title: Organ perfusion during voluntary pulmonary hyperinflation; a magnetic resonance imaging study.
abstract: Pulmonary hyperinflation is used by competitive breath-hold divers and is accomplished by glossopharyngeal insufflation (GPI), which is known to compress the heart and pulmonary vessels, increasing sympathetic activity and lowering cardiac output (CO) without known consequence for organ perfusion. Myocardial, pulmonary, skeletal muscle, kidney, and liver perfusion were evaluated by magnetic resonance imaging in 10 elite breath-hold divers at rest and during moderate GPI. Cardiac chamber volumes, stroke volume, and thus CO were determined from cardiac short-axis cine images. Organ volumes were assessed from gradient echo sequences, and organ perfusion was evaluated from first-pass images after gadolinium injection. During GPI, lung volume increased by 5.2 ± 1.5 liters (mean ± SD; P < 0.001), while spleen and liver volume decreased by 46 ± 39 and 210 ± 160 ml, respectively (P < 0.05), and inferior caval vein diameter by 4 ± 3 mm (P < 0.05). Heart rate tended to increase (67 ± 10 to 86 ± 20 beats/min; P = 0.052) as right and left ventricular volumes were reduced (P < 0.05). Stroke volume (107 ± 21 to 53 ± 15 ml) and CO (7.2 ± 1.6 to 4.2 ± 0.8 l/min) decreased as assessed after 1 min of GPI (P < 0.01). Left ventricular myocardial perfusion maximum upslope and its perfusion index decreased by 1.52 ± 0.15 s(-1) (P < 0.001) and 0.02 ± 0.01 s(-1) (P < 0.05), respectively, without transmural differences. Pulmonary tissue, spleen, kidney, and pectoral-muscle perfusion also decreased (P < 0.05), and yet liver perfusion was maintained. Thus, during pulmonary hyperinflation by GPI, CO and organ perfusion, including the myocardium, as well as perfusion of skeletal muscles, are reduced, and yet perfusion of the liver is maintained. Liver perfusion seems to be prioritized when CO decreases during GPI.
authors.affiliation: Cardiac MRI Group, Department of Cardiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark; kasperkyhl@gmail.com.
authors.forename: Kasper
authors.identifier: http://orcid.org/0000-0001-6570-1674
authors.initials: K
authors.lastname: Kyhl
authors.affiliation: School of Kinesiology, University of Zagreb, Zagreb, Croatia;
authors.forename: Ivan
authors.initials: I
authors.lastname: Drvis
authors.affiliation: Department of Integrative Physiology, School of Medicine, University of Split, Split, Croatia; Department of Physiology, School of Medicine, University of Novi Sad, Novi Sad, Serbia;
authors.forename: Otto
authors.initials: O
authors.lastname: Barak
authors.affiliation: Department of Integrative Physiology, School of Medicine, University of Split, Split, Croatia;
authors.forename: Tanja
authors.initials: T
authors.lastname: Mijacika
authors.affiliation: Cardiac MRI Group, Department of Cardiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Thomas
authors.initials: T
authors.lastname: Engstrøm
authors.affiliation: Department of Anesthesiology, The Copenhagen Muscle Research Center, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Niels H
authors.initials: NH
authors.lastname: Secher
authors.affiliation: Department of Integrative Physiology, School of Medicine, University of Split, Split, Croatia;
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Dujic
authors.affiliation: Department of Radiology, Clinical Hospital Center, Split, Croatia; and.
authors.forename: Ante
authors.initials: A
authors.lastname: Buca
authors.affiliation: Cardiac MRI Group, Department of Cardiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark; Department of Cardiology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Per Lav
authors.initials: PL
authors.lastname: Madsen
mesh_terms: D000328:Adult; D062485:Breath Holding; D002302:Cardiac Output / Q000502:physiology*; D002306:Cardiac Volume / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D004242:Diving; D005260:Female; D006801:Humans; D008102:Liver Circulation / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply*; D011652:Pulmonary Circulation / Q000502:physiology*; D012039:Regional Blood Flow; D012079:Renal Circulation / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology
keywords: cardiac output; humans; kidney blood flow; liver blood flow; magnetic resonance imaging