Albarado Ibáñez A.1, Berra Romani R 2, Hernández García V.3 Sanchez-Chapula J.A4. Torres-Jacome J.1, 1IF, 2Facultad de Medicina. Benemérita Universidad Autónoma Puebla, 3ICB, Universidad Autónoma de Ciudad Juárez. 4CUIB, Universidad de Colima, México Diabetes mellitus (DM) has been considered as a cardiovascular disease. The patients with DM show alterations of segment QT of the ECG. It has been reported that these ventricular alterations are responsible for taquiarritmias. 90% of taquiarritmias supraventricular are originated in the node to auriculoventricular (NAV). For this reason we decided to study the alterations that the DM in the electrical activity of the NAV causes. We used male rabbits New Zealand between 1.5-2 kg. The DM was induced by the administration of a unique dose of Alloxan (200 mg/Kg of weight IV). Twelve weeks after the administration, the rabbits were anesthetized with sodium pentobarbital; we dissected the NAV and recording their spontaneous activity to temperature of 35 degree. The treatment of the animals was approved by the committee of ethics of the University of Colima México. In conditions control, we characterized two types of Action Potential (AP) (nodales and transicionales) p< 0.05, n= 21. The nodales cells have a maximal velocity of depolarization (MVD) of 10.5 ± 2 V/s, they have amplitude of 84.2 ± 8 mV, slope of phase 4 (S4) of 0,021 ± 0.01 V/s and a threshold of -50.4 ± 9.9 mV. Whereas the transicionales cells have an amplitude of 95.2 ± 11 mV a MVD 30.8 ± 13 V/s, an S4 of 0,006 ± 0.004 V/s and a threshold of -71 ±. 6 mV We used the statistical test t-student for data nonmatched up, the results appear with the mean value ± SD. Comparing the control nodales cells versus Diabetic, we found that the amplitude increased the 6.3% and in diabetic transicionales cells in the VMD we found a diminution of 47.4% we registered an increase in the S4 of 79% like in the Potential threshold of a 37.8%. Let us think that these changes are explained because the DM diminishes the currents density that participates in the AP. We constructed to the Poincaré plots of control and diabetic, using the time of appearance between a pair of AP (ti) versus the time of appearance of the following pair of AP (ti+1). In both cases the graphs are delimited by an ellipse. Making the quotient of the smaller between the greater ellipse axis, we determined that the value in control is of 0.28 and for diabetics it is of 0.522, which this associate with a greater probability of deaths by arrhythmias.