A new metabolic mechanism for absence of pain in patients with silent myocardial ischemia.

Background And Aims: We undertook this study to detect if there is a relationship between lactate production in the myocardium and the presence or absence of chest pain in patients with coronary artery disease (CAD).

Methods: Forty six patients with significant CAD including left anterior descending artery underwent echocardiography study, coronary angiography and pacing-induced ischemia. Serum lactate levels were determined in four blood samples, from mid-LV cavity and from coronary sinus before and after pacing-induced ischemia.