What occurs in the heart during ventricular tachycardia?

During ventricular tachycardia, there is rapid firing from an ectopic focus located within the ventricles of the heart. This means that instead of the heart beating due to electrical impulses generated from the sinoatrial (SA) node, the impulses are originating from an abnormal or excitable region within the ventricles themselves.

This ectopic focus can cause the ventricles to contract at a much faster rate than normal, typically exceeding 100 beats per minute. This rapid heartbeat can lead to decreased cardiac output and may compromise perfusion to vital organs. The absence of coordinated atrial contraction during ventricular tachycardia is key; the atria do not communicate properly with the ventricles, further leading to potential complications and symptoms of cardiovascular instability.

Understanding this mechanism is crucial for recognizing why option B accurately describes what happens in ventricular tachycardia, differentiating it from other arrhythmias where the heart maintains a normal rhythm or where contractions are better coordinated.