Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seismocardiography is a new noninvasive technique for recording cardiac vibrations. Changes in the recorded waves have been correlated with acute and chronic changes in left ventricular function. In this report, we describe a patient who developed ischemia induced by coronary angiography in the cardiac catheterization laboratory. The patient's seismocardiogram showed distinct changes during the ischemic episode that actually preceded the onset of symptoms and resolved after nitroglycerin therapy. The patient's seismocardiographic recordings were significantly different from the recordings from five control individuals. This observation suggests that seismocardiography may be helpful for monitoring left ventricular function during episodes of myocardial ischemia.
 ...
PMID:Seismocardiography for monitoring changes in left ventricular function during ischemia. 191 18

For 18 patients consecutively admitted to the coronary care unit for unstable angina, 48-hour electrocardiographic Holter monitoring was performed after they were randomly assigned in a single-blind fashion to 1 of 2 treatment groups. The first group was treated with acetylsalicylic acid (ASA) and intravenous nitroglycerin, the second with ASA and intravenous diltiazem. All of the patients treated with nitroglycerin still had ischemic episodes after 48 hours (33% were symptomatic), in contrast with 11% of the diltiazem group (11% asymptomatic). Maximal ST-segment depressions of symptomatic and asymptomatic episodes were significantly different; and no significant increases in heart rate were observed either during the 15 seconds before ischemia began or during the ischemic episode. During the 48 hours, the diltiazem group had significantly fewer ischemic episodes (17) than did the nitroglycerin group (145). We concluded that "on-line" ST-segment observation is of prime importance for monitoring unstable angina; that the majority of the ischemic episodes associated with unstable angina are silent; and that intravenous diltiazem could be an effective pretreatment for patients who must undergo mechanical or surgical therapy.
 ...
PMID:Intravenous diltiazem versus nitroglycerin for silent and symptomatic myocardial ischemia in unstable angina pectoris. 195 Nov 2

The effects of repeated episodes of demand-induced ischemia on regional myocardial wall thickening, endocardial electrogram, and regional myocardial blood flow are not well delineated. We studied the cumulative effects of six periods of pacing-induced ischemia in 35 chloralose-anesthetized dogs with circumflex coronary stenosis. Repetitive ischemia of the posterior left ventricular free wall was induced with six 5-min pacing periods separated by 15-min recovery periods. The three groups of dogs studied were 1) saline control, 2) the purine precursor 5-aminoimidazole 4-carboxamide riboside (AICA-r), and 3) nitroglycerin (NTG). During the initial pacing period (before treatment), thickening of the posterior wall declined in the saline group (43 +/- 5% of control), the AICA-r group (47 +/- 8% of control), and the NTG group (55 +/- 3% of control), associated with endocardial S-T segment elevation and a decrease in subendocardial blood flow. Wall thickening continued to decrease in each group with each successive pacing episode. However, during the sixth pacing period wall thickening was significantly (P less than 0.05) less in the saline group (2 +/- 5% of control) than in the AICA-r (31 +/- 7% of control) or NTG (61 +/- 7% of control) group. The progressive decline in wall thickening was accompanied by a further decrease in subendocardial blood flow and a rise in S-T segment in the saline group but not in the AICA-r or NTG group (P less than 0.05). These results demonstrate that sequential periods of ischemia and reperfusion cause a progressive decline in regional wall motion, coincident with a progressive decrease in subendocardial blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Progressive cardiac dysfunction with repeated pacing-induced ischemia: protection by AICA-riboside. 195 44

Unstable angina is a clinical syndrome characterized by increased rate and severity of angina pectoris attacks and, sometimes but not always, accompanied by ECG changes similar to those seen in coronary insufficiency. According to the present conception of the pathogenesis, ruptures at points of high-grade stenosis in the epicardial coronary arteries with simultaneous apposition of thrombi and vasoconstriction cause critical narrowing of the vascular lumen, which means that with the same level of oxygen consumption, coronary blood flow might be inadequate even at rest. In this way the development of severe ischemia, sudden cardiac death or myocardial infarction is programmed. Therapy must accordingly aim at avoiding or eliminating the progression of thrombosis and at increasing the reduced coronary blood flow. The prognosis is unequivocally improved by aspirin. In addition, heparin, 400 units/kg body weight, should be given. Thrombolysis may be possible after mechanical recanalization, depending on the individual results of coronary angiography. Providing the adverse reactions are monitored, nitroglycerin given intravenously is the basic drug therapy, although comparative studies against other drugs are not available and some data show the development of tolerance during prolonged use. Therefore, an early change to sustained-release nitrates or mononitrates can be justified. beta-receptor blockers reduce the frequency of silent ischemia and of myocardial infarction. By these means, in 80% of the patients affected, unstable angina will be converted to the stable form of the disease. If symptoms persist coronary angiography is urgently indicated, to allow the selection of PTCA or aortocoronary bypass surgery according to the findings.
 ...
PMID:Unstable angina: pathophysiology and drug therapy. 197 60

A new transdermal beta-blocker containing system (Mepindolol BIO TSD) was compared in a placebo controlled cross over trial with a transdermal nitrate system in 14 patients suffering from coronary heart disease with stable angina pectoris. Under Mepindolol TSD both the incidence of angina pectoris attacks and the consumption of oral nitroglycerin dropped significantly. Under ergometry it resulted in an improvement in the maximum exercise tolerance and in a significant reduction in the ischemic ST-Segment deviation. Under Holter monitoring the number of manifest (MMI) and silent (SMI) ischemic episodes was significantly reduced. In addition the total duration of ischemia was significantly reduced. All the examined parameters showed Mepindolol BIO TSD to be significantly more effective than transdermal nitrate, and the duration of action was longer. No clinically relevant adverse events were observed in any of the therapeutic regimes.
 ...
PMID:[Anti-ischemic action of the transdermally-applied beta-receptor blocker, mepindolol, in patients with stable angina pectoris. Comparison with transdermal nitrate]. 197 80

In a double-blind, randomized, multicenter study, the efficacy and safety of intravenous (IV) nicardipine was compared with placebo in the control of postoperative hypertension in cardiac and noncardiac surgical patients. One hundred twenty-two patients (17 cardiac and 105 noncardiac surgery) met the entry criteria (systolic BP greater than or equal to 140 mm Hg or diastolic BP greater than or equal to 95 mm Hg) and were randomized (3:2) to receive IV nicardipine (n = 71) or placebo (n = 51). Therapeutic response (greater than or equal to 15 percent reduction in BP from baseline) was achieved in 94 percent of patients treated with IV nicardipine vs 12 percent with placebo (p less than 0.001). The mean response time and infusion rate for IV nicardipine were 11.5 (+/- 0.8) minutes and 12.8 (+/- 0.3) mg/h, respectively. The magnitude of BP reduction was similar in both cardiac and noncardiac postsurgical patients. Blood pressure control was sustained with minimal dose adjustments of IV nicardipine (3.0 +/- 0.2 mg/h) during a prolonged maintenance infusion period of 6.8 +/- 0.5 h. A reflex mean increase in heart rate of 5 bpm was seen in patients treated with IV nicardipine. Sixteen patients (15 noncardiac and one cardiac surgery) had a sustained heart rate of greater than 100 bpm, with a mean increase of 24 bpm from the baseline. In all these patients except three, tachycardia was resolved while receiving nicardipine. None of these patients who had development of tachycardia during nicardipine therapy had exhibited ST segment changes indicative of ischemia. One patient with tachycardia at baseline had exhibited ST segment depression (3 to 4 mm) during nicardipine treatment, which was resolved following discontinuation of nicardipine therapy and application of nitroglycerin (Nitropaste). Hemodynamic evaluation revealed that IV nicardipine significantly decreased mean arterial pressure, systemic vascular resistance, and significantly increased cardiac index with no change in heart rate. These hemodynamic changes were similar in cardiac and noncardiac surgical patients. Adverse experiences reported with IV nicardipine included hypotension (4.5 percent), tachycardia (2.7 percent), and nausea/vomiting (4.5 percent). In the placebo group, the incidence of adverse experience was 6 percent, with an equal distribution of hypotension (2 percent), nausea/vomiting (2 percent), and headache (2 percent). No clinically important changes in laboratory variables related to IV nicardipine were reported. In conclusion, these findings indicate that nicardipine, a titratable intravenous calcium channel blocker, can rapidly and effectively control postoperative hypertension in cardiac and noncardiac surgical patients.
 ...
PMID:Efficacy and safety of intravenous nicardipine in the control of postoperative hypertension. IV Nicardipine Study Group. 198 1

To know whether the pathogenesis of impending myocardial infarction(IMI) could be predicted by the direction of ST segment shifts during an ischemic chest pain, we studied 62 patients with IMI and undergoing emergent coronary angiography(CAG). They were selected from a consecutive number of 474 patients with unstable angina. IMI was defined when patients had more than 2 episodes of chest pain at rest under intensive pharmacological interventions after their CCU admission, and at least one of those was not relieved by nitroglycerin given intravenously. They were divided into 2 groups according to ST segment shifts during chest pain; 35 patients with ST elevation (G-1) and 27 patients with ST depression (G-2). The time of CAG was individually determined in each patient according to the severity of illness. Those with acute MI within 3 months before the study and 24 hours following the chest pain just before CAG were excluded from the study. New onset angina accounted for 49% in G-1 and 4% in G-2(p less than 0.01). Average history length of IMI, frequency of symptoms after CCU admission, and interval from the last symptom to CAG were similar in each groups. Single vessel disease was more predominant in G-1 than in G-2 (54% vs 11% p less than 0.01). Intracoronary thrombus(IT) in an ischemia related artery(IRA) was found in 97% of G-1 and 22% of G-2(p less than 0.001), while complex lesions(CL) proposed by Ambrose as another genesis of IMI were in 26% of G-1 and 74% of G-2(p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Clinical significance of ST segment shifts during chest pain in predicting the pathogenesis of impending myocardial infarction]. 202 79

A woman had diffuse vascular spasm related to cocaine use. She presented with evidence of an acute anterior myocardial infarction but had no rise in creatinine phosphokinase levels. Cardiac catheterization showed 90 percent proximal left main coronary artery narrowing. The catheterization was complicated by right femoral artery spasm. A repeat catheterization after treatment with nitroglycerin and diltiazem showed 30 percent proximal left main coronary artery narrowing. This catheterization was complicated by left femoral artery spasm. An exercise treadmill test was negative for ischemia.
 ...
PMID:Left main coronary artery and femoral artery vasospasm associated with cocaine use. 206 Mar 57

We performed exercise thallium-201 myocardial scintigraphy in 32 patients with angina pectoris to study the incidence of perfusion defects, who had no significant organic stenosis on coronary angiography. None of them had myocardial infarction or cardiomyopathy. Thallium-201 myocardial scintigraphy and 12-lead ECG recording were performed during supine bicycle ergometer exercise. Perfusion defects in thallium-201 scintigrams in SPECT images were assessed during visual analysis by two observers. In the coronary angiograms obtained during intravenous infusion of nitroglycerin, the luminal diameter of 75% stenosis or less in the AHA classification was regarded as an insignificant organic stenosis. Myocardial perfusion defects in the thallium-201 scintigrams were detected in eight (25%) of the 32 patients. Six of these eight patients had variant angina documented during spontaneous attacks with ST elevations in standard 12-lead ECGs. Perfusion defects were demonstrated at the inferior or inferoposterior regions in six patients, one of whom had concomitant anteroseptal defect. The defects were not always accompanied by chest pain. All but one patient demonstrating inferior or inferoposterior defects showed ST depression in leads II, III and aVF on their ECGs, corresponding to inferior wall ischemia. The exception was a case with right bundle branch block. Thus, 25% of the patients with angina pectoris, who had no evidence of significant organic stenosis on their coronary angiograms, exhibited exercise-induced perfusion defects in their thallium-201 scintigrams. Coronary spasms might have caused myocardial ischemia in these patients.
 ...
PMID:[Exercise-induced thallium-201 myocardial perfusion defects in angina pectoris without significant coronary artery stenosis]. 209 48

Exercise treadmill tests and ambulatory monitoring were used in a double-blind, placebo-controlled, double-dummy crossover comparison of nifedipine (10 mg, 3 times daily) and transdermal nitroglycerin (15 mg). All patients (n = 20) had chronic stable angina with symptomatic and silent events. All patients had 3 episodes of angina/week and 3 episodes of ischemia/24 hr. The protocol was made up of 2 weeks of placebo followed by 2 weeks of active drug, then crossed over for 2 weeks of placebo followed by the other active drug. At the end of each 2-week period, patients had ambulatory monitoring and exercise treadmill testing. All ambulatory monitoring reports were read blind and entered into an independent data base. The results were the following: on transdermal nitroglycerin, the duration of ischemia decreased by 57% from 140 min/24 hr to 60 min/24 hr (p = 0.0054). The exercise time increased by 5.5% from 4.8 to 5.0 minutes (p = 0.16). With nifedipine, the duration of ischemia decreased by 22% from 175 min/24 hr to 137 min/24 hr (p = 0.16). The exercise tolerance time increased by 13% from 4.5 to 5.0 minutes (p = 0.0264). Nifedipine increased exercise time without altering total ischemic time, while transdermal nitroglycerin decreased total ischemic time without increasing exercise time. Thus, changes in exercise time do not necessarily predict changes in total ischemic time.
 ...
PMID:Dissociation of exercise tolerance and total myocardial ischemic burden in chronic stable angina pectoris. 211 64


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>