Low-Intensity Ultrasound Modulation May Prevent Myocardial Infarction-induced Sympathetic Neural Activation and Ventricular Arrhythmia
Songyun Wang, Binxun Li, Xuemeng Li, Lin Wu, Tongjian Zhu, Dongdong Zhao, Hong Jiang
Journal of Cardiovascular Pharmacology 2020, 75, 432-438 · 10.1097/fjc.0000000000000810
Abstract
Background Low-intensity focused ultrasound (LIFU) has been shown to be a beneficial tool for autonomic nervous system modulation, but its effect on the left stellate ganglion (LSG) remains unknown. Objective To seek the effect of LIFU on myocardial infarction (MI)-induced LSG activation and ventricular arrhythmias (VAs). Methods In this study, 20 dogs were included and randomly divided into the LIFU (LIFU & MI, n = 8), Sham (sham LIFU & MI, n = 8), and Control group (sham LIFU & sham MI, n = 4). For each LIFU intervention (1.0-2.0 W, 10 minutes) of the LSG, the LSG function, ventricular effective refractory period (ERP), and temperature were tested pre-intervention and postintervention. Thereafter, MI was induced by left anterior artery ligation and VAs were recorded for 1 hour. At the end, both the LSG and the heart were extracted for biomedical and histological analysis. Results In the Sham group, no significant change was shown in ventricular ERP or LSG function for any intensity settings of sham LIFU intervention when compared with the group baseline. In the LIFU group, however, both 1.5 and 2.0 W LIFU modulation of LSG resulted in significant prolongation of ERP and attenuation of LSG function. Furthermore, the incidence of VAs was significantly attenuated in the LIFU group compared with the Sham group. Moreover, histological analysis showed that no damage or apoptosis was observed in LSG although a statistically significant increase was shown in temperature (maximal increase Conclusion LIFU stimulation may be a safe and beneficial tool for LSG attenuation and VA prevention in the MI canine model.
Abstract via europepmc.
Exposures
Exposure 1: LIFU to left stellate ganglion (1.0, 1.5, 2.0 W)
Target: superior cervical ganglion — “left stellate ganglion (LSG)”
Device: other named manufacturer · Ultrasound Institute of Chongqing Medical University · GGT2007 ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 1,000 | ✓✓✓ |
| Pulse duration (ms) | not reportedimplied by duty cycle ÷ PRF: 0.5 ms (not stated by the paper) | ⚑ |
| Pulse repetition frequency (Hz) | 1,000 | ✓✓✓ |
| Duty cycle (%) | 50 | ✓✓✓ |
| Sonication duration (s) | 600 | ✓✓✓⚑ |
| Free-field pressure (kPa) | not reported | |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | not reported | |
| In-situ estimate | not reported | |
| In-situ pressure (kPa) | not reported | |
| In-situ Isppa (W/cm²) | not reported | |
| In-situ Ispta (W/cm²) | not reported |
LIFU (frequency 1 MHz, pulse repetition frequency 1 KHz, duty cycle 8 seconds, and duty cycle % 50%) with intensities of 1.0, 1.5 and 2.0 W applied to the LSG for 10 minutes at each intensity, in increasing order, with ERP and LSG function measured before and after each.
Flags from extraction
exposures[0].timing.sonication_duration_s— Text states 'duty cycle 8 seconds' as well as 50 %, which is unexplained; 10 min per intensity is recorded as the sonication duration.exposures[0].free_field— Intensity given only as electrical/acoustic power in W (1.0, 1.5, 2.0 W); no pressure or W/cm2.exposures[0].timing.pulse_duration_ms— Not stated; not computed.safety_notes— Abstract gives maximal temperature increase as garbled ',18C'; results text gives 0.7 C.n_subjects— 20 dogs: LIFU+MI 8, sham LIFU+MI 8, sham LIFU+sham MI 4; only the 8 LIFU dogs received active ultrasound.sham_type— Sham LIFU mechanism not described.