With the first ribs fixed by neck muscles (scalene muscles and sternocleidomastoid muscle), the intercostals muscles (especially external intercostal muscles and interchondral part of internal intercostal muscles of opposite side), elevate the 2nd to 12th ribs and thus act as inspiratory muscles.
Medical Dictionary. arrhythmia. play. noun arÂ·rhythÂ·mia \Ä-Ërith-mÄ-É\. Medical Definition of arrhythmia. : an alteration in rhythm of the heartbeat either in time or force.
An arrhythmia is any irregularity in the heart's rhythm. If the heart beats more rapidly than normal, this arrhythmia is called tachycardia. An unpleasant sensation in the heart, whether rapid or slow, regular or irregular, and of which one is consciously aware, is called a palpitation.