Chordae tendineae rupture: a rare cause of tricuspid regurgitation following coronary artery bypass grafting

BACKGROUND: Tricuspid regurgitation is classified broadly by its etiology being either structural or functional. New or worsening tricuspid regurgitation upon weaning from cardiopulmonary bypass is rare and often functional. However, iatrogenic structural causes are possible and should be investigated with a high index of suspicion when issues separating from cardiopulmonary bypass arise. Currently, isolated coronary artery bypass grafting is not a class I indication for intraoperative transesophageal echocardiography, leading to significant practice variation. However, intraoperative transesophageal echocardiography, even during routine isolated coronary artery bypass grafting, can be a valuable tool in differentiating between functional and structural causes of post-cardiopulmonary bypass tricuspid regurgitation, allowing for prompt surgical intervention when required. CASE PRESENTATION: We report a case of a 63-year-old female, American Society of Anesthesiologists physical status 4, who underwent an isolated coronary artery bypass grafting surgery and subsequently developed difficulty weaning from cardiopulmonary bypass after completion of revascularization. Intraoperative transesophageal echocardiography revealed severe tricuspid regurgitation with evidence of right ventricular dysfunction which was initially presumed to be functional in etiology. However, further investigation with transesophageal echocardiography revealed a flail posterior tricuspid valve leaflet with an anteriorly directed jet. The decision was made to re-institute cardiopulmonary bypass for prompt surgical correction of what was determined to be an acutely ruptured chordae tendineae originating from an anomalous papillary muscle of the posterior tricuspid leaflet. Successful surgical repair was performed with neochord implantation and a 26 mm tricuspid annuloplasty ring. Final intraoperative transesophageal echocardiography demonstrated mild residual tricuspid regurgitation with normal biventricular size and systolic function and the patient was subsequently weaned off cardiopulmonary bypass without issue. CONCLUSIONS: We describe a case of a ruptured chordae tendineae causing new severe tricuspid regurgitation after an isolated coronary bypass grafting surgery. The use of intraoperative transesophageal echocardiography was essential for the prompt diagnosis and surgical correction of this rare structural cause of post-cardiopulmonary tricuspid regurgitation. This case lends support to the routine use of intraoperative transesophageal echocardiography in isolated coronary artery bypass grafting surgery.