Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Nifedipine Gastro-Intestinal Therapeutic System (GITS) Circadian Anti-ischemia Program (N-CAP) was designed to test the effect of nifedipine GITS as monotherapy or in combination with a beta-adrenergic blocking agent on the circadian pattern of angina and silent ischemia in patients with chronic stable angina. At 118 sites in the United States, 1,174 patients were screened for entry into this study. To be eligible for participation patients were required to have at least two episodes of angina a week and at least two episodes of myocardial ischemia during 48-h ambulatory electrocardiographic (ECG) monitoring during the baseline placebo period. A total of 207 patients completed all phases of the study. Beta-blockers were continued in those patients already receiving them. In this 7- to 10-week single-blind placebo withdrawal study, a 1-week placebo run-in was followed by up to 5 weeks of single-blind titration with nifedipine GITS, a 4-week efficacy phase with an established dose and a final single-blind 2-week placebo withdrawal period. Ambulatory ECG monitoring was performed at the end of each placebo phase and at the end of the efficacy phase with a digital monitoring device that was validated in a pilot study. Overall, nifedipine GITS significantly reduced the weekly number of anginal episodes from 5.7 to 1.8 (p = 0.0001) and the number of ischemic events from 7.3 to 4 (p = 0.0001) reported during the 48-h monitoring periods, with a significant increase in both during the placebo withdrawal period. The baseline circadian pattern of ischemia showed an early morning peak and a secondary peak in the afternoon. Nifedipine GITS significantly reduced ischemia during the 48-h period when administered as monotherapy or in combination with a beta-blocker. Patients were also randomized to receive nifedipine GITS in either a morning or an evening dose. The two regimens resulted in equal anti-ischemic benefit. The primary side effect of nifedipine GITS was edema, which was dose related. In summary, nifedipine GITS reduced the number of anginal and ischemic episodes when given alone or in combination with a beta-blocker. Nifedipine GITS had a sustained effect: a single daily dose was effective over 24 h regardless of whether it was administered in the morning or evening. This study also suggests that combination therapy with nifedipine GITS and a beta-blocker is especially efficacious in reducing ischemia.
 ...
PMID:Attenuation of the circadian patterns of myocardial ischemia with nifedipine GITS in patients with chronic stable angina. N-CAP Study Group. 135 May 96

Calcium antagonists are generally considered to have no substantial effect on repolarization of the myocardium, so they have no direct effect on T wave, either. But in a pig model of myocardial ischemia, intracoronary nifedipine was found to reverse the inverted T wave induced by ischemia to upright promptly. Ten pigs were anesthetized with the chest opened, anterior interrentricular branch of left coronary artery (LAD) was narrowed to 4.67 kPa of LAD pressure, and then adenosine or nifedipine was infused into the coronary respectively. During the 9-minute ischemia, intracoronary adenosine or intracoronary nifedipine got the similar HR, LVEDP, LVDP, CAP, CAQ, and the intracoronary adenosine even got higher CAQ than the intracoronary nifedipine did. However, the T wave was retained inverted during the adenosine infused, but during the intracoronary nifedipine, the inverted T wave was promptly turned upright. The relevant factors and mechanisms are discussed.
 ...
PMID:[Effect of nifedipine on T wave in ischemic myocardium]. 789 45