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.
What is an arrhythmia (heart rhythm disorder)? Arrhythmias are abnormalities of the heartbeat. There are many types of arrhythmias, and they are classified by some researchers and doctors by where they begin in the heart (the atria, AV node, or the ventricles). Others classify arrhythmias as one of four types -- premature beats, supraventricular, ventricular, and bradyarrhythmias.