Myocardial extraction of lactates, non-esterified fatty acids and their fractions in patients with dilated cardiomyopathy at rest and after the cold pressor test.

A decrease in the myocardial extraction or excretion of lactates indicates its hypoxia. The authors analyzed changes in the extraction of lactates, non-esterified fatty acids (NEFA) and their fractions: C 14:0, C 16:0, C 16:1, C 18:1, C 18:2 in a group of 15 patients with dilated cardiomyopathy (DC) and in 10 controls at rest and after the cold pressor test (CPT). At rest, 5 patients with DC produced lactates or extracted less than 10%. During CPT, production of lactates was observed in another four patients (mean values: 17.9 +/- 32.6% vs 24.5 +/- 5.2%, ns). NEFA extraction was found in the DC group: 18.4 +/- 20.6% vs. 13.9 +/- 33.3% /p < 0.05/). The acids involved were C 14:0, C 16:0, C 16:1 and C 18:0. In the controls, NEFA extraction did not change significantly: 12.1 +/- 8.6% vs 29.7 +/- 33.2%.

CONCLUSIONS

1. In part of patients with DC, production of lactates was found. The degree of lactate excretion increased due to CPT; 2. In DC, adrenergic stimulus (CPT) impairs the myocardial utilization of NEFA. This applied mainly to myristic acids, palmitic acid, palmitooleic acid and stearic acid; 3. This phenomenon probably is a result of profound functional and morphological damage to the mitochondrial system in DC.