Left Stellate Ganglion and Vagal Nerve Activity and Cardiac Arrhythmias in Ambulatory Dogs With Pacing-Induced Congestive Heart Failure
Masahiro Ogawa, MD, PhD*,
Shengmei Zhou, MD*,
Alex Y. Tan, MD*,
Juan Song, PhD*,
Ghassan Gholmieh, MD, PhD ,
Michael C. Fishbein, MD, FACC ,
Huai Luo, MD*,
Robert J. Siegel, MD, FACC*,
Hrayr S. Karagueuzian, PhD*,
Lan S. Chen, MD,
Shien-Fong Lin, PhD* and
Peng-Sheng Chen, MD, FACC*,*
* Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California
Division of Neurology, Department of Pediatrics, Children's Hospital, Los Angeles and USC Keck School of Medicine, Los Angeles, California
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California
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Figure 1 Examples of Autonomic Nervous System Activity From Dog #1
(A) Simultaneous stellate ganglion nerve activity (SGNA) and vagal nerve activity (VNA) discharges cause bradycardia at baseline. (B) Similar phenomenon after the induction of congestive heart failure (CHF). (C) A brief period of sympathovagal discharge (between first and second arrows) induced long paroxysmal atrial tachycardia during CHF. ECG = electrocardiography.
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Figure 2 LABDA and HASDA
(A) High amplitude spike discharge activity (HASDA) induced couplets and abruptly increased heart rate 6 days after cessation of rapid pacing in dog #2. (B) Low amplitude burst discharge activity (LABDA) episodes associated with isolated premature ventricular contraction and couplets 1 day after cessation of rapid pacing in dog #3. (C) LABDA episodes associated with isolated premature ventricular contraction and triplets (ventricular tachycardia) 1 day after cessation of rapid pacing in dog #2. Abbreviations as in Figure 1.
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Figure 3 HASDA and Premature Contractions
(A) HASDA induced isolated premature atrial contraction 1 day after cessation of rapid pacing in dog #2. (B) HASDA induced isolated premature ventricular contraction 7 days after cessation of rapid pacing in the same dog. Abbreviations as in Figures 1 and 2.
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Figure 4 Circadian Variations of HASDA
We manually analyzed the number of high amplitude spike discharge activity (HASDA) episodes at baseline (1 day before commencement of rapid pacing) and during congestive heart failure (CHF) (1 day after cessation of pacing). The data of all dogs were then pooled together. There were circadian variations of HASDA, with peak incidence 7:00 AM to 8:00 AM.
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Figure 5 SGNA and Prolonged Sinus Pause
(A) Abrupt termination of LABDA preceded a prolonged sinus pause (PSP) episode. (B) Intermittent LABDA (arrows) associated with intermittently increased heart rate, and a large LABDA (*) induced tachycardia. Sudden SGNA withdrawal resulted in 5.5-s PSP. (C) The data within the dotted line in panel B. Abbreviations as in Figures 1 and 2.
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Figure 6 Heart Failure Increases Autonomic Nerve Activity
This figure shows 24-h distributions of integrated SGNA and VNA at baseline and after cessation of rapid pacing in all dogs. Abbreviations as in Figure 1.
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Figure 7 Histological Studies
(A and B) Masson's trichrome stain of sinus node and right atrium, respectively. There was increased fibrosis (blue) in these tissues. The objective was 4x, and the calibration bar is 1 mm. (C and D) TH and ChAT staining, respectively, of the vagal nerves. Arrows point to positively stained structures in brown color. The objective was 10x, and the calibration bar is 0.1 mm.
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