Primary concerns in patients with MS include management of heart rate, ventricular preload, potentially diminished right and left ventricular contractile function, and coexisting pulmonary hypertension. The most important hemodynamic goal is to avoid tachycardia (keep heart rate within its normal range). Tachycardia is poorly tolerated because of the decreased time for diastolic filling. Also, pressure gradients are somewhat flow-dependent in MS. Elevated flow states, such as increased sympathetic activity from any source, can dramatically increase the pressure gradient across the valve. Echocardiographically, the concept of valve gradients is derived through the use of a modified form of Bernoulli’s equation, ΔP = 4v2, where “v” is the measured velocity of blood flow through the valve. Thus, any increase in transvalvular flow rate caused by an increase in heart rate will have a significant impact on transvalvular flow dynamics and on left atrial pressure.