Análise Comparativa do Padrão de Fluxo de Artérias Coronárias das Hipertrofias Miocárdicas Secundárias e por Mutação Sarcomérica / Comparative Analysis of the Coronary Arteries Flow Pattern in Secondary Myocardial Hypertrophies and by Sarcomeric Mutation

Fundamento: O fluxo coronariano com predomínio diastólico aumenta duas a cinco vezes na hiperemia, mediada por vasodilatação (reserva de fluxo coronariano), podendo, na hipertrofia, ocorrer isquemia relativa. Na hipertrofia secundária, o fluxo em repouso torna-se isquêmico pelo aumento da demanda. Na cardiomiopatia hipertrófica com fibrose perivascular, há funcionalização de vasos colaterais, para aumentar a irrigação dos segmentos hipertrofiados. Objetivo: Determinar o padrão do fluxo coronariano em pacientes com hipertrofia secundária e cardiomiopatia hipertrófica, avaliando a reserva de fluxo coronariano. Métodos: Avaliamos o fluxo coronariano em 34 pacientes com hipertrofia secundária, em 24 com cardiomiopatia hipertrófica e em 16 controles. A artéria descendente anterior foi detectada com Doppler transtorácico com calibração adequada do equipamento. Nos grupos controle e com hipertrofia secundária, foi calculada a reserva de fluxo coronariano com dipiridamol (0,84 mg/kg) endovenoso. O mesmo procedimento foi realizado em seis pacientes do grupo com cardiomiopatia hipertrófica, nos quais também foi avaliado o fluxo das colaterais da região hipertrófica. Os dados foram comparados por variância com significância de 5%. Resultados: Na hipertrofia secundária, houve aumento do índice de massa e, na cardiomiopatia hipertrófica, predominou o aumento da espessura relativa. A fração de ejeção e a disfunção diastólica foram maiores no grupo com cardiomiopatia hipertrófica. A reserva de fluxo coronariano foi menor no grupo com cardiomiopatia hipertrófica, sendo detectado, também, fluxo de colaterais com redução da reserva de fluxo coronariano. Conclusão: A análise da circulação coronariana com Doppler transtorácico é possível em indivíduos normais e hipertróficos. Pacientes com hipertrofia secundária e cardiomiopatia hipertrófica apresentam diminuição da reserva de fluxo coronariano, e aqueles com cardiomiopatia hipertrófica mostram fluxo de vasos colaterais dilatados observados na região hipertrófica, com diminuição da reserva de fluxo coronariano.(AU)

Background: Coronary flow with a diastolic predominance increases two to five times in hyperemia, mediated by vasodilation (coronary flow reserve, CFR) and, in hypertrophy, relative ischemia may occur. In secondary hypertrophy (LVH), the flow, normal at rest, becomes ischemic due to increased demand. In hypertrophic cardiomyopathy (HCM) with perivascular fibrosis, collateral vessels appear to increase the irrigation of hypertrophied segments. Objective: To determine the coronary flow pattern in patients with secondary hypertrophy and hypertrophic cardiomyopathy, evaluating the coronary flow reserve. Methods: Coronary flow was evaluated in 34 patients with secondary hypertrophy, 24 with hypertrophic cardiomyopathy and in 16 controls. The anterior descending artery was detected with transthoracic Doppler with adequate equipment calibration. In the hypertrophic cardiomyopathy group, the flow of collaterals from the hypertrophic region was evaluated. In the control and secondary hypertrophy groups and in six patients in the hypertrophic cardiomyopathy group, the intravenous dipyridamole (0.84 mg) coronary flow reserve was calculated. The data were compared by variance with a significance of 5%Results: In secondary hypertrophy there was an increase in mass index and blood pressure, and in hypertrophic cardiomyopathy an increase in relative thickness predominated. Ejection fraction and diastolic dysfunction were higher in the hypertrophic cardiomyopathy group. The coronary flow reserve was lower in the hypertrophic cardiomyopathy group, and flow of collaterals was also detected, with a reduction in the coronary flow reserve. Conclusion: the analysis of coronary circulation with transthoracic Doppler is possible in normal and hypertrophic individuals. Patients with secondary hypertrophy and hypertrophic cardiomyopathy have a decrease in the coronary flow reserve, and patients with hypertrophic cardiomyopathy show a hyper flow of dilated collateral vessels observed in the hypertrophic region, with a decrease in the coronary flow reserve.(AU)

The value of a simplified approach to end-systolic volume measurement for assessment of left ventricular contractile reserve during stress-echocardiography.

The peak stress/rest ratio of left ventricular (LV) elastance, or LV force, is a load-independent index of left ventricular contractile reserve (LVCR) with stress echo (SE). To assess the accuracy of LVCR calculated during SE with approaches of different complexity. Two-hundred-forty patients were referred to SE for known or suspected coronary artery disease or heart failure and, of those, 200 patients, age 61 ± 15, 99 females, with interpretable volumetric SE were enrolled. All readers had passed the upstream quality control reading for regional wall motion abnormality (RWMA) and end-systolic volume (ESV) measurement. The employed stress was dipyridamole (0.84 mg, 6 min) in 86 (43%) and dobutamine (up to 40 mcg/kg/min) in 114 (57%) patients. All underwent SE with evaluation of RWMA and simultaneous LVCR assessment with stress/rest ratio of LV force (systolic blood pressure by cuff sphygmomanometer/ESV). ESV was calculated in each patient by two of three methods: biplane Simpson rule (S, in 100 patients), single plane area-length (AL, apical four-chamber area and length, in 100 patients), and Teichholz rule (T, from parasternal long axis and/or short axis view, in 200 patients). RMWA were observed in 54 patients. Success rate for ESV measurement was 76% (100/131) for S, 92% (100/109) for AL, and 100% (240/240) for T. There were 100 paired measurements (rest and stress) with S versus T, and 100 with AL versus T. The analysis time was the shortest for T (33 ± 8 s at rest, 34 ± 7 s at stress), intermediate for AL (70 ± 22 s at rest 67 ± 21 s at stress), and the longest for S (136 ± 24 at rest 129 ± 27 s at stress, p < 0.05 vs. T and AL). ESV absolute values were moderately correlated: T versus S (r rest = 0.746, p < 0.01, n = 100; r stress = 0.794, p < 0.01, n = 100); T vs. AL (r = 0.603 p < 0.01, n = 100, at rest and r = 0.820 p < 0.01 n = 100 at peak stress). LVCR values were tightly correlated independently of the method employed: T versus S (r = 0.899, p < 0.01, n = 100), and T versus AL (r = 0.845, p < 0.01, n = 100). LVCR can be accurately determined with all three methods used to extract the raw values of ESV necessary to generate the calculation of Force. Although S is known to be more precise in determining absolute ESV values, the relative (rest-stress) changes can be assessed, with comparable accuracy, with simpler and more feasible T and AL methods, characterized by higher success rate, shorter imaging and analysis time.

Prolonged dipyridamole administration reduces myocardial perfusion defects in experimental chronic Chagas cardiomyopathy.

BACKGROUND: Myocardial perfusion defects (MPD) due to coronary microvascular dysfunction is frequent in chronic Chagas cardiomyopathy (CCC) and may be involved with development of myocardial damage. We investigated whether MPD precedes left ventricular systolic dysfunction and tested the hypothesis that prolonged use of dipyridamole (DIPY) could reduce MPD in an experimental model of CCC in hamsters. METHODS AND RESULTS: We investigated female hamsters 6-months after T. cruzi infection (baseline condition) and control animals, divided into T. cruzi-infected animals treated with DIPY (CH + DIPY) or placebo (CH + PLB); and uninfected animals treated with DIPY (CO + DIPY) or placebo (CO + PLB). The animals were submitted to echocardiogram and rest SPECT-Sestamibi-Tc99m myocardial perfusion scintigraphy. Next, the animals were treated with DIPY (4 mg/kg bid, intraperitoneal) or saline for 30 days, and reevaluated with the same imaging methods. At baseline, the CH + PLB and CH + DIPY groups showed larger areas of perfusion defect (13.2 ± 13.2% and 17.3 ± 13.2%, respectively) compared with CO + PLB and CO + DIPY (3.8 ± 2.2% e 3.5 ± 2.7%, respectively), P < .05. After treatment, we observed: reduction of perfusion defects only in the CH + DIPY group (17.3 ± 13.2% to 6.8 ± 7.6%, P = .001) and reduction of LVEF in CH + DIPY and CH + PLB groups (from 65.3 ± 9.0% to 53.6 ± 6.9% and from 69.3 ± 5.0% to 54.4 ± 8.6%, respectively, P < .001). Quantitative histology revealed greater extents of inflammation and interstitial fibrosis in both Chagas groups, compared with control group (P < .001), but no difference between Chagas groups (P > .05). CONCLUSIONS: The prolonged use of DIPY in this experimental model of CCC has reduced the rest myocardial perfusion defects, supporting the notion that those areas correspond to viable hypoperfused myocardium.

Terapia de Resgate com Nifurtimox e Dipiridamol na Miocardite Chagásica Aguda Grave com Insuficiência Cardíaca em Camundongos NMRI / Rescue Therapy with Nifurtimox and Dipyridamole for Severe Acute Chagas Myocarditis with Congestive Heart Failure in NMRI Albino Mice

Fundamento: A doença de Chagas é um problema de saúde global, sendo necessário o desenvolvimento de novos protocolos terapêuticos. Nosso grupo demonstrou recentemente que o nifurtimox associado ao dipiridamol tem efeitos curativos em camundongos com doença de Chagas aguda. Neste estudo, avaliamos o efeito deste protocolo terapêutico em camundongos chagásicos com insuficiência cardíaca. Objetivo: Avaliar se o nifurtimox e o dipiridamol são úteis no tratamento de resgate em camundongos com miocardite chagásica aguda com insuficiência cardíaca. Métodos: Foram divididos em três grupos 42 camundongos com miocardite chagásica aguda e insuficiência cardíaca congestiva: Controle Chagas (n = 11); Nif-Dip, tratados com nifurtimox e dipiridamol (n = 14); e Nif-Dip-Insuficiência Cardíaca, tratados com nifurtimox e dipiridamol, associados com digoxina, furosemida e captopril (n = 17). As doses de nifurtimox e dipiridamol foram de 40 e 30mg/kg/dia, respectivamente, durante 6 semanas. Os camundongos foram submetidos a avaliações clínicas, eletrocardiográficas, hemoparasitológicas e histopatológicas. Resultados: Observou-se menor mortalidade no Grupo Nif-Dip (n = 4; 28,57%) em relação ao Controle Chagas (n = 6; 54,54%) e ao Nif-Dip-Insuficiência Cardíaca (n = 9; 52,9%). Clinicamente, os camundongos tratados com nifurtimox e dipiridamol aumentaram o peso corporal e melhoraram a insuficiência cardíaca, sem mostrar esplenomegalia. Nestes grupos, foram erradicadas as parasitemias e os parasitas teciduais; a fibrose, a miocitólise, o infiltrado de células inflamatórias e os mastócitos diminuíram. Os distúrbios de repolarização, os intervalos QRS e o QT prolongados, o aumento da amplitude da onda S e a dissociação atrioventricular foram revertidos pelo tratamento. Conclusão: O tratamento com nifurtimox e dipiridamol pode ser usado no resgate em camundongos com doença chagásica aguda grave, já que o nifurtimox teve atividade tripanocida, e o dipiridamole potenciou seu efeito. O dipiridamol seria útil na insuficiência cardíaca chagásica

Background: Chagas disease is a global health problem; therefore, the development of new therapeutic protocols is necessary. Our group recently demonstrated that nifurtimox associated with dipyridamole has curative effects in mice with acute Chagas disease. In this study, we assess the effect of this therapeutic protocol in chagasic mice with heart failure. Objective: To evaluate whether nifurtimox and dipyridamole are useful to rescue mice with severe acute chagasic myocarditis with heart failure. Methods: 42 mice with acute chagasic myocarditis and congestive heart failure were divided into three groups: control chagas (n = 11), Nif-Dip treated with nifurtimox and dipyridamole (n = 14) and Nif-Dip-heart failure treated with nifurtimox and dipyridamole associated with digoxin, furosemide, and captopril (n = 17). Nifurtimox and dipyridamole doses were 40 and 30 mg/kg/day, respectively, for 6 weeks. Mice underwent clinical, electrocardiographic, hemoparasitological and histopathological assessments. Results: Lower mortality in Nif-Dip (28.57%; n = 4) compared to control chagas (54.54%; n = 6) and Nif-Dip-heart failure (52.9%; n = 9) was observed. Clinically, nifurtimox and dipyridamole-treated mice increased body weight and improved heart failure without splenomegaly. In these groups, parasitemia and tissue parasites were eradicated; fibrosis, myocytolysis, inflammatory cell infiltrate and mast cells decreased. Repolarization disorders, prolonged QRS and QT intervals, increase of S wave amplitude and atrioventricular dissociation were reversed by the treatment. Conclusion: Nifurtimox with dipyridamole can rescue NMRI mice from severe acute chagas disease, as nifurtimox showed trypanocidal activity and dipyridamole potentiated its effect. Dipyridamole would be useful in chagasic heart failure

Análise de segurança do ecocardiograma sob estresse farmacológico com dipiridamol em octogenários / Safety analysis of pharmacological stress echocardiography with dipyridamole in octogenarians

Fundamento: O ecocardiograma sob estresse farmacológico, utilizando dipiridamol, é reconhecido como teste acurado e seguro para investigação diagnóstica e prognóstica de doença arterial coronariana, especialmente útil na avaliação de indivíduos com idade avançada que apresentam comorbidades limitantes ao uso do estresse físico. Poucos estudos avaliaram a segurança desse método em pacientes com mais de 80 anos. Objetivo: Avaliar a segurança do ecocardiograma sob estresse farmacológico com dipiridamol em octogenários. Métodos: Estudo descritivo retrospectivo. Resultados: Foram avaliados 262 pacientes com idade média de 82,8 ± 2,9 anos submetidos à realização de ecocardiograma sob estresse farmacológico com dipiridamol 0,84 mg/kg em 4 minutos. A incidência de complicações foi de 3,4% (9 casos), com apenas uma complicação maior (0,4%), que foi um caso de isquemia prolongada necessitando tratamento invasivo de urgência. As demais complicações foram 2 casos de isquemia prolongada tratadas com betabloqueador; 3 casos de taquicardias supraventriculares transitórias; 1 caso de taquicardia supraventricular sustentada revertida com adenosina; 1 caso de fibrilação atrial; e 1 caso de bloqueio atrioventricular 2:1 transitório. Conclusão: No presente estudo o ecocardiograma sob estresse com dipiridamol mostrou ser um teste seguro na população selecionada de octogenários.

Background: The pharmacological stress echocardiography with dipyridamole is known as safe and accurate test for diagnostic and prognostic investigation of coronary artery disease, particularly useful for elderly who have comorbidities that limit the use of physical stress. Few studies have evaluated the safety of this method in patients over 80 years. Objective: Evaluate the safety of pharmacological stress echocardiography with dipyridamole in octogenarians. Methods: A retrospective descriptive study. Results: The study included 262 patients with a mean age of 82.9 ± 2.9 years who under went a pharmacological stress echocardiogram with dipyridamole 0.84 mg/kg over 4 minutes. The incidence of complications was 3.4% (nine cases), only one major complication (0.4%), which was a case of prolonged ischemia requiring urgent invasive treatment. Other complications were two cases of prolonged ischemia treated with beta blocker, three cases of transient supraventricular tachycardias, one case of sustained supraventricular tachycardia reversed with adenosine,one case of atrial fibrillation and one case of transitory atrioventricular block 2:1. Conclusion: In this study the stress echocardiography with dipyridamole was shown to be a safe test in the selected population of octogenarians.

Prognostic implications of the difference between left ventricular ejection fractions after stress and at rest in addition to the quantification of myocardial perfusion abnormalities obtained with gated SPECT.

BACKGROUND: The prognostic significance of the difference between poststress and at rest left ventricular ejection fraction (ΔLVEF) in patients sent for diagnostic myocardial perfusion study (MPS) is not well characterized. The purpose of this study was to prospectively evaluate the ability of ΔLVEF in further risk stratifying these patients in addition to the severity/extent of myocardial perfusion abnormalities expressed as the total perfusion deficit at stress (sTPD), according to the type of stress used. METHODS AND RESULTS: Two-day 99mTc-MIBI MPS after stress and rest were obtained for 507 patients subdivided according to the type of stress used, sTPD values, and ΔLVEF. Subsequent cardiac events were determined through a standardized questionnaire applied 1, 2, and 6 years after MPS. Independent of the type of stress used, the 6-year event rate with progressive perfusion and functional abnormalities combined was significant for total events, all-cause death, cardiac death, and revascularization but not for myocardial infarct. When ΔLVEF decreased by more than -10%, only those individuals with sTPD of 5% or less had increased 6-year total event rates [5.9% vs 15% for those submitted to treadmill test (P < 0.001) and 8.3% vs 19% when submitted to pharmacological stress (P = 0.001)]. An sTPD greater than 5% was the only variable predictive of total events when multivariate analysis was applied (P < 0.001 for treadmill exercise and P = 0.033 for dipyridamole). CONCLUSIONS: Estimation of ΔLVEF in addition to sTPD seems to improve risk stratification for future events when ΔLVEF decreases by more than -10% for those individuals with normal or near-normal myocardial perfusion (sTPD ≤ 5%). An sTPD greater than 5% was a better prognostic indicator of future events when compared with ΔLVEF for individuals with greater perfusion abnormality at stress.

Influência da fístula arteriovenosa sobre a resposta da frequência cardíaca ao dipiridamol em pacientes renais crônicos submetidos à cintilografia miocárdica / Influence of arteriovenous fistula on the heart rate response to dipyridamole in chronic renal patients undergoing

Fundamentos: Uma resposta diminuída da frequência cardíaca (FC) ao dipiridamol ocorre nos portadores de doença renal crônica (DRC) por razões não elucidadas. Após ampla revisão da literatura, não se encontraram estudos sobre a contribuição da fístula arteriovenosa (FAV) para esse fenômeno. Objetivo: Avaliar o papel da FAV para a resposta diminuída da FC ao dipiridamol em renais crônicos submetidos à cintilografia miocárdica. Métodos: Estudados 516 pacientes adultos, sendo 45 renais crônicos (25 com FAV e 20 sem FAV) e 471 comfunção renal normal, submetidos à cintilografia miocárdica em hospital terciário, entre 2006 e 2009. Todos os pacientes foram avaliados quanto à resposta hemodinâmica ao dipiridamol e a alguns parâmetros clínicos e cintilográficos. A resposta anormal da FC ao dipiridamol foi definida como razão FC pico/FC basal≤1,2 e diferença FC pico-Fc basal<12bpm. Resultados: A resposta diminuída da FC ao dipiridamol ocorreu de forma equivalente em ambos os grupos de renais crônicos, com ou sem FAV, e mais frequente do que no grupo de não DRC (68% vs. 70% vs. 29,7%, p<0,001, respectivamente). Pela regressão logística, determinou-se como preditores de resposta anormal daFC ao dipiridamol a DRC, a idade mais elevada e a disfunção ventricular esquerda. Conclusões: Há relação entre DRC e a resposta anormal da FC ao dipiridamol, mas a FAV não explica a influência da doença renal sobre essa resposta.

Background: An abnormal heart rate (HR) response to dipyridamole occurs in patients with chronic renal disease for unknown reasons. A broad-ranging review of the literature did not disclose any studies on the contribution of arteriovenous fistula (AVF) to this phenomenon. Objective: To evaluate the role of AVF in reduced HR response to dipyridamole in patients with CRFundergoing myocardial perfusion scintigraphy. Methods: 516 adult patients were studied, 45 with CRF(25 with AVF and 20 without AVF) and 471 with normal kidney function, consecutively undergoing myocardialscintigraphy in a tertiary care hospital between 2006 and 2009. Hemodynamic responses to dipyridamole wereevaluated in all these patients, as well as clinical and scintigraphic parameters. An abnormal HR response to dipyridamole was defined as the peak HR/basal HR≤1.2 ratio and the difference as the peak HR-HR basal<12bpm. Results: The reduced HR response to dipyridamole was equivalent in both groups of CRF patients (with or without AVF), although more frequent than in patients without CRF (68% vs 70.0% vs 29.7%, p<0.001, respectively). Using logistic regression, the predictors of an abnormal HR response to dipyridamole were found to be the presence of CRF, older age and left ventriculardysfunction. Conclusions: There is a link between CRF and the abnormal HR response to dipyridamole, but the presence of AVF does not explain the influence of kidney disease on this response.

Dipyridamole and low doses of heparin as a new successful physiopathologic and therapeutic approach in 2 cases of disseminated intravascular coagulation.

UNLABELLED: OPERATIVE: We report 2 cases of disseminated intravascular coagulation (DIC) successfully treated with the combination of the platelet adhesiveness blocker dipyridamole and low doses of intravenous heparin. METHODS: The first patient was a 17-year-old boy with septic arthritis; the second patient was a 12-year-old boy with a liver abscess. Both had hemocultures positive for Staphylococcus aureus. The diagnosis of DIC was defined by clinical signs of septicemia with fever, tachypnea, peripheral vasoconstriction, and low platelet counts (67,000/mm3 and 47,000/mm3, respectively). The second patient also presented with acute ischemia of the fingers and toes. General care was provided in the intensive care unit, and high doses of antibiotics were provided continuously (metronidazole and oxacillin or ceftriaxone). A 5% glucose solution containing dipyridamole (Persantine; Istituto De Angeli/Boheringer Ingelheim, Reggello, Italy) was administered by continuous intravenous infusion (20 mg/24 hours). In addition, regular heparin (Liquemin; Roche, Indianapolis, IN, USA) was administered at a dosage of 250 microg/kg per hour or 25 IU/kg per hour (6 mg/kg per 24 hours). These heparin doses are not able to promote complete blood anticoagulation. Treatment with heparin and dipyridamole was maintained for 10 days in the first patient and for 18 days in the second. RESULTS: By 48 hours after treatment with dipyridamole and low-dose heparin, both patients recovered and presented with a good clinical condition and increased numbers of circulating platelets. Both patients were discharged in a safe clinical condition in the second month after hospital admission. CONCLUSION: Successful clinical recovery of 2 young patients with DIC with an unfavorable clinical evolution and a prognosis for a lethal outcome was achieved with the combination of a continuous infusion of dipyridamole and low doses of heparin.

Ressonância magnética cardiovascular na doença arterial coronária / Role of cardiovascular magnetic resonance in coronary artery disease

A ressonância magnética cardiovascular avançou de forma bastante rápida na última década, sobretudo na avaliação da doença arterial coronaria. Com o advento de técnicas de imagem cada vez mais rápidas e com maior resolução espacial, hoje é possível à ressonância avaliar diversos componentes da doença arterial coronária em um único exame de curta duração. Destacam-se nesta avaliação a possibilidade de estudar a perfusão miocárdica para detecção da relevância funcional de estenoses coronárias, a avaliação de contratilidade em repouso e no repouso e no estresse farmacológico com dobutamina, e a presença ou ausência de viabilidade miocárdica. Além de integrar todos esses elementos diagnósticos em um único exame com alta sensibilidade e especificidade, a ressonância magnética cardiovascular ainda fornece dados prognósticos de curto e longo prazos, tornando o método um dos mais completos para a prática clínica da avaliação da doença arterial coronária.

Preditores da resposta anormal da frequência cardíaca em pacientes submetidos a estresse farmacológico com dipiridamol / Abnormal heart rate response predictors in patients subjected to pharmacological stress with dipyridamole

Pacientes com resposta da frequência cardíaca (FC) diminuída apresentam mortalidade cardíaca aumentada embora o mecanismo para isso seja desconhecido...

Influence of chronic renal failure on the heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT.

BACKGROUND: Dipyridamole promotes a reduction in blood pressure and an increase in heart rate (HR), considered the normal hemodynamic response to the drug. Data suggest that patients with chronic renal failure (CRF) have an attenuation of this hemodynamic response. This study sought to evaluate the HR response to dipyridamole and its determinants in patients with or without CRF undergoing gated myocardial perfusion single photon emission computed tomography. METHODS AND RESULTS: Consecutive patients (n = 355, 9.6% with CRF) undergoing rest/dipyridamole myocardial perfusion single photon emission computed tomography were evaluated. The HR response to dipyridamole was considered to be reduced if the HR ratio (maximal HR/rest HR) was 1.20 or less. A logistic regression analysis determined independent predictors of a blunted HR response. A reduced HR response was found in 84.4% of patients with CRF and 40.6% of those without CRF (P < .0001). In patients without CRF the independent predictors of abnormal HR response were hypertension, rest and differential perfusion scores, and left ventricular ejection fraction. In contrast, in CRF patients there was no significant association of any of the studied variables with abnormal HR response. CONCLUSIONS: An abnormal HR response to dipyridamole is frequently found in patients with CRF. Different mechanisms may account for abnormal HR response in patients with or without CRF.

Resultados preliminares de um novo protocolo de estresse farmacológico para cintilografia de perfusão miocárdica / Preliminary results of a new pharmacologic stress protocol for myocardial perfusion imaging

Fundamentos: O estresse farmacológico é frequentemente realizado com agentes vasodilatadores, como o dipiridamol (Dip) ou inotrópicos, como a dobutamina (Dob). Objetivo: Avaliar a segurança e os resultados obtidos com um novo protocolo, associando Dip, Dob e atropina (Dip-Dob) comparando ao protocolo tradicional com Dip. Métodos: Dez pacientes foram submetidos à cintilografia de perfusão do miocárdio (CPM). Tl-201 (2,5-3,0mCi) foi injetado em repouso e a imagem foi iniciada 10 minutos após. Dip foi administrado por infusão intravenosa (0,56mg/kg) durante quatro minutos e Tc-99m sestamibi (20-25mCi) foi injetado três minutos após. Em outro dia, foi administrada a dose de Dip, imediatamente seguida da infusão da Dob...

Determinantes da hipotensão induzida pelo dipiridamol em pacientes submetidos à cintilografia miocárdica de perfusão / Determinants for dipyridamole-induced hypotension in patients undergoing myocardial perfusion single-photon emission computer tomography

Os vasodilatadores são freqüentemente empregados para a fase de estresse da cintilografia miocárdica de perfusão e, geralmente, provoca leve diminuição da pressão arterial e aumento da freqüência cardíaca. Hipotensão eventualmente ocorre e tem sido associada a uma mortalidade cardíaca aumentada. A razão para isso, entretanto, não é conhecida. Objetivo: Investigar os determinantes da hipotensão induzida por dipiridamol (HIPO) em pacientes submetidos à cintilografia miocárdica. Métodos: Hipotensão foi definida como uma queda >20% na pressão arterial sistólica ou uma pressão arterial sistólica <90mmHg. Escores somados de estresse e de repouso e o escore diferencial (SSS, SRS e SDS, respectivamente) foram calculados. Fração de ejeção do ventrículo esquerdo foi obtida automaticamente. Resultados: Trezentos e trinta e cinco pacientes foram estudados; 10 (3,0%) apresentaram uma queda >20% da pressão arterial sistólica e 4 (1,2%) atingiram uma pressão arterial sistólica <90mmHg. Nenhuma diferença foi observada entre os pacientes com queda da pressão arterial sistólica >20% e aqueles sem hipotensão. Para aqueles com pressão sistólica <90mmHg, as únicas diferenças significativas encontradas foram SDS e fração de ejeção de ventrículo esquerdo menores em comparação aos pacientes sem hipotensão. Conclusão: Esses achados sugerem que a disfunção ventricular pode desempenhar um papel na gênese da hipotensão induzida pelo dipiridamol, embora outros mecanismos possam estar envolvidos nesse fenômeno.

Background: Vasodilators are frequently used for the stress phase of myocardial perfusion SPECT and usually cause a mild decrease in blood pressure and increase in heart rate. Hypotension sometimes occurs and has been linked to increased cardiac mortality. However, the reasons for this are still unknown. Objective: To study determining factors for dipyridamoleinduced hypotension in patients undergoing gated myocardial perfusion SPECT. Methods: Hypotension was defined as a >20% drop in systolic blood pressure or peak systolic blood pressure <90mmHg. The summed stress, rest and difference scores (SSS, SRS and SDS, respectively) were calculated. The left vent r i cul a r e j e c t ion f r a c t ion wa s obt a ine d automatically. Results: Three hundred and thirty five patients were studied; 10 (3.0%) presented >20% decrease in systolic BP and 4 (1.2%) developed peak systolic blood pressure <90mmHg. There were no differences between patients with >20% drop in systolic blood pressure compared to patients without hypotension. For those with peak systolic blood pressure <90mmHg, the only significant differences in comparison to patients without hypotension were the lower SDS and left ventricle ejection fraction in the former. Conclusion: These findings suggest that left ventricular dysfunction may play a role in the genesis of dipyridamoleinduced hypotension, although other mechanisms are probably also involved in this phenomenon.

Avaliação ds diferentes variáveis prognósticas durante o ecocardiograma de estresse com dipiridamol e atropina / Evoluation of different prognostic variables during dipyridamol-atropine stress echocardiogram

Fundamentos: Com o envelhecimento da população, no Brasil e no mundo, cresce o número de doenças crônicas, dentre elas a doença arterial coronariana. Faz-se, portanto, necessária a adoção de estratégias racionais na avaliação dessa população. Objetivo: Avaliar o impacto prognóstico do ecocardiograma de estresse com dipiridamol e atropina (Eco-Dip-Atro) e determinar as variáveis durante o exame com maior poder para estratificação. Métodos: Foram realizados, consecutivamente, 151 ecocardiogramas de estresse com dipiridamol (até 0,84mg/kg em 10min) e atropina (até 1mg em 4 min) em pacientes com suspeita ou com coronariopatia conhecida. O tempo mediano de acompanhamento foi de 596 dias. Resultados: Na análise univariada, a idade não foi preditiva para eventos combinados...

Segurança na realização da ressonância magnética cardíaca pela técnica combinada, utilizando dose máxima de dipiridamol para investigação de isquemia miocárdica / Safety during combined technique cardiac magnetic resonance imaging using the maximum dose of dipyridamole for investigating myocardial ischemia

Objetivo: Avaliar a segurança do uso do dipiridamol (dipi) em dose máxima com a técnica combinada para a pesquisa de isquemia miocárdica(TCPI). Métodos: Foram avaliados, prospectivamente, 110 pacientes, encaminhados no período de junho 2006 a abril 2007, com indicação de pesquisa de isquemia miocárdica, associada ou não à pesquisa de viabilidade miocárdica, que não apresentassem alguma contra-indicação ao exame. Resultados: Todos os pacientes conseguiram realizar o exame completo, sem interrupção por sintomas. O tempo médio de aquisição das imagens durante os exames foi de 39,6min, com o tempo de estresse de 11,8min. Conclusão: É possível realizar o exame completo de TCPI pela RMC, com dose máxima do dipi, com boa tolerabilidade e segurança, e com tempo de aquisição de imagem em média inferior a 40 minutos.

Objective: To assess the safety of using a maximum dose of dipyridamole through the combined technique forinvestigating myocardial ischemia.Methods: A prospective assessment of 110 patients from June 2006 to April 2007, recommended for myocardialischemia investigation and associated or not with myocardial feasibility studies, presenting no counterindicationsfor this examination. Results: All the patients managed to complete the fullexamination with no interruptions caused by symptoms. The average time of image acquisition was 39.6 minutes,with a stress time of 11.8 minutes.Conclusion: It is possible to use the combined technique for investigating myocardial ischemia through magneticresonance imaging (MRI) with a maximum dose of dipyridamole, without causing hemodynamic effects orsymptoms that interrupt the examination. This procedure may be performed in less than forty minutes, providing important clinical information.

Short-term risk stratification with accelerated high-dose dipyridamole stress echocardiography: follow-up into 301 consecutive outpatients.

AIM: This study aimed to assess the short-term predictive value of a pharmacologic stress echocardiography test performed with accelerated high-dose dipyridamole (0.84 mg/kg over 6 minutes). METHODS: In all, 301 patients (161 men, mean age 61.41 +/- 11.62 years) were scheduled for accelerated high-dose dipyridamole stress test. A total of 22 tests were interrupted prematurely because of side effects (overall feasibility 92.7%). The patients were followed up for nonfatal myocardial infarction, unstable angina, myocardial revascularization, and sudden death at first and third months and each 6 months (maximum 18 months). RESULTS: A positive echocardiographic response was found in 25 patients. Six patients with negative stress test experienced events. Eight patients with positive stress test went to coronary revascularization procedure. Negative predictive value was 97.8%, positive predictive value was 32%, sensitivity was 57%, and specificity was 94%. CONCLUSIONS: Risk stratification with accelerated high-dose dipyridamole stress echocardiography is effective. A negative test predicts favorable short-term cardiovascular prognosis.

Livedo vasculitis con ulceraciones de verano / Livedo Vasculitis, with sommer ulcers

Se presenta una paciente con lesiones ulcerosas en miembros inferiores. Al interrogatorio y análitica sanguínea se detectan otras enfermedades que la paciente ignora, entre ellas un sindrome anticuerpo antifosfolipídico (SAAF). Se describe la afección y su relación con etioligías que se hace obligatoriobuscar ante este cuadro clínico. (AU)

Corticosteroids in the treatment of the acute phase of Kawasaki disease.

OBJECTIVES: Corticosteroids are considered to be contraindicated during the acute phase of Kawasaki disease (KD) based on unfavorable results in early studies. In our hospital, however, corticosteroids have been used in some cases of KD with satisfactory results. We analyzed outcomes of patients with KD treated with or without corticosteroids. STUDY DESIGN: Medical records of 299 children with KD treated with one of the 4 regimens were reviewed retrospectively. Regimen 1 consisted of aspirin, dipyridamole, and propranolol; regimen 2 was regimen 1 plus prednisolone, 2 mg/kg/d, for 1 week, followed by tapering over 2 weeks; regimen 3 was regimen 1 plus intravenous gamma-globulin (IVGG), 200 or 400 mg/kg/d, for 5 consecutive days; and regimen 4 was regimen 1 plus both prednisolone and IVGG. RESULTS: Although patients treated with regimens 2 and 4 were more ill at presentation than those treated with regimens 1 and 3, respectively, the duration of fever was shorter in the former patient groups (P =.0013). Coronary aneurysms developed least frequently in patients treated with regimen 4 and less frequently with regimen 2 than with regimen 1 (P =.0730). Multiple regression analysis showed significant reductions of fever and coronary aneurysm incidence with prednisolone (P <.0001 and P =.0307, respectively). CONCLUSION: Our data suggest a possible role of corticosteroids in the treatment of the acute phase of KD.

[Intravenous dipyridamole in acute cerebral infarct. Is it efficacious?]. / Dipiridamidol intravenoso en infarto cerebral agudo. Es eficaz?

OBJECTIVE: To evaluate the efficiency of intravenous dipyridamole in the evolution of patients with acute ischemic stroke. METHODS: A double-blind clinical trial was conducted with 60 patients having a 24-h evolution of acute vascular stroke at the Hospital General No. 1 IMSS in the city of Colima, Mexico. After diagnosis, the patients were randomly assigned to two study groups. 10 mg of dipyridamole were administered intravenously every 8 h to the patients in one group, and 300 mg of aspirin were administered orally every 24 h to patients in the other. The patients in both groups received 25 to 50 ml/ kg of saline solution over a 24-h period. Basal conditions were registered using five parameters (food intake, walking, eye opening, motor activity and verbal responsiveness) during the first 5 days of evolution. RESULTS: Six patients died, four from the group treated with dipyridamole and two treated with aspirin. There was no significant difference between the groups in reference to age (66 +/- 11 years) or sex, nor was there a difference in the severity of stroke between the groups. When the values of the parameters recorded for both groups were compared before and after treatment, the group receiving dipyridamole showed no significant change (p < 2), while the group receiving aspirin showed an improvement in three of the parameters (food intake, walking and motor activity (p < 0.003). CONCLUSION: Our results indicate that dipyridamole does not modify basal conditions in patients suffering from acute ischemic stroke, while aspirin mildly favors improvement in these patients. We conclude that appropriate medical care, in the absence of complications, is the underlying condition permitting a satisfactory evolution in patients afflicted with brain vascular disease.