What are percussion wave and tidal wave?

What are percussion wave and tidal wave?

Percussion wave and tidal wave are the waves seen on a pulse tracing. Reflected wave from the periphery is thought to be the mechanism behind the tidal wave which occurs after the percussion wave which is due to the direct transmission of the left ventricular ejection. Percussion wave is noted mainly in the central aorta, brachiocephalic and carotid arteries. Usually percussion wave is taller than the tidal wave. But in the elderly with increased peripheral resistance, the tidal wave may be taller so that the pulse may peak later in systole.