title: Noninvasive assessment of cardiac output by brachial occlusion-cuff technique: comparison with the open-circuit acetylene washin method.
abstract: Cardiac output (CO) assessment as a basic hemodynamic parameter has been of interest in exercise physiology, cardiology, and anesthesiology. Noninvasive techniques available are technically challenging, and thus difficult to use outside of a clinical or laboratory setting. We propose a novel method of noninvasive CO assessment using a single, upper-arm cuff. The method uses the arterial pressure pulse wave signal acquired from the brachial artery during 20-s intervals of suprasystolic occlusion. This method was evaluated in a cohort of 12 healthy individuals (age, 27.7 ± 5.4 yr, 50% men) and compared with an established method for noninvasive CO assessment, the open-circuit acetylene method (OpCirc) at rest, and during low- to moderate-intensity exercise. CO increased from rest to exercise (rest, 7.4 ± 0.8 vs. 7.2 ± 0.8; low, 9.8 ± 1.8 vs. 9.9 ± 2.0; moderate, 14.1 ± 2.8 vs. 14.8 ± 3.2 l/min) as assessed by the cuff-occlusion and OpCirc techniques, respectively. The average error of experimental technique compared with OpCirc was -0.25 ± 1.02 l/min, Pearson's correlation coefficient of 0.96 (rest + exercise), and 0.21 ± 0.42 l/min with Pearson's correlation coefficient of 0.87 (rest only). Bland-Altman analysis demonstrated good agreement between methods (within 95% boundaries); the reproducibility coefficient (RPC) = 0.84 l/min with R2= 0.75 at rest and RPC = 2 l/min with R2= 0.92 at rest and during exercise, respectively. In comparison with an established method to quantify CO, the cuff-occlusion method provides similar measures at rest and with light to moderate exercise. Thus, we believe this method has the potential to be used as a new, noninvasive method for assessing CO during exercise.
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota; Sajgalik.Pavol@mayo.edu.|1st Department of Internal Medicine, Cardio Angiology-International Clinical Research Center, Masaryk University; Brno, Czech Republic.
authors.forename: Pavol
authors.initials: P
authors.lastname: Sajgalik
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota.|Czech Institute of Informatics, Robotics, and Cybernetics, Czech Technical University in Prague, Prague, Czech Republic; and.
authors.forename: Vaclav
authors.initials: V
authors.lastname: Kremen
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota.
authors.forename: Alex R
authors.initials: AR
authors.lastname: Carlson
authors.affiliation: Department of Physics, Czech Technical University in Prague, Prague, Czech Republic.
authors.forename: Vratislav
authors.initials: V
authors.lastname: Fabian
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota.
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota.
authors.forename: Courtney
authors.initials: C
authors.lastname: Wheatley
authors.affiliation: Czech Institute of Informatics, Robotics, and Cybernetics, Czech Technical University in Prague, Prague, Czech Republic; and.
authors.forename: Vaclav
authors.initials: V
authors.lastname: Gerla
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota.
authors.forename: John A
authors.initials: JA
authors.lastname: Schirger
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Olson
authors.affiliation: Department of Internal Medicine; Division of Cardiovascular Diseases, Mayo Clinic & Foundation, Rochester, Minnesota.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Johnson
mesh_terms: D000114:Acetylene / Q000494:pharmacology; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001916:Brachial Artery / Q000187:drug effects / Q000502:physiology*; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology
chemical_list: D000114:Acetylene
keywords: brachial cuff; cardiac output; noninvasive; occlusion