title: The acute phase of experimental cardiogenic shock is counteracted by microcirculatory and mitochondrial adaptations.
abstract: The mechanisms contributing to multiorgan dysfunction during cardiogenic shock are poorly understood. Our goal was to characterize the microcirculatory and mitochondrial responses following ≥ 10 hours of severe left ventricular failure and cardiogenic shock. We employed a closed-chest porcine model of cardiogenic shock induced by left coronary microembolization (n = 12) and a time-matched control group (n = 6). Hemodynamics and metabolism were measured hourly by intravascular pressure catheters, thermodilution, arterial and organ specific blood gases. Echocardiography and assessment of the sublingual microcirculation by sidestream darkfield imaging were performed at baseline, 2 ± 1 and 13 ± 3 (mean ± SD) hours after coronary microembolization. Upon hemodynamic decompensation, cardiac, renal and hepatic mitochondria were isolated and evaluated by high-resolution respirometry. Low cardiac output, hypotension, oliguria and severe reductions in mixed-venous and hepatic O2 saturations were evident in cardiogenic shock. The sublingual total and perfused vessel densities were fully preserved throughout the experiments. Cardiac mitochondrial respiration was unaltered, whereas state 2, 3 and 4 respiration of renal and hepatic mitochondria were increased in cardiogenic shock. Mitochondrial viability (RCR; state 3/state 4) and efficiency (ADP/O ratio) were unaffected. Our study demonstrates that the microcirculation is preserved in a porcine model of untreated cardiogenic shock despite vital organ hypoperfusion. Renal and hepatic mitochondrial respiration is upregulated, possibly through demand-related adaptations, and the endogenous shock response is thus compensatory and protective, even after several hours of global hypoperfusion.
authors.affiliation: Cardiovascular Research Group, Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway; Department of Cardiothoracic and Vascular Surgery, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Thor Allan
authors.initials: TA
authors.lastname: Stenberg
authors.affiliation: Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway; Department of Cardiothoracic and Vascular Surgery, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Anders Benjamin
authors.initials: AB
authors.lastname: Kildal
authors.affiliation: Cardiovascular Research Group, Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway.
authors.forename: Espen
authors.initials: E
authors.lastname: Sanden
authors.affiliation: Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway.
authors.forename: Ole-Jakob
authors.initials: OJ
authors.lastname: How
authors.affiliation: Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway.
authors.forename: Martin
authors.initials: M
authors.lastname: Hagve
authors.affiliation: Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway.
authors.forename: Kirsti
authors.initials: K
authors.lastname: Ytrehus
authors.affiliation: Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway.
authors.forename: Terje S
authors.initials: TS
authors.lastname: Larsen
authors.affiliation: Cardiovascular Research Group, Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway; Department of Cardiothoracic and Vascular Surgery, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Truls
authors.initials: T
authors.lastname: Myrmel
mesh_terms: D000208:Acute Disease; D000222:Adaptation, Physiological; D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008929:Mitochondria, Heart / Q000502:physiology; D010101:Oxygen Consumption; D012770:Shock, Cardiogenic / Q000503:physiopathology*; D034421:Sus scrofa