Lamb HJ, Beyerbacht HP, Ouwerkerk R, Doornbos J, Pluim BM, van der Wall EE, van der Laarse A, de Roos A. Metabolic response of normal human myocardium to high-dose atropine-dobutamine stress studied by 31P-MRS.
Circulation 1997;
96:2969-77. [PMID:
9386164 DOI:
10.1161/01.cir.96.9.2969]
[Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND
31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phosphate metabolism of the myocardium. Accordingly, the purpose of the present study was to determine the metabolic response of normal human myocardium to severe atropine-dobutamine (A-D) stress. To corroborate the results from the present in vivo study, a 31P-MRS experiment was performed with a moving phantom to simulate respiratory motion.
METHODS AND RESULTS
The phantom experiment showed no relation (P=.371) between the intensity ratio of two separate phosphate peaks and amplitude of phantom excursions. The phosphocreatine (PCr) and ATP signal strength and the PCr/ATP ratio were determined from the left ventricular wall in 20 healthy subjects (posttest likelihood for coronary artery disease was <2.5%) with 31P-MRS at rest and during high-dose A-D stress (rate-pressure product increased threefold). Stress-induced changes were -21% for PCr (P<.001) and -9% for ATP (P<.05). The average PCr/ATP value at rest was 1.42+/-0.18 and decreased by 14% to 1.22+/-0.20 during stress (P<.001).
CONCLUSIONS
The phantom experiment shows that the in vivo decrease of myocardial PCr/ATP due to high-dose A-D stress we observed is not a motion artifact. Consequently, this indicates that myocardial high-energy phosphate metabolism of the normal human heart is altered at high workloads.
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