A system for optimizing right ventricular cardiac pacing for a patient, the system comprising: an internal pacing device implanted in the patient's body and configured to: determine a first atrial event at a first time and second atrial event at a second time; and pace the patient's right ventricle after a first atrioventricular pacing delay elapses after sensing the first atrial event, and pace the patient's right ventricle after a second atrioventricular pacing delay elapses that differs from the first right ventricular pacing delay after sensing the second atrial event; a set of external electrodes configured to detect first torso-surface potential signals in response to pacing the patient's right ventricle after the first right ventricular pacing delay elapses, and configured to detect second torso-surface potential signals in response to pacing the patient's right ventricle after the second right ventricular pacing delay elapses; and an external computing device configured to: compare the first torso-surface potential signals with the second torso-surface potential signals; and determine an appropriate correction factor for future right ventricular cardiac pacing for the patient based on the comparison; characterized in that the first torso-surface potential signals are compared with the second torso-surface potential signals by comparing a global cardiac electrical heterogeneity represented by the first signals with a global cardiac electrical heterogeneity represented by the second signals; and wherein the correction factor is selected for future right ventricular only cardiac pacing based on the global cardiac electrical heterogeneity comparison indicating that applying the correction factor results in a lower global electrical heterogeneity. determine a first atrial event at a first time and second atrial event at a second time; and pace the patient's right ventricle after a first atrioventricular pacing delay elapses after sensing the first atrial event, and pace the patient's right ventricle after a second atrioventricular pacing delay elapses that differs from the first right ventricular pacing delay after sensing the second atrial event; a set of external electrodes configured to detect first torso-surface potential signals in response to pacing the patient's right ventricle after the first right ventricular pacing delay elapses, and configured to detect second torso-surface potential signals in response to pacing the patient's right ventricle after the second right ventricular pacing delay elapses; and an external computing device configured to: compare the first torso-surface potential signals with the second torso-surface potential signals; and determine an appropriate correction factor for future right ventricular cardiac pacing for the patient based on the comparison; characterized in that the first torso-surface potential signals are compared with the second torso-surface potential signals by comparing a global cardiac electrical heterogeneity represented by the first signals with a global cardiac electrical heterogeneity represented by the second signals; and wherein the correction factor is selected for future right ventricular only cardiac pacing based on the global cardiac electrical heterogeneity comparison indicating that applying the correction factor results in a lower global electrical heterogeneity. compare the first torso-surface potential signals with the second torso-surface potential signals; and determine an appropriate correction factor for future right ventricular cardiac pacing for the patient based on the comparison; characterized in that the first torso-surface potential signals are compared with the second torso-surface potential signals by comparing a global cardiac electrical heterogeneity represented by the first signals with a global cardiac electrical heterogeneity represented by the second signals; and wherein the correction factor is selected for future right ventricular only cardiac pacing based on the global cardiac electrical heterogeneity comparison indicating that applying the correction factor results in a lower global electrical heterogeneity.