颤动 chàndòng to vibrate Origin Definitions Defs Strokes Stroke Words Sentences Sents 心室颤动 xīnshìchàndòng ventricular fibrillation A serious heart rhythm problem where the lower chambers of the heart quiver instead of pumping blood; often referred to as V-fib.心房颤动 xīnfángchàndòng atrial fibrillation A condition where the heart's upper chambers beat irregularly and fast.