The colitis-induced increase in AngII signaling attenuated the conduction velocity and increased APD through the remodeling of INa, intercellular coupling, and Ito,f. The results are consistent with clinical reports showing an increased vulnerability of colitis patients to atrial arrhythmia, and suggest that in especially hypertensive colitis patients, ACE inhibitors should be the treatment of choice, and increased RAS signaling could serve as a marker for colitis patients at risk for atrial arrhythmia. The gene discussed is AGT; the disease is colitis.