Frequency of Electrical Acupoint Stimulation on Hypotension in TAVR Patients

• electrical acupoint stimulation (Other): Electrical stimulation are administered at Neiguan, Jian Shi, and Baihui. The stimulation starts at 15 minutes before anesthesia induction and ends at 15 minutes after anesthesia induction.

Primary outcomes

• The area under the curve representing the change in mean arterial pressure during the induction period relative to the baseline. [from start of induction to 15 minutes after induction]: The MAP is continuously recorded by the DoCare Information System every 30 seconds. The AUC below baseline MAP is calculated as: ∑ (((Si - Sbaseline)+(Si-1 - Sbaseline))/2 × ΔX), where Sbaseline is the baseline MAP, Si is the MAP at minute i (i = 0.5, 1, 1.5, …, 15) after start of anesthesia induction, and ΔX is the time interval between measurements.

Secondary outcomes

• Incidence of hypotension during the induction period [from start of induction to 15 minutes after induction]
• The dosage of vasoactive drugs [from start of induction to 15 minutes after induction]
• The incidence of major complications (cardiovascular adverse events, acute kidney injury, delirium) [from end of surgery to discharge from the hospital, at an average of 5 days]
• Length of hospital stay [from end of surgery to discharge from the hospital, at an average of 5 days]
• The rate of patients admitted to the intensive care unit (ICU) after surgery [from end of surgery to discharge from the hospital, at an average of 5 days]
• The rate of patients achieving the best recovery after surgery (discharged within 5 days after surgery, without major complications, no incision infection, no readmission, and survive within 30 days after surgery) [from end of surgery to 30 days after surgery]
• The score of the discharge quality assessment scale [at discharge from the hospital, at an average of 5 days after surgery]: Quality of Recovery, QoR-15 15 items across 5 dimensions: physical comfort, physical independence, psychological support, emotional state, and pain. Each item is scored from 0 to 10. The total score ranges from 0 to 150, with a higher score representing better recovery. A change of 8 points or more is considered a Minimally Clinically Important Difference (MCID), meaning a meaningful improvement or decline from the patient's perspective.

Sex: All, ages: 60 Years to any

Inclusion Criteria:

* The age of the patients is 60 years or older;
* Patients who are scheduled to undergo TAVR surgery under general anesthesia;

Exclusion Criteria:

* Body mass index less than 18 kg/m2 or greater than 30 kg/m2;
* Hemodynamic instability (severe arrhythmia, decompensated heart failure);
* Hypotension after admission requiring intervention with vasoactive drugs;
* Severe liver or kidney dysfunction;
* Those who are contraindicated for electrical stimulation, including those with local skin damage, infection, or having implanted electrophysiological devices in the body.