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)

Twenty patients with ischemic heart disease documented by coronary angiograms or ST segment depression in the ECG during treadmill walking, were administered sublingual nitroglycerin 0.3 to 0.6 mg on one occasion and a chewable form of isosorbide dinitrate 5 mg on another occasion during treadmill walking when anginal discomfort was definitely present at a mild degree of intensity. Despite continued walking at a constant speed and grade, angina was relieved in all patients, completely in most patients, partially in a few. The average time from administration of the medication to onset to relief was 74.7 seconds for nitroglycerin and 107.6 seconds for chewable isosorbide dinitrate. Average time to complete relief or maximal incomplete relief was 190.3 seconds for nitroglycerin and 315.1 seconds for chewable isosorbide dinitrate. Ischemic electrocardiographic changes were reverted toward normal by nitroglycerin in 13 subjects and by isosorbide dinitrate in 15. The differences in onset to complete relief were all statistically significant indicating that nitroglycerin is more rapid in its action than is chewable isosorbide dinitrate.
 ...
PMID:Effectiveness of isosorbide dinitrate and nitroglycerin in relieving angina pectoris during uninterrupted exercise. 80 37

In 14 patients with hypertensive crisis treated with diazoxide, close monitoring of blood pressure, heart rate, and symptoms was performed. Standard 12-lead electrocardiograms were recorded before and after diazoxide. All patients showed a significant fall in blood pressure after drug administration. Seven patients (50%) showed significant ST-T changes after diazoxide. Six patients (43%) developed substernal discomfort demonstrated by substernal pain of tightness. Five patients (35%) had both chest discomfort and ST-T changes. One of these patients with substernal pain and ST elevation had evidence of acute myocardial infarction with serial enzyme studies. In the patients with significant ST-T changes, the average fall in blood pressure was significantly greater than the average fall in blood pressure in the patients without significant ST-T changes. These findings suggest that both ST-T changes and substernal discomfort were due to myocardial ischemia secondary to a sudden severe drop in blood pressure.
 ...
PMID:Angina-like syndrome with diazoxide therapy for hypertensive crisis. 93 81

Angina pectoris is chest discomfort associated with myocardial ischemia. When coronary blood flow is inadequate to meet myocardial tissue demand, lactate accumulates, resulting in diastolic and systolic left ventricular dysfunction. This leads to ST-segment abnormalities and eventually to angina pectoris. Angina, most commonly a pressure-type sensation in the midanterior chest precipitated by exercise, stress, or cold, typically lasts 1-5 minutes and is alleviated by rest or nitroglycerin. Diagnostic studies to assess myocardial ischemia include treadmill exercise testing, Holter monitoring, and coronary angiography. Treadmill exercise testing has a relatively low accuracy for diagnosing coronary artery disease. This can be improved by combining exercise with thallium-201 imaging, two-dimensional echocardiography, or positron emission tomography (PET). Thallium-201 scintigraphy and exercise echocardiography have reported sensitivities of 70-85% and specificities of 50-60% when applied to low-risk, asymptomatic populations. PET scanning has a high predictive accuracy (sensitivity 90%, specificity 90-95%) and is more useful as a screening test; it can also assess the functional significance of coronary artery stenoses and differentiate viable myocardium from infarcted tissue. Holter monitoring is too insensitive and nonspecific to be used as a screening test for coronary artery disease; it can, however, assess the total ischemic burden in patients with known coronary artery disease and correlate symptoms and ST-segment abnormalities during episodes of pain at rest. Coronary angiography has been the gold standard for diagnosing coronary artery stenoses. Quantitative angiography has improved the assessment of coronary artery narrowing but is still limited in evaluating coronary blood flow. Doppler flow studies provide useful information regarding coronary flow reserve. Myocardial ischemia as a cause of chest pain is determined by evaluating the clinical characteristics consistent with angina, correlating electrocardiographic abnormalities with perfusion defects or wall motion abnormalities, and determining the extent and functional significance of coronary artery stenoses by coronary angiography.
 ...
PMID:Excluding heart disease in the patient with chest pain. 159 64

Cine magnetic resonance imaging (MRI) provides a tomographic method of assessing regional ventricular function in any desired plane. It has not been possible to obtain adequate images during dynamic exercise, and this has limited its value in patients with coronary artery disease (CAD). Therefore, an infusion of dobutamine was used to study 25 patients with exertional chest pain and abnormal exercise electrocardiograms. Areas of abnormal wall motion were compared with areas of abnormal myocardial perfusion imaged by dobutamine thallium emission tomography and with coronary arteriography. Twenty-two patients had significant CAD. Twenty-one (96%) of these patients had reversible myocardial ischemia shown by dobutamine thallium tomography, and 20 (91%) had reversible wall motion abnormalities shown by dobutamine MRI. Comparison of abnormal segments of perfusion and wall motion showed 96% agreement at rest, 90% agreement during stress, and 91% agreement for the assessment of functional reversibility. The normalized magnetic resonance signal intensity of the ischemic segments showed a small but significant reduction when compared with that of normal segments (-67 units [9.2%]; p less than 0.05). Dobutamine infusion was well-tolerated, despite causing chest discomfort in 24 patients (96%). Nine patients (36%) developed a minor dysrhythmia that was usually ventricular premature complexes, but this did not limit infusion, and other side effects were mild. The short plasma half-life of dobutamine makes it ideal as a stress agent for imaging techniques (such as MRI), and these results suggest that it is more effective in the provocation of wall motion abnormalities than is dipyridamole in patients with CAD.
 ...
PMID:Magnetic resonance imaging during dobutamine stress in coronary artery disease. 161 67

A balloon catheter with six electrodes has been developed for transesophageal atrial stimulation of the human heart. Introduction is easy and its positioning is simple with the help of six unipolar atrial electrograms. In a group of 20 healthy volunteers, stimulation and discomfort thresholds (intolerable discomfort) were measured for three levels of pulse widths (12, 16, and 20 msec) and for five electrode configurations. Stimulation thresholds were below discomfort thresholds in each case. The stimulation threshold depended on pulse width and not on electrode configuration. The discomfort threshold, however, depended on the electrode configuration and not on the pulse width. A moderate but potentially important increase of the ratio between stimulation threshold and discomfort threshold could be achieved by combining a long pulse width (20 msec) and avoiding the largest distance between the active (cathode) and the passive (anode) electrode. Transesophageal atrial stimulation promises to be a practical noninvasive tool for the termination of regular supraventricular tachycardias, basal electrophysiological studies, and controlled acceleration of the heart rate in the study of myocardial ischemia.
 ...
PMID:Transesophageal atrial pacing--stimulation and discomfort thresholds: the role of electrode configuration and pulse width. 172 May 29

The clinical, electrocardiographic, and coronary hemodynamic responses to sequential 90-second occlusions of the left anterior descending coronary artery in 12 patients undergoing elective percutaneous transluminal coronary angioplasty were examined. Transmyocardial lactate metabolism was examined in an additional group of seven patients with clinical and hemodynamic features similar to the first group. We noted that in comparison with the initial balloon occlusion the second occlusion was characterized by less subjective anginal discomfort, less ST segment shift (0.44 +/- 0.13 versus 0.21 +/- 0.07 mV, p = 0.01), and lower mean pulmonary artery pressure (25 +/- 1.0 versus 20 +/- 1.7 mm Hg, p = 0.005). In addition, for the same heart rate-blood pressure product, cardiac vein flow during the second inflation was significantly lower than that recorded during the first inflation (96 +/- 1.4 versus 83 +/- 2.4 ml/min, p = 0.005). Finally, there was significantly less myocardial lactate production during the second inflation (lactate extraction ratio: first inflation, -0.11 +/- 0.03; second inflation, -0.03 +/- 0.02; p = 0.04). We conclude that the lessened clinical, electrocardiographic, hemodynamic, and metabolic evidence of myocardial ischemia during the second of two periods of coronary artery occlusion during percutaneous transluminal coronary angioplasty supports the concept of adaptation to myocardial ischemia (ischemic preconditioning).
 ...
PMID:Adaptation to ischemia during percutaneous transluminal coronary angioplasty. Clinical, hemodynamic, and metabolic features. 214 94

This study reports the results of a retrospective review of the case records of 28 seriously ill patients who received intravenous cimetidine (generally 300 mg q8h) for the treatment of gastric discomfort and/or hemorrhage or for prophylaxis against stress-induced ulcers. Most of these patients presented with complex symptoms arising from a variety of pathological conditions including ischemic heart disease, myocardial infarction, cerebrovascular accident, pneumonia, and trauma. A number of patients also had acute gastrointestinal hemorrhage. Over two-thirds of the patients treated with intravenous cimetidine demonstrated a reduction in gastrointestinal symptom severity, and a statistically significant reduction in the mean severity rating for all patients was observed. Adverse reactions reported during cimetidine therapy were generally mild to moderate in severity and required discontinuance of therapy in only one patient. The most common complaint was headache. Intravenous cimetidine administered q8h offers a safe and cost-effective approach to H2-receptor blockade and reduction of gastric acid secretion in patients who are temporarily unable to take oral medication.
 ...
PMID:Intensive care experience with intravenous cimetidine. 228 32

Synchronized coronary venous retroperfusion was applied and studied in 16 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) balloon dilatation of proximal left anterior descending (LAD) coronary artery stenosis. The rationale for using retroperfusion support during the PTCA-induced coronary artery occlusions was to ameliorate or prevent myocardial ischemia and possibly facilitate extension of the PTCA balloon-inflation period. After therapeutic PTCA treatment, which successfully dilated the culprit coronary artery in all 16 patients, and a 5-minute recovery period, a single retroperfusion-treated LAD occlusion (101 +/- 36 seconds) was compared with equivalent untreated control LAD occlusions (86 +/- 24 seconds) before and after the retroperfusion-supported balloon occlusion. Observations and measurements encompassed 1) ease and time of coronary sinus catheterization, 2) incidence of anginal pain during LAD occlusion, 3) electrocardiographic signs of myocardial ischemia, and 4) two-dimensional echocardiographic indexes of global left ventricular function. The coronary sinus was successfully catheterized within 139 +/- 140 seconds, and in 12 of the 16 patients, the tip of the special autoinflatable retroperfusion balloon catheter could be placed in the desired location of the great cardiac vein. The retroperfusion protocol interfered minimally with the PTCA procedure, and application of the support system had no deleterious effects. As compared with the pain reported 23 (72%) times during the 32 control LAD occlusions, only five (31%) of the patients indicated pain or discomfort during the retroperfused occlusions. Treated occlusions exhibited delayed or significantly lower electrocardiographic ST segment elevations (sum, 10.4 +/- 7.8 mm) as compared with the controls (sum, 16.2 +/- 7.9 mm and 18.8 +/- 10.6 mm; both p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Coronary venous synchronized retroperfusion during percutaneous transluminal angioplasty of left anterior descending coronary artery. 230 48

A 48-year-old female, who had been having episodes of chest discomfort and oppression lasting for several minutes for 15 years was diagnosed as having a single left coronary artery by coronary angiography. The electrocardiogram taken during a chest pain attack demonstrated the depression of the ST-segment in leads II, III, aVF, and V4-6. The chest pain was relieved, and the ischemic change in ECG was improved by sublingual nitroglycerine. 201Thalium single photon emission computed tomography under stress indicated poor uptake in both the anterior and infero-posterior myocardium, which was compatible with the change in ECG either during the attack or during exercise. The anterior myocardial ischemia was reduced by propranolol and the chest pain was successfully relieved by propranolol. The chest pain in this case might have partly been due to the myocardial ischemia in the anterior and infero-posterior myocardium, under stress, which could have been the steal phenomenon to lateral myocardium due to the anatomical anomaly, besides other possible mechanisms for chest pain proposed in the case of single coronary artery. Our findings suggested that 201Thalium stress single photon emission computed tomography is a useful method for detecting the myocardial ischemia in patients with single coronary artery and those suffering from chest pain without any coronary stenosis.
 ...
PMID:The study of a case of single coronary artery using stress 201thalium single photon emission computed tomogram. 249 6

In patients with recurrent chest pain in the immediate postinfarction state, one must determine whether the recurrent chest discomfort is related to myocardial ischemia or not. If recurrent ischemia is present then it may be due to either (1) transient increase of myocardial oxygen demand over a fixed coronary reserve, (2) transient decrease of myocardial oxygen supply, or (3) a combination of both. Coronary angiography reveals that most patients have double or triple vessel disease. The presence of postinfarction angina portends a poor prognosis. Reinfarction rate has been reported as high as 28% during initial hospitalization and mortality has been as high as 57% at six months follow-up. Intravenous nitroglycerin seems to be an important foundation therapy for the management of postinfarction angina. The use of beta blockers has reduced mortality by 24% compared to placebo in this patient subgroup. Calcium antagonists have proven efficacious in patients with non-Q-wave myocardial infarction and postinfarction angina. Thrombolytic therapy, chronic anticoagulation and antiplatelet therapy are not proven efficacious at this time. Coronary angioplasty is usually successful initially but is associated with an early myocardial infarction rate varying from 1.4 to 13%. Mortality rate is usually low as is late myocardial infarction rate. Recurrent angina occurs commonly in these patients. Surgical therapy in the early infarction state should be offered to those patients who have a poor response to maximal medical therapy whose coronary artery obstructions are not amenable to PTCA. At the time of coronary angiography if partially occlusive thrombus is identified, intravenous heparin and aspirin should be given to prevent more thrombus formation and total occlusion.
 ...
PMID:Early postinfarction angina: therapeutic strategies. 269 Nov 42


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