[Interatrial electromechanic resynchronization by dual atrial pacing in the prevention of paroxysmal atrial fibrillation --report of a case].

We presented the case of a 78 year old woman who five years ago underwent myectomic surgery, and aortic valvular replacement, for obstructive cardiomyopathy and valvular aortic stenosis. After surgery, the aortic transvalvular gradient was insignificant (20 mm/Hg). In spite of this she suffers from frequent AF crises, (3 times a month), with a cardiac frequency of 140-150/min. She was in sinus bradycardia (40-45/min), which was a clear counter-indication for the use of antiarrhythmic drugs. Her ECG showed sinusal bradycardia with 45/min, a two-phase P-wave (positive-negative) in DII, DIII aVF, and bimodal P-wave in DI. Furthermore, she showed a 1st degree auriculo-ventricular block with complete left-branch block. In her echocardiogram there was concentric left ventricular hypertrophy, with diastolic disfunction and left atrial dilatation. In the auricular IEGM we observed a slowed-down interauricular conduction (right atrium-left atrium = 120 msecs); The A-wave was fragmented. The auriculo-ventricular Wenckbach point was at 90/min. In view of these findings we proceeded with the implantation of a DDD-pacemaker with biauricular stimulation, as follows: 1. We used two auricular electrodes, one with an active fixation to the crista terminalis of the right atrium and the other (having in mind the stimulation of the left atrium) applied to the proximal coronary sinus. These two electrodes were connected to the auricular pin of the pacemaker by means of an "Y"--type Biotronick adaptor. 2. The right ventricular stimulation was done with a normal, bipolar ventricular electrode, on the apex of the ventricle. After biauricular, simultaneous, stimulation, we proceeded with interauricular re-synchronization. After this procedure, the A-wave no longer appeared fragmented, and the right auricular--left auricular waves were then simultaneous and with two-phase morphology. Three months later the interauricular resynchronization procedure was induced and without any antiarrhythmic drugs, the Holter showed no cardiac arrhythmias, there is no auricular fibrillation. The morphology of the P-wave has changed. The patient has an improved exercise capacity and a better quality of life.