Vasoactive peptide release in relation to hemodynamic and metabolic changes during rapid ventricular pacing

Plasma atrial natriuretic peptide (ANP) concentration increases during vent ricular arrhythmias and rapid ventricular pacing but less is known about pl asma brain natriuretic peptide (BNP) and endothelin (ET-1). In the present study concentrations of ANP, the amino terminal part of the proANP (NT-proA NP), BNP, and ET-1 were measured in the coronary sinus and femoral artery b efore and at the end of rapid ventricular pacing in 15 patients with corona ry arterial disease. The changes were compared with the changes in mean art erial blood pressure, pulmonary capillary wedge pressure (PCWP), transcardi ac differences in pH, pCO(2), lactate, and norepinephrine. There was an inc rease in PCWP and a transient decrease in blood pressure after initiation o f pacing. Pacing caused a decrease in ST-segment, transcardiac difference o f norepinephrine, lactate extraction, pCO(2) difference, and an increase in pH difference. Concentration of ANP in the coronary sinus and femoral arte ry and its transcardiac difference increased during pacing (P < 0.001), whe reas changes in NT-proANP were small and BNP and ET-1 levels remained uncha nged. The change in transcardiac ANP difference correlated with the change in lactate (r = 0.53, P < 0.05) but not that of norepinephrine, PCWP, or bl ood pressure. The results show that the plasma concentration of ANP increas es more than that of NT-proANP during rapid ventricular pacing. Ischemia-in duced release of ANP and its diminished elimination may contribute to the i ncreased plasma ANP level.