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Biomedical subjects

A Sheikhzadeh

Publications and source records attributed to A Sheikhzadeh.

At least 19 recordsLinked to original sources

Cardiac release and kinetics of endothelin after uncomplicated percutaneous transluminal coronary angioplasty.

This study was designed to assess the release kinetics of endothelin after percutaneous transluminal coronary angioplasty (PTCA) and to prove the coronary endothelium as the source of the endothelin release. Twenty-seven patients with single-vessel coronary artery disease underwent PTCA. Endothelin, troponin T, myoglobin, and creatine phosphokinase paired blood samples were withdrawn from the coronary sinus and a peripheral vein before the balloon maneuver and at 1, 5, 10, 30, 45 minute(s), and at 1, 2, 3, 6, 12, and 24 hour(s) after the last balloon maneuver. Myocardial ischemia was monitored by means of cardiac lactate metabolism and 12-lead electrocardiogram. Thirteen patients who underwent a diagnostic cardiac catheterization served as a control group. In the left coronary artery, PTCA (n = 19) endothelin concentrations increased from 4.1 pg/ml as a common mean baseline level before intervention to 13.9 +/- 2.6 pg/ml (mean +/- SD) in the coronary sinus and 7.9 +/- 2.2 pg/ml (mean +/- SD) in the peripheral vein at 1 minute after the intervention (p <0.001). The levels remained elevated for 3 hours with higher coronary sinus than peripheral venous concentrations due to persistent cardiac endothelin release. PTCA of the right coronary artery (n = 8) also led to an instantaneous endothelin increase from a mean concentration of 4.4 before intervention to 8.3 pg/ml after intervention with identical coronary sinus and peripheral venous levels (p <0.001). Endothelin levels gradually decreased to normal within 6 hours. No patient developed a measurable myocardial ischemia or a myocardial infarction. In the control group all parameters remained unchanged. Uncomplicated PTCA was followed by a significant cardiac endothelin release that seems to indicate endothelial injury and not myocardial ischemia.

Aged

Relation between QT dispersion and the extent of myocardial ischemia in patients with three-vessel coronary artery disease.

The aim of the study was to examine the relation between the extent of myocardial ischemia and changes in QT interval dispersion in patients with obstructive coronary artery disease and in patients with normal coronary arteries. QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies showed QT interval dispersion changes during episodes of myocardial ischemia in patients with coronary artery disease, but no data on the relation between extent of myocardial ischemia and degree of QT interval dispersion changes are available. To assess the effects of myocardial ischemia on myocardial repolarization by analyzing the change in QT dispersion during incremental atrial pacing, we studied 33 patients (7 women and 26 men, mean age 60.1 +/- 5.1 years, 18 patients with normal coronary arteries, 15 patients with coronary 3-vessel disease). QT dispersion was measured at baseline, after each pacing period, within 30 seconds after cessation of pacing ("peak ischemic stress"), and at 1-minute intervals for up to 5 minutes. Paired blood samples for determination of serum lactate were withdrawn from the coronary sinus and radial artery to determine the cardiac lactate extraction ratio at each point of electrocardiographic registration. In patients with coronary artery disease, QT dispersion increased from a baseline value of 39 +/- 7 ms to a peak ischemic stress value of 63 +/- 10 ms (p <0.0001). Patients with normal coronary arteries showed almost unchanged values of QT dispersion (41 +/- 9 vs 42 +/- 7 ms). There was a significant relation between the pacing-induced change in QT dispersion and the induced change in myocardial lactate extraction ratio (r = 0.76, p <0.0001). The change in QT dispersion (baseline vs peak pacing stress) was related to the extent of the cardiac lactate extraction ratio (r = -0.79, p <0.0001). These data indicate that the severity or extent of induced myocardial ischemia was related to the degree of induced changes of the variability in the timing of the ventricular recovery pattern.

Aged

Myocardial ischemia in generalized coronary artery-left ventricular microfistulae.

Generalized (multiple) arterio-systemic fistulae are fistulae arising from all three major coronary arteries and drain into the left ventricle are rare and the clinical and hemodynamic sequelae are incompletely understood. This communication is based on the clinical and hemodynamic data of a series of patients (eight cases out of 7262 consecutive patients) incidentally identified at coronary angiography combined with data from cases previously reported in literature. The aim was to assess the role of generalized coronary artery fistulae as a non-atherosclerotic cause of myocardial ischemia by means of a coronary sinus lactate study. Coronary sinus lactate study demonstrated myocardial ischemia in 6/7 patients. Mean arterio-coronary venous lactate difference decreased from 0.31+/-0.18 mmol/l (lactate extraction ratio, LER, 29.4+/-13.9%) at rest to 0.04+/-0.13 mmol/l (LER -4.0+/-13.3%) at peak exercise. Five minutes after cessation of pacing, lactate difference increased to 0.22+/-0.21 mmol/l (LER -20.7+/- 13.2%). At peak pacing stress, 4/7 patients showed frank lactate production, and two patients presented with a reduced cardiac lactate extraction rate also indicating myocardial ischemia metabolically. In the present study, we demonstrated a possible role of a coronary steal mechanism due to microfistulae pathways in the pathogenesis of myocardial ischemia in patients with generalized coronary artery-left ventricular microfistulae.

Aged

Neutrophil-derived oxidative stress after myocardial ischemia induced by incremental atrial pacing.

We studied the effect of atrial pacing-induced myocardial ischemia on the generation of oxygen free radicals (OFR) in 8 patients with verified coronary artery disease (CAD) and in a control group of 4 patients without coronary atherosclerosis. Myocardial ischemia was measured metabolically by simultaneous lactate sampling from coronary sinus (CS) and arterial blood. Generation of OFR from purified viable polymorphonuclear neutrophils (PMN) was assessed by means of the chemiluminescence (CL) method. At peak pacing, 7 of 8 patients with CAD exhibited transient myocardial ischemia (mean lactate extraction ratio at rest: 23.6 +/- 7.7 vs 5.21 +/- 5.1% at peak pacing, p = 0.012). In these patients, unstimulated PMN harvested from the CS depicted a significant increase of luminol-enhanced CL (from 1.06 +/- 0.54 to 2.15 +/- 1.28 cpm x 10(5), p = 0.012) after atrial pacing. There was no additional effect from further ex vivo stimulation with phorbol myristate acetate. This finding underscores the role of myocardial ischemia as a potent endogenous activator of PMN function and may have implications in the pathogenesis and progression of atherosclerosis.

Cardiac Pacing, Artificial

Topographic pattern of advanced atherosclerotic lesions in carotid arteries.

Ulcers in extracranial carotid arteries are a known source of cerebral embolism. However, there are no data available on the prevalence of ulcerations located at the origin of these vessels in the aortic arch. Therefore, in this pathological study the topographic distribution of ulcerated lesions were determined in these arteries. One hundred and one consecutively autopsied patients composed the study group. Ulcerated plaques were sought for in both carotid arteries, from their origin in the arch up to the carotid canal, and also in the aortic arch and ascending aorta. The two anatomical sites mostly affected by atherosclerosis were the region of the carotid sinus and the orifices of cervical arteries in the aortic arch. More than one third of all ulcers were at the orifices of cervical arteries in the arch. Interestingly, ulcers at the orifice of the left common carotid artery in the arch were accompanied with other ulcers located elsewhere in the remaining segments of the left carotid system, whereas ulcerations at the orifice of brachiocephalic trunk were not accompanied with other concomitant lesions in the right carotid system. Furthermore, there was no symmetric distribution of ulcerated plaques in both carotid systems.

Adult

Cardiomyopathic lentiginosis/LEOPARD syndrome presenting as sudden cardiac arrest.

A 26-year-old apparently healthy man with numerous pigmented skin lesions collapsed during an evening party and was resuscitated from ventricular fibrillation. Hypertrophic cardiomyopathy and subaortic tunnel were disclosed by angiocardiography. A diagnosis of cardiomyopathic lentiginosis/lentigines (multiple), electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of the genitalia, retardation of growth, and deafness (sensorineural) syndrome was made. The patient then underwent treatment with an implantable pacer-cardioverter-defibrillator device. Further evaluation revealed several well-established features of the disorder. This is the first reported case of survival from ventricular fibrillation associated with this rare and little known multifaceted syndrome. Disseminated lentiginosis must prompt clinicians to evaluate such cases further since underlying disorders may be associated with considerable morbidity and, apparently, sudden death.

Abnormalities, Multiple

Priming of neutrophils after elective percutaneous transluminal coronary angioplasty is unrelated to accompanying brief myocardial ischemia.

OBJECTIVE: The purpose of this study was to investigate the effect of brief myocardial ischemia and vascular trauma induced by elective percutaneous transluminal coronary angioplasty on in vivo 'priming' and activation of neutrophils. PATIENTS AND METHODS: We studied 16 patients undergoing elective coronary angioplasty for symptomatic coronary artery disease and a control group of seven patients undergoing diagnostic cardiac catheterization. Free radical production from purified neutrophils (Ficoll-Hypaque density gradient method) was measured indirectly by the chemiluminescence method. Myocardial ischemia during balloon inflation was assessed by serial lactate determinations from coronary sinus and arterial blood. The degree of transient angioplasty-related myocardial ischemia was related to the oxidative response of activated neutrophils. RESULTS: Mean (+/-S.E.M.) oxidative response, i.e. the lucigenin- and luminol-enhanced-chemiluminescence (counts per minute) of neutrophils sampled from the coronary sinus increased significantly after percutaneous transluminal coronary angioplasty (Lucigenin-chemiluminescence: pre-angioplasty 3.69+/-0.64x10(5) vs. post-angioplasty 7.08+/-1.2x10(5), P<0.01; Luminol-chemiluminescence: pre-angioplasty 2.81+/-0.67x10(6) vs. post-angioplasty 5.2+/-0.92x10(6), P<0.01). Twelve of 16 patients developed transient cardiac lactate production (mean coronary sinus lactate excess: +0.12 mmol/l) and three disclosed a lactate extraction ratio <10%, both suggestive of myocardial ischemia. However, there was no correlation between the cardiac lactate production and the increased oxidative response after coronary angioplasty (r2 (Lucigenin-chemiluminescence)=0.02, n.s.; r2 (Luminol-chemiluminescence)=0.06, n.s.). CONCLUSION: 'Priming' of neutrophils, as reflected by increased oxidative response, is likely to occur after coronary angioplasty, but not after the angiographic procedure itself. However, 'priming' seems to be unrelated to the transient brief period of myocardial ischemia and rather depends on an alternative mechanism.

Adult

Cardiac release and kinetics of endothelin after severe short-lasting myocardial ischemia.

OBJECTIVES: The aim of this study was to investigate the release kinetics of endothelin after induced short-lasting myocardial ischemia. BACKGROUND: Endothelin is an endothelium-derived vasoactive peptide. Unequivocal proof of its cardiac release in ischemic syndromes has not yet been demonstrated. METHODS: A coronary sinus study with atrial pacing was performed in 23 patients with coronary artery disease. Endothelin (ET), cardiac troponin-T (TnT), myoglobin (Mb) and creatine kinase (CK) samples were withdrawn from the coronary sinus and a peripheral vein before and 1, 5, 10, 30 and 45 min and 1, 2, 3 and 6 h after pacing. The appearance of angina pectoris, abnormal cardiac lactate metabolism and ST segment depression were further criteria for myocardial ischemia. RESULTS: In the study group, pacing stress induced severe ischemia (mean duration +/- SD 6.1 +/- 1.2 min), with a maximum of 0.34 +/- 0.12-mV ST segment depression in 21 of 23 patients and angina pectoris in 22 of 23. The maximal cardiac lactate production was 42.8 +/- 17.3% (p < 0.03). TnT and CK levels in the total group were normal; in 14 of 23 patients a transient elevation of Mb with a maximum after 3 h was detected (86.4 +/- 27.1 micrograms/liter, p < 0.03). The ET concentrations increased significantly (p < 0.001) in the coronary sinus (from 4.6 +/- 0.8 [baseline] to 12.9 +/- 2.7 pg/ml at 1 min after cessation of pacing) and the peripheral vein, respectively (from 4.7 +/- 0.7 [baseline] to 8.3 +/- 2.1 pg/ml at 1 min). ET further remained elevated for 1 h with persisting higher coronary sinus than peripheral venous concentrations, indicating cardiac ET release. In a control group of 18 patients without heart disease, all variables were unchanged. CONCLUSIONS: Short-lasting severe myocardial ischemia was associated with significant ET release of cardiac origin that lasted up to 1 h.

Cardiac Pacing, Artificial

Impact of early accelerated dose tissue plasminogen activator on in-hospital patency of the infarcted vessel in patients with acute right ventricular infarction.

OBJECTIVE: To assess the efficacy of early accelerated dose tissue plasminogen activator on in-hospital patency of the infarct related artery in patients with inferior myocardial infarction with and without right ventricular involvement. DESIGN: Single centre prospective assessment before discharge of infarct related vessel patency after early thrombolysis. SETTING: Tertiary cardiac referral centre at a university hospital. PATIENTS AND METHODS: 90 consecutive unselected patients with acute myocardial infarction, of whom 35 (39%) had electro-cardiographic evidence of right ventricular involvement (ST segment elevation greater than 0.1 mV in right precordial lead V4R), were studied. All patients received accelerated dose tissue plasminogen activator 100 mg within six hours from the onset of symptoms and had control angiography before discharge. MAIN OUTCOME MEASURES: Infarct related coronary artery patency using the Thrombolysis in Myocardial Infarction (TIMI) grading system before discharge. Incidence of prolonged systemic hypotension, sinus bradycardia, complete atrioventricular block, and ventricular tachyarrhythmia during early hospitalisation. RESULTS: Despite aspirin and bolus heparinisation before thrombolysis and high dose heparinisation thereafter for at least 48 hours the infarct related artery was more likely to be occluded (TIMI 0 or 1 flow) in patients with right ventricular involvement than in those without (69 v 29%, P < 0.001), as shown by control angiography performed a mean of 12.8 days after thrombolysis. These findings may be explained, at least in part, by predominant involvement of the proximal right coronary artery (66 v 31%, P < 0.05) and a low cardiac output syndrome, being indirectly reflected by a high incidence of prolonged hypotension (26 v 7%, P = 0.02), bradycardia (34 v 14%, P = 0.03), and complete atrioventricular block (37 v 5%, P = 0.0001). CONCLUSION: Primary angioplasty should be considered as the treatment of choice in patients with acute inferior infarction with right ventricular involvement because of the high failure rate of thrombolysis.

Coronary Angiography

Vascular events during follow-up in patients with aortic arch atherosclerosis.

BACKGROUND AND PURPOSE: An association between aortic arch atherosclerosis and vascular events has been demonstrated. However, few data exist regarding follow-up evaluation of this disease. METHODS: In this study, 183 patients with the diagnosis of aortic arch atherosclerosis were prospectively followed up. This diagnosis was made during an echocardiographic cross-sectional study. In 136 patients, raised plaques with thickness < 5 mm had been shown to exist, and in 47 patients complex plaques with thickness > or = 5 mm or plaques with mobile components had been demonstrated on the initial transesophageal echocardiography. RESULTS: During a mean follow-up period of 16 +/- 7 months, vascular events with a presumed embolic origin occurred in 15 patients. The incidence was 4.1 per 100 person-years in patients with raised plaques compared with 13.7 per 100 person-years in the group with complex plaques. The Kaplan-Meier survival analysis revealed a significantly higher rate of vascular events in patients who were found to have complex plaques (P < .01). In the Cox proportional hazards analysis, the finding of complex plaques (relative risk [RR], 4.3; 95% confidence interval [CI], 1.5 to 12.0; P = .006), coronary artery disease (RR, 4.0; 95% CI, 1.2 to 13.1; P = .02), and a history of previous embolism (RR, 4.0; 95% CI, 1.1 to 14.4; P = .03) were independent predictors of vascular events. CONCLUSIONS: Patients with the finding of protruding plaques or plaques with mobile components have a high risk of subsequent vascular events.

Adult

Apical hypertrophic cardiomyopathy of the Japanese type coexistent with a coronary muscle bridge. A case report and review.

We describe the case of a 21-year-old Italian male who presented with giant negative T-waves and left ventricular hypertrophy on the electrocardiogram suggestive of apical hypertrophic cardiomyopathy. Clinically, he suffered from new onset of exertional angina, dyspnea and palpitations during soccer playing or heavy exercise beginning one week before admission. Echocardiography and cardiac catheterization conformed the rare combination of a nonobstructive apical hypertrophic cardiomyopathy of the "Japanese" type coexistent with an extensive muscular bridge involving almost the entire anterior interventricular branch of the left coronary artery. Although the patient complained of exertional angina pectoris, absence of objective evidence of myocardial ischemia by means of treadmill stress test, exercise thallium scan, dobutamine stress echocardiography as well as atrial pacing stress emphasized the benign nature of this complex anomaly.

Adult

Embolism from the aortic arch in patients with cerebral ischemia.

The pathogenic role of aortic arch atherosclerosis (AAA) in embolic stroke is not well understood. We investigated, prospectively, the prevalence and severity of AAA in patients with embolic stroke to ascertain its role as a risk factor for cerebral ischemia. We examined 100 consecutive patients who had experienced acute symptoms due to cerebral ischemia. Clinical examination, electrocardiogram, x-ray, ultrasound examination of craniocervical arteries, transesophageal echocardiography (TEE), cranial computerized tomography, and magnetic resonance imaging were undertaken. Seventy-five patients showed evidence of AAA; 34 patients had moderate to severe (> 5 mm thickening) AAA. Age was positively related to the severity of AAA, as were smoking, coronary heart disease, diabetes mellitus, internal carotid artery (ICA) occlusive disease, and embologenic heart disease. Hypertension, which was evident in 52 patients, did not distinguish those cases showing AAA. Twelve patients showed evidence of high-degree ICA stenosis on the symptomatic side, although the extent of ICA stenosis and AAA were unrelated. A cardiac source of emboli was found in 28 patients. AAA was found to be the probable source for embolic stroke in 14 patients. These data indicate that aortic arch atherosclerosis is an important source of cerebral emboli which may increase the risk for ischemic stroke. Furthermore, we suggest that TEE examination of the aortic arch may be important for the diagnosis of AAA and ultimately for the prophylactic treatment of severe cerebral ischemia.

Adult

Aortic atherosclerotic plaques as a source of systemic embolism.

OBJECTIVES: Our study was designed to determined the significance of aortogenic embolism in an unselected autopsy collective. BACKGROUND: Although embolism arising from atherosclerotic plaques in the aorta has been acknowledged, the role of aortic atheromatosis among other well known sources of embolism remains to be further clarified. METHODS: We examined the proximal part of the arterial system with regard to the presence of atherosclerotic lesions as well as cardiac changes in 120 consecutive necropsy studies. Pathologic evidence of embolic events was recorded. Clinical and neuropathologic data were also surveyed in all patients. RESULTS: Among atherosclerotic lesions, fibrous plaques (p < 0.05) and calcified (p < 0.0001) and ulcerated lesions (p < 0.0001) as well as thrombi (p < 0.005) were observed significantly more frequently in the aortic arch and in the descending aorta than in the ascending aorta, whereas fatty streaks were distributed uniformly. In 40 (33%) of the 120 patients, we found pathologic evidence of arterial embolization. Multiple logistic regression analysis revealed a significant correlation between embolism and complicated atherosclerotic plaques in the aortic arch (odds ratio [OR] 5.8, 95% confidence interval [CI] 1.1 to 31.7, p < 0.05), severe ipsilateral carotid artery disease (OR 3.1, 95% CI 3.1 to 45.3, p < 0.001) and atrial fibrillation (OR 3.5, 95% CI 1.1 to 9.9, p < 0.05). CONCLUSIONS: Complicated atherosclerotic plaques in the aortic arch represent an independent risk factor for systemic embolism similar to atrial fibrillation and severe atherosclerosis of the carotid arteries.

Adult

[Detection of stress-induced myocardial ischemia in isolated coronary ectasia and aneurysm (dilatative coronaropathy)].

Forty eight patients with bilateral isolated non-stenotic coronary artery ectasia or aneurysm without associated cardiac defects ("dilated coronaropathy") were identified in consecutive diagnostic cardiac catheterizations between 1986-6/1994 (angiographic incidence 0.44%). Ectasia was defined as a luminal dilatation of the 1.5-2-fold, aneurysm of more than double the normal limits. In 16 patients a myocardial infarction (5 non-q-infarctions/11 q-wave-infarctions) was the indication for coronary angiography, a thrombotic occlusion of the infarct vessel was documented in 8/16 patients. In patients without myocardial infarction (study group) an evaluation of exercise-induced myocardial ischemia was performed by means of a coronary sinus lactate study, treadmill ergometry and Thallium-201-scintigraphy. A corresponding coronary insufficiency was objective in all tests in the study group. An exercise-induced myocardial ischemia was found in 21/31 in the coronary sinus study, 19/29 in the treadmill ergometry and 13/26 patients in the scintigraphy; significant differences were found in comparison to the results of a control group of patients without heart disease (n = 29, p < 0.001). After administration of 0.8 mg nitroglycerin (NTG) a further significant deterioration of myocardial ischemia was measured in the 21 patients with pathologic lactate metabolism developing a frank cardiac lactate production (p < 0.03). The extent of myocardial ischemia in the coronary sinus study was significantly correlated to the coronary diameters of the proximal and middle segments of the Ramus interventricularis anterior and the middle segment of the Ramus circumflexus (r = 0.87, p < 0.02). A differentiation between ectasia and aneurysm therefore seems to be of functional relevance. Angiographic stigmata of an impaired coronary blood flow such as a segmental to and from movement and a local deposition of dye were found significantly more often with increasing coronary diameters (p < 0.04). "Dilated coronaropathy" is an entity of non-stenotic, ischemic coronary artery disease. NTG was of no therapeutic benefit or led to an aggravation of the exercise-induced myocardial ischemia. Because of this potential adverse effect the administration of NTG should be avoided in "dilated coronaropathy".

Adult

Detection of a hypercoagulable state in nonvalvular atrial fibrillation and the effect of anticoagulant therapy.

The purpose of the study was to evaluate alterations of the hemostatic system and the effect of anticoagulant therapy in nonvalvular atrial fibrillation. A set of molecular hematologic markers was measured prospectively in 69 patients with atrial fibrillation and 28 age-matched patients in sinus rhythm. Significantly elevated levels of thrombin-antithrombin III complex (8.5 +/- 1.6 vs. 2.5 +/- 0.3 micrograms/l; p < 0.001), fibrin monomers (27.1 +/- 3.2 vs. 13.4 +/- 3.7 nM; p < 0.001), D-dimers (788 +/- 76 vs. 405 +/- 46 micrograms/l; p < 0.005), and tissue-type plasminogen activator (9.6 +/- 0.5 vs. 7.2 +/- 0.5 micrograms/l; p < 0.05) were observed in patients with atrial fibrillation compared to those in sinus rhythm. In a subgroup of patients in whom anticoagulant therapy with oral coumadin or standard intravenous heparin was established after the initial study, hemostatic activation decreased significantly. In conclusion, molecular hematologic markers indicate a hypercoagulable state in atrial fibrillation which may characterized a group of patients at elevated risk of thromboembolic disease.

Aged

[Effect of lowered cholesterol on the course of coronary heart disease. An analysis of the results of controlled, angiographically documented intervention studies].

AIM: To find out from published reports whether the tendency of coronary heart disease (CHD) to progress can be retarded by lowering total and LDL cholesterol concentrations. METHODS: After a data-base search a meta-analysis was undertaken of all those randomized, controlled and angiographically documented studies which contained informations about the effect of cholesterol reduction on the course of CHD over a period of at least 2 years. A total of 12 studies covering 3781 patients met the stated criteria. RESULTS: The different lipid-lowering measures (usually drugs) achieved a statistically significant reduction of the number of patients with progression of the coronary angiographic findings and a significant increase in the number of those with actual regression. The number of coronary incidents, such as myocardial infarction, unstable angina, sudden cardiac death, necessary aortocoronary bypass operations or percutaneous transluminal coronary angioplasty was lower by 34% in the groups with measures to influence cholesterol metabolism than in the untreated groups. In the studies in which coronary arteriograms were evaluated quantitatively there was an annual increase in the mean degree of stenosis of 1.01% in the untreated and 0.37% in the treated groups. CONCLUSIONS: The difference in the increase of the mean degree of stenosis is probably not only important because of the resulting haemodynamic changes in myocardial perfusion. The quantitatively only slightly increased trend towards progression in the untreated groups can be interpreted as a marker for an active process of atherogenesis with a tendency of plaques to break off and of plaque thromboses.

Anticholesteremic Agents