This Article Abstract Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (50) Citing Articles via Google Scholar Google Scholar Articles by Scherlag, B. J. Articles by Jackman, W. M. Search for Related Content PubMed PubMed Citation Articles by Scherlag, B. J. Articles by Jackman, W. M.

Autonomically Induced Conversion of Pulmonary Vein Focal Firing Into Atrial Fibrillation

Cardiac Arrhythmia Research Institute, Oklahoma University Medical Center, Oklahoma City, Oklahoma.

View larger version (36K): [in a new window]   Figure 1 Diagrammatic representation of the heart viewed through a right thoracotomy at the fourth intercostal space. An acrylic plaque electrode was sutured to the fat pad (FP) (shaded area) on the epicardium containing autonomic ganglia (AG) found at the base of the right superior pulmonary vein (RSPV). Multi-electrode catheters were sutured to the pleura so as to rest against the RSPV, attached to the left atrium (LA) extending along the superior vena cava (SVC) and to the right atrium (RA) extending toward the right atrial appendage (RAAp). In each position the distal bipolar electrode pairs were closest to the FP. SAN = sinoatrial node; IVC = inferior vena cava.

View larger version (32K): [in a new window]   Figure 2 The tracings from the top: electrocardiogram lead II; a His bundle recording (Hb); bipolar electrograms recorded from the distal electrode pair (D-2) of the catheter along the left atrium toward the SVC and the RA close to the FP (D-2) toward the RA appendage. In the baseline state (A), with no stimulation applied to the FP containing the AG, 10 atrial premature depolarizations (A2-A11) delivered just outside the local refractory period at the RSPV induced three beats of atrial tachycardia (AT). (B) During the delivery of 1.5 V to the AG, six atrial extra-stimuli applied with the same coupling (120 ms) to the RSPV induced atrial fibrillation (AF). Other abbreviations as in Figure 1.

View larger version (35K): [in a new window]   Figure 3 Same experiment as shown in Figure 2. (A) When 3.2 V was applied to the autonomic ganglia only four atrial premature depolarizations (APDs) were required to induce atrial fibrillation. (B) At an applied voltage of 7.0 V, atrial fibrillation was induced by only one APD at the same coupling (S1-S2 = 120 ms).

View larger version (71K): [in a new window]   Figure 4 A single extra stimulus at RSPV 3–4 during AG stimulation initiated a short run of AT. Traces from the top: electrocardiogram leads II and aVR; a His bundle recording (Hb); right atrial electrogram (RA); multi-electrode catheter extending from the AG toward the superior vena cava (SVC D27–8); pacing site from the second pair of electrodes on the RSPV (3–4); multi-electrode catheter extending from the AG toward the right atrial appendage (RA D-27–8); arterial blood pressure (BP). (A) AG stimulation at 4 V slowed the heart rate from 126 to 99/min (not shown). The last S1-S1 interval is shown followed by a single atrial premature depolarization (APD) (S1-S2 = 120 ms), which induced a short run of AT. The cycle length of the AT progressively slowed (cycle length 98, 106, 110, and 124 ms) before terminating. (B) Initiation and maintenance of AF during AG stimulation by a single APD at the same S1-S2 coupling, 120 ms, as in A. Autonomic ganglia stimulation at 7 V induced heart rate slowing from 132 to 81/min (not shown). A single APD S1-S2-120 ms now initiated AF, which was associated with complex fractionated electrograms (SVC 5–6; RA 3–4; boxed areas). This type of electrogram was seen in all episodes of induced AF at one or more sites. When AG stimulation stopped, the electrograms invariably showed restoration of discrete potentials with isoelectric intervals before termination. Autonomic ganglia stimuli have been reduced in order to clearly differentiate the electrograms from the AG stimulus artifacts. Other abbreviations as in Figures 1 and 2.