An Unusual Cause of Exercise Dyspnea and Hypoxia After Cardiac Surgery

Dyspnea is a cardinal clinical feature of post-cardiac surgery patients, resulting from the most important post-surgical complications, whether they are cardiac or pulmonary related. Cardiac rehabilitation is the setting of a multidisciplinary approach where post-operative transthoracic echocardiogram (TTE) and cardiopulmonary exercise test (CPET) can be used to allow early identification of the dyspnea causes including cardiovascular and respiratory. In this paper we examined the case of 52-years-old woman, affected by mitral valve prolapse with severe regurgitation associated with mild-to-moderate tricuspid regurgitation and mild increase in pulmonary artery pressure, treated surgical with mitral and tricuspid valvuloplasty (Guiraudon approach). In the post-surgery phase, the patient complained a persistent dyspnoea during minimal effort with evidence of mild hypoxemia at rest and of significant drop in oxygen saturation during effort. At TTE, a large ostium secundum type atrial septal defect was detected with a significant bi-directional shunt, confirmed by transesophageal approach. The patient underwent to a repeat cardiac surgery during which a large opening of the interatrial septum correction due to the rupture of the suture thread was corrected. The post-operative phase was regular. The TTE showed a good outcome of mitro-tricuspid valve repair and a stable closure of the atrial septum and the CPET data demonstrated significant improvement of functional capacity without oxygen desaturation. In conclusion, this clinical case demonstrated the need of a multiparametric approach and the crucial role of experts-performed and surgery-technique-guided instrumental insights in the common challenge of dyspnea and oxygen desaturation at rest and during exercise after cardiac surgery.