The importance of myocardial amino acids during ischemia and reperfusion in dilated left ventricle of patients with degenerative mitral valve disease.
Level 4 - case-series / case-control
Observational paired biopsy study in patients undergoing cardiac surgery
PubMed 19363596 · doi:10.1007/s11010-009-0101-x
What was done
Researchers evaluated intracellular free amino acid concentrations (taurine, glutamine, glutamate, aspartate, and alanine) in myocardial biopsies taken from the left and right ventricles of patients undergoing mitral valve surgery for degenerative mitral valve disease. Biopsies were sampled before cardioplegic arrest with Custodiol HTK solution and 10 minutes following reperfusion to assess metabolic differences between the dilated left ventricle and the right ventricle.
What was found
Before cardioplegia, the dilated left ventricle had significantly higher baseline concentrations (nmol/mg wet weight; P < 0.05) compared to the right ventricle for taurine (17.0 ± 1.5 vs. 10.9 ± 1.5), glutamine (20.5 ± 2.4 vs. 12.1 ± 1.2), and glutamate (18.3 ± 2.2 vs. 11.4 ± 1.5). Baseline levels of alanine and aspartate did not differ significantly. After 10 minutes of reperfusion, a significant (P < 0.05) decrease in taurine and glutamine occurred exclusively in the left ventricle. Both ventricles displayed an increased alanine-to-glutamate ratio accompanied by global lactate release.
Why it matters
These findings suggest that structural remodeling in dilated ventricles involves an accumulation of specific amino acids that are subsequently consumed or lost during ischemia-reperfusion. Understanding ventricle-specific metabolic alterations could inform tailored myocardial protection strategies during cardiac surgery.
Limits
The abstract omits the total sample size, patient demographic characteristics, and clinical outcomes. The study relies on tissue biopsies and surrogate biochemical markers without evaluating post-operative functional recovery, and it cannot distinguish whether observed differences stem from intrinsic metabolic remodeling or uneven cardioplegic delivery between ventricles.
Cited by
- supports Taurine is one of the most abundant free amino acids in human heart muscle.