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Mechanism of Atrial Fibrillation:
Author(s) -
COZMA DRAGOS,
KALIFA JEROME,
LIGHEZAN DANIEL,
PESCARIU SORIN,
DEHARO JEANCLAUDE,
MORNOS CRISTIAN,
DJIANE PIERRE,
DRAGULESCU STEFANIOSIF
Publication year - 2005
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.2005.00020.x
Subject(s) - medicine , atrial fibrillation , cardiology , coronary sinus , atrium (architecture) , anesthesia , electrical conduction system of the heart , electrocardiography
Atrial fibrillation (AF) has been associated with premature beats and decreased atrial conduction velocity. This study examined a new index of dynamic inter‐atrial conduction time (iaCT) in patients with paroxysmal AF (PAF). We compared 42 consecutive patients with paroxysmal AF (mean age = 52 ± 16 years) without structural heart disease with 39 age‐matched patients (mean age = 49 ± 15 years) who underwent ablation of junctional tachycardias. Prior to investigation, all antiarrhythmic drugs were discontinued for an appropriate period of time. The following measurements were made: baseline iaCT (iaCTb) between high right atrium (HRA) and distal coronary sinus, iaCT during HRA pacing S1S1 600 ms (iaCTS1), maximum prolongation of iaCT during S2 and S3 delivery (iaCTS2, iaCTS3). We then derived the decremental index (DI), the maximum percent prolongation of iaCT = iaCT S3‐iaCTS1/iaCTS1%. In patients with PAF, iaCTb was 81.3 ± 24 ms versus 59.5 ± 14 ms in controls (P = 0.0001). Atrial fibrillation was reproducibly and easily induced with a prominent increase in iaCT in 11 patients with AF. In this subgroup DI was 92 ± 17%, compared to 45 ± 21% in the other patients with AF (P = 0.0001) and 21 ± 15% in the control group (P = 0.0001). Spontaneous isolated or repetitive ectopic activity was observed in 11 patients with AF (26%), and decremental atrial conduction was observed in 76% of patients with AF. This study supports the role of dynamic inter‐atrial conduction disturbances in patients with lone PAF. The DI may be a new index of vulnerability to paroxysmal AF.