Reduction of CK and CK-MB indexes of infarct size by intravenous nitroglycerin.

Abstract

SUMMARY The effect of i.v. nitroglycerin administration on indexes of infarct size was examined in 31 patients with acute myocardial infarction. Serial creatine kinase (CK) and CK-MB isoenzyme determinations were used to calculate infarct size. Twenty-nine patients served as controls. Two subgroups of the study group were formed to evaluate differences between early and late intervention. In the first group (n = 22), continuous infusion of nitroglycerin over 48 hours was initiated within 8 hours (mean 4.5 hours) after the onset of symptoms. Peak CK activity for the nitroglycerin-treated patients (n = 9) in this subgroup was 544 U/1 vs 871 U/1 for the controls (n = 13) (p < 0.05). The rate of CK release was reduced from 79 to 33 U/1.hr (58%), as was total CK and CK-MB release (p < 0.02 (fig. 3).The f^ollowing additional measurements were determined using a computer program developed by Shell et al. '5 16 (1) Individual appearance curves of CK and CK-MB, including the quantity of enzymes normally lost through excretion, were standardized to 0 hour.(2) The rate of CK and CK-MB release was calculated as 90% of total appearance divided by the time to 90% appearance (U/l.hr17).(3) The disappearance rate (kd) was derived from the end part of the CK and CK-MB curve by the best fit regression line.'8

Part 5: Adult Basic Life Support

“…Although it is reasonable to consider the early administration of nitroglycerin in select hemodynamically stable patients, insufficient evidence exists to support or refute the routine administration of nitroglycerin in the ED or prehospital setting in patients with a suspected ACS (Class IIb, LOE B). [241][242][243] Nitrates in all forms are contraindicated in patients with initial systolic blood pressure Ͻ90 mm Hg or Ն30 mm Hg below baseline and in patients with right ventricular infarction (see Part 10). Caution is advised in patients with known inferior wall STEMI, and a right-sided ECG should be performed to evaluate right ventricular infarction.…”

Intravenous nitroglycerin therapy to limit myocardial infarct size, expansion, and complications. Effect of timing, dosage, and infarct location.

“…[3][4][5][6] Experimental studies suggest that the dose might be of critical importance.78 Thus, intravenous NG therapy in low dose during the first 6 hours after coronary artery ligation reduced the size ofboth inferior7 and anterior8 infarcts, but the beneficial effects on infarct size and collateral flow were abolished when hypotension was induced by higher doses of NG. 8 An additional benefit of low-dose NG therapy over the first 6 hours of AMI in the canine model was a decrease of infarct expansion at 7 days.…”

Nitrate Therapy in Heart Failure

“…The patients were ran domly allocated to either intravenous nitro glycerin or placebo. Infarct size assessed by serial determinations of creatine kinase and QRS measurements was significantly re duced in the nitroglycerin group [8]. In addi tion to a reduction of infarct size, the infarctrelated complications such as arrhythmias could be favorably influenced, too [12].…”