Diagnosis of atrial arrhythmias using the Holter function of a new DDD pacemaker.

UNLABELLED: The extension of random access memory now makes it possible to store electrocardiographic (ECG) information, referred to here as Holter function (HF), in the memories of new pacemakers, which can be used as diagnostic tools during long-term follow-up. This report describes our experience in 26 consecutive patients for whom the device was used to detect episodes of atrial arrhythmias (AA). An illustrative case is also presented to describe in detail the device's analytical method.
RESULTS: Fourteen AA profiles were successfully recorded in 10 patients by the pacemaker HF and correlated with confirmatory simultaneous surface ECG tracings. Three additional profiles were recorded in three other patients without simultaneous ECG recordings. A diagnosis of AA is established when the following findings are combined: (1) in all cases a large number of short interatrial intervals (A INT); (2) in presence of AV block, interventricular intervals (V INT) stored between the lower programmed pacing rate and the upper rate limit or the fallback rate; (3) in absence of AV block, V INT stored between the basic rate and the AV node refractory period; (4) in case of fallback, (VVI function) no stored AV INT; and (5) in absence of fallback, great variability of AV INT (Wenckebach function).
CONCLUSIONS: (1) Diagnoses of AA can be made with the pacemaker HF; (2) The homogeneity of the HF profiles makes them useful for long-term follow-up and will probably contribute and clarify the natural history of AA in DDD patients; (3) HF may also serve to monitor the safety and efficacy of antiarrhythmic drug therapy during long-term follow-up.