Myocardial ischemia in aortic stenosis: insights from arterial pulse-wave dynamics after percutaneous aortic valve replacement.

Wave-intensity analysis is a technique that can qualify both the direction and magnitude of the forces accelerating and decelerating coronary blood flow and is derived from simultaneously acquired measures of coronary pressure and velocity using invasive intracoronary wires. Using this technique during TAVI, the dominant force (or 'wave') acting to increase the coronary blood flow which originates from microvascular relaxation is shown to be elevated in severe aortic stenosis and decreased post-implantation. Additionally, with increasing heart rate a progressive fall in the magnitude of this wave is noted and after TAVI this effect is reversed (returning towards the physiological norm). The potential causes of myocardial ischemia in aortic stenosis are clearly multi-factorial but this observation suggests a decoupling between the aorta and myocardium in aortic stenosis, the effects of which are magnified during increased heart rate.