INTRODUCTION:
Right ventricular (RV) dysfunction in the setting of chronic mitral regurgitation (MR) is common and occurs as a result of intrinsic myocardial dysfunction, maladaptive left ventricular (LV) remodeling, impaired ventricular septal motion, and pericardial constraint imposed by progressive LV volume overload [1-6]. Pulmonary hypertension secondary to severe MR exacerbates RV dysfunction by increasing RV afterload. RV dysfunction may be further exacerbated by tricuspid valve regurgitation (TR), which results from progressive RV and tricuspid annular dilatation. RV dysfunction has important prognostic implications following mitral valve surgery [7, 8], and both impaired RV function and pulmonary hypertension are independent predictors of long-term post-operative cardiovascular mortality [2, 3, 9-11]. Patients with impaired RV function and significant pulmonary hypertension are frequently excluded from conventional surgical repair but might benefit from transcatheter mitral valve (MV) interventions. Transapical transcatheter mitral valve implantation (TMVI) is an emerging therapeutic alternative to conventional MV surgery for patients deemed to be at prohibitively high risk. The objective of our study was to examine the immediate and short-term impact of transapical TMVI using the Tendyne mitral valve system [12, 13] on RV loading and function.