title: Hemodynamic and metabolic responses to pacing in patients with chest pain and normal coronary arteriograms.
abstract: Hemodynamic and metabolic responses to pacing from either the coronary sinus or right atrium were evaluated in 41 patients with chest pain and normal coronary arteriograms. A group of patients (group II) with angina, lactate production, or significant ST segment depression had a significantly higher mean pulmonary capillary pressure on peak pacing or angina than did a group of patients considered to have a normal pacing response (group I). In 6 of 9 group II patients, the left ventricular end-diastolic pressure either rose abnormally with pacing or was greater than 14 mm Hg immediately after pacing and resembled that of a group of patients with coronary artery disease; Patients with a prolapsing mitral valve (group III) also had a significantly higher pulmonary capillary pressure on peak pacing as compared to those of group I, although abnormal left ventricular pressure responses occurred in only 2 of 9 of these patients. The stroke index was significantly lower in group III on peak pacing while group II was no different from group I. Lactate production occurred in 6 of 9 group II patients. However, only 1 of 6 patients with a prolapsing mitral valve who were studied for lactate production was found to produce lactate, suggesting a different mechanism for their pain.
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000378:metabolism / Q000503:physiopathology*; D001794:Blood Pressure; D002302:Cardiac Output; D017023:Coronary Angiography; D004562:Electrocardiography; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005260:Female; D006321:Heart / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D007773:Lactates / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010138:Pacemaker, Artificial; D011312:Pressure
chemical_list: D005230:Fatty Acids, Nonesterified; D007773:Lactates