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 Definition. A heart arrhythmia is an irregular heart beat: the beat may be too fast, too slow, or the rhythm may be irregular. Types. Arrhythmias can be classified by their origin (atria or ventricles) and by heart rate. Tachycardia. A fast (over 100 beats per minute) heart rate is called tachycardia.