monomorphic ventricular tachycardia ventricular flutter 2026-04-20T07:25:09Z MP:0031720 MPheno.ontology Ventricular flutter is a severe form of rapid monomorphic ventricular tachycardia with no distinguishable QRS, P, or T waves that almost always degenerates rapidly into ventricular fibrillation. Do not confuse the two terms. Ventricular flutter is a macroreentrant prefibrillatory rhythm that presents as a smooth, undulating sine-wave pattern with the ECG often looking identical when viewed upside down. Ventricular fibrillation is characterized by a chaotic, irregular waveform with deflections of varying morphology and amplitude and represents a state of complete electrical disorganization, where the ventricles quiver instead of contracting synchronously, resulting in total loss of cardiac output. a life-threatening, hemodynamically unstable ventricular tachycardia characterized by an extremely rapid heart rate and a smooth, undulating sine-wave pattern with regular, large oscillations