Electrocardiographic studies during hypotensive anaesthesia using sodium nitroprusside.

Area of Science:

• Cardiology
• Anesthesiology
• Cardiovascular Physiology

Background:

• Induced hypotension is used during surgery to reduce blood loss.
• Sodium nitroprusside is a potent vasodilator used for inducing hypotension.
• Potential effects of induced hypotension on myocardial ischemia require careful evaluation.

Purpose of the Study:

• To assess the impact of sodium nitroprusside-induced hypotension on myocardial ischemia.
• To evaluate electrocardiographic changes during and after induced hypotension.
• To determine if temporary hypotension causes permanent cardiac damage.

Main Methods:

• Electrocardiographic (ECG) recordings from multiple leads were obtained.
• 20 patients undergoing induced hypotension with sodium nitroprusside were studied.
• ECG data were analyzed before, during, and after the hypotensive period.

Main Results:

• Minor ST segment and T wave changes were noted in 9 patients, but resolved postoperatively.
• Temporary cardiac rhythm disturbances occurred in 2 patients, spontaneously reverting to sinus rhythm.
• No persistent ischemic myocardial changes were detected in any patient.

Conclusions:

• Induced hypotension with sodium nitroprusside does not appear to cause permanent myocardial ischemic changes.
• Temporary ECG alterations and arrhythmias during the procedure are reversible.
• The findings support the safety of using sodium nitroprusside for induced hypotension regarding myocardial ischemia.