibrillation.