Source:http://linkedlifedata.com/resource/umls/id/C0003813
MSH: Irregular HEART RATE caused by abnormal function of the SINOATRIAL NODE. It is characterized by a greater than 10% change between the maximum and the minimum sinus cycle length or 120 milliseconds.,NCI: Irregularity of the heartbeat due to a variation in the sinus rhythm resulting in cyclic changes in the heart rate during breathing. This rhythm is most commonly seen with breathing due to fluctuations in parasympathetic vagal tone. During inspiration stretch receptors in the lungs stimulate the cardioinhibitory centers in the medulla via fibers in the vagus nerve. Irregularity of the heartbeat due to a variation in the sinus rhythm resulting in cyclic changes in the heart rate during breathing. This rhythm is most commonly seen with breathing due to fluctuations in parasympathetic vagal tone. During inspiration stretch receptors in the lungs stimulate the cardioinhibitory centers in the medulla via fibers in the vagus nerve.,NCI: Irregularity of the heartbeat due to a variation in the sinus rhythm result