Objectives <p>Left atrial (LA) and left ventricular (LV) venting during open-heart surgery is essential for myocardial protection, maintaining a bloodless field, and facilitating air removal. However, catheter malposition and inadequate venting are not uncommon because of limited visibility. Although transesophageal echocardiography (TEE) can assist in catheter monitoring, TEE-guided management strategies remain underreported. This study aimed to characterize catheter-related issues and describe effective troubleshooting approaches.</p> Methods <p>We retrospectively analyzed intraoperative TEE findings in 304 patients who underwent open-heart surgery at Kochi University Hospital, including 200 with LV venting and 104 with LA venting. TEE records of catheter-related events and corrective maneuvers were reviewed, and challenges in TEE assessment were identified.</p> Results <p>No catheter-related injuries were observed. In the LV group, TEE identified failure of ventricular entry (n = 5), impingement on papillary muscles or the apex (n = 18), and catheter-induced mitral regurgitation (n = 11). Residual air was frequently localized distant from the catheter tip. In the LA group, misplacement into pulmonary veins (n = 9) or the left atrial appendage (LAA) (n = 2) was noted. Venting was ineffective in cases of acute LV distension during antegrade cardioplegia or due to Thebesian venous return. In some cases, deep catheter placement resulted in incomplete drainage of the right-sided LA.</p> Conclusions <p>Both LA and LV venting have distinct pitfalls. TEE facilitates identification and correction of catheter-related problems, but structured training in TEE assessment is essential to optimize outcomes.</p>