Patient P., 56 years old admitted to the tachyarrhythmia surgical treatment unit at the Medical Center with the diagnosis "CHD, cardiosclerosis atherosclerotic. Persisting atrial flutter".
ECG registered first type atrial flutter with ventricular conduction 2:1 – 4:1.
Fig. 1. Patient P. I type atrial flutter. ECG in 12 standard leads.
The patient underwent Non-invasive heart EPI using the diagnostic system "AMYCARD 01 C".
We chose an ECG fragment containing four F-waves of flutter for analysis.
The Phase mapping mode was used for electrophysiological analysis.
The isopotential map mode showed movement of a negative potential counterclockwise around the tricuspid and mitral valves (look above Fig. 2).
Phase maps clearly visualized phase dynamics of atrial flutter cycle (Fig. 3). The rotation of the reentry wave around the tricuspid valve counterclockwise was observed. This pattern corresponds to the classic isthmus-depending right atrium flutter.
Fig. 2. Type I atrial flutter. Epi-endocardial atrial fibrillation model. View from the ventricles. Isopotential maps. Area of negative potential moves counterclockwise.
Fig. 3. Patient P. I type atrial flutter. Polygonal endo-epicardial atrial model. Phase maps. View of the side of the ventricles.
To build an isochronous map, in the phase compound of electrogram there was selected an interval between phase leaps corresponding to the reentry cycle duration (Fig. 4).
Fig. 4. Patient P. I type atrial flutter. A phase compound of the atrial electrogram. Selecting an interval corresponding to the length of atrial flutter cycle.
After switching to the isochronous map mode there was obtained an isochronous map by the method of phase mapping. The process of activation spread (from red to purple) corresponds to the wave movement reentry counterclockwise (Fig.5).
The patient was exposed to an invasive electrophysiological heart investigation using the CARTO III navigation system. Mapping of the right atrium was performed in the rhythm of atrial flutter, then a mapping electrode was moved into the left atrium by transseptal access, and the left atrium was mapped. There was revealed a typical rotation of the reentry wave around the tricuspid valve with a typical delay in the region of cavo-tricuspid isthmus. Activation maps obtained during an invasive EPI perfectly matched activation maps obtained during a Non-invasive investigation using the Amycard 01 C system (Fig. 5).
There was performed an ablation of cavo-tricuspid isthmus. During repeated mapping of the right atrium in the rhythm of cardiac stimulation from the coronary sinus there were not revealed activation breaks through the ablation line.
During postoperative period of 6 months no recurrent of atrial flutter were observed.
Fig. 5. Patient P. Type I atrial flutter. To the right there is an isochronous map obtained during electro anatomic mapping using the CARTO III navigation system. To the left there is an isochronous map built on the basis of phase mapping using the Amycard system.