RESUMO
A diagnosis of constrictive pericarditis is suggested by the presence of pericardial thickening (>=4 mm in thickness) and abnormal motion of the interventricular septum. Additional findings have been reported: tubular appearance of the right or left ventricles, dilatation of the vena cava, atrial dilatation or abnormal diastolic expansion of one or both ventricles. In patients with suspected chronic pericarditis, CT can more easily demonstrate the presence of pericardial calcifications compared to US and MRI, as well as detect the presence of mediastinal adenopathy and lung lesions, suggesting tuberculosis. Septal motion analysis should be performed during protodiastole and systole using a cine technique with both CT and MR.
Assuntos
Imageamento por Ressonância Magnética , Pericardite/diagnóstico , Tomografia Computadorizada por Raios X , Doença Crônica , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
There is a need to define the current indications for coronary CT angiography (CCTA) even as technology continuously evolves. CCTA using 64 MDCT units has shown to be highly accurate for diagnosis of stenoses >or=50% on selected populations. It is currently used for its negative predictive value (96-98%). Stenosis quantification remains inferior to conventional coronary angiography with tendency to overestimate stenoses <70%. For diagnosis of coronary artery disease, CCTA is considered based on clinical findings (pre-test probability of coronary artery disease) and presence of myocardial ischemia on other functional studies. The main appropriate indications include: In the setting of acute coronary syndrome, CCTA excludes coronary artery disease with excellent NPV and good negative likelihood ratio (0.05) when ECG is non-contributory, 2 consecutive troponin levels at 6 hours are negative in a patient with low risk of coronary artery disease. In the setting of stable angina or atypical precordial chest pain, CCTA is indicated in patient with low to medium risk when functional test are non-contributory or unavailable, or ECG is non-interpretable. CCTA is a complement to coronary angiography for morphological evaluation of some lesions prior to angioplasty and stent placement (long segment occlusion, proximal lesions involving LAD and circumflex arteries). In selected patients, CCTA may replace coronary angiography prior to valvular surgery.
Assuntos
Angiografia Coronária/métodos , Cardiopatias/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Humanos , Guias de Prática Clínica como AssuntoRESUMO
PURPOSE: The purpose of this study was to retrospectively assess the accuracy of the maximal left atrial volume (LAVmax) measured at 75% of the cardiac cycle compared to the 40% measurements and to evaluate this volume according to age and gender. PATIENTS AND METHOD: A total of 150 patients with a mean age of 50±17 (SD) years (range: 21-79 years) were analyzed. There were 78 men and 72 women. LAVmax were measured from retrospective triphasic cardiac-gated multi-detector computed tomography (MDCT) data at the 40% (LAV40) and 75% (LAV75) of the RR cycle phases by a semi-automatic method. RESULTS: LAV40was 50.7±14mL/m2 and LAV75 was 42.5±13mL/m2. The difference was statistically significant. Considering the reference range of LAVmax reported in the literature, 33% of the patients had enlarged LA with LAV40 and only 17% with LAV75. These volumes were positively influenced by age but not by gender. The relationship between LAV75 and LAV40 was: LAV75=0.908 LAV40-3.486 (r2=0.92) or LAV40=1.1×LAV75+3.8 (r2=0.92). CONCLUSION: LAVmax measured at the 75% of the cardiac cycle phase significantly underestimates actual LAV leading to reconsider normal values. LAV40 can be computed from the measured value of LAV75 obtained on prospective ECG-gated MDCT.
Assuntos
Técnicas de Imagem de Sincronização Cardíaca , Eletrocardiografia , Átrios do Coração/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
The duration of anticoagulant therapy after a first attack of venous thromboembolic disease (VTE) is related to the risk of recurrence and the iatrogenic complication of bleeding. Recent prospective trials have provided information concerning the clinical and biological profiles of those at greatest risk of recurrence of deep vein thrombosis. The value of ultrasonic investigations and of D-Dimer measurements have also been assessed. The risk of recurrence is not negligible, about 10% in the first year after stopping treatment and 2/3 of recurrences occurring in the first two years. There are several risk factors for recurrence: male gender, past history of renal transplant, presence of malignant disease, proximal site of the initial thrombosis, initial presentation with pulmonary embolism, previous deep vein thrombosis and the co-existence of two thrombophilic factors. On the other hand, age, single deep vein thrombosis and a family history of deep vein thrombosis are not significantly related to increased risk. The presence of a residual thrombus at the end of treatment remains a subject of controversy. The risk of recurrence when the D-Dimers are normal one month after stopping the anticoagulants seems to be low, especially in cases of an associated thrombophilia. Finally, the risk of haemorrhage is related to the duration of oral anticoagulant therapy and the age of the patient. These trials have provided information for the issue of recommendations by consensus conferences and allow better economic evaluation of the duration of treatment after a first episode of deep vein thrombosis with respect to differing clinical situations.
Assuntos
Tromboembolia/patologia , Trombose Venosa/patologia , Anticoagulantes/uso terapêutico , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Humanos , Masculino , Recidiva , Fatores de Risco , Fatores Sexuais , Tromboembolia/tratamento farmacológico , Tromboembolia/epidemiologia , Trombose Venosa/tratamento farmacológico , Trombose Venosa/epidemiologiaRESUMO
Aspirin is the most commonly used therapeutic agent in prevention of vascular ischemic events. Aspirin exerts its antithrombotic effect primarily by interfering with the biosynthesis of thromboxane A2 (TXA2) and inhibition of TXA2 -dependent platelet aggregation. A meta-analysis of secondary prevention trials indicated that aspirin reduced major cardiovascular or cerebral events by 25%. This led to the widespread use of aspirin for prevention of cardiovascular events. However, it appears that aspirin antiplatelet effect is not uniform in all patients and previous studies estimated that 8-45% of the population were aspirin resistant. Furthermore, (i) the optimal dosage of aspirin for complete inhibition of platelet aggregation by physiological agonists (i.e arachidonic acid) is subject to great interindividual variability, (ii) the tests to detect aspirin resistance in vitro are subject to debate and (iii) the mechanisms by which some patients are resistant to aspirin in vitro remain to be determined. Despite these unresolved questions, recent clinical studies provide the reliable evidence that aspirin resistance correlates with confirmed clinical unresponsiveness, highlighting the clinical interest of determining the aspirin inhibitory effects on patients' platelets. In conclusion, discovery of aspirin resistance in individuals might be important in order to devise better anti-platelet strategies and improve our ability to prevent acute thrombotic complication.
Assuntos
Aspirina/uso terapêutico , Isquemia/prevenção & controle , Inibidores da Agregação Plaquetária/uso terapêutico , Animais , Aspirina/farmacologia , Doença das Coronárias/epidemiologia , Doença das Coronárias/prevenção & controle , Resistência a Medicamentos , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/prevenção & controle , Humanos , Isquemia/epidemiologia , Inibidores da Agregação Plaquetária/farmacologia , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controleRESUMO
The existence of cell free fetal DNA, derived from apoptotic syncytiotrophoblast, in the maternal circulation has opened new possibilities of non-invasive prenatal diagnosis. Although still some technical problems exists, especially the lack of a generic positive control on the presence of fetal DNA and the aspecific amplification of background maternal DNA, non-invasive prenatal RHD typing has been successfully introduced in several laboratories, especially in Europe. The diagnostic accuracy reaches>99%. In the Netherlands PCR guided administration of antenatal anti-D prophylaxis is cost-effective and nearby. In this review the main characteristics and applications of cell free fetal DNA are discussed, with an emphasis on prenatal RHD genotyping.
Assuntos
Incompatibilidade de Grupos Sanguíneos/diagnóstico , Tipagem e Reações Cruzadas Sanguíneas/métodos , DNA/sangue , Transfusão Feto-Materna , Diagnóstico Pré-Natal/métodos , Sistema do Grupo Sanguíneo Rh-Hr/genética , Incompatibilidade de Grupos Sanguíneos/embriologia , Tipagem e Reações Cruzadas Sanguíneas/economia , Análise Custo-Benefício , Eritroblastose Fetal/prevenção & controle , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Sangue Fetal/imunologia , Genótipo , Humanos , Reação em Cadeia da Polimerase , Gravidez , Diagnóstico Pré-Natal/economia , Pseudogenes , Sensibilidade e EspecificidadeRESUMO
The objective of this study was to propose diagnostic reference levels (DRLs) for coronary computed tomography angiography (CCTA), in the context of a large variability in patient radiation dose, and the lack of European recommendations. Volume Computed Tomography Dose Index (CTDIvol) and dose-length product (DLP) were collected from 460 CCTAs performed over a 3-month period at eight French hospitals. CCTAs (â¼50 per centre) were performed using the routine protocols of the centres, and 64- to 320-detector CT scanners. ECG gating was prospective (n = 199) or retrospective (n = 261). The large gap in dose between these two modes required to propose specific DRLs: 26 and 44 mGy for CTDIvol, and 370 and 970 mGy cm for DLP, respectively. This study confirms the large variability in patient doses during CCTA and underlines the need for the optimisation of cardiac acquisition protocols. Availability of national DRLs should be mandatory in this setting.
Assuntos
Angiografia Coronária/estatística & dados numéricos , Angiografia Coronária/normas , Radiometria/estatística & dados numéricos , Radiometria/normas , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Tomografia Computadorizada por Raios X/normas , Doses de Radiação , Valores de Referência , Inquéritos e QuestionáriosRESUMO
This paper describes the preparation of 6-[18F]fluoro-L-dopa by a no-carrier-added method based on the nucleophilic displacement of nitro groups of two commercially available substrates, 3,4-dimethoxy-2-nitrobenzaldehyde (nitroveratraldehyde) and 6-nitropiperonal. Fluorination was conducted in DMSO with fluorine-18 (18F) in the presence of the aminopolyether Kryptofix 222 and potassium carbonate. The condensation of the fluorinated aldehydes with phenyloxazolone and the subsequent hydrolysis with HI/P yield, after purification by HPLC, only the 6-(D, L) isomers. The racemic mixture (50/50) was resolved on an analytical scale chiral column. The method, which requires 100 min (EOB) to complete, produces 6-[18F]fluoro-L-dopa with a decay-corrected radiochemical yield of 10%, an enantiomeric purity greater than 99%, and a specific activity of 1.2 Ci/mumole.
Assuntos
Di-Hidroxifenilalanina/análogos & derivados , Benzaldeídos , Cromatografia Líquida de Alta Pressão , Di-Hidroxifenilalanina/síntese química , Dimetil Sulfóxido , Radioisótopos de Flúor , HidróliseRESUMO
No-carrier-added [18F]altanserin was synthesized by nucleophilic substitution of the corresponding nitro compound with [18F]fluoride in the presence of kryptofix 222 and K2CO3. After purification by preparative HPLC, [18F]altanserin was produced in less than 2 hr with a radiochemical yield of 10% (EOS) and a specific activity of 0.8-1.3 Ci/mumol. In rats, the tracer localized rapidly in the whole brain (0.5% ID/g organ) with a high binding to the frontal cortex. The frontal cortex/cerebellum ratio increased with time and reached a plateau of 11 at 2 hr postinjection. This uptake in S2 receptor regions was saturable and could be blocked by pretreatment with various S2 antagonists. This radiopharmaceutical appears to be more selective for S2 receptor sites than other ligands available today and allows the study of S2 receptors under in vivo conditions.
Assuntos
Ketanserina/análogos & derivados , Receptores de Serotonina , Tomografia Computadorizada de Emissão , Animais , Feminino , Radioisótopos de Flúor , Marcação por Isótopo , Ketanserina/farmacocinética , Ratos , Ratos Endogâmicos , Distribuição TecidualRESUMO
A large intraluminal thrombus within an otherwise normal sinus of Valsalva was diagnosed in a 41 year old man who was investigated for myocardial infarction. The thrombus was suspected by aortic root injection, confirmed by transoesophageal echocardiography, and treated surgically.
Assuntos
Infarto do Miocárdio/diagnóstico por imagem , Seio Aórtico/diagnóstico por imagem , Trombose/diagnóstico por imagem , Adulto , Aortografia , Ecocardiografia Transesofagiana , Humanos , Masculino , Infarto do Miocárdio/cirurgia , Trombose/cirurgiaRESUMO
BACKGROUND: Platelet activation plays an important role in arterial thrombosis and the widespread use of aspirin has reduced major events by 25% in the secondary prevention of cardiovascular diseases. However, it appears that aspirin antiplatelet effect is not uniform and 8-45% of the population are, in vitro, aspirin resistant, and it is well recognized that platelets can be activated by pathways that are not blocked by aspirin, such as adenosine diphosphate (ADP). OBJECTIVES: To investigate whether aspirin-resistant patients have a modified sensitivity to ADP-induced platelet activation MATERIALS AND METHODS: Seventy-two patients were enrolled. Platelet function was measured by the PFA-100(R) analyser; platelet GP IIb-IIIa activation by ADP 10 micro M was assessed by flow cytometry using PAC-1 MoAb. RESULTS: Using a collagen/epinephrine coated cartridge on the PFA-100(R), the prevalence of aspirin resistance was 29.2% (n=21). For aspirin-resistant patients, the collagen/ADP coated cartridge showed a closure time significantly shorter (p=0.004) compared to the sensitive and control groups. Platelets from aspirin-resistant patients bound PAC-1 significantly more (p=0.03) than the aspirin-sensitive patients and controls when activated with 10 micro M ADP. CONCLUSIONS: Platelets from aspirin-resistant patients appear to be more sensitive and activable by ADP. This hypersensitivity could provide a possible explanation for the so-called aspirin resistance, and this could justify therapeutic improvement with alternative antiplatelet agents.
Assuntos
Difosfato de Adenosina/farmacologia , Aspirina/farmacologia , Plaquetas/efeitos dos fármacos , Resistência a Medicamentos , Idoso , Angina Pectoris/sangue , Estudos de Casos e Controles , Doença da Artéria Coronariana/sangue , Fosfatase 2 de Especificidade Dupla , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/efeitos dos fármacos , Testes de Função Plaquetária , Proteína Fosfatase 2 , Proteínas Tirosina Fosfatases/metabolismoRESUMO
BACKGROUND: Acetylsalicylic acid, or aspirin, is widely used in secondary prevention of coronary artery diseases, but the inhibition of platelet aggregation is not uniform in all individuals. OBJECTIVE: To investigate the prevalence of aspirin resistance at rest and during exercise in coronary artery disease patients. MATERIALS AND METHODS: Fifty patients with stable coronary artery disease were prospectively studied. All patients received aspirin (75-300 mg/day for >1 month) and no other antiplatelet therapy. Aspirin resistance was studied, at rest and immediately after a stress test, using the standardized platelet function analyzer (PFA-100(R), Dade-Behring). Aspirin resistance was defined as a normal collagen/epinephrine closure time (<186 s). RESULTS: Ten patients (20%) were aspirin-resistant at rest. Out of the 40 patients who were aspirin-sensitive at rest, 9 (22%) were aspirin-resistant immediately after the exercise stress test. There were no differences in aspirin sensitivity regarding gender, age, diabetes, hypertension, dyslipidemia, platelet count, medical treatment or number of the coronary arteries involved. CONCLUSIONS: Aspirin resistance is detected, at rest, in 20% of our patients with stable coronary artery disease. Aspirin treatment does not seem to protect against exercise-induced platelet activation in 22% of such patients, despite aspirin sensitivity at rest.
Assuntos
Aspirina/farmacologia , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/tratamento farmacológico , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Idoso , Doença da Artéria Coronariana/prevenção & controle , Resistência a Medicamentos , Teste de Esforço , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/efeitos dos fármacos , Testes de Função Plaquetária , DescansoRESUMO
[5-131I]Iodotropapride is a benzamidic compound which displays high affinity and selectivity for dopaminergic receptors. It was prepared from the corresponding brominated compound by a nucleophilic substitution with [131I]iodine (t1/2 = 8.02 days, E gamma = 364 keV) based on the use of Cu(I) as catalyst and high specific activity of [131I]NaI. After i.v. injection in rats the tracer crosses the blood-brain barrier (0.42 +/- 0.06% of injected dose in the total brain) and demonstrates a high affinity binding to the striatum. The striatum-to-cerebellum ratio increases with time and reaches values of 9 and 22 at 30 and 120 min after injection, respectively. This specific uptake in the striatum is saturable and can be blocked by pretreatment with different D2 antagonists. When labeled with 123I (t1/2 = 13 h, E1 = 159 keV), the corresponding [123I]iodotropapride may be useful for the investigation of the D2 dopamine receptors in humans with single photon emission computer tomography (SPECT).
Assuntos
Encéfalo/metabolismo , Nortropanos/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Receptores de Dopamina D2/metabolismo , Animais , Cerebelo/metabolismo , Lobo Frontal/metabolismo , Radioisótopos do Iodo , Masculino , Nortropanos/metabolismo , Octanóis , Ligação Proteica , Compostos Radiofarmacêuticos/metabolismo , Ratos , Ratos Wistar , Distribuição Tecidual/fisiologia , ÁguaRESUMO
Non-invasive assessment of the stenotic mitral valve area is often difficult when the mitral stenosis is associated with atrial fibrillation. In this study, 16 patients with mitral stenosis and atrial fibrillation were evaluated by transthoracic Doppler echocardiography. The mitral valve area calculated by the pressure half-time method was 1.65 +/- 0.73 cm2. The enddiastolic mitral gradient was obtained from the enddiastolic forward mitral flow velocity by application of the simplified Bernoulli equation. For each patient there was a linear relationship between the enddiastolic mitral gradient and the corresponding RR interval. The slope and intercept of this relationship were significantly correlated with the mitral valve area. From the regression equations describing these correlations we established a nomogram ascertaining mitral valve area from enddiastolic mitral gradient and corresponding heart rate. This nomogram was helpful in the non-invasive assessment of stenotic mitral valve area in the presence of atrial fibrillation.
Assuntos
Fibrilação Atrial/diagnóstico por imagem , Ecocardiografia Doppler , Estenose da Valva Mitral/diagnóstico por imagem , Idoso , Fibrilação Atrial/fisiopatologia , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Diástole , Feminino , Frequência Cardíaca/fisiologia , Humanos , Modelos Lineares , Masculino , Valva Mitral/diagnóstico por imagem , Valva Mitral/fisiopatologia , Estenose da Valva Mitral/fisiopatologia , Análise Multivariada , Análise de RegressãoRESUMO
We present a case study of a 54-year-old patient with a perforated aneurysm of the anterior mitral valve leaflet, diagnosed 13 years after an episode of bacterial endocarditis by transesophageal echocardiography. This report illustrates the superiority of transesophageal echocardiography in the diagnosis and management of valvular endocarditis.
Assuntos
Aneurisma Infectado/diagnóstico por imagem , Aneurisma Roto/diagnóstico por imagem , Aneurisma Cardíaco/diagnóstico por imagem , Valva Mitral , Adulto , Aneurisma Infectado/etiologia , Aneurisma Roto/etiologia , Ecocardiografia Transesofagiana , Endocardite Bacteriana/complicações , Aneurisma Cardíaco/etiologia , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/etiologia , Humanos , Masculino , Valva Mitral/diagnóstico por imagem , Ruptura EspontâneaRESUMO
Despite the development of new molecules, aspirin remains a mainstay of the antiplatelet therapy, indispensable for the secondary prevention of cardiovascular events. The therapeutic used is based on the platelet aggregation inhibition induced by aspirin. The concept of aspirin resistance corresponds to a total or almost total absence of the platelet aggregation inhibition generally observed in vitro under aspirin. The frequency of this resistance depends on the platelet aggregation test used and the population studied. In a population with stable coronary disease treated in the long term with 160 to 325 mg of aspirin daily, 8 to 35% of patients are non-responders. Many hypothesis on the mechanisms of the lack of antiplatelet effect of aspirin are under investigation. The clinical implication of the in vitro antiplatelet effect resistance of aspirin has recently been evidenced by a relative risk of cardiovascular events at two years at 3. This would support an individual adaptation of the anti-platelet therapy.
Assuntos
Aspirina/farmacologia , Resistência a Medicamentos , Inibidores da Agregação Plaquetária/farmacologia , HumanosRESUMO
Rupture of the atheromatous plaque, thrombosis and local vasoconstriction are involved in the genesis of acute myocardial infarction. The vulnerability of the plaque depends on its histological structure. Its fragility is related to the size of the lipid core, the thinness of the fibrous capsule and the inflammatory reaction. External aggression favourites rupture. This triggers both thrombogenesis by bringing the blood cells into contact with thrombogenic subendothelial factors and local vasoconstriction due to endothelial dysfunction. Although rupture of the plaque is an unpredictable event, there is a circadian variability the highest incidence of infarction being between 6 a.m. and midday. Comprehension of the physiopathology of myocardial infarction has opened up new therapeutic approaches which should reduce the incidence of plaque rupture. Prevention is based on stabilisation of the plaque by dietary hygiene, lipid-lowering drugs and, maybe, in the future, by local application of antisense oligonucleotides. Finally, anti-aggregant therapy (aspirin or anti-GIIb-IIIa) could prevent the formation or extension of the thrombus.
Assuntos
Infarto do Miocárdio/fisiopatologia , Colesterol/metabolismo , Ritmo Circadiano , Doença das Coronárias/fisiopatologia , Vasos Coronários/patologia , Endotélio Vascular , Humanos , Metabolismo dos Lipídeos , Agregação Plaquetária , Fatores de RiscoRESUMO
Echocardiography is a routine daily cardiological investigation. Recent technological developments suggest that it may become possible to quantify myocardial texture and thereby achieve histological and functional definitions of cardiac diseases. Two approaches are under evaluation: "videodensitometry" uses tools of statistical quantification from the echocardiographic image; more recently, analysis of the radiofrequency signal has been proposed. This is based on direct exploitation of a continuous signal at the transducer head of wide dynamic range containing all the information received by the piezo-electric crystals. These two approaches have given encouraging preliminary results in the recognition of different myocardial hypertrophic reactions, in diabetic cardiac disease and in the identification of myocardial viability. Despite the many remaining problems, the perspectives are promising and a new field of echocardiography should see the light of day.
Assuntos
Ecocardiografia/métodos , Cardiopatias/diagnóstico por imagem , Coração/fisiologia , Humanos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Gravação em VídeoRESUMO
Acute occlusion of the left main coronary artery is usually responsible for cardiogenic shock, severe arrhythmias or sudden death. Despite the widespread use of emergency coronary angiography in acute myocardial infarction, occlusion of the left main coronary artery is rarely observed and its treatment remains controversial. The authors report the case of a young man with a previous history of radiotherapy for Hodgkin's disease, admitted for acute myocardial infarction due to complete thrombosis of the left main coronary artery treated as an emergency by percutaneous transluminal angioplasty and implantation of a Palmaz Schatz stent. There were no complications of the procedure and the patient was asymptomatic one year later.
Assuntos
Trombose Coronária/complicações , Trombose Coronária/terapia , Infarto do Miocárdio/complicações , Infarto do Miocárdio/terapia , Adulto , Angioplastia Coronária com Balão , Humanos , Masculino , StentsRESUMO
Doppler echocardiographic evaluation of mitral stenosis is often difficult in patients with atrial fibrillation. Sixteen patients were examined by transthoracic Doppler echocardiography and the relation between the variations in transmitral end diastolic pressure gradient and the length of the corresponding cardiac cycles was analysed. Mitral valve surface area (1.65 +/- 0.73 cm2) was determined by the pressure half-time method. The end diastolic transmitral pressure gradient was calculated from the simplified Bernouilli formula applied to end diastolic mitral flow velocity. In each patient, a linear relationship was observed between the end diastolic mitral gradient and the corresponding RR interval. The slope and intercept of the graph correlated significantly to mitral valve surface area (r = 0.72, p < 0.002 and r = 0.93, p < 0.00001, respectively). Using regression equations describing these correlations, it has been possible to construct a nomogramme indicating mitral valve surface area as a function of mitral end diastolic pressure gradient and the duration of the corresponding RR cycle. This nomogramme facilitates Doppler evaluation of mitral stenosis in atrial fibrillation.