RESUMO
Five methods are currently used to demonstrate coronary spasm: they use derivatives of ergotamine, alkalinisation, cold, adenosine triphosphate and exercise stress test. The criteria used to confirm spasm are either direct visualisation at coronary angiography or indirect electrocardiographic changes. The value of these test is beginning to be established: --their specificity is excellent with all methods (a positive test is diagnostic); --their sensitivity is mediocre (a negative test does not exclude the diagnosis). This depends on three factors: the choice of criteria of positivity: angiographic appearances is the most reliable; the timing of the test: it is more likely to be positive when the test is carried out close to episodes of chest pain; the method of provocation: the most sensitive tests use either the ergotamine derivatives or alkalinisation; --reproductibility is satisfactory at short and long term. These tests have diagnostic and therapeutic indications. It is preferable to perform diagnostic tests during coronary angiography in patients with normal coronary arteries and unexplained episodes of chest pain. However, in patients with fixed coronary lesions (except triple vessel and left main stem disease) when coronary bypass surgery is planned, the results of the test can help in the choice of associated therapy, such as plexectomy and calcium antagonist drugs. The repetition of the test is useful in the evaluation of antispastic therapy: when the test becomes negative the drug used is probably effective. In conclusion, with equal patient comfort and MSR, provocation tests using the ergotamine derivatives would seem to be the method of choice: alkalinisation is a good alternative.
Assuntos
Vasoespasmo Coronário/diagnóstico , Ergotaminas , Trifosfato de Adenosina , Temperatura Baixa , Vasoespasmo Coronário/diagnóstico por imagem , Eletrocardiografia , Teste de Esforço , Humanos , RadiografiaRESUMO
Twenty three patients with mitral valve prolapse underwent ambulatory 20 to 24 hour electrocardiography to study the incidence and severity of ventricular arrhythmias. These arrhythmias were found in 20 cases (87 p. 100). Ventricular extrasystoles were usually grouped (14 cases) causing doublets in 8 cases and bursts of ventricular tachycardia in the 6 others. The importance of the information obtained by Holter monitoring should not detract from the value of the standard resting electrocardiogramme. In fact, there appears to be a good correlation between the severity of the ventricular arrhythmia and the presence of ST changes over the postero-inferior zones. These abnormalities were never present in patients without ventricular extrasystoles but on the other hand they were observed in 5 of the 6 patients with ventricular tachycardia. From a practical point of view this may represent a simple means of identifying patients at high risk of dangerous arrhythmias.
Assuntos
Arritmias Cardíacas/diagnóstico , Eletrocardiografia/métodos , Prolapso da Valva Mitral/complicações , Adolescente , Adulto , Idoso , Arritmias Cardíacas/etiologia , Criança , Feminino , Ventrículos do Coração , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia/diagnóstico , Taquicardia/etiologiaRESUMO
Disappearance of the collateral coronary circulation was observed during an attack of spontaneous angina. During coronary angiography, the patient developed precordial pain, ST depression in Leads I, II, III, AVL, AVF, and V2 to V6. The two coronary arteries were opacified: there was no change in the left coronary tree but the collateral circulation arising from the right coronary artery and revascularising the obstructed left anterior descending artery the ECG reverted to its previous state and the collateral circulation reappeared. This case suggests that coronary artery spasm may lead to disappearance of the collateral circulation. It raises problems of methodology in the demonstration of spastic phenomena and emphasises the role of the collateral circulation in the genesis of ischaemia. It is another illustration of coronary artery spasm accompanied by ST depression.
Assuntos
Angina Pectoris Variante/diagnóstico , Circulação Colateral , Circulação Coronária , Vasoespasmo Coronário/diagnóstico , Circulação Colateral/efeitos dos fármacos , Angiografia Coronária , Circulação Coronária/efeitos dos fármacos , Eletrocardiografia , Humanos , Masculino , Pessoa de Meia-Idade , Nitroglicerina/uso terapêuticoRESUMO
Blockade of the autonomic nervous system by injection of propranolol (0,2 mg/Kg) and atropine (0,04 mg/Kg) was carried out in a series of 48 patients classified in 3 groups:--Group I:sinus bradycardia (22 cases)--Group II:suspected tachycardia-bradycardia syndrome (14 cases)--Group III:suspected sinus node dysfunction (12 cases). Two parameters were studied after autonomic blockade: observed intrinsic sinus node frequency (OIF) and corrected "adjusted" sinus node recovery time (CASRT). The results were compared with those obtained during basal electrophysiological investigation. The OIF was abnormal in 26 cases (54%) and junctional rhythm was observed 9 times (19%). Prolongation of the post-stimulation pause occurred in 32 cases (67%), transformation from a normal to a pathological pause in 15 cases and normalisation of a pathological pause in 4 cases (8%). Sinus node recovery time did not change significantly in the other cases. There was a good correlation between OIF and CASRT when the OIF was abnormal and mediocre (48%), when the OIF was normal. The following conclusions were made:--CASRT improves diagnosis of organic sinus node dysfunction which may escape detection by basal electrophysiological investigation and excludes functional abnormalities.--OIF is of good diagnostic value when pathological. However, the integrity of sinus node function cannot be affirmed when this parameter is normal.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Nó Sinoatrial/fisiopatologia , Idoso , Arritmia Sinusal/diagnóstico , Arritmias Cardíacas/fisiopatologia , Atropina/farmacologia , Sistema Nervoso Autônomo/efeitos dos fármacos , Eletrocardiografia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Propranolol/farmacologia , Fatores de TempoRESUMO
120 patients with ilio-caval thrombosis were managed medically. 55 patients were given heparin (5 mg/Kg/day for 15 days), 50 patients received streptokinase (loading dose 250,000 u; maintenance dose 100,000 m/h for 48 hours) and 15 patients had urokinase (112,500 u/h for 44 hours). Thrombolytic therapy was prescribed, in the absence of contraindications, for patients below 70 year of age: other patients were treated with heparin. The results were assessed by venography performed before and after treatment: success was defined as the complete disappearance of the thrombus of disobliteration of the ilio-caval axis. The overall success rate was 32%, with 68% failures. Success was higher with streptokinase (50%) than with heparin (20%) or urokinase (13%). The site, extension ans aetiology of the thrombosis did not affect the results. On the other hand, two other factors seemed to play an important role: - the duration of thrombosis: this only affected the streptokinase group; 23 of the 25 successes were obtained in patients treated before the tenth day. The results were unaffected by the duration of the thrombosis in the heparin group; - the biological effectiveness of therapy: 7 out of the 11 successes in the heparin group had been constantly well anticoagulated; there were only 4 successes out of 38 patients in whom the biological effectiveness had been intermittent. There were 21 successes out of 32 patients treated by streptokinase with serum fibrin levels of less than 1 g. There were only 4 successes in the 18 other cases. The incidence of haemorrhage was identical in the 3 groups. Embolism was slightly commoner in the streptokinase (3) than in the heparin group (2).
Assuntos
Veia Ilíaca , Trombose/tratamento farmacológico , Veias Cavas , Adulto , Idoso , Feminino , Heparina/efeitos adversos , Heparina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estreptoquinase/efeitos adversos , Estreptoquinase/uso terapêutico , Ativador de Plasminogênio Tipo Uroquinase/efeitos adversos , Ativador de Plasminogênio Tipo Uroquinase/uso terapêuticoRESUMO
The aetiology of syncope in a 53 year old man was discovered on continuous ambulatory electrocardiography. A ventricular arrhythmia associated with ST elevation was recorded. It proved resistant to medical therapy and a double aorto-coronary bypass graft was performed. Post-operative Holter monitoring showed surgery to have been effective.
Assuntos
Arritmias Cardíacas/complicações , Síncope/etiologia , Arritmias Cardíacas/diagnóstico , Doença das Coronárias/complicações , Doença das Coronárias/diagnóstico , Eletrocardiografia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The fate of 60 cases of apparently primary cardiomyopathy were studied by angiocardiography and coronary arteriography over a 2 to 6 year period, with a mean of 4 years. Correlations were established between the clinical, paraclinical, haemodynamic and angiocardiographic findings on the one hand, and the quality and length of survival on the other. Among the criteria leading to an improved prognosis, the most precise was the left ventricular ejection fraction.
Assuntos
Cardiomiopatias/diagnóstico , Adolescente , Adulto , Idoso , Angiocardiografia , Angiografia , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/mortalidade , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos ProspectivosRESUMO
The hyperirritable carotid sinus syndrome may have three different expressions: 1. a prolonged ventricular pause, the cardioinhibitory type and the most common; 2. hypotension without slowing of the heart rate, the vasodepressor type; 3. the association of a prolonged ventricular pause and hypotension, the mixed type. The aim of this communication is to present 6 cases of the cardioinhibitory type of hyperirritable carotid sinus syndrome. Three cases were selected from a series of 242 patients investigated for syncopal episodes. The results of carotid sinus massage and electrophysiological investigation could be classified into 4 goups: --Carotid sinus massage reproducing the clinical symptoms negative electrophysiological investigation: pure carotid sinus syndrome. --Carotid sinus massage negative, electrophysiological investigations negative: pure hyperirritable carotid sinus syndrome. --Carotid sinus massage reproducing the clinical symptoms, electrophysiological investigation positive: associated carotid sinus syndromes. --Carotid sinus massage negative: electrophysiological investigations positive: associated hyperirritable carotid sinus syndrome. The diagnosis of the cardioinhibitory type of hyperirritable carotid sinus syndrome was made on four criteria: 1. the association of hyperirritable carotid sinus and spontaneous syncopal or minor syncopal episodes; 2. the reproduction of symptoms together with a ventricular pause of over three seconds by carotid sinus massage under cover of pacing (to exclude the rare mixed forms); 4. the absence of associated sinus node dysfunction or atrioventricular conduction defects on endocavitary electrophysiological recordings. This syndrome should be tested for as a routine in patients with syncope as usually no suggestive trigger factors are found. Carotid sinus massage in this series of patients caused quite long ventricular pauses (average: 7,5 sec.) with serious symptoms (2 syncopes). Therefore, in the investigation of patients with syncope it would seem to be useful to perform this manoeuvre during electrophysiological investigation with pacing cover. The treatment of choice of the cardioinhibitory carotid sinus syndrome is permanent pacing. This was undertaken in 5 out of four 6 patients leading to total regression of all symptoms. It seems justifiable to propose permanent pacing for patients who have syncope with hyperirritable carotid sinus syndrome, easily demonstrated by carotid sinus massage, but in whom massage does not provoke symptoms, reasoning by analogy with patients with atrioventricular conduction defects or sinus node dysfunction.
Assuntos
Doenças das Artérias Carótidas/diagnóstico , Seio Carotídeo , Síncope , Idoso , Atropina/farmacologia , Doenças das Artérias Carótidas/fisiopatologia , Doenças das Artérias Carótidas/terapia , Eletrocardiografia , Feminino , Massagem Cardíaca , Frequência Cardíaca , Humanos , Masculino , Marca-Passo Artificial , SíndromeRESUMO
Methods of using intramuscular lignocaine and its relay with an intravenous infusion were studied in 34 patients with reference to serum levels. A first group of 9 patients with myocardial infarction received an intramuscular injection of 300 mg lignocaine into the deltoid or gluteral muscles at five day intervals. The deltoid appears to be the better site of injection in patients confined to bed because of its quick absorption, higher serum levels between the 15th and 90th minute (+47%), and longer duration of action (180 compared to 120 minutes). The difference is not observed in ambulatory patients and seems to be related to sluggish circulation in the gluteral muscles during bed rest. Its relay with intravenous infusion was studied in 14 patients. In the first 6 patients, intradeltoid injection was immediately followed by an infusion of 2.5 mg/mn, giving an average plasma lignocaine level between the 15th and 60th minute greater than 5 mu/ml. In the 8 other patients, a period of I hour was allowed to elapse before starting the infusion. The plasma levels were found to be within the therapeutic range in all patients and no side effects were observed. The administration of an intravenous infusion of 150 mg/hr of lignocaine for 48 hours led to excessively high plasma levels in 8 patients at the 24th hour, 3 of whom had side effects. Reducing the dosage to 100 mg/hr from the 12th hour onwards in II patients avoided this complication. A 300 mg intradeltoid injection of lignocaine is easy to give in the patient's home and therefore, is the best adapted method for the pre hospital treatment of myocardial infarction. When necessary, it may be relayed with an intravenous infusion one hour later, in the coronary care unit.
Assuntos
Lidocaína/administração & dosagem , Infarto do Miocárdio/tratamento farmacológico , Idoso , Arritmias Cardíacas/prevenção & controle , Feminino , Humanos , Infusões Parenterais , Injeções Intramusculares , Lidocaína/efeitos adversos , Lidocaína/sangue , Masculino , Pessoa de Meia-IdadeRESUMO
Selective angiopneumography is considered to be the best diagnostic investigation for pulmonary embolism. However, the technique has to be performed in a specialised unit, is associated with a certain degree of risk and does not explore the lower limb veins which are the usual site of migratory thrombi. The authors have therefore developed a new angiographic technique, ascending venous angiopneumography (AVAP) which successively opacifies the lower limb veins, inferior vena cava (IVC) and pulmonary arteries. It was used in 180 patients suspected of having a recent pulmonary embolism. It has three main advantages: 1) TECHNIQUE: this only involves injection of a vein on the dorsum of the foot, may be carried out in any radiological centre and is repeatable. 2) DIAGNOSIS: the investigation is more sensitive but less specific than selective angiopneumography when compared in a series of 25 cases: it was never normal in the 16 cases of pulmonary embolism, but in its absence there were 4 doubtful cases out of 8. This lack of specificity is compensated by the data obtained during the initial phlebocavographic times. The diagnosis of pulmonary embolism may be made when the context is suggestive and radiological evidence of venous thrombosis is obtained (124 cases). The diagnosis is very improbable when all phases of AVAP are normal (45 cases). 3) THERAPY: treatment should take the initial venous thrombosis into account, especially with regards to the choice of thrombolytic agents and surgical clipping of the IVC. Finally, this is a low-risk procedure.
Assuntos
Angiografia/métodos , Pulmão/diagnóstico por imagem , Embolia Pulmonar/diagnóstico por imagem , Humanos , Perna (Membro)/irrigação sanguínea , Flebografia/métodos , Artéria Pulmonar/diagnóstico por imagem , Veia Cava Inferior/diagnóstico por imagemRESUMO
The effects of intravenous nitroglycerin (Lenitral) on the calibre of coronary arteries and their lesions was studied in 100 consecutive patients undergoing coronary angiography. The coronary arteries were divided into segments (3 for the right coronary, 2 for the left anterior descending, and 2 for the circumflex artery). 510 segments were assessed (279 normal, and 231 pathological). The diameter of each was measured through the mid point before and after injection of a bolus of 0.3 mg nitroglycerin. The calibre of the coronary segments increased in 325 cases (63.7%). In 49 cases, the increase was greater than 50%. It remained the same in 151 cases (29,6%) and decreased in 84 cases (6,7%). The average increase in calibre was 16% (p less than 0.01). This had little relation to the artery under study, the location of the segment or whether the segment was pathological or normal. However, two findings were of interest: - the percentage of segments which increased their calibre was significantly higher in the normal segments (191 out of 279 cases, 68%) than in the pathological segments (134 out of 231 cases, 58%) (p less than 0.01). - Coronary lesions may change in appearance: images of stenosis or obstruction completely regressed in 4 cases, the degree of stenosis seemed to increase in 11 cases because of dilatation of the coronary vessel proximal and distal to the narrowing, and distal vessels appeared much more dilated in 5 cases. The factors which seem to affect the vasomotor response are multiple, and include the state of the arterial wall, the presence of vasodilatation or vasoconstriction prior to injection and the mode of administration of the nitroglycerin. The test should be performed by intravenous or intracoronary injection at the end of coronary angiography so as not to mask spastic phenomena. Some errors in the interpretation of the degree of stenosis or the quality of the distal post-stenotic coronary bed could thus be avoided.
Assuntos
Angiografia Coronária , Nitroglicerina , Pressão Sanguínea , Vasos Coronários/efeitos dos fármacos , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Nitroglicerina/farmacologia , Sistema Vasomotor/efeitos dos fármacosRESUMO
The authors have made a study of the fate of 118 patients with pulmonary embolism. The mortality (21.8%) is related not only to the embolus itself (especially to the recurrent types) but also to the condition of the affected area. Recurrence is common (34%), serious (9 deaths out of 25), and early (during the first three months.). No treatment or inadequate treatment are the main causes. Treatment works effectively on the pulmonary circulation, which becomes reestablished in the majority of cases, but it carries the risk of a high incidence of haemorrhage (29%) which is severe (2 deaths and 10 tranfusions of more than one litre of blood). In the long term, the prognosis is linked to the developments in the lower limbs, in which there is a progressive failure of venous drainage (46 cases out of 57), even in cases in which there was no local sign of phlebitis at the time of the original embolus.
Assuntos
Embolia Pulmonar/fisiopatologia , Adulto , Idoso , Anticoagulantes/efeitos adversos , Feminino , Fibrinolíticos/efeitos adversos , Seguimentos , Hemorragia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Embolia Pulmonar/complicações , Embolia Pulmonar/mortalidade , Recidiva , Insuficiência Venosa/etiologiaRESUMO
The effects of intravenous trinitrin on myocardial function have been studied in 40 patients with heart failure (26 cases of coronary artery disease and 14 of apparently primary cardiomyopathy). Each patient had measurements made of left ventricular pressure, of cardiac output by the dye dilution method, of volume, of the left ventricular ejection fraction, and of the segmental parietal kinetics by means of left side ventriculography both before and after trinitrin. The following results were obtained after injection of trinitrin:--no change in rhythm and cardiac index;--an almost constant decrease in left ventricular end diastolic pressure (38 cases out of 40);--a decrease in arterial pressure and ventricular volume in about two thirds of cases;--improvement of the ejection fraction (25 cases out of 40), and of segmental parietal kinetics (26 cases out of 40) in the left ventricle. These findings were equally true in the patients with coronary artery disease and in the cardiomyopathies. In the light of these results, it appears that when used in left ventricular failure, trinitrin almost always decreases the load, but improves ventricular kinetics only in two thirds of cases, while it has no influence on cardiac output. In addition, given the difficulties in establishing a standard dose of trinitrin, the authors discuss the methods of establishing the optimal dose.
Assuntos
Cardiomiopatias/tratamento farmacológico , Doença das Coronárias/tratamento farmacológico , Coração/efeitos dos fármacos , Nitroglicerina/administração & dosagem , Pressão Sanguínea , Débito Cardíaco , Cardiomiopatias/fisiopatologia , Doença das Coronárias/fisiopatologia , Feminino , Coração/fisiopatologia , Ventrículos do Coração/efeitos dos fármacos , Humanos , Infusões Parenterais , Masculino , Pessoa de Meia-Idade , Nitroglicerina/farmacologia , Nitroglicerina/uso terapêutico , PressãoRESUMO
The antiarrhythmic efficiency of quinidine arabogalactan-sulphate (QAGS) and disopyramide were determined in 38 patients showing chronic, stable frequency premature ventricular beats (PVB). The study which was carried out in 4 medical Centers, used a longitudinal cross-over design. After a baseline evaluation which consisted of two 24 hours electrocardiograms, the patients were randomised to one of the two drugs during a period of 6 or 7 days. The drug sequence were followed by a placebo sequence. A 24 hours electrocardiogram was performed at the end of each sequence. The daily doses were equivalent to 660 mg of quinidine base for QAGS and 600 mg for disopyramide. Among the 38 patients who entered in the study, 32 went through each sequence of the test. The average number of PVB was significantly reduced by QAGS and disopyramide (p less than 0.0001). With QAGS 18 patients had more than 65 p. 100 reduction of PVB and 12 of them more than 80 p. 100. With disopyramide, 14 patients had more than 65 p. 100 reduction of PVB and 12 of them more than 80 p. 100. There was no statistical difference in the overall efficiency of the two drugs. Three patients died, one from myocardial reinfarction, one from ventricular fibrillation; in one other case, the cause of the death remained undetermined. QAGS was better tolerated than disopyramide; adverse effects occurred in 6 patients with QAGS and in 10 with disopyramide. The responsibility of disopyramide in the occurrence of two severe ventricular arrhythmia may be questioned.
Assuntos
Complexos Cardíacos Prematuros/tratamento farmacológico , Disopiramida/uso terapêutico , Quinidina/análogos & derivados , Adulto , Idoso , Disopiramida/efeitos adversos , Feminino , Ventrículos do Coração , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Quinidina/efeitos adversos , Quinidina/uso terapêutico , Distribuição AleatóriaRESUMO
Two-dimensional echocardiography (2D echo) was performed in 103 patients (94 men, 9 women, aged 35 to 76 years; mean 55,4 years) during the acute phase of primary myocardial infarction in order to detect left ventricular thrombi (LVT). This investigation was carried out between the 7th and 30th days with an 84 degrees phased array sector scanner. A total of 17 LVT were visualised, all at the apex of the left ventricle. There factors seemed to predispose to this condition: --the site of infarction: LVT were more common in anterior (16/56) than inferior infarcts (1/47) (p less than 0,001); --the extent of the necrosis: LVT occurred in 13/30 antérior infarcts when the akinesia involved at least two antero-apical segments, compared to only 3/26 when the necrosis was less extensive (p less than 0,05); --cardiac failure in anterior myocardial infarction: LVT were found in 11/21 cases with cardiac failure and in only 5/35 without cardiac failure (p less than 0,01). The outcome of 45 patients was assessed by 2D echo 3 to 12 months after the acute episode (mean 7,6 months). Control echo was unchanged in 35 patients (15 inferior, 20 anterior infarcts) without LVT. In 10 patients with LVT treated by oral VitK antagonists, the thrombus disappeared in 5 cases without embolism; it decreased in volume in 3 cases and persisted unchanged in 2 cases.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Ecocardiografia/métodos , Ventrículos do Coração/patologia , Infarto do Miocárdio/complicações , Trombose/diagnóstico , Adulto , Idoso , Feminino , Insuficiência Cardíaca/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , Trombose/etiologia , Tomografia/métodosRESUMO
Phlebography is the best diagnostic technique for deep venous thromboses of the lower limbs. The authors use the "free flow" technique which they have modified by visualisation of the I. V. C. and I. V. A lacunar appearance or cupola-shaped interruption are indicative of a recent thrombosis, whilst the absence of a main venous trunk and a collateral circulation are more common in the presence of an old thrombosis. They emphasise the possible sources of error in interpretation and the difficulty in determining how long the thrombosis has been present. Despite its disadvantages, phlebography remains the essential examination in order to select treatment in patients in whom there is a suspicion of venous thrombosis or pulmonary embolism. Venous Doppler and rheoplethysmography, less sensitive and less specific, have a place in routine detection and the surveillance of treatment.
Assuntos
Flebografia/métodos , Tromboflebite/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Perna (Membro)/irrigação sanguínea , Tromboflebite/cirurgiaRESUMO
The principal angiography images found in cases of recent pulmonary embolism include intravascular lacunae, dome-shaped obstructions, a "dead tree" appearance and an avascular region. The first two are specific, but are mainly observed during the few days following the embolism. Highest quality images are obtained by selective angiography of the pulmonary artery, but this technique, which involves transfer of the patient to a specialized unit and catheterization of the pulmonary artery, is not without risk and, more particularly, does not explore the veins of the lower limbs. However, in a series of 110 cases of recent pulmonary embolism, venous thrombosis, usually femoroiliocaval, was present in 102 patients. A new technique is therefore proposed, ascending venous angiopneumography, which has two advantages: --It can be performed in any radiological department as a catheter does not have to be inserted. --It explores both pulmonary and venous systems. Though pulmonary images are less specific (false positives occur more frequently), the simultaneous exploration of the veins allows logical determination of therapy based on the size and site of the embolus and possible associated extension of the venous thrombosis.
Assuntos
Embolia Pulmonar/diagnóstico por imagem , Angiografia/efeitos adversos , Angiografia/métodos , HumanosRESUMO
Identification of an amiodarone metabolite in the plasma of patients receiving a single dose of the drug was carried out by mass-spectrometry following extraction and HPLC separation. The kinetics of the plasma concentrations of unchanged compound and its identified metabolite (N-monodesthyl-amiodarone) were studied in six patients after a single administration of amiodarone by oral or intravenous routes, using a sensitive and specific high-performance liquid chromatographic method. The observed plasma clearance rate for the drug varied from 0.2 to 0.5 1.h-1.kg-1 of body weight; and the elimination half-life of the unchanged compound was found to be approximately 21 hours. Oral bioavailability, as determined in one patient, was about 60%. The proportion of the metabolite found in the plasma following a single oral administration was significantly higher than that observed after infusion. The ratio of areas under the curves for metabolite-to-unchanged compound was 0.55 and 0.13 for oral and intravenous doses respectively. During a circumscribed study carried out in five patients receiving oral doses of the drug (daily dose varied from 2.6 to 9.3 mg/kg) accumulation of the metabolite was observed. The mean of the plasma level ratios (metabolite to-unaltered drug) obtained in five patients was approximately 0.97.