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.
Arrhythmia refers to any kind of abnormal heart rhythm. There are two types of arrhythmias: atrial arrhythmia, also called supraventricular arrhythmia, which begins in the upper chambers of the heart, and ventricular arrhythmia, which begins in the lower chambers of the heart.