What are the most common arrest rhythms encountered in adult patients?

Ventricular fibrillation and pulseless ventricular tachycardia are the most common cardiac arrest rhythms encountered in adult patients experiencing sudden cardiac arrest. These rhythms are characterized by ineffective pumping of the heart, leading to the cessation of effective circulation and, subsequently, inadequate perfusion of vital organs.

Ventricular fibrillation (VF) occurs when the heart's electrical activity becomes chaotic, preventing the heart from contracting effectively and resulting in no blood flow. In pulseless ventricular tachycardia (VT), the heart beats in a rapid manner that is also ineffective in producing a measurable pulse, which similarly leads to inadequate blood flow. Both rhythms require immediate intervention—specifically, defibrillation and advanced life support—to restore a normal heart rhythm and improve the likelihood of survival.

In contrast, other options mention rhythms that are less commonly associated with cardiac arrest. Atrial fibrillation and asystole, for example, may occur in patients with cardiac conditions but are not typically the primary rhythms witnessed during cardiac arrest situations. Sinus tachycardia and atrial flutter, though notable arrhythmias, do not usually lead to collapse and require resuscitation. Bradycardia can be serious but does not represent the most common rhythms found during complete