Which rhythms are more likely to be terminal in older children who suddenly collapse or have underlying cardiovascular conditions?

The correct choice identifies the rhythms that are often more indicative of a critical situation and associated with a poorer prognosis in cases of cardiac events, particularly in older children with underlying cardiovascular issues. Ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) are both lethal arrhythmias that indicate severe disturbances in the heart's electrical activity.

When a child suddenly collapses, especially if they have a history of cardiovascular conditions, the likelihood of experiencing VF or pVT increases significantly. These rhythms disrupt the heart's ability to effectively pump blood, leading to compromised circulation and potential loss of consciousness. Immediate defibrillation and advanced cardiac life support measures are crucial in these scenarios to restore a viable heart rhythm.

In contrast, the other rhythms presented—such as asystole (no electrical activity) and bradycardia (slow heart rate)—can also indicate serious problems but may not represent the immediate, high-risk scenarios associated with sudden collapse as VF and pVT do. PEA (pulseless electrical activity) signifies a situation where there is electrical activity without an effective heartbeat, which can be critical but often follows other rhythms rather than being the immediate cause of collapse. Normal sinus rhythm, sinus tachycardia,