Reply to the Editor — Fusion During Entrainment at the Cavotricuspid Isthmus: When Entrainment Does Not Match Our Expectation

We appreciate the interest and the insightful comments expressed by Noheria on our case where entrainment on the cavotricuspid isthmus (CTI) showed conflicting response in typical CTI-dependent flutter. We proposed a single tachycardia involving two different groups of muscle fibers on the CTI: fast pathway and slow pathway, each of which has different conduction velocity, effective refractory period and connecting site to the coronary sinus. An alternative explanation raised by Noheria is that there are two tachycardias utilizing different groups of muscle fibers on the CTI that connect to the coronary sinus separately and perhaps sharing the rest of the tricuspid annulus as a common circuit.

Source: Heart Rhythm - June 22, 2018 Category: Cardiology Authors: Mark J. Shen, Bradley P. Knight, Susan S. Kim Source Type: research