Whether isoflurane has the potential to produce coronary artery steal and associated myocardial ischemia is still controversial. Previous studies addressing this issue in humans did not purposefully control hemodynamics or use continuous measures of myocardial ischemia. The authors used transesophageal echocardiography (TEE) and continuous Holter electrocardiography (ECG) to study the ...

Perioperative myocardial ischemia is associated with an increased risk of perioperative myocardial infarction (PMI). Several attempts have been made to define intraoperative hemodynamic predictors of myocardial ischemia. In a canine preparation with coronary stenosis, a pressure rate quotient (PRQ = mean arterial pressure/heart rate) less than one (PRQ less than ...

Among the clinical manifestations of ischemic heart disease, right coronary artery (RCA) disease offers a wide variety of right and left ventricular ischemic involvement, including prevalent right ventricular dysfunction and severe cardiac failure. Whether the right ventricular impairment is dependent primarily on ischemia of the right ventricle or requires a ...

A 62-year-old world record marathon runner was found to have silent ischemia manifested by a very abnormal stress test, whereas at autopsy nine months later, there was virtually no coronary atherosclerosis nor other disease of the coronary microvasculature. However, there was focal fibrosis of the papillary muscles consistent with remote ...

OBJECTIVE: To compare angina and ST-segment depression during exercise testing, as markers for coronary artery disease. DESIGN: Retrospective analysis of exercise test responses and cardiac catheterization results. SETTING: A U.S. Veterans Affairs medical center. PATIENTS: Four hundred and sixteen men who were referred for the evaluation of symptoms, postmyocardial infarction ...

The anti-ischemic effects of atenolol and nifedipine were compared in a randomized double-blind crossover manner in 24 patients with stable exertional angina and transient silent ischemia during ambulatory electrocardiographic (ECG) monitoring. Both atenolol and nifedipine were effective (p less than 0.005) in reducing the average number and duration of transient ...

Because of the importance of postoperative myocardial ischemia and because substantial physiologic changes can occur for prolonged periods postoperatively, the incidence, severity and temporal course of myocardial ischemia were studied in 100 high risk patients during the 1st week after major noncardiac surgery. Electrocardiographic (ECG) changes consistent with ischemia were ...

Cardiac morbidity and mortality after coronary artery bypass graft (CABG) surgery continue to be significant problems. To determine the prevalence, characteristics, and prognostic importance of postoperative myocardial ischemia after CABG surgery, the authors monitored 50 patients continuously for 10 perioperative days with the use of two-lead electrocardiography (ECG). ECG changes ...

We report a 33-year-old man who developed cutaneous necrosis of the lower extremities with extensive bulla formation after i.v. administration of vasopressin for the treatment of bleeding esophageal varices. Due to its potent nonselective vasoconstrictive action, vasopressin not only may induce cardiac and gastrointestinal ischemia, but cutaneous ischemia as well. ...

The myocardium is a complex three-dimensional structure consisting of myocytes interconnected by a dense collagen weave that courses in different directions. Regional ischemia can be expected to produce complex changes in ventricular deformation. In the present study, we examined the effects of ischemia on two- and three-dimensional finite strains during ...

A randomized study was performed on 104 patients undergoing elective coronary artery bypass grafting to examine whether the infusion of nifedipine (n = 53) reduces the incidence of perioperative myocardial ischemia and necrosis in the early postoperative period. Continuous hemodynamic and three-channel Holter monitoring was performed for 24 hours and ...

The effect of brief myocardial ischemia on the expression of heat shock protein (HSP 70) was examined in an in vivo rabbit model of myocardial ischemia using Northern blotting. Functional studies were carried out in the open-chested anesthetized rabbit. The large marginal branch of the left circumflex was occluded four ...

Silent myocardial ischemia is a frequent finding when Holter monitoring is done in patients with advanced coronary disease. Silent ischemia is associated with a worse prognosis in patients with stable or unstable angina, survivors of myocardial infarction, and populations at risk for coronary disease. Whether medical therapy for silent ischemia ...

Eighty one patients with ischemic heart disease divided in four groups (group 1, n = 24, without ischemia; group II, n = 20, myocardial ischemia before invasive procedure; group III, n = 18, myocardial ischemia during invasive procedure, group IV, n = 19, myocardial ischemia before and during the invasive ...

Silent myocardial ischaemia (significant ST depression without chest pain) is a common occurrence in most forms of coronary heart disease and can be associated with permanent changes in myocardial structure. The haemodynamic and ECG manifestations of silent episodes are similar to those observed in painful ischaemia. Exercise testing is the ...

The physical examination in acute cardiac ischemia remains a valuable tool when done with skill. Ischemia without infarction alters cardiac function, and the physical examination yields findings that reflect these changes. Ischemia with infarction alters structure and function, resulting in physical findings that are usually more dramatic and of longer ...

The effect of verapamil on death and reinfarction in patients with and without exercise-induced myocardial ischemia after acute myocardial infarction was studied in a double-blind, placebo-controlled multicenter study. Two hundred ninety-eight patients were included. A symptom-limited exercise test was carried out 9 days after the myocardial infarction but before randomization. ...

The purpose of this study was to assess the empirical relationship between myocardial integrated backscatter (IB) and myocardial wall thickness (WT) in normal myocardium. A second object was to estimate the additional contribution to acute ischemic integrated backscatter levels given this relationship. Myocardial IB measurements and simultaneous myocardial WT measurements ...

The circadian variation of myocardial ischemia detected during 24-h ambulatory electrocardiographic monitoring (AEM) was analyzed in 123 patients with stable angina pectoris, positive exercise test, and angiographically proven coronary artery disease. A total of 437 ischemic episodes (ST-segment depression greater than or equal to 1 mm and duration greater than ...

Sixteen middle-aged, normotensive, slightly overweight male patients with previous myocardial infarction were studied during Holter-checked silent myocardial ischaemia. As reference, stress and late 201-T1 scintigraphy served for comparison with Cardiolite-MIBI silent ischaemic perfusion scan, both carried out in planar mode. The circumferential profiles differed in 9 cases, on region of ...

This study compares the metabolic and functional effects of three different models of ischemia in the immature heart. The intent was (1) to develop a model of energy-depleted and functionally depressed heart to be used in subsequent studies of myocardial protection and (2) to characterize the biochemical changes following different ...

In asymptomatic patients the importance of silent ischemic ST-T wave changes on Holter monitoring is known to be a significant predictive variable for one-year mortality of postmyocardial infarction patients. This case report represents the uses of ambulatory ECG to detect ischemic ST changes in patients who have had recent strokes. ...

To examine the relationship between myocardial ischemia in patients with steal-prone coronary anatomy and the administration of isoflurane anesthesia, we reviewed coronary angiograms of 955 patients who had participated in a randomized trial of the use of one of four primary anesthetics for coronary artery bypass operations. Steal-prone anatomy was ...

We studied the prognostic significance of preoperative silent myocardial ischemia in patients undergoing coronary artery bypass grafting (CABG). Nonfatal and fatal perioperative myocardial infarction were regarded as prognostically important endpoints. Ninety-five patients (9 women) with stable-effort angina pectoris were studied during their hospital stay in the surgery ward before CABG. ...

To assess the long-term prognostic significance of myocardial ischemia, as measured by ambulatory electrocardiographic monitoring, in patients with occlusive peripheral arterial disease, 176 eligible patients scheduled for elective peripheral arterial surgery at Brigham and Women's Hospital were prospectively studied. All patients were monitored preoperatively without alterations to baseline medications. Prospective ...

Nitrous oxide (N2O) has been implicated as a cause of myocardial ischemia. We investigated whether substitution of N2O for a portion of the anesthesia supplied by isoflurane increased myocardial ischemia in patients at risk for such ischemia. Seventy patients having carotid endarterectomies (63 patients) or other carotid surgery (seven patients) ...

To determine the extent to which different electrocardiographic systems account for differences in reported incidence of perioperative myocardial ischemia, the authors simultaneously recorded in 109 patients undergoing coronary artery bypass grafting (CABG) the V5 or modified CM5 lead on five ECG systems by means of a specially constructed common V5 ...

Circadian variations of transient myocardial ischemia and heart rate have been identified, but the rhythms and their response to beta blockade have not been fully characterized. Time-series analysis, a mathematical technique to describe oscillatory activity occurring within a continuous data set was used, to address these issues. Nine men with ...

1. The diagnosis of silent ischemia in asymptomatic patients with known coronary artery disease is adequately achieved by stress testing. 24 hour monitoring allows to assess the total ischemic burden which has prognostic implications. 2. The diagnosis of silent ischemia in asymptomatic patients without documented coronary artery disease is difficult. ...

We investigated the incidence of silent myocardial ischemia and infarction as assessed by dipyridamole thallium scintigraphy in 30 diabetic patients with peripheral vascular disease and without clinical suspicion of coronary artery disease. Seventeen patients (57%) had thallium abnormalities, with reversible thallium defects compatible with ischemia in 14 patients (47%) and ...

Tissue characterization reflects structural and functional integrity of tissues. Inasmuch as reversible ischemia causes no structural damage and irreversible ischemia results in persistent structural myocardial damage, we postulated that ultrasonic tissue characterization can distinguish the two types of injuries. Anesthetized open chest dogs underwent 15 minutes (group 1, n = ...

To clarify the central effects of physical training on patients with coronary heart disease, 81 subjects were selected for the present study. Evaluations of the oxygen transport system function were performed according to the definition proposed by Bruce and others in terms of FAI (functional aerobic impairment), LVI (left ventricular ...

Nuclear magnetic resonance (NMR) spectroscopy can nondestructively evaluate changes in metabolites with different disease states, as well as with therapeutic interventions. Animal studies have provided the basis for understanding changes in high-energy phosphates with myocardial ischemia. Studies of graded ischemia due to partial coronary stenosis have shown the sensitivity of ...

A recent case in California raises legitimate concern about the risks of a lawsuit arising out of a routine physical examination. This ruling has an ominous portent for many physicians who either are not current or are not comfortable with the available testing procedures for screening asymptomatic patients for silent ...

The effects of angiotensin converting enzyme inhibitors (ACEIs), CGS 14831 (CAS 86541-78-8) and captopril, on the mechanical function and energy metabolism were studied in isolated rat hearts using global ischemia-reperfusion model. The myocardial tissue levels of ATP, creatine phosphate (CP) and pH were determined with 31P-nuclear magnetic resonance (31P-NMR). Global ...

To determine the circadian distribution of episodes of myocardial ischemia, studies were performed in 111 patients with chronic stable angina pectoris, positive exercise test results and angiographically proven coronary artery disease. During 24 hours of ambulatory electrocardiographic monitoring, 101 symptomatic and 298 asymptomatic ischemic episodes (ST-segment depression greater than 1 ...

Prognostic data on the importance of silent ischemia is lacking. Preliminary reports suggest that ambulatory electrocardiographic monitoring provides additional information not contained in the exercise test, but it is still unclear whether silent ischemia is a marker of subsequent events or is responsible for their development. Recent investigations also suggest ...

Asymptomatic ischemia after myocardial infarction is a common clinical problem. As much as 50% of the postinfarction patient population who have ischemia on exercise testing may have no symptoms at all. In these patients, ischemia detected by either exercise testing or ambulatory electrocardiographic monitoring, with or without symptoms, confers a ...

Humoral changes, changes in hemodynamics, and the incidence of ischemia appear to be highest during the postbypass-postoperative period. Preliminary data also suggest that postbypass ischemia detected by transesophageal echocardiography may be predictive of outcome. Our previous experience with postoperative hypertension following coronary artery surgery has led us to increase analgesic ...

Recent technologic advances have yielded diverse techniques for studying myocardial ischemia, a useful functional expression of coronary artery disease. These techniques have revealed new characteristics and expanded our understanding of myocardial ischemia. In turn this has led to the establishment of more realistic and discriminating criteria on which to base ...

A patient presented with a neuropathy originally ascribed to prolonged effect of epidural anesthesia following major intraabdominal surgery. Subsequent investigation revealed the cause of the neuropathy to be an arterial thrombosis. Two percent lidocaine and 0.5% bupivicaine were used intraoperatively and epidural morphine was administered at the end of the ...

A case is presented that demonstrates heart rate (HR)--related silent myocardial ischemia occurring preoperatively, subsiding intraoperatively, then recurring and leading to a post-operative cardiac death in a patient undergoing peripheral vascular surgery. This case illustrates that patients may have an ischemic threshold for HR whereby recurrent depression of the ST ...

Silent myocardial ischemia is increasingly recognized as a common phenomenon in a variety of populations with coronary artery disease. In patients with angina pectoris, this condition has been recognized during either exercise stress testing or ambulatory monitoring when ischemic-type ST-segment shifts occur without symptoms. Although more information is clearly needed, ...

Effects of a selective alpha 1-adrenergic blocking agent, bunazosin, on myocardial energy metabolism in the ischemic heart were studied. Ischemia was induced by ligating the left anterior descending coronary artery of the dog heart. Bunazosin was injected intravenously either 5 or 20 min before coronary artery ligation. Hearts were removed ...

The realization that the majority of ischemic episodes in ambulatory patients with coronary artery disease are not associated with angina has raised important questions regarding the medical management of such individuals. Data from studies utilizing ambulatory Holter monitoring of the ST segment suggest that ischemia is likely to be due ...

The effects of combined thromboxane synthetase inhibition and thromboxane receptor antagonism (TSI/TRA) were studied in conscious and in anesthetized canine models of sudden cardiac death. Administration of the TSI/TRA, R68070 10 mg/kg intravenously (i.v.), decreased thrombin-stimulated thromboxane synthesis and significantly antagonized platelet aggregation in response to the thromboxane-mimetic U46,619. In ...

In this paper we review the main mechanisms leading to primary and secondary ischemic attacks, the clinical manifestations of ischemic heart disease as well as the goals of treatment. Particular attention is paid to the neurohormonal regulation of coronary blood flow. The most recent advances in this field, achieved in ...

Silent myocardial ischemia (SMI) is a common ischemia process which can be defined as objective evidence of myocardial ischemia without chest pain or other equivalent indications. SMI can occur in totally asymptomatic patients, as well as in patients who have documented coronary artery disease (CAD) and who, on exercise and/or ...

The anti-ischemic efficacy of isosorbide-5-mononitrate, 20 mg 3 times daily, on silent myocardial ischemia after myocardial infarction was studied in 28 Chinese patients with use of 48 hours of ambulatory electrocardiographic monitoring in a randomized, crossover, single-blind, placebo-controlled study. Isosorbide mononitrate reduced both painful and painless episodes of ischemia compared ...

In a prospective study the significance of silent ischemia was evaluated in 66 patients with a clinical diagnosis of unstable angina (no requirement for reversible ST-T changes during pain on 12-lead electrocardiograms before entry), and the results of continuous 2-channel electrocardiographic (ECG) recordings, begun within 24 hours of admission, were ...