hourglass pattern

hour·glass pat·tern

a vigorous ringlike contraction observed angiographically in the left ventricular angiogram in the right anterior oblique projection, resembling an hourglass; it is seen in the prolapsed mitral valve leaflet syndrome.
References in periodicals archive ?
It often has a black and white geometric pattern on its dorsal abdomen and a ventral abdominal orange to yellowish hourglass pattern. Its envenomations can be severe.
I instantly ran through a mental checklist: large triangular head; thick, heavy body; brown and tan hourglass pattern; vertical pupils.
Common dolphins, slim and streamlined with precise markings and an hourglass pattern on their sides streaked around and under the boat, twisting and turning as they rode on the bow wave.
This, by the way, was the only one of two dozen spectacular Badula corundum crystals which showed the hourglass pattern distinctly.