A system and method for cardiac resynchronization therapy in which pacing control parameters are automatically adjusted by comparison of local electrograms acquired by a cardiac implantable electrical device with a model of cardiac electrical activity derived from surface-lead electrocardiograph measurements under baseline and paced conditions is provided. The adjusted pacing control parameters guarantee substantially maximum evidence of ventricular activation wavefront fusion while reducing the risk of compromising diastolic function. Atrioventricular intervals (AVIs] are measured and utilized to constrain the adjustment of pacing control parameters such that diastolic dysfunctions are not induced in the patient's heart.
