A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether there was a difference in postoperative outcomes [namely permanent pacemaker (PPM) insertion, rhythm disturbance, reoperation for bleeding, hospital stay and in-hospital mortality] between trans-septal or superior (extended) trans-septal (STS) approaches in comparison with the conventional left atriotomy (LA) used in mitral valve surgery. Using the reported search strategy, 353 papers were found of which 11 represented the best evidence to answer the clinical question. The authors, journal, year and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Two papers compared all 3 atrial incisions with neither showing a difference in PPM implantation rate, whereas 2 papers compared just the trans-septal with the LA approach, again both finding no significant difference in PPM implantation. Seven studies compared the STS approach with the LA approach with regard to PPM implantation; 1 study showed that the STS approach was an independent risk factor for PPM implantation, PPM insertion was not necessary in 2 studies and there was no difference in PPM insertion in 4 studies. Postoperative junctional rhythm was studied in 5 papers that compared the STS approach with the LA approach; junctional rhythm was more prevalent in the STS approach in 2 studies, albeit transient, whereas 3 papers did not show a significant difference. Mortality, hospital stay and re-exploration for bleeding did not differ among the 3 groups.