Could stress magnetic resonance imaging be useful in patients with a low probability of ischemic heart disease? / ¿Podría ser útil la resonancia magnética de estrés en pacientes con baja probabilidad de cardiopatía isquémica?

OBJECTIVE: To assess the usefulness of cardiac stress magnetic resonance imaging (MRI) with adenosine in the detection of ischemic heart disease in patients with a low pretest probability of disease. MATERIAL AND METHODS: We used the probability ratio to analyze the usefulness of cardiac stress MRI in a selection of patients with a low pretest probability of ischemic heart disease (low or moderate cardiovascular risk, atypical chest pain, or absence of prior ischemic heart disease). RESULTS: We included 295 patients followed up for a median of 28 (19-36) months. A total de 60 patients had an event. Cardiac stress MRI was more useful in patients with a low pretest probability: atypical chest pain (probability ratio [PR] positive 8.56), absence of prior ischemic heart disease (PR positive 4.85), and low or moderate cardiovascular risk (PR positive 3.87). CONCLUSIONS: Cardiac stress MRI can be useful in the diagnosis of ischemic heart disease in patients with a low pretest probability.

[Patients with vulnerable coronary plaques have higher serum metalloproteinase-1 levels]. / Los pacientes con placas coronarias vulnerables presentan mayores niveles séricos de metaloproteinasa-1.

BACKGROUND: Most acute coronary syndromes are caused by the fracture of a vulnerable atherosclerotic plaque. These plaques are thin cap fibroatheromas, which can only be detected with invasive coronary imaging techniques. It is necessary to find a non-invasive biomarker of these vulnerable plaques in order to identify patients at risk without a coronary angiography. Metalloproteinase-1 is an enzyme involved in extracellular matrix metabolism which has been correlated with the rupture of atherosclerotic plaques. Its serum levels in patients with vulnerable plaques remain unknown. METHODS: Patients with suspected stable coronary artery disease undergoing coronary angiography in our hospital were in-cluded. The coronary arteries were studied with optical coherence tomography to detect vulnerable plaques. Blood samples were taken from a peripheral vein and from the coronary sinus, to assess metalloproteinase-1 levels. RESULTS: Fifty-one patients were included, 13 of whom had at least one vulnerable plaque. There were not significant dif-ferences in clinical characteristics, lipid profile or C reactive protein levels, between patients with or without vulnerable plaques. Patients with vulnerable plaques had significant higher metalloproteinase-1 levels both in peripheral (7330±5541 vs 2894±1783 pg/ml, p=0.025) and coronary sinus serum (6012±3854 vs 2707±1252 pg/ml, p=0.047). CONCLUSIONS: Patients with vulnerable plaques had significantly higher metalloproteinase-1 serum levels. Further studies with clinical follow up are needed to assess the prognostic value of serum metalloproteinase-1.

Electrocardiographic findings in acute right ventricular infarction: sensitivity and specificity of electrocardiographic alterations in right precordial leads V4R, V3R, V1, V2, and V3.

To determine the sensitivity, specificity, predictive value and diagnostic efficiency of electrocardiographic alterations in the diagnosis of acute right ventricular infarction, 43 autopsy patients with acute myocardial infarction and an electrocardiogram including 12 leads plus leads V3R and V4R were studied. Group A included 21 patients with right ventricular infarction, of whom 14 (group AI) had posterior and 7 (group AII) had anterior right ventricular infarction. Group B included 22 patients without right ventricular infarction. Excluding group AII patients, the sensitivity of the presence of a Q wave reached 78.6% in lead V4R and decreased in leads V1 to V3; its specificity was low in all the leads. The sensitivity of ST segment elevation reached 100% in lead V4R and decreased in leads V1 to V3; its specificity was highest (68.2%) in leads V4R and V3R, its negative predictive value was 100% and its diagnostic efficiency was 80.6%. The criterion of ST segment elevation in lead V4R being higher than that in leads V1 to V3 was less sensitive (78.6%) than ST segment elevation in lead V4R alone, but its specificity reached 100%, its positive predictive value 100% and its diagnostic efficiency 91.7%. In conclusion, there are no electrocardiographic criteria to identify anterior right ventricular necrosis, but posterior right ventricular necrosis may be identified by the presence of a Q wave or ST segment elevation in the right precordial leads, reaching the highest sensitivity and specificity in lead V4R. The criterion of ST segment elevation in lead V4R being higher than that in leads V1 to V3 offers the highest specificity and efficiency in the diagnosis.

The dobutamine stress test with thallium-201 single-photon emission computed tomography and radionuclide angiography: postinfarction study.

OBJECTIVES: The purpose of this study was to investigate left ventricular wall motion changes during dobutamine-induced myocardial ischemia. BACKGROUND: Dobutamine is increasingly used as a stress test. It has been assumed that high doses of the drug induce the same changes in contractility as physical exercise. However, some data suggest that ischemic myocardium can respond to dobutamine with an increase in contractility. METHODS: Sixty-three postinfarction patients twice underwent the dobutamine test (up to 40 micrograms/kg per min) within 1 to 2 days. Thallium-201 single-photon emission computed tomography (SPECT) and gated equilibrium radionuclide ventriculography were performed on each patient at rest and with dobutamine. Both global and regional ejection fractions were quantified. Sixty patients underwent coronary cineangiography within 1 week. The presence of redistribution was correlated with global and regional ejection fraction changes and with coronary lesions. RESULTS: Redistribution was present in 45 patients, and no change or a decrease in global or regional ejection fraction was detected in 22. In the entire group of patients global ejection fraction increased from 46 +/- 12% to 56 +/- 14%. The six patients with triple-vessel disease had a flat (-0.2 +/- 5%) ejection fraction response to dobutamine, whereas the remaining patients had an increase of 11 +/- 7% (p = 0.003). The regional ejection fraction of the hypokinetic area increased from 27 +/- 10% to 41 +/- 19%, showing no change or a decrease in 13 patients. The 44 patients with peri-infarct redistribution had a significantly higher increase in regional ejection fraction than those without redistribution (16.4 +/- 10% vs. 4.7 +/- 17%, p = 0.003). In the patients with peri-infarct redistribution, an inverse linear correlation was found between redistribution score and dobutamine-induced regional ejection fraction change (r = -0.44, p = 0.004). CONCLUSIONS: Mild to moderate dobutamine-induced peri-infarct ischemia is compatible with an increase in contractility, whereas severe ischemia induces worsening of wall motion.

Diagnosis of subacute ventricular wall rupture after acute myocardial infarction: sensitivity and specificity of clinical, hemodynamic and echocardiographic criteria.

When ventricular free wall rupture after acute myocardial infarction is not followed by sudden death, it is referred to as subacute ventricular rupture. The sensitivity and specificity of clinical, hemodynamic and echocardiographic diagnostic variables obtained at bedside are unknown and were therefore prospectively studied in 1,247 consecutive patients with acute myocardial infarction including 33 patients with subacute ventricular rupture diagnosed at operation (group A) and 1,214 patients without ventricular rupture (at operation, postmortem study or at discharge) (group B). The incidence of syncope, recurrent chest pain, hypotension, electromechanical dissociation, cardiac tamponade, pericardial effusion, high acoustic intrapericardial echoes, right atrial and right ventricular wall compression identified in two-dimensional echocardiograms and hemopericardium demonstrated during pericardiocentesis was higher in group A than in group B (p less than 0.00001). The presence of cardiac tamponade, pericardial effusion greater than 5 mm, high density intrapericardial echoes or right atrial or right ventricular wall compression had a high diagnostic sensitivity (greater than or equal to 70%) and specificity (greater than 90%). The number of false positive diagnoses was always high for each diagnostic variable alone (greater than 20%), but the combination of clinical (hypotension), hemodynamic (cardiac tamponade) and echocardiographic variables allowed a sensitivity of greater than or equal to 65% with a small number of false positive diagnoses (less than 10%) and provided useful information for therapeutic decisions. The diagnosis of subacute ventricular rupture requires a surgical decision. Twenty-five (76%) of the 33 patients with subacute ventricular rupture survived the surgical procedure and 16 (48.5%) are long-term survivors. Thus, subacute ventricular wall rupture is a relatively frequent complication after acute myocardial infarction that can be accurately diagnosed and successfully treated.

[Heart failure. Current pharmacologic treatment]. / Insuficiencia cardiaca. tratamiento farmacológico actual.

Treatment of heart failure (HF) has changed in recent years, despite the paucity of new approved drugs. Current treatment is directed not only towards improving symptoms, but also to preventing the development from asymptomatic systolic dysfunction to symptomatic heart failure, to preventing cardiac remodelling, renal dysfunction and to reducing mortality. The main families of drugs currently used are: cardiac glycosides, diuretics, angiotensin-converting enzyme inhibitors (ACEI), beta-blocking drugs (BB), angiotensin-II receptor blockers (ARB) and aldosterone receptor antagonists. The combination isosorbide dinitrate + hydralazine is hardly used due to its side effects and none of the new positive inotropic drugs has been approved in chronic HF, because all of them increase mortality. Levosimendan is a new positive inotropic agent approved for acute HF by an intravenous route, with a favourable effect on prognosis vs placebo and vs dobutamine (which worsens the prognosis). The approved oral drugs can be given at the same time if the patient tolerates them, because their beneficial effect is additive. Mortality in two years in mild to moderate HF is 34% with glycosides + diuretics. It falls to 22% when an ACEI is added, to 14% when a BB is added and to 10% when an aldosterone antagonist is added. ARB can be given instead of an ACEI or be added to the other drugs.

Ventricular compliance in ischemic right ventricular dysfunction.

Ischemic right ventricular dysfunction was diagnosed in 54 patients with acute myocardial infarction who had a right atrial pressure disproportionately increased in relation to the pulmonary capillary pressure. The right atrial pressure curve in 40 patients (74 percent) was M- or W-shaped, termed a noncompliant pattern, and was similar to the pattern found in constrictive pericarditis. Kussmaul's sign was found in the patients whose respiration was recorded. This pattern, which represents poor right ventricular compliance, was severe in 30 cases (y descent greater than x descent) and slight in 10 cases (y descent = x descent). Its duration was variable, ranging from days to years. Of the 54 patients, 32 (59 percent) had a low output syndrome, diagnosed in the presence of a cardiac index of less than 2.2 liters/min per m2, with signs of poor tissue perfusion. The severe noncompliant pattern was significantly related to the presence of a low output syndrome (p less than 0.01) and mortality from this cause (p less than 0.05). The jugular venous tracing pulse had a pattern similar to that of the right atrial pressure recording and therefore may be valuable in the noninvasive diagnosis of right ventricular dysfunction and in the study of the evolution of the noncompliant pattern and, hence, of ventricular compliance.

Radionuclide assessment of right ventricular contractile reserve after acute myocardial infarction.

Conflicting data have been reported about the implications of a decreased right ventricular (RV) contractile reserve (i.e., a < 5% stress-induced increase in ejection fraction [EF]). If a reduced reserve corresponds to ischemia, it will probably be associated with an electrocardiographic marker of RV ischemia, stress-induced ST-segment elevation (increases ST) in leads V3R to V6R. To test this hypothesis, 98 asymptomatic postinfarction patients (27 with RV infarction) were assigned to a dobutamine stress test (maximal dose 40 micrograms/kg/min) with equilibrium radionuclide angiography and electrocardiographic study, including leads V3R to V6R. All but 11 patients underwent coronary angiography. A dobutamine-induced increases ST in VR leads was seen in 24 patients with and in 8 without RV infarction. This electrocardiographic sign was 75% sensitive and 84% specific for the diagnosis of proximal right coronary artery disease. It was 61% sensitive and 74% specific for the detection of reduced RV contractile reserve. Patients with RV infarction had reduced RVEF at rest (38 +/- 9%), but the mean contractile reserve was normal (12 +/- 12%). The contractile reserve was significantly smaller in patients with proximal versus distal or no right coronary artery disease. It was also smaller (P < 0.01) in patients with increased ST versus no increased ST. In conclusion, high doses of dobutamine are useful in assessing RV contractile reserve after acute myocardial infarction. In these patients, a reduced RV contractile reserve is related to proximal right coronary artery disease and is associated with stress-induced increased ST in VR leads.

Segmental right ventricular function after acute myocardial infarction: two-dimensional echocardiographic study in 63 patients.

Right ventricular (RV) segmental contraction was studied in 63 patients with acute myocardial infarction (MI), using 2-dimensional (2-D) echocardiography. Group A included 32 patients with ischemic RV dysfunction: 19 had a disproportionate increase in right atrial pressure at the time of the examination (Group AI) and in 13 patients, right atrial pressure was normal when the echocardiogram was obtained (Group AII). Group B included 31 patients without ischemic RV dysfunction. Alkinesia or dyskinesia of the RV wall was found in 30 patients: 19 from Group AI, 8 from Group AII, and 3 from Group B. Asynergy could be identified in all segments of the RV wall including the outflow tract, RV apex, and anterior wall, but was more frequently found in the posterior wall (29 patients), best seen in the transversal subcostal short-axis view. A significant difference was found either in the frequency of wall motion abnormalities or in the number of segments with asynergy among the 3 groups (p less than 0.001). However, asynergy of the RV wall may be present in some patients with normal right heart hemodynamic function, suggesting that asynergy may be more sensitive than hemodynamic function in the diagnosis of acute RV infarction. Paradoxical septal motion was found in 8 patients, all in Group AI, and all had a right atrial pressure equal to or greater than pulmonary capillary pressure.

Identification of blood in the pericardial cavity in dogs by two-dimensional echocardiography.

The echocardiographic characteristics of hemopericardium with and without thrombus formation were investigated in 10 dogs and compared with that of saline solution injected into the pericardial cavity. Injection of 80 to 120 ml of saline solution produced an echolucent space between both pericardial layers and was considered as the control image in each dog for comparison with hemopericardium. Injection of heparinized blood filled the pericardial cavity with irregular echoes of variable acoustical impedence. High-density echoes of irregular distribution were observed in 3 dogs, in 5 dogs the echoes were of low acoustical density and in 2 dogs blood echoes were present but scarcely visible. Injection of clotted blood in 9 dogs (adding 20 mg of protamin sulphate and 8 mg of aminocaproic acid) produced echoes of high acoustical density easily identified in the 2-dimensional echocardiographic images. In 4 dogs attenuation and damping controls were increased to the point where myocardial echoes disappeared, while intrapericardial echoes were still visible. Thus, hemopericardium with or without thrombus formation may be identified by 2-dimensional echocardiography and differentiated from other types of pericardial effusion of lower acoustical density. Echogenicity of fluid blood in the pericardial cavity may be related to blood stasis.

Clandestine ischemia in patients with vasospastic angina.

BACKGROUND: Coronary vasospasms generally occur at rest, but can also be triggered by physical exercise. Anginal pain and ST-segment elevation may be seen during exercise-stress tests. ST-segment depression, due to nonocclusive vasospasms, has also been found to occur. When the result of a test is positive, scintigraphy usually reveals perfusion defects. True silent or clandestine ischemia (normal result of exercise test with perfusion defects) in these patients is very uncommon. OBJECTIVE: To stress the need for suspecting occurrence of coronary vasospasms in order to perform a proper diagnosis. METHODS: Eight patients with angina were selected for this study. They had negative results of exercise tests with perfusion defects detected by thallium-201 tomography, normal coronary arteries and vasospasms. Maximal exercise-stress tests with thallium-201 tomography were performed. Sizes of perfusion defects were quantified by examining polar maps. Coronary angiography and then an intracoronary ergonovine test were performed for each patient. RESULTS: Significant defects were seen in territory of the right coronary artery, the left anterior descending artery, or both. Lung:heart ratio was normal in every case. The coronary arteries were normal and vasospasms were elicited with ergonovine in all the patients. Correspondence between the location of perfusion defects and angiographic spasms was generally observed. After treatment with calcium antagonists and nitrates all of them improved and defects detected by thallium tomography were no longer found when tests were repeated. CONCLUSIONS: Some patients with vasospastic angina may have normal results of exercise-stress tests and reversible perfusion defects detectable by scintigraphy. This finding must lead one to perform coronary angiography without administration of nitroglycerine beforehand and an ergonovine test if the coronary arteries are normal.

Changes in plasma potassium during the dobutamine stress test.

We performed serial determinations of levels of potassium in 198 patients with suspected or proven coronary arterial disease who underwent a dobutamine stress test, so as to investigate if the depression in the ST segment induced by the test may be due to hypokalemia. The test consisted of an intravenous infusion of dobutamine, starting with a dose of 5 micrograms/kg/min for 5 minutes and continuing with 10, 15, 20 and up to 40 micrograms/kg/min every 5 minutes (mean peak dose = 20 micrograms/kg/min). Serial 12-lead electrocardiograms were taken to detect changes in the ST segment. The double product changed with dobutamine from 8844 +/- 6000 to 15201 +/- 3030. The peak dose of dobutamine induced a small but significant decrease in levels of serum potassium, with a further decrease 10 minutes later. In the 198 patients, the plasma potassium changes from 4.22 +/- 4.8 to 3.86 +/- 0.35 mmol/l (P less than 0.00001). The maximum decrease in potassium (0.56 +/- 0.49) occurred in the patients who received the highest dose of dobutamine (30 to 40 micrograms/kg/min). Only 17 patients reached levels lower than 3.5 mmol/l, and 4 of them achieved levels lower than 3.1 mmol/l. No correlation was found between depression of the ST segment equal to or greater than 1 mm on the electrocardiogram and the level of potassium after the test. No correlation was found between ventricular arrhythmias and levels of potassium. High doses of dobutamine, therefore, produce a small but significant decrease in potassium.(ABSTRACT TRUNCATED AT 250 WORDS)

[The first-choice technic for assessing myocardial viability. Cardiac perfusion gammagraphy]. / Técnica de primera elección para la valoración de la viabilidad miocárdica. Gammagrafía cardíaca de perfusión.

Stress echocardiography and perfusion scintigraphy are both useful techniques in the assessment of myocardial viability. The use of one technique or the other as the first choice test depends mainly on each hospital's experience. Perfusion scintigraphy should be chosen as the first technique in the following situations: a) hospitals with little experience in stress echocardiography and a good Nuclear Medicine department; b) patients with a bad acoustic window in rest echocardiography; c) contraindication of a high dobutamine dose, and d) need of quantification of viable area. When having chosen echocardiography as the first technique, perfusion scintigraphy is indicated when the response to dobutamine of the asynergic area does not allow the confirmation or the rejection of the presence of viability.

[Clinical usefulness of positron emission tomography (PET) in the evaluation of myocardial viability]. / Utilidad clínica de la tomografía de emisión de positrones (PET) en la valoración de la viabilidad miocárdica.

Positron emission tomography (PET) is a radionuclide imaging technique that allows quantitative assessment of regional myocardial function. It is mainly used in clinics to assess viability of dissynergic myocardium, by means of combined images of flow (with ammonia) and metabolism (with fluordeoxyglucose). The mismatch pattern, with an increase in fluordeoxyglucose metabolism in hypoperfused regions, is indicative of viability. The match pattern (a decrease in flow and metabolism in the same areas) is indicative of necrosis. Viability can also be assessed with water or fluordeoxyglucose independently quantified. Other promising methods are based in the study of oxygen consumption with 11C acetate and the study of hypoxia with 18F-misonidazole.

[Role of noninvasive examinations in the management of ischemic heart disease. III. Assessment of myocardial viability]. / Papel de las exloraciones no invasivas en el manejo de la cardiopatía isquémica. III. Estimación de la viabilidad miocárdica.

Assessment of myocardial viability is a field of growing interest. This article summarizes the pathophysiology of myocardial stunning and hibernation; both phenomena are associated with the presence of dysfunctional, viable myocardium. The techniques that are currently available for the assessment of viability, and the clinical situations in which these assessments may be more useful are discussed.

[Changes in the diameter of the coronary arteries in heart transplant recipients with angiographically normal vessels during five years]. / Cambios de diámetro de las arterias coronarias en receptores de transplante cardíaco con vasos angiográficamente normales durante cinco años.

INTRODUCTION: Diffuse or focal coronary artery narrowing is a frequent complication of cardiac transplantation. Coronary enlargement has also been described although it is less known. To study the changes of the coronary arteries in transplant recipients, we have performed a quantitative study throughout 5 years. METHODS: Serial coronary angiography was performed annually in all survivors of heart transplant. Forty four patients with visually normal coronary arteries and at least 5 years of evolution were selected for this study. Quantitative measurements of the diameter of the coronary arteries were performed in each angiogram at different levels: proximal, medium and distal left anterior descending coronary artery; proximal and distal left circumflex; proximal, medium and distal right coronary artery. Changes in diameter were compared throughout the 5 years. RESULTS: In the entire group of patients there was a small increase in the diameter of each segment. Taking each patient separately, an enlargement of the diameter of the proximal descending coronary artery was seen in 17 cases; medium descending coronary artery in 13; distal descending coronary artery in 8; proximal left circumflex in 11; distal left circumflex in 14; proximal right coronary artery in 18; medium right coronary artery in 18 and distal right coronary artery in 15. In total, 114 of 352 coronary segments (32%) underwent dilatation. Only 6 patients failed to have dilatation of any segment. CONCLUSIONS: Enlargement of the coronary arterial diameter was seen in 32% of segments of the main coronary arteries in heart transplant recipients with angiographically normal coronary arteries during 5 years of evolution. This could be due to intimal thickening with overcompensation by an additional vessel enlargement with net lumen gain.

[Isotopic ventriculography in healthy young volunteers. Their response to different types of stress]. / Ventriculografía isotópica en voluntarios jóvenes sanos. Respuesta a diferentes tipos de estrés.

BACKGROUND: Due to the increasing use of pharmacologic stress tests and the lack of comparative studies on ventricular function, this study was designed to establish the average limits in ventricular function with different kinds of stress, and to compare the response among them. METHODS: A randomized, open, controlled phase II clinical trial in 4 parallel groups was designed. Forty healthy male volunteers between 18 and 25 years were randomized into 4 groups of 10 individuals each: physical exercise (group 1), dobutamine (group 2), adenosine triphosphate (ATP) (group 3) and dipyridamole (group 4). Each volunteer underwent equilibrium radionuclide angiography, at rest and during stress. RESULTS: The global and regional ejection fraction increased significantly with the 4 kinds of stress. The maximal increase was reached with dobutamine and the minimal with dipyridamole. Physical exercise induced an increase in global ejection of 13 +/- 5%; dobutamine 16 +/- 6%; ATP 9 +/- 3% and dipyridamole 4 +/- 3%. CONCLUSIONS: The global and regional ejection fraction increases significantly more with dobutamine than with the other stress tests. Dipyridamole elicits the minimal increase.

[Guidelines of the Spanish Society of Cardiology for cardiopulmonary resuscitation]. / Guías de actuación clínica de la Sociedad Española de Cardiología en resucitación cardiopulmonar.

Cardiac arrest, consistent on cessation of cardiac mechanical activity, is diagnosed in the absence of consciousness, pulse and breath. The totality of measurements applied to revert it is called cardiopulmonary resuscitation. Two different levels can be distinguished: basic vital support and advanced cardiac vital support. In the basic vital support methods which do not require special technology are used: opening of air lines, mouth to mouth ventilation, cardiac massage; recently, there is a tendency to include the use of defibrillator. Advanced cardiac vital support should be the continuation of basic vital support. In this situation defibrillator, venous cannulation, orotracheal intubation, mechanical ventilation with high content in oxygen and drugs are used. Before beginning cardiopulmonary resuscitation, one should make sure that a real cardiac arrest is present, less than 10 min have elapsed, the victim does not have an immediately fatal prognosis and there is no deny by the victim or his/her family to receive cardiopulmonary resuscitation. In case of doubt it should be always practised. It is important to know the diagnosis and prognosis of the cause of cardiac arrest as soon as possible, in order to treat it and decide if the maneuvers should be continued. Hydro-electrolytic disturbances must be treated and neurological damage after cardiopulmonary resuscitation must be assessed. Only 20% of patients who recover an effective cardiac rhythm after cardiopulmonary resuscitation are discharged from hospital without neurological sequelae.

[Study of myocardial viability using single-photon emission computed tomography with 201-thallium and re-injection in 4 series (early and late images]. / Estudio de la viabilidad miocárdica mediante tomografía de emisión de fotón único con talio-201 y reinyección en 4 series (imágenes precoces y tardías).

OBJECTIVE: The present study was designed to determine whether 24-hour imaging after thallium reinjection or imaging obtained shortly after reinjection provides better results regarding reversibility of fixed perfusion defects observed in conventional stress-redistribution imaging. PATIENTS AND METHODS: We studied 24 patients undergoing stress-redistribution thallium tomography with fixed defects (15 exercise, 6 adenosine, 3 dobutamine). All patients had coronary angiography and 17 a history of myocardial infarction. After obtaining the redistribution images, 1 mCi thallium was injected at rest, and images were acquired at 30 minutes and 24 hours after reinjection. The tomograms obtained were divided into 12 segments and analyzed quantitatively. RESULTS: Of the 190 abnormal segments on the stress images, 53 (28%) demonstrated improved thallium uptake on redistribution images and 137 had persistent defects. Shortly after reinjection, 33 (24%) segments had improved thallium uptake and 104 had persistent defects, 29 (28%) of which showed further improvement in the 24-hour study. In patients with myocardial infarction, of the 36 fixed severe defects, 9 (25%) had improved thallium uptake shortly after reinjection, increasing activity from 36 +/- 10% to 53 +/- 8%, and 22 (61%) defects improved at 24 hours, increasing activity from 37 +/- 8% to 56 +/- 6%. Therefore, 13 irreversible segments in the short-term study after reinjection were reversible on 24-hour images. CONCLUSION: These data indicate that 24-hour imaging after thallium reinjection provides better results regarding reversibility of fixed perfusion defects observed in conventional stress-redistribution imaging than imaging obtained shortly after reinjection.

[Clinical practice guidelines of the Spanish Society of Cardiology on unstable angina/infarction without ST elevation]. / Guías de práctica clínica de la Sociedad Española de Cardiología en la angina inestable/infarto sin elevación ST.

This paper up-dates the Clinical Guidelines for Unstable Angina/Non Q wave Myocardial Infarction of the Spanish Society of Cardiology. Due to the increased efficacy of adequate management in the early phases, it has been considered necessary to include recommendations for the pre Hospital and Emergency department phase. Prehospital management. Patients with thoracic pain compatible with myocardial ischemia should be transferred to Hospital as quickly as possible and an ECG tracing performed. Initial management includes rest, sublingual nitroglycerin and aspirin. In the Emergency department. Immediate clinical attention and accessibility to a defibrillator should be available. If ECG tracing discloses ST elevation reperfusion strategy is to be implemented immediately. If no ST elevation is present, the probability of myocardial ischemia and risk factor evaluation is essential for adequate management. A simplified risk stratification classification is presented, that also determines the most adequate site for admission: Coronary Care Unit if high risk factors are present, Cardiology ward for the intermediate risk patient and ambulatory treatment if low risk. Management in Coronary Care Unit. Includes routine ECG monitoring and analgesia. Antithrombotic and anti ischemic treatment include new indication for GP IIb-IIIa and Low molecular weight heparins. Coronary arteriography and revascularisation are recommended, if refractory or recurrent angina, left ventricles dysfunction or other complications are present. Management in the ward is based on adequate chronic medical treatment, risk stratification, and secondary prevention strategy. Coronary arteriography before discharge must be considered in the light of the result of non-invasive tests.