Complications of gastroscopy include -

• Perforation of esophagus or stomach - The upper esophagus appears most vulnerable to injury during the procedure.(6^✔) Perforation of the esophagus may also be more common in patients with esophageal cancer, strictures, or cervical osteophytes (small bony projections in the spine of the neck).
• Bleeding - Bleeding is considered rare even after biopsies, at 0.3/1000 cases. In most cases, bleeding is not due to a coagulation defect; rather it results from biopsy of friable tissue.
• Heart complications - Significant cardiac arrhythmias (abnormal cardiac rhythms) are distinctly unusual. If a Holter monitor is placed, transient rhythm disturbances such as sinus tachycardia, premature ventricular contractions (PVCs), premature atrial contractions (PACs), and rarely ischemic changes (changes due to reduced blood supply) may be recorded in 22% of cases. Few adverse clinical outcomes have been reported.
• Lung infections due to vomiting and aspiration during the procedure.