Selective autonomic stimulation of the AV node fat pad to control rapid post-operative atrial arrhythmias

Figures

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  Fig 1. Anatomic relation of seven-pole plaque electrode. Posterior view of right atrium (RA), inferior right fat pad area (FP), and implantation site of seven-pole plaque electrode as seen intra-operatively. The anatomical relation among the left atrium (LA), Coronary Sinus (CS) dimple and right ventricle (RV) is also visible.

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  Fig 2. Fat pad stimulation results in slowing of ventricular rate during atrial fibrillation. Fat pad stimulation during atrial fibrillation showing marked slowing of ventricular rate. In sequence from top to bottom, the recordings represent: femoral artery BP tracing, two electrocardiographic leads, atrial and ventricular epicardial electrogram recordings, stimulation artifact documenting FP stimulation, and instantaneous heart rate.

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  Fig 3. Heart rate reduction following selective site stimulation. Shown are the maximum and minimum heart rate reductions (bpm) at the best and worst selective electrode positions within the seven-pole plaque electrode. ***p<0.001 (two-tailed Student’s t-test)

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  Fig 4. AV Node fat pad stimulation during atrial fibrillation results in voltage-dependent decrease in ventricular rate. Shown is a representative experiment demonstrating AV node fat pad stimulation during atrial fibrillation using the most effective bipolar combination at a constant stimulation frequency and pulse width demonstrating a voltage-dependent decrease in ventricular rate.

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  Fig 5. Voltage-dependent response to inferior right fat pad stimulation. Displayed is the relationship between stimulation voltage and absolute heart rate reduction (bpm), n = 10 experiments, illustrating a voltage-dependent response to inferior right fat pad stimulation as voltage amplitude was increased. **p<0.01 (two-tailed Student’s t-test)

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  Fig 6. Fat pad stimulation during Junctional Ectopic Tachycardia (JET) at 10 volts. Stimulation during JET resulted in sinus rhythm (SR) with 1:1 atrioventricular (AV) conduction with a normal PR interval. In sequence from top to bottom, the recordings represent: two electrocardiographic leads, atrial and ventricular epicardial electrogram recordings, and stimulation artifact documenting FP stimulation.

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  Fig 7. Fat pad stimulation during Junctional Ectopic Tachycardia (JET) at 15 volts. Stimulation during JET resulted in sinus rhythm with second-degree AV block, Mobitz type I AV block. In sequence from top to bottom, the recordings represent: two electrocardiogram leads, atrial and ventricular epicardial electrogram recordings, and stimulation artifact documenting FP stimulation.

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  Fig 8. Fat pad stimulation during Junctional Ectopic Tachycardia (JET) at 20 volts. Stimulation during JET resulted in sinus rhythm with 2:1 second degree AV block. In sequence from top to bottom, the recordings represent: two electrocardiogram leads, atrial and ventricular epicardial electrogram recordings, and stimulation artifact documenting FP stimulation.