Objectives: The aim of the study was to study some anatomic and electrophysiological features of the right atrium, related to the presence of atrial flutter.
Materials and methods: A total 23 patients with type I atrial flutter and 22 patients without atrial flutter were studied. Right atrium size was assessed using echocardiography before intracardiac examination and radiofrequency ablation.
Results: Effective refractory periods of coronary sinus, high right atrium, low right atrium were different comparing with the control group (P<0.05). A stimulus-response time between high right atrium and low right atrium positions in anterograde and retrograde ways, an impulse propagation speed along the lateral wall of the right atrium were statistically different comparing both groups (P<0.05). There was a significant correlation among effective refractory periods measured in different sites of the right atrium (r2=0.64, 0.44, 0.44, respectively). All measured effective refractory periods also correlated with stimulus-response time in anterograde way (P<0.05) and impulse propagation speed (P<0.05). Right atrium dimensions were significantly larger in atrial flutter group. There was no correlation between the right atrium dimensions and measured electrophysiological parameters in both groups.
Conclusions: The presence of atrial flutter associates with diffuse alterations of the right atrium, but not the focal or single changes of refractoriness.