Low prevalence of coronary artery spasm in patients with normal coronary angiograms and unexplained ventricular fibrillation

AIMS: The aetiology of ventricular fibrillation in patients without identifiable structural heart disease is unknown. Recently, high prevalence of silent ischaemia due to coronary artery spasm has been reported in such patients. However, in at least one report, all patients had non-critical coronary artery lesions. Identification of coronary artery spasm as the underlying aetiology of ventricular fibrillation has important therapeutic implications. METHODS AND RESULTS: We performed ergonovine provocation tests in 18 patients (14 males, and four females; mean age, 36 years) with documented ventricular fibrillation in the absence of identifiable structural heart disease who had undergone aborted sudden death. In group I (n = 7) ergonovine provocation tests were performed at a mean interval of 31 months (range 21-42 months) after the index episode. These patients had already received an implantable cardioverter defibrillator, after failed electrophysiologically guided antiarrhythmic therapy. In group II (n = 11) the ergonovine provocation test was performed prospectively as part of the diagnostic evaluation. All patients were off antiarrhythmic drugs, calcium entry or beta-adrenoceptor blockers at the time of the ergonovine provocation test. Ergonovine was administered intravenously as a bolus injection, beginning with 0.05 mg followed every 3 min by incremental doses up to a cumulative maximum dose of 0.45 mg. Predefined end-points were (1) recording of ischaemic ST segment shifts of > or = 1 mm in at least two corresponding leads of the 12-lead electrocardiogram; (2) induction of ventricular tachycardia or ventricular fibrillation; and (3) administration of a cumulative dose of 0.45 mg. A positive response to ergonovine was seen in only one patient (5%) in group I in whom there developed ST segment elevation without angina and a short burst of rapid ventricular tachycardia. CONCLUSIONS: This study found a low prevalence of coronary artery spasm in patients with aborted sudden death resulting from documented ventricular fibrillation and non-apparent underlying heart disease. All patients had normal coronary angiograms and a negative history for spontaneous episodes of chest pain. The mechanism of arrhythmogenesis in such patients remains largely unknown.     

Angiographic progression in patients with angina pectoris and normal or near normal coronary angiograms who are restudied due to unstable symptoms

In this work we studied the mechanism of nitric oxide (NO) release underlying the vasorelaxant and antiaggregant effect of 3,4-dihydrodiazete 1,2-dioxides (DD). Six derivatives were included in the investigations, namely, 3-bromo- and 3-chloro-3,4,4-trimethyl-DD (1a,b), 3-bromo- and 3-chloro-4-methyl-3,4-hexamethylene-DD (2a,b), 3,3,4,4-tetramethyl-DD (3), and 3-methyl-3,4-hexamethylene-DD (4), and their reactivity toward thiols was analyzed. The 3-bromo- and 3-chloro-DD derivatives were found to react with thiols; this reaction can lead to NO formation, DD 2a being the most reactive compound. 2-(Hydroxyamino)-2-methylbutan-3-one oxime (5a) and 2-hydroxy-2-methylbutan-3-one oxime (6) were the main products isolated from the reaction of 1a with cysteine. Reaction rates of DD with thiols were dependent upon pH and concentration of the reagents. Maximum rates of NO release corresponded to thiol concentrations in the range of 1 mM. Consistent with reaction kinetics data and products isolated, a reaction mechanism was proposed. Addition of 2a to bovine aortic endothelial cells led to strong NO release indicating a reaction with endogenous thiols. In rat mesenterial arteries, the vasorelaxant action of 2a was only slightly influenced by addition of thiol to the incubation medium. For the most reactive DD derivatives, cytotoxic effects were observed at concentrations roughly 2 orders of magnitude higher than those inducing vasorelaxation.     

Echocardiography with dobutamine in hypertensive patients with chest pain

INTRODUCTION: The exercise stress test shows limited diagnostic accuracy for the detection of coronary artery disease in hypertensive patients. Echocardiography with dobutamine is a useful tool in the assessment of coronary artery disease. PURPOSE: Our purpose has been to compare dobutamine stress echocardiography and exercise stress test for diagnosing coronary disease in hypertensive patients. MATERIAL AND METHODS: Dobutamine stress echocardiography (administered up to 40 micrograms/kg/min, and atropine when necessary), exercise stress test and coronary arteriography were performed on 74 hypertensive patients with chest pain and no previous history of coronary artery disease. RESULTS: Forty-eight (65%) patients underwent a diagnostic exercise stress test and 66 (89%) a diagnostic dobutamine stress echocardiography. Coronary artery disease (> or = 70% stenosis in, at least, one major vessel) was demonstrated in 28 (58%) patients who underwent a diagnostic exercise stress test, and in 39 (59%) patients who completed a dobutamine stress echocardiography. Sensitivity for exercise stress test was 82%, and 79% for dobutamine stress echocardiography (p = NS). Specificity was higher for dobutamine stress echocardiography (100% vs 60%; p < 0.005). CONCLUSIONS: Dobutamine stress echocardiography has high sensitivity and specificity for the detection of coronary artery disease in hypertensive patients. Dobutamine stress echocardiography has higher feasibility and specificity than exercise stress test in this group of patients.     

Prevalence of coronary blood flow reserve abnormalities among patients with nonobstructive coronary artery disease and chest pain

BACKGROUND: Very little is known about the mechanisms underlying adverse reactions to radiocontrast medium. On the basis of the clinical features of the adverse reactions, it has generally been considered that an IgE-dependent mechanism is not involved in these adverse reactions, and only a few studies have demonstrated the presence of IgE antibody to radiocontrast medium in patient sera. METHODS: We assayed for IgE antibody to ioxaglic acid (Hexabrix), a representative radiocontrast medium, in the sera of patients who had developed adverse reactions to ioxaglic acid. A conjugate was prepared by coupling succinyl ioxaglic acid to human serum albumin. Enzyme immunoassay and radioimmunoassay for the detection of IgE antibody to ioxaglic acid in patient sera were constructed by physical adsorption or by covalent coupling of the conjugate on solid supports. RESULTS: When the radioactivity or the absorbance exceeding the mean plus 3 SD for normal healthy subjects was regarded as positive, IgE antibody was detected in the sera of 47.1% of the patients who had a past history of adverse reactions to ioxaglic acid and 16.2% of those who had experienced adverse reactions to ioxaglic acid within 24 h before the blood collection, although the IgE antibody levels were low. On the other hand, IgE antibody to ioxaglic acid was not detected in the sera of patients with no history of adverse reactions to ioxaglic acid. Inhibition experiments revealed the presence of IgE antibody specific to ioxaglic acid in the serum defined as positive for IgE antibody to ioxaglic acid. The presence of IgE antibody to ioxaglic acid did not always correlate with the activation of mast cells due to the occurrence of adverse reactions to ioxaglic acid. CONCLUSIONS: A small amount of IgE antibody to ioxaglic acid was detected in the sera of some patients with a history of adverse reactions to ioxaglic acid, and these adverse reactions may be partly explained by the presence of IgE antibody in the serum of at least some patients.     

Communication problems for patients hospitalized with chest pain

In many settings, primary care physicians have begun to delegate inpatient care to hospitalists, but the impact of this change on patients' hospital experience is unknown. To determine the effect on physician-patient communication of having the regular outpatient physician (continuity physician) continue involvement in hospital care, we surveyed 1,059 consecutive patients hospitalized with chest pain. Patients whose continuity physicians remained involved in their hospital care were less likely to report communication problems regarding tests (20% vs 31%, p =.03), activity after discharge (42% vs 51%, p =.02), and health habits (31% vs 38%, p =. 07). In a setting without a designated hospitalist system, communication problems were less frequent among patients whose continuity physicians were involved in their hospital care. New models of inpatient care delivery can maintain patient satisfaction but to do so must focus attention on improving physician-patient communication.     

Psychological comorbidity in patients with alarming chest pain symptoms]

About 1/3 of patients with chest pain undergoing coronary arteriography (CA) have no coronary artery disease (CAD). Individuals with non-CAD chest pain may be younger and more likely to be female; they may express higher degrees of neuroticism. Are those features stable enough to justifi; exclusion from CA if present? To investigate this issue, data on psychodiagnostic parameters (depression, anxiety, somatic complaints) were obtained in patients before this were referred to CA. Inclusion criteria were a chief complaint of chest pain with episodes of angina-like pain at rest, suspicious enough to warrant cardiac catherisation; and no prior history of CAD or other organic heart disease. The sample consisted of 77 patients, recruited from 89 eligible patients. 12 patients were excluded because CA findings were missing for multiple reasons. CA was conducted by Judkins technique. Patients were labeled as CAD (-) if no stenosis were detectable. In 50 (65%) of cases CA findings were positive and in 27 (35%) findings were negative. CAD+ were significantly older (p < 0.05); the superiority in both groups were male. Prevalence of emotional disorders was markedly more pronounced in both groups in comparison to the normal population and to a group of male myocardial infarction survivors. However, those features did not discriminate between the groups. Long acting chest pain was predictive for high degrees of emotional disability (relative risk 5.33; 95% Kl 1.6-61.6; p < 0.012). Chest pain at rest is a major source of anxiety, depression and subsequent somatic preoccupation despite its ischaemic or functional origin. It leads to clinically relevant adjustment disorders in a significant proportion of chest pain patients and triggers emotional disstress. These factors may thus have less impact on risk stratification than expected.     

Prognostic significance of normal dobutamine-atropine stress sestamibi scintigraphy in women with chest pain

The high risk of vaso-occlusive events in children younger than 4 years with cyanotic congenital heart disease and polycythaemia has been attributed to increased thromboxane (Tx) A2 formation. In older children with cyanotic congenital heart disease, however, the risk of vaso-occlusive events is much lower. We therefore hypothesized that the formation of TxA2 and prostacyclin is not disturbed in this age group. We measured urinary excretion of stable index metabolites of in vivo TxA2 and prostacyclin formation by gas chromatography-mass spectrometry in nine children (age 5.9-14.4, median 8.7 years) with cyanotic congenital heart disease, and in nine healthy, age-matched control subjects. The patients excreted less 2,3-dinor-TxB2 (systemic TxA2 formation, P = 0.03), 2,3-dinor-6-keto-PGF1 alpha (systemic prostacyclin formation. P = 0.03) and TxB2 (renal TxA2 formation, P = 0.01) than the control subjects. We conclude that in children older than 5 years with cyanotic congenital heart disease, endogenous synthesis of TxA2 and prostacyclin is not stimulated. This result may explain the lower risk of vaso-occlusive events in this age group as compared with younger children. In addition, our results suggest that chronic hypoxaemia may affect the in vivo formation of TxA2 and prostacyclin and the metabolic disposition of TxB2.     

How to manage the dyspeptic patient

A simple system which facilitates the verification of the calibration of iodine-125 sources in rigid absorbable suture, on the remote traceability basis, was developed. It consists of a plastic jig accommodating a sterile closed-end 16 gauge plastic catheter. The iodine-125 source in rigid absorbable suture is placed into the sterile closed-end 16 gauge plastic catheter. The jig fits in a standard dose calibrator. The sterility of the strand is maintained while a reasonable number of seeds used for an actual implant can be easily measured. This is an improvement over the current recommended practice of assaying just one separate seed of the same strength designation. This system brings the calibration procedure for the rigid sterile seed strands in line with the AAPM TG-40 recommendation for the rest of radioactive seed products.     

如何管理建筑工程项目质量

通过对低劣质量建筑项目的危害性的认识和对造成质量问题原因的分析,使我们认识到工程质量管理的重要性。要管好工程项目质量就必须要有效进行预先控制,有计划有准备推进项目工作,建立和完善以项目部为主体的施工管理体制,选好配强项目班子,做好施工过程中的质量控制;通过对工程质量管理过程中应注意的几个问题的讨论,使我们更全面、科学地了解工程项目质量管理,确保工程建设在质量、成本、进度上的最佳平衡,实现综合效益最大化。     

Electrocardiographic left ventricular hypertrophy in chest pain patients: differentiation from acute coronary ischemic events

Electrocardiographic left ventricular hypertrophy (LVH) and related repolarization changes alter the morphology of the ST segment and/or the T wave. Such electrocardiographic abnormalities--all features that are encountered in patients with acute ischemic heart disease--may confound the early emergency department evaluation of the chest pain patient. In the instance of the chest pain patient demonstrating ST segment/T wave abnormality, the correct electrocardiographic diagnosis must be made not only to offer appropriate management for that particular illness but also to avoid the incorrect application of potentially dangerous therapies such as thrombolysis. This report presents two cases in which the electrocardiogram demonstrated significant repolarization changes consistent with LVH, and focuses on the recognition of the expected ST segment/T waves changes and their differentiation from the primary ST segment/T wave changes associated with acute ischemic heart disease.     

Chest pain in patients with normal coronary angiography (syndrome X): new concepts]

Bone is continuously being formed and resorbed. This process is accomplished by the precise coordination of two cell types: osteoblasts and osteoclasts. Osteoclasts are large, multinucleated cells that are derived from the same hematopoietic precursors as macrophages. However, these bone-resorbing cells are difficult to study directly because of their relative inaccessibility. The purification of primary osteoclasts from rabbit bones by their adherent nature provides an opportunity for investigating the molecules in osteoclasts. We have examined the expression of receptor tyrosine kinase by polymerase chain reaction (PCR) and found that Tyro 3 was frequently identified from primary osteoclasts in PCR cloning. Immunohistochemistry revealed that Tyro 3 was expressed on the multinucleated osteoclasts which were positive for tartrate-resistant acid phosphatase (TRAP), but not on mononuclear TRAP-positive cells. The Tyro 3 ligand, Gas6, induced the phosphorylation of Tyro 3 receptors in osteoclasts in two to five min. Gas6 and protein S directly enhanced the bone resorbing activity of mature osteoclasts. This effect of Gas6 was inhibited by the addition of a tyrosine kinase inhibitor, herbimycin A. However, Gas6 did not affect the differentiation of osteoclasts from bone marrow cells. Gas6 and protein S are dependent on vitamin K, a cofactor for the enzyme responsible for carboxylation of glutamic acid residues. The findings in this study are the first to indicate a new biological activity of Gas6 and protein S as a direct regulator of osteoclastic function; they give an insight into the role of these vitamin K-dependent ligands in bone resorption in vivo.     

How to manage HIV seropositive or AIDS patients in rural Burkina Faso?

The application of molecular biology to the study of electroneutral cation-chloride cotransporters has been extremely successful, resulting in the identification of a new gene family of five membrane proteins. The function, expression, and regulation of these important proteins can increasingly be described in molecular terms. In addition, mutations in two renal cation-chloride transporter genes have been found in patients with Bartter's and Gitelman's syndromes, autosomal recessive disorders of renal salt excretion.     

Coping in chest pain patients with and without psychiatric disorders.

We first examined relations between psychiatric disorder and coronary heart disease (CHD) in 77 patients presenting with chest pain. The coping profiles of chest pain patients with and without psychiatric disorder and CHD were then compared. Psychiatric patients with no medical illness (n?=?129) were also studied. On the basis of previous research we hypothesized specific coping differences across the groups. As expected, chest pain patients without psychiatric disorder scored significantly higher on a problem-focused coping scale than chest pain patients with psychiatric disorder, who in turn scored higher on this scale than psychiatric patients with no medical illness. The opposite pattern occurred for a measure of wishful thinking. Scores of chest pain patients with psychiatric disorder were higher on a measure of avoidance and lower on a measure of seeking of social supports than those without psychiatric disorder. Scores on a self-blame measure were not different across the groups. The results are discussed in the context of illness behavior and somatization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in coronary vasodilation in hypertensive patients with angiographically normal coronary arteries

In normal subjects, coronary arteries dilate in response to sympathetic stimulation evoked by the cold pressor test. Similarly, in normal coronary arteries the increase in blood flow velocity induced by papaverine results in flow-dependent coronary dilation. In order to assess the coronary responses to both stimuli in hypertensive patients, variations of proximal left anterior descending coronary artery diameters and coronary blood flow velocity have been measured using quantitative coronary angiography and intracoronary Doppler in 10 control subjects and in 12 hypertensive patients. All the patients had angiographically normal coronary arteries. Total serum cholesterol, triglycerides, HDL- and LDL-cholesterol were within normal range in all patients. All patients were nonsmokers and none of them had diabetes mellitus. During the cold pressor test (hands immersed in ice water for 120 s), the rate-pressure product and coronary blood flow velocity increased respectively by 33 +/- 9% (p < 0.001) and 51 +/- 26% (p < 0.05) in control subjects, by 28 +/- 18% (p < 0.001) and 68 +/- 52% (p < 0.05) in hypertensive patients. In control subjects, coronary arteries dilated by + 12.0 +/- 4.4% (p < 0.001), and constricted by -10.3 +/- 8.5% (p < 0.001) in hypertensive patients. After injection of 10 mg of papaverine into the distal left anterior descending coronary artery, proximal left anterior descending coronary artery dilated by + 17.0 +/- 10.6% (p < 0.001) in control subjects, and did not vary (-0.7% +/- 10.6%) in hypertensive patients, when blood flow velocity was increased respectively by 449 +/- 97% and 383 +/- 103% (p < 0.001 in both groups).(ABSTRACT TRUNCATED AT 250 WORDS)     

Can measures of coronary dynamics explain chest pain without coronary artery disease?

There is reason to believe that clear parathyroid cysts are a separate pathologic entity distinct from degenerative cystic tumors of the parathyroid. They probably derive from enlargement of vestigial tubules or canals associated with parathyroid embryogenesis and they are rarely, if ever, hyperfunctioning. Indeed, if a clear parathyroid cyst is encountered in the clinical setting of primary hyperparathyroidism, then it is important to exclude a concomitant tumor in one of the other parathyroid gland, as in the case presented here. If the ionized serum calcium level is normal then clear parathyroid cysts can be diagnosed and treated definitively by percutaneous needle aspiration of their crystal clear fluid contents.