TCL in electrophysiology stands for Tachycardia Cycle Length. What does this term describe?

• A. Tachycardia Cycle Length
• B. Time to Conduction Latency
• C. Transmural Conduction Level
• D. Temporal Circuit Length

Answer: (A)

Tachycardia Cycle Length describes the duration of one complete tachycardia loop—the interval from one activation to the next in the same chamber during a tachycardia. In practice, it’s measured as the time between successive activations, typically from one ventricular activation to the next during ventricular tachycardia (the R–R interval) or from one atrial activation to the next during atrial tachycardia. This interval, in milliseconds, reflects the tachycardia rate: a shorter cycle length means a faster tachycardia, while a longer one means a slower tachycardia. For example, a cycle length of 400 ms corresponds to about 150 beats per minute.