Electrocardiographic changes during upper gastrointestinal endoscopy in ambient hypoxia

Area of Science:

• Cardiology
• Gastroenterology
• Altitude Medicine

Background:

• Upper GI endoscopy is a common procedure.
• High altitude environments present unique physiological challenges due to hypoxia.
• The impact of ambient hypoxia on cardiac function during endoscopy is not well-established.

Purpose of the Study:

• To evaluate electrocardiographic (ECG) changes during and after upper GI endoscopy.
• To assess the safety of the procedure in ambient hypoxia at high altitude (2200 m).
• To identify patient factors influencing ECG alterations.

Main Methods:

• Prospective study of 120 consecutive subjects undergoing upper GI endoscopy.
• ECG monitoring during and after the procedure without premedication.
• Analysis of ECG parameters stratified by age, sex, and cardiac disease status.
• Subjects were studied at high altitude (Shimla, 2200 m) with ambient hypoxia (PO2-120 mmHg).

Main Results:

• Significant increase in heart rate observed in 96.6% of subjects, most pronounced in cardiac patients.
• ST depression occurred in 14.2%, T wave inversion in 13.3%, supraventricular tachycardia in 5.8%, and ventricular ectopics in 1.6%.
• ST depression was more frequent in patients with cardiac diseases (P < 0.001), and T wave inversion was more frequent in women (P < 0.001).

Conclusions:

• Upper GI endoscopy in ambient hypoxia at high altitude is a safe procedure, even without premedication.
• Observed ECG changes are transient and revert to normal within 10 minutes post-procedure.
• The study highlights the need for careful ECG monitoring in susceptible patient groups during endoscopy at high altitudes.