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 an abnormal rate and/or rhythm of the heartbeat. There are various types, but all are due to some problem with the electrical conducting system of the heart. Some arrhythmias are more serious than others. Some come and go (are intermittent); others are permanent unless treated.