title: Progressive and biphasic cardiac responses during extreme mountain ultramarathon.
abstract: Investigations on the cardiac function consequences of mountain ultramarathon (MUM) >100 h are lacking. The present study assessed the progressive cardiac responses during the world's most challenging MUM (Tor des Géants; Italy; 330 km; 24,000 m of cumulative elevation gain). Resting echocardiographic evaluation of morphology, function, and mechanics of left and right ventricle (LV and RV) including speckle tracking echocardiography was conducted in 15 male participants (46 ± 13 yr) before (pre), during (mid; 148 km), and after (post) the race. Runners completed the race in 126 ± 15 h. From pre to post, the increase in stroke volume (SV) (103 ± 19 vs. 110 ± 23 vs. 116 ± 21 ml; P < 0.001 at pre, mid, and post) was concomitant to the increase in LV early filling (peak E; 72.9 ± 15.7 vs. 74.6 ± 13.1 vs. 82.1 ± 11.5 cm/s; P < 0.05). Left and right atrial end-diastolic areas, RV end-diastolic area, and LV end-diastolic volume were 12-19% higher at post compared with pre (P < 0.05). Resting heart rate and LV systolic strain rates demonstrated a biphasic adaptation with an increase from pre to mid (55 ± 8 vs. 72 ± 11 beats/min, P < 0.001) and a return to baseline values from mid to post (59 ± 8 beats/min). Significant correlations were found between pre-to-post percent changes in peak E and LV end-diastolic volume (r = 0.63, P < 0.05) or RV (r = 0.82, P < 0.001) or atrial end-diastolic areas (r = 0.83, P < 0.001). An extreme MUM induced a biphasic pattern of heart rate in parallel with specific cardiac responses characterized by a progressive increase in diastolic filling, biventricular volumes, and SV. The underlying mechanisms and their clinical implications remain challenging for the future.
authors.affiliation: Avignon University, LAPEC EA 4278, F-84000, Avignon, France;
authors.forename: Claire
authors.initials: C
authors.lastname: Maufrais
authors.affiliation: ISSUL Institute of Sport Sciences, Faculty of Biology and Medicine, Department of Physiology-University of Lausanne, Lausanne, Switzerland;
authors.forename: Grégoire P
authors.initials: GP
authors.lastname: Millet
authors.affiliation: Dysfunction of Vascular Interfaces Research Laboratory, Faculty of Medicine, Montpellier I University and Nîmes University Hospital Center, Nîmes, France; and.
authors.forename: Iris
authors.initials: I
authors.lastname: Schuster
authors.affiliation: Laboratory of Exercise Physiology, University of Savoie, Chambery, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rupp
authors.affiliation: Avignon University, LAPEC EA 4278, F-84000, Avignon, France; stephane.nottin@univ-avignon.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Nottin
mesh_terms: D000064:Acclimatization; D000328:Adult; D000531:Altitude; D059267:Cardiomegaly, Exercise-Induced; D003971:Diastole; D015150:Echocardiography, Doppler; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology*; D012420:Running; D013599:Systole; D013997:Time Factors; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D055815:Young Adult
keywords: diastolic function; exercise-induced cardiac fatigue; speckle tracking echocardiography