The goal of this multicenter, double-blind, randomized controlled trial is to evaluate the efficacy and safety of low-intensity focused ultrasound (LIFU) stellate ganglion modulation for improving autonomic function and sleep quality in perioperative cardiovascular disease patients.

The main questions it aims to answer are:

1. Does LIFU improve heart rate variability and sleep characteristics from baseline at 3-7 days post-surgery compared to sham ultrasound?
2. Does LIFU improve serological markers, vital signs, Pittsburgh Sleep Quality Index (PSQI), and reduce >30-second perioperative arrhythmias?
3. What is the safety profile of LIFU in this population? 200 eligible patients will be randomized 1:1 to receive either active LIFU (2.0W, 1MHz, 50% duty cycle, 30min daily for 3-7 days) plus standard care, or identical sham ultrasound plus standard care. A four-party double-blind design (subjects, operators, assessors, analysts) will be implemented. The study will run from May 1, 2026 to April 1, 2027 at 6 centers in China.

Participants will:

1. Complete pre-surgery screening and baseline assessments (PSQI, 12h ECG/sleep monitoring, residual blood sample collection)
2. Receive daily assigned ultrasound intervention for 3-7 consecutive days post-surgery
3. Undergo 72h continuous ECG monitoring post-surgery, and repeat assessments at 3-7 days
4. Have all adverse events and arrhythmias recorded throughout the study
5. May withdraw voluntarily at any time without affecting routine medical care

Inclusion Criteria:

1. Diagnosed with cardiovascular disease (CVD) and scheduled to undergo cardiology-related surgical treatment
2. Able to receive and tolerate the aforementioned cardiology-related surgical treatment
3. Aged between 18 and 79 years (inclusive), with no restriction on gender
4. Agree to accept random allocation of the treatment strategies
5. With clear consciousness, no severe mental disorders or cognitive impairment; voluntarily sign the written informed consent form (ICF) and are willing to actively cooperate with the study treatment

Exclusion Criteria:

1. Have used sedative-hypnotic drugs, antipsychotic drugs, opioid analgesics, antihistamines, non-steroidal anti-inflammatory drugs (NSAIDs), central nervous system (CNS) stimulant drugs, or any other medications that alter sleep architecture within the past 30 days
2. Have a history of cervical infection, trauma, severe cervical deformity, or prior cervical surgery
3. Unable to complete the daily study intervention as required by the trial protocol
4. Are participating in another clinical trial, or have participated in other clinical trials with interventions that may interfere with the results of this study
5. Have undergone major surgery or general anesthesia within the past 30 days
6. Have a history of alcohol abuse
7. Are female subjects who are pregnant or lactating, or plan to become pregnant during the study period
8. Have severe cognitive impairment, severe psychiatric disorders, epilepsy, or other related neurological disorders
9. Have concomitant malignant tumor or severe dysfunction of vital organs
10. Have active systemic infection
11. Have significant bleeding tendency, or renal failure undergoing regular hemodialysis
12. Are deemed unsuitable for the trial by the investigator for any other reason -

Due to considerations for protecting participant privacy, undetermined data ownership, or the absence of a detailed data-sharing policy.