LDP was suggested to represent the excitation at the entrance to the specialized area with a conduction delay in response to the increase in the rate within the critical slow conduction zone participating in the reentry circuit of this VT. LDP can be a useful marker for successful RF ablation for this VT.

No abstract

Allopurinol, an inhibitor of xanthine oxidase, was shown to improve the regional ventricular function after coronary artery occlusion and reperfusion in animal models. The effects of oral administration of allopurinol on a transient increase in free radical generation after primary percutaneous transluminal coronary angioplasty (PTCA) in patients with acute myocardial infarction (AMI) and on their clinical outcomes were examined. Thirty-eight AMI patients undergoing primary PTCA were randomly assigned to control (group 1, n = 20) and allopurinol treatment groups (group 2, n = 18). Allopurinol (400 mg) was administered orally just after the admission (approximately 60 min before reperfusion). Free radical production was assessed by successive measurement of urinary excretion of 8-epi-prostaglandin F(2alpha) (PGF(2alpha)) after PTCA. Urinary 8-epi-PGF(2alpha) excretion was increased by twofold at 60-90 min after PTCA compared with the baseline value in group 1. This increase was completely inhibited in group 2. Plasma allopurinol concentration was 1,146 +/- 55 ng/ml in group 2 when reperfusion was achieved. Slow flow in the recanalized coronary artery after PTCA occurred less frequently in group 2 than in group 1. Cardiac index determined just after reperfusion and left ventricular ejection fraction at 6 months after PTCA were both significantly greater in group 2 than in group 1 although pulmonary capillary wedge pressure was similar in the two groups. In conclusion, allopurinol pretreatment is effective in inhibiting generation of oxygen-derived radicals during reperfusion therapy and the recovery of left ventricular function in humans.