PLASMA NOREPINEPHRINE INCREASED DURING CORONARY-OCCLUSION IN HYPERTENSIVE PIGS THAT DEVELOPED VENTRICULAR-FIBRILLATION

Although hypertension is associated with increased risk of sudden card iac death, the mechanisms involved remain enigmatic. Little is known a bout hemodynamic and plasma catecholamine concentration changes during coronary artery occlusion in hypertensive subjects. To study this, 30 pigs were implanted with catheters in the aorta and a silk snare arou nd the left anterior descending coronary artery that could later be pu lled to permanently occlude the artery. Perinephritic hypertension was induced in 14 of the animals over 3 weeks by wrapping one kidney in s ilk followed by contralateral nephrectomy. Coronary artery occlusion ( CAO) was carried out in all pigs in the conscious resting state. Ventr icular fibrillation (VF) developed in 50% of each group within 15 min after coronary artery occlusion. The hypertensive VF group showed an i ncrease in norepinephrine concentration of 112 +/- 46%; a significantl y greater increase than the intact VF group, which showed a 29 +/- 7% increase in norepinephrine concentration 5 min after coronary artery o cclusion (p < 0.05). Copyright (C) 1996 Elsevier Science Inc.