Cardiac Sympathetic Afferent Denervation Protects Against Ventricular Arrhythmias by Modulating Cardiac Sympathetic Nerve Activity During Acute Myocardial Infarction

Figures

• 

  Figure 1. Experimental flow chart. Sham group, sham operation without cardiac sympathetic afferent denervation; CSAD group, with cardiac sympathetic afferent denervation; RTX – resiniferatoxin; LSG – left stellate ganglion; LADO – left anterior descending branch occlusion; ERP – effective refractory period; APD90 – 90% repolarization duration; APDA – action potential duration alternans; HRV – heart rate variability; AMI – acute myocardial infarction; Vas – ventricular arrhythmias.

• 

  Figure 2. Effects of CSAD on VAs. (A) Representative AMI-induced ventricular arrhythmias. (B–E) The occurrence of the VAs in both groups. NS, P>0.05; ** P<0.01, and *** P<0.001 versus sham group. VPB – ventricular premature beat; VT – ventricular tachycardia; VF – ventricular fibrillation; BS – baseline. Other abbreviations as in Figure 1.

• 

  Figure 3. Effect of CSAD on ventricular electrophysiological properties. (A) Representative examples of MAP from the IA in the both groups. (B–K) The changes in ERP, APD90, ERP dispersion, APD90 dispersion, beat-to-beat variability of repolarization and APDA cycle length in both groups at baseline, 30 minutes after epicardial RTX or vehicle intervention (30min), and 60 minutes after acute myocardial infarction (AMI). NS, P>0.05; * P<0.05, ** P<0.01, and *** P<0.001 versus group baseline; # P<0.05, ## P<0.01, and ### P<0.001 versus sham group. IA – ischemia area; IRA – ischemia remote area; BVR – beat-to-beat variability of repolarization. Other abbreviations as in Figure 1.

• 

  Figure 4. Effect of CSAD on cardiac autonomic nervous activity. (A–C) The changes in HRV between 2 groups at baseline, 30 minutes after epicardial RTX or vehicle intervention (30 min), and 15 minutes after acute myocardial infarction (AMI). (D) Effect of LADO and CSAD on serum norepinephrine (NE) at baseline, 30 minutes after intervention (30 min), and 60 minutes after acute myocardial infarction (AMI). (E–G) Typical images and the quantitative analysis of the LSG neural activity at each time points in the 2 groups. (H) Effect of CSAD on LSG function at the same time point. * P<0.05, ** P<0.01, and *** P<0.001 versus group baseline; # P<0.05, ## P<0.01, and ### P<0.001 versus sham group. HF – high frequency; LF – low frequency; LF/HF – ratio between LF and HF. Other abbreviations as in Figure 1.

• 

  Figure 5. Effect of CSAD on c-fos and nerve growth factor (NGF) protein expression. (A) Representative western blot images, and (B,C) quantitative analyses of the expressions of c-fos and NGF in LSG in both groups. # P<0.05 versus sham group. Other abbreviations as in Figure 1.