What is the name of the rhythm characterized by a heart rate of 20-40 BPM with a wide QRS complex and completely absent P waves?

The rhythm characterized by a heart rate of 20-40 beats per minute with a wide QRS complex and completely absent P waves is known as idioventricular rhythm. This rhythm arises from the ventricles when the intrinsic pacemaker of the heart, usually the SA node, is not functioning properly. In idioventricular rhythm, the ventricles take over the pacing of the heart, generating impulses at a much slower rate compared to normal. The absence of P waves indicates that there is no atrial depolarization occurring; the heart's electrical activity is limited to the ventricles. This characteristic of wide QRS complexes signifies that the electrical impulse is originating within the ventricles themselves, leading to a slower conduction through the heart’s ventricles.

In contrast, bradycardia generally refers to a slower heart rate but does not specify the characteristics of the QRS complex or the presence of P waves. Fibrillation is an erratic, irregular heart rhythm with chaotic electrical activity but does not fit the described rate and waveforms. Tachycardia, on the other hand, signifies a fast heart rate and is not associated with a rate as low as 20-40 BPM or wide QRS complexes and absent P waves. Therefore