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 preventing ventricular arrhythmias after ST-segment elevation myocardial infarction (STEMI) in patients undergoing percutaneous coronary intervention (PCI).

The main questions it aims to answer are:

1. Does LIFU reduce the frequency and duration of ventricular arrhythmias within 72 hours post-PCI compared to sham ultrasound?
2. Does LIFU improve electrophysiological stability, myocardial injury markers, cardiac function and heart rate variability, and reduce inflammatory markers and sympathetic neurotransmitters?
3. What is the safety profile of LIFU in this population?

100 eligible patients will be randomized 1:1 to receive either active LIFU (2.0W, 1MHz, 50% duty cycle, 30min per session: 1 intra-PCI session + 7 daily post-PCI sessions) plus standard care, or identical sham ultrasound plus standard care. A comprehensive double-blind design (subjects, operators, assessors, statisticians) will be implemented. The study will run from May 2026 to April 2027 at 7 centers in China, led by Renmin Hospital of Wuhan University.

Participants will:

1. Complete pre-PCI screening and baseline assessments (informed consent, demographic/medical history, physical examination, electrocardiogram, echocardiogram, blood sample collection) within 12 hours of symptom onset
2. Receive 1 assigned ultrasound intervention during PCI, followed by 1 daily intervention for 7 consecutive days postoperatively
3. Undergo 72h continuous ECG monitoring post-PCI, blood sampling at baseline and postoperative days 1, 3, 7, and echocardiography assessment at postoperative day 7
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. Age between 18 and 80 years (including 18 and 80 years); gender is not restricted;
2. Agree to be randomly assigned to a treatment strategy and be able to undergo follow-up as required;
3. Patients with a clinical diagnosis of acute ST-segment elevation myocardial infarction;
4. Presented within 12 hours of symptom onset and underwent PCI;
5. Killip functional class I-III;
6. Agree to participate in this study and voluntarily sign the informed consent form.

Exclusion Criteria:

1. Patients with a history of myocardial infarction;
2. Patients with a history of cardiac pacemaker or implantable cardioverter-defibrillator (ICD) implantation;
3. Patients with severe bradycardia or high-degree atrioventricular block;
4. Patients with severe heart failure (left ventricular ejection fraction <30%);
5. Patients with cardiogenic shock (Killip Class IV);
6. Patients admitted with frequent ventricular fibrillation or cardiac arrest;
7. Patients with a history of malignant hematological disorders or renal failure (estimated eGFR <30 ml/min);
8. Patients with skin lesions, infections, or benign or malignant tumors in the left neck;
9. Pregnant or breastfeeding women, or women planning to become pregnant during the study;
10. Patients with severe cognitive impairment, psychiatric disorders, epilepsy, etc.;
11. Patients with concurrent malignant tumors or diseases of vital organs;
12. Patients with active systemic infections;
13. Patients who have participated in other drug or medical device clinical trials within the past 3 months;
14. Patients who are unable or unwilling to provide informed consent;
15. Patients deemed unsuitable for participation in this clinical trial by the investigator.

IPD sharing is currently undecided due to ongoing evaluation of participant privacy safeguards, data security requirements, and multicenter regulatory frameworks.