Heart rate influence on the systolic gradient across the stenotic aortic valve: theoretical evaluation and implications.

Peak systolic gradient across the aortic value, measured invasively or noninvasively is used in many laboratories for estimation of the severity of the stenosis (= actual valve area). This study shows that when cardiac output is normal the gradient across the valve is influenced by heart rate (HR) apart from valve area. A rate-corrected peak systolic gradient (PSGc) is defined by the formula (formula; see text) and its importance for clinical decision making is demonstrated. The significance of bradycardia in the pathogenesis of syncope in aortic stenosis is discussed.