LV oxygen consumption and pressure-volume area: Role of norepinephrine and verapamil

N. Chung, X. Wu, E. L. Ritman

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10 Scopus citations

Abstract

The effect of norepinephrine or verapamil on the relationship of left ventricular (LV) myocardial oxygen consumption (MV̇O2) and systolic pressure-volume area (PVA) was investigated in hearts within the never-opened thorax of dogs with blocked baroreceptor reflex. LV chamber volumes and myocardial blood flow were measured using a fast computed tomography scanner. At 10 μg/min delivery rate of norepinephrine, MV̇O2 (mJ·g-1·cycle-1) equals (2.30 ± 0.48) PVA + (20.60 ± 4.24) (n = 11; 1 mJ·g-1·cycle-1 is equivalent to 0.563 ml O2·100 g-1·min-1 at 112 beats/min). With verapamil infusion, MV̇O2 equals (2.57 ± 1.33)PVA + (10.73 ± 3.16) (n = 17). The regression slopes did not differ (P > 0.25) for any of the conditions. At comparable PVA values the norepinephrine group showed an increase of MV̇O2 compared with the prenorepinephrine baseline state (P < 0.01), and the verapamil group showed a reduction of MV̇O2 compared with the preverapamil baseline state (P < 0.05). We conclude that the MV̇O2 to LVPVA relationship in the in situ heart, within the never-opened thorax, conveys that the oxygen-wasting effect of catecholamines is quantifiable using the shift in this relationship.

Original languageEnglish (US)
Pages (from-to)H77-H82
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume261
Issue number1 30-1
StatePublished - Jan 1 1991

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Keywords

  • Angiography
  • Calcium channel blocker
  • Catecholamines
  • Fast computed tomography
  • Left ventricular chamber volume

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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