Ventricular arrhythmias are abnormal heart rhythms that originate in the ventricles, the lower chambers of the heart. These arrhythmias can disrupt the heart's ability to pump blood effectively, leading to symptoms such as palpitations, dizziness, or even fainting. In severe cases, they can result in cardiac arrest. Common types of ventricular arrhythmias include ventricular tachycardia and ventricular fibrillation. Ventricular tachycardia involves a rapid heartbeat that can be sustained, while ventricular fibrillation is a chaotic rhythm that prevents the heart from pumping blood. Both conditions require prompt medical attention to prevent serious complications.