The purpose of this study was to define the clinical-electrophysiological features of sinoatrial disease in order to furnish more detailed criteria for differential diagnosis between in two main forms of this syndrome. The study group consisted of 15 normal subjects (N) (mean age 63 ± 10), 20 patients with sick sinus syndrome (SSS) (mean age 65 ± 9) and 17 patients with bradycardia-tachycardia syndrome (BT) (mean age 55 ± 13). High right atrium (RHA) and His bundle recording (HBE), premature programmed stimulation (PAS) and overdrive asynchronous atrial stimulation (AAS) were performed. SSS showed the typical clinical-electrophysiological pattern, characterized by a 30% incidence of syncopal attacks and impaired sinus node function and sinoatrial (SA) conduction. A significant lengthening of SCL vs. N and BT, of sinoatrial conduction time (SACT) vs. N, of atrial functional refractory period (AFRP) vs. N and AB and mainly of corrected sinoatrial recovery time (CSRT) vs. the other three groups was observed. PAS showed abnormal (chaotic, overcompensatory and linear) responses, a longer extension of zone of interference (ZI) vs. AB. Atrial echoes and suppraventricular tachycardias (SVT) were not induced in any patients of this group. In BT clinical features usually were milder than in SSS, patients were younger and a persistent bradycardia in resting conditions was not a constant factor. SCL was in the normal range and significantly shorter than in AB and SSS. Mean values of AH intervals were longer than in N. Mean values of CSRT, SACT, AERP and AFRP were normal. PAS showed a significantly higher incidence of atrial > vs. N and SSS, and of functional dissociation of AV node (FAVND) vs. the other three groups. These features are known to allow supraventricular reentry arrhytthmias. Both PAS and AAS easily induced SVT. In two cases PAS induced short episodes of atrial fibrillation (AF). Patients with BT were divided into two subgroups according to the absence (A) or presence (B) of induced atrial tachyarrhythmias. B differed from A in that there was no correlation between SCL and atrial refractoriness (AERP and AFRP). These data indicate that BT is characterized by its own clinical-electrophysiological features and it is better defined as >.
|Translated title of the contribution||Criteria of differential diagnosis of sinoatrial disease with particular regard for the brady-tachy syndrome|
|Number of pages||15|
|Journal||Giornale Italiano di Cardiologia|
|Publication status||Published - 1980|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine