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

Calcium channel blockers are widely used in the treatment of ischemic heart disease, hypertension, and supraventricular tachycardia. The prototype agents, verapamil, nifedipine, and diltiazem, represent three classes of calcium channel blockers, each of which has different pharmacologic effects. Nifedipine and the other dihydropyridines primarily are vasodilators and have no clinical effects on cardiac conduction or contractility. Diltiazem and verapamil also are vasodilators, but they possess, to varying degrees, negative inotropic, chronotropic, and dromotropic effects. Side effects of these drugs are relatively rare and usually not serious, with the exception of potential conduction disturbances and heart failure in patients with underlying cardiac disease. To assess patients taking these medications and provide the necessary teaching, the nurse needs an understanding of the pharmacologic properties, clinical indications, and potential adverse effects of the various drugs.
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PMID:Calcium channel blockers. 131 59

A number of studies have addressed the response to calcium antagonists, used alone or combined with other therapy, in patients with silent myocardial ischemia (SMI). Nifedipine, the first calcium antagonist to be studied, was shown to be superior to pindolol in patients with effort angina. Although both nifedipine and diltiazem significantly reduced episodes of ST depression, compared with placebo, in patients with stable effort angina, the addition of nifedipine to diltiazem removed the beneficial effect of diltiazem in another study. Studies have shown a reduced incidence of ischemic episodes during nicardipine treatment in patients with ambulatory ischemia, predominantly SMI, and rest angina due to coronary artery spasm. Other workers similarly reported that verapamil was superior to both placebo and propranolol in reducing painful and painless ischemia in patients with angina at rest. It has been demonstrated that, compared with placebo, nifedipine reduced ischemic episodes by 50% and also markedly reduced total ischemic time in totally asymptomatic men with coronary artery disease and SMI. It was suggested that the well-documented increase in SMI occurring between 0600 and 1200 h was reduced, but not eliminated, by nifedipine. Diltiazem may also attenuate the circadian variation in SMI. Nifedipine has been shown to be particularly effective in SMI when combined with a beta-blocker. This has been substantiated in a large group of patients; both drugs reduced the number of episodes of SMI when used as monotherapy, and the combination decreased the incidence by 95%. These findings collectively indicate that calcium antagonists are effective in reducing or preventing SMI.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical effects of calcium antagonists in silent ischemia. 136 8

The effects of nicorandil and diltiazem on serum lipid, apolipoprotein, and lipoprotein levels in 37 patients with ischemic heart disease were examined in a randomized, multicenter study. Nicorandil (n = 20, 10-40 mg/day, b.i.d.) and diltiazem (n = 17, 60-240 mg/day, b.i.d.) were administered for 12 weeks. Both nicorandil and diltiazem administration showed an effective antianginal effect. Diltiazem administration showed a significant hypotensive action. There were no significant changes in serum lipids, apolipoproteins, and lipoproteins for both nicorandil and diltiazem. There were no significant changes in body weight, uric acid, and fasting blood sugar levels during the test period for both drugs. These data show that nicorandil, like diltiazem, does not have any adverse effects on lipid metabolism and that it is a favorable drug to use as an agent for treating arteriosclerotic heart disease.
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PMID:A multicenter comparison of nicorandil and diltiazem on serum lipid, apolipoprotein, and lipoprotein levels in patients with ischemic heart disease. 145 91

Plasma bradykinin and prostaglandin metabolism are related to the anginal pain modulating system in patients with ischemic heart disease. We carried out a placebo controlled single blind test of diltiazem (30 mg three times a day) in 15 patients with chronic stable angina. The effect of diltiazem was evaluated by exercise treadmill testing and 48-h ambulatory electrocardiographic monitoring. Plasma bradykinin, thromboxane B2, and 6-keto-prostaglandin F1 alpha levels were determined by radioimmunoassay prior to and during diltiazem therapy. Diltiazem significantly increased the exercise time and reduced episodes of angina. Diltiazem, however, did not appreciably improve either the frequency of silent myocardial ischemic episodes or the total duration of the silent myocardial ischemic episodes. Diltiazem also tended to decrease plasma bradykinin, thromboxane B2, and 6-keto-prostaglandin F1 alpha levels. When ischemic episodes on ambulatory electrocardiographic monitoring are categorized according to heart rate change at the onset of episode (type A, preceded by heart rate increase > or = 5 beats/min; type B, no preceding heart rate increase), diltiazem was only effective on type A ischemic episodes as well as on symptomatic ischemia. Further, bradykinin was significantly decreased by diltiazem only in patients with exercise-induced silent ischemia or no exercise-induced ischemia, while the thromboxane B2/6-keto-prostaglandin F1 alpha ratio was unaffected by the administration of diltiazem. Thus, silent and symptomatic ischemia may be associated with different bradykinin and prostaglandin responses.
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PMID:Effect of diltiazem on silent ischemic episodes, plasma bradykinin and prostaglandin metabolism. 145 74

Because the choice of anesthetic technique does not influence the incidence of perioperative myocardial ischemia, reduction of ischemic risk may require specific antianginal therapy. Calcium entry blockers are effective drugs in antianginal therapy. Diltiazem reduces myocardial oxygen demand through decreases in heart rate, inotropy, and systolic function, while increasing myocardial oxygen delivery through coronary vasodilation. These potentially beneficial effects of diltiazem were evaluated in 15 of 29 patients (diltiazem v placebo, double-blind study) scheduled for coronary artery bypass graft surgery. Continuous infusion of diltiazem (0.15 mg/kg bolus followed by 2 micrograms/kg/min), during anesthesia and surgery before cardiopulmonary bypass, significantly reduced the major MVO2 determinants during anesthesia with moderate doses of fentanyl and a benzodiazepine (midazolam in 8 of 14 control patients and 9 of 15 treated patients, or flunitrazepam in the others). Heart rate, mean arterial pressure, and inotropy were decreased during the most stressful events of surgery when plasma diltiazem concentrations were in the therapeutic range (greater than 96 ng/mL). The number of patients with perioperative ischemia was 2 of 15 in the treated group and 4 of 14 in the control group. Provided that diltiazem plasma concentrations are sufficient, it can contribute to lowering the ischemic burden during anesthesia for coronary artery surgery.
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PMID:Hemodynamic effect of calcium channel blockade during anesthesia for coronary artery surgery. 149 96

Changes in tissue lactate, ATP, and cytosolic free calcium (Cai) were examined in isolated, perfused rat hearts receiving 20 min of zero-flow global ischemia (37 degrees C). Addition of diltiazem before ischemia caused a concentration-dependent decrease in lactate accumulation. This effect was not mediated by modulation of norepinephrine release since depletion of catecholamines by reserpine did not alter lactate accumulation, and diltiazem treatment reduced lactate accumulation in catecholamine-depleted hearts. Diltiazem-treated hearts showed a concentration-dependent decrease in tissue ATP utilization that was associated with the decrease in tissue lactate during ischemia. Basal time averaged Cai, determined by fluorine NMR using 5FBAPTA, was 620 nM. Diltiazem (0.9 microM) decreased this value to 489 nM and reduced heart rate and maximum pressure developed (81.3 and 53.9% of control, respectively) before ischemia. Cai increased fourfold between 9 and 15 min of ischemia in hearts receiving no drug, while there was no increase in Cai in diltiazem-treated hearts. These results show that diltiazem reduces the use of ATP and therefore production of lactate during ischemia, and indicate a relationship between preservation of ATP and maintenance of Cai that may be important in the beneficial effects of diltiazem during myocardial ischemia.
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PMID:Effects of diltiazem on lactate, ATP, and cytosolic free calcium levels in ischemic hearts. 168 81

We tested the benzazepine, SQ 31,486 for its ability to selectively block the voltage-dependent calcium channel and to protect the ischemic myocardium. SQ 31,486 was found to be a selective calcium antagonist in vascular tissue with an IC50 value of 1.5 microM in KCl-contracted rabbit aorta. SQ 31,486 decreased contractile function and increased coronary flow in nonischemic isolated rat hearts in a concentration-dependent manner. SQ 31,486 also significantly reduced postischemic lactate dehydrogenase (LDH) release and end-diastolic pressure (EDP) compared to vehicle. Reperfusion double product [heart rate (HR) x left ventricular developed pressure (LVDP)] was also significantly improved by SQ 31,486. Diltiazem was a less potent anti-ischemic agent and was significantly more cardiodepressant relative to its anti-ischemic efficacy than was SQ 31,486. Thus, SQ 31,486 should have a larger therapeutic index. In a model of pacing-induced myocardial ischemia in anesthetized, open chest dogs, SQ 31,486 reduced pacing-induced ST-segment elevation approximately 50% at 10, 40, and 70 min after drug administration. This protective effect occurred despite a lack of effect of SQ 31,486 on ischemic regional blood flow and peripheral hemodynamic status.
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PMID:Anti-ischemic activity of the novel benzazepine calcium antagonist SQ 31,486. 169 77

Treatment of patients with heart failure due to major ventricular systolic dysfunction should aim not only at symptomatic but also at prognostic improvement. If correction of the underlying problem is not possible, treatment should slow down the progression of cardiac failure and eliminate triggers for sudden cardiac death due to electromechanical dissociation or arrhythmias. In every patient with chronic congestive heart failure screening for myocardial ischemia and complete revascularization is mandatory, if possible. In patients with coronary artery disease and diminished systolic function, beta-blockade may improve prognosis by reducing ischemic events and sudden cardiac death. The incidence of life-threatening arrhythmias in patients with heart failure may be reduced by eliminating facilitating factors like electrolyte disturbances, altered autonomic tone and raised intracardiac pressure rather than by antiarrhythmic medical treatment itself. One of the most important prognostic aspects in treatment is the interference with the development of the cardiomyopathy of overload, uniformly observed in chronic congestive heart failure. Modification of mechanical and neuroendocrine stimuli may postpone myocardial hypertrophy and interstitial hyperplasia as a consequence of altered gene expression. Early treatment with ACE inhibitors and in certain patients with betablockers are the most promising strategies to delay the progression of the disease. In contrast, positive inotropic drugs, including digitalis and phosphodiesterase inhibitors, do not improve prognosis. Calcium antagonists should also be used with restriction, as Verapamil and Diltiazem, but also Nifedipine may adversely affect the outcome in congestive heart failure patients.
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PMID:[Prognostic aspects in the treatment of chronic heart insufficiency]. 173

Content of prostacyclin and thromboxane was studied in blood plasma of patients with ischemic heart disease after single administration of calcium antagonist diltiazem. The drug caused an increase in content of prostacyclin and in the ratio prostacyclin/thromboxane. Diltiazem appears to differently affect the arachidonic acid metabolism in platelets and endothelial cells that may be involved in therapeutic effect of the drug under conditions of ischemic heart disease.
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PMID:[Effect of the calcium antagonist diltiazem on the prostacyclin-thromboxane ratio in the plasma of ischemic heart disease patients]. 189 89

Episodes of transient myocardial ischemia during ambulatory activities are common in patients with stable coronary artery disease and who are often asymptomatic. Selection of therapy for episodes of asymptomatic ischemia is limited by a lack of direct comparative studies. To determine the most effective monotherapy for patients with stable angina and a high frequency of asymptomatic ischemic episodes, propranolol-LA (mean daily dose, 293 mg), diltiazem-SR (mean daily dose, 350 mg), nifedipine (mean daily dose, 79 mg) were each compared with placebo, each for 2 weeks, in a randomized, double-blinded, crossover trial. Entry criteria were a positive exercise treadmill test during placebo therapy characterized by 1.0 mm or more ST segment depression and angina pectoris, and six or more episodes of transient ST segment depression of 1.0 mm or more on a 48-hour ambulatory electrocardiogram. One hundred ninety-four patients were screened, 63 were eligible and received randomized therapy, of which 56 patients completed at least two of the four treatment periods and were included in an intent-to-treat analysis. Fifty patients completed all four treatment phases and were included in the protocol-completed analysis. Anti-ischemia efficacy was assessed by 48-hour ambulatory electrocardiographic monitoring, exercise treadmill tests, and anginal diaries. Ninety-four percent of all episodes of ambulatory ischemia were asymptomatic. Compared with placebo, only propranolol was associated with a marked reduction in all manifestations of asymptomatic ischemia during ambulatory electrocardiographic monitoring (2.3 versus 1.0 episodes/24 hr; mean duration of ischemia per 24 hours, 43.6 versus 5.7 minutes; both p less than 0.0001). Diltiazem's reduction of the frequency of episodes compared with placebo (2.3 versus 1.9 episodes/24 hr) was associated with a trend (p = 0.08) in the protocol-completed analysis and with a significant reduction in the intent-to-treat analysis (p = 0.03). Nifedipine had no significant effect on any measured variable of ambulatory ischemia. The dosages of medication used may have been excessive for some patients, and a more beneficial effect may have been evident at a lower dose. In contrast to the marked effects of the active agents on ambulatory asymptomatic ischemia, the effects on exercise performance and angina pectoris were slight. The active agents modestly improved treadmill exercise duration time until 1 mm ST segment depression (3%), and only propranolol and diltiazem had significant effects. Only diltiazem significantly prolonged the total exercise time. Anginal frequency was significantly decreased by both propranolol and diltiazem.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Comparison of propranolol, diltiazem, and nifedipine in the treatment of ambulatory ischemia in patients with stable angina. Differential effects on ambulatory ischemia, exercise performance, and anginal symptoms. The ASIS Study Group. 224 50


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