Final answer:
Capture beats and fusion beats are characteristic of Ventricular Tachycardia (VT), which is a type of ventricular arrhythmia indicated by a heart rate over 100 beats per minute and arising from the heart's lower chambers.
Step-by-step explanation:
Capture beats and fusion beats confirm the diagnosis of Ventricular Tachycardia (VT). Ventricular Tachycardia is one of the types of ventricular arrhythmias that include conditions where the heart beats with abnormal rhythm due to issues in the electrical conduction system. In VT, the heart rate is fast, usually over 100 beats per minute, and originates from the ventricles (the heart's lower chambers).
The normal heartbeat starts in the sinoatrial (SA) node with an electrical impulse that travels to the atria causing them to contract. Then it proceeds to the atrioventricular (AV) node, through the bundle of His, into the bundle branches, and finally through the Purkinje fibers, resulting in the synchronized contraction of the ventricles.
In VT, capture beats are those rare moments where the SA node manages to 'capture' the rhythm and a normal beat occurs amidst the fast rhythm of the VT. Fusion beats are a mixture of a normal SA node beat and a ventricle beat where the timings overlap. This abnormal combination of beats is a characteristic sign of Ventricular Tachycardia, helping to distinguish it from other cardiac dysrhythmias.