Arrhythmia related to a dual chamber DDD pacemaker: a study using intra-atrial dynamic electrocardiographic monitoring

The intra-atrial Holter monitoring (IAHM) has been recently suggested to accurately analyze atrial activity in some complex arrhythmias. We have used this new method to examine DDD pacing-related tachyarrhythmias (DDD/TAs). Fifteen patients underwent IAHM (24 hours) early after DDD pacemaker (PM) implantation. The intra-atrial ECGs were obtained through a multipolar electrode catheter; simultaneously a chest wall lead (CM5) was recorded. A standard Holter equipment was used. When DDD/TAs were observed, a second 24-hours recording was performed after a suitable PM re-programming. In 9 patients (60%) 1 or more DDD/TAs were observed, due to the following mechanisms: PM re-entry, oversensing of extra atrial potentials, fast ventricular stimulation triggered by spontaneous atrial tachyarrhythmias. Whereas the diagnostic accuracy of the IAHM was manifest, the DDD/TAs were often misdiagnosed on the basis of the CM5 lead data. At last, a right DDD PM re-programming, based on IAHM results, was able to solve or minimize the referred arrhythmic problems. In conclusion, the IAHM can be an useful method to understand the electrogenetic causes of the DDD/TAs and to optimally program the dual chamber PM. However, on account of the invasivity of the procedure, the IAHM must be used only when the noninvasive techniques fail to detect the mechanisms of the DDD/TAs.