RT Journal Article SR Electronic T1 Heart rate variability with deep breathing as a clinical test of cardiovagal function JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP S37 OP S40 DO 10.3949/ccjm.76.s2.08 VO 76 IS 4 suppl 2 A1 Robert W. Shields, Jr. YR 2009 UL http://www.ccjm.org/content/76/4_suppl_2/S37.abstract AB Research into heart rate variability (HRV) and respiration over the past 150 years has led to the insight that HRV with deep breathing (HRVdb) is a highly sensitive measure of cardiovagal or parasympathetic cardiac function. This sensitivity makes HRVdb an important part of the battery of cardiovascular autonomic function tests used in clinical autonomic laboratories. HRVdb is a reliable and sensitive clinical test for early detection of cardiovagal dysfunction in a wide range of autonomic disorders.