Electromechanical effects of sitagliptin on left atrium (LA). An example and average data (n = 7) show that the RMP, APA, APD20, APD50 of LA are not different between WKY and SHR with or without sitagliptin treatment. The treatment of sitagliptin decreased the APD90 of WKY LA, but did not change the APD90 of SHR LA. The treatment of sitagliptin decreased the contractile forces of WKY LA, but did not change the contractile forces of SHR LA.