Behavior of cardiac variables in animals exposed to cigarette smoke

OBJECTIVE: To assess the behavior of cardiac variables in animals exposed to cigarette smoke. METHODS: Two groups of Wistar rats were studied as follows: control group (C), comprising 28 animals; and smoking group (S), comprising 23 animals exposed to cigarette smoke for 30 days. Left ventricular cardiac function was assessed in vivo with transthoracic echocardiography, and myocardial performance was analyzed in vitro in preparations of isolated left ventricular papillary muscle. The cardiac muscle was assessed in isometric contractions with an extracellular calcium concentration of 2.5 mmol/L. RESULTS: No statistical difference was observed in the values of the body variables of the rats and in the mechanical data obtained from the papillary muscle between the control and smoking groups. The values of left ventricular systolic diameter were significantly greater in the smoking animals than in the control animals (C= 3.39 ± 0.4 mm and S= 3.71 ± 0.51 mm, P=0.02). A significant reduction was observed in systolic shortening fraction (C= 56.7 ± 4.2% and S= 53.5 ± 5.3%, P=0.02) and in ejection fraction (C= 0.92 ± 0.02 and S= 0.89 ± 0.04, P=0.01). CONCLUSION: The rats exposed to cigarette smoke had a reduction in left ventricular systolic function, although their myocardial function was preserved.

ProBNP for stratifying patients with heart failure

OBJECTIVE: To verify whether the serum levels of N-Terminal ProBNP fraction (ProBNP) allow us to identify with accuracy the clinical functional status of patients with heart failure (HF), because the clinical diagnosis of this syndrome is based basically on clinical data when the complementary tests have lower specificity. METHODS: Sixty-nine patients with a history of HF were studied. Their mean age of was 53.5 years and 78.3% were males. All underwent clinical and echocardiographic evaluations and a test to determine the serum dosage of ProBNP. According to clinical manifestation, patients were in the following functional classes (FC), 14% FC I, 40.6% FC II, 28.1% FC III, and 23.4% FC IV. The mean ejection fraction (EF) was 0.28. RESULTS: ProBNP did not differ according to age, sex, and cause of cardiopathy. No correlation existed between EF and the ProBNP serum level. ProBNP levels were significantly lower in patients in FC I than those in FC II (42 vs 326.7 pmol/L; P=0.0001), and in FC II than those in FC III (P=0.01). ProBNP levels did not differ statically between FC III and IV patients (888.1 vs 1082.8 pmol/L; P=0.25). ProBNP values greater than 100 pmol/L identify patients with decompensated HF with a sensitivity of 98%. CONCLUSION: ProBNP values over 100 pmol/L were indicative of HF, and patients with advanced HF had values over 270 pmol/L. A ProBNP dosage test was an excellent auxiliary in the clinical characterization of patients with HF.

Kawasaki disease: involution of giant coronary aneurysms after prolonged anti-inflammatory treatment

The patient is a 5-year-old male with Kawasaki disease, whose involution of giant aneurysms of the left coronary arteries was surprising after a prolonged period of treatment, which lasted 80 uninterrupted days and comprised anti-inflammatory drugs associated with anticoagulation agents. The distal diameters of the anterior interventricular, the diagonal, and the circumflex arteries normalized by the end of the treatment. A residual giant aneurysm localized at the beginning of the anterior interventricular artery did not cause ischemia. Continuation of the medication for a prolonged period was recommended.

Follow-up study of morphology and cardiac function in rats undergoing induction of supravalvular aortic stenosis

OBJECTIVE: To characterize the follow-up of an experimental model of left ventricular hypertrophy (LVH) induced by supravalvular ascending aortic stenosis in young rats. METHODS: Wistar rats were submitted to thoracotomy and aortic stenosis was created by placing a clip on the ascending aorta (AoS group, n=12). Age-matched control animals underwent a sham operation (C group, n=12). Cardiac function was analysed by echocardiograms performed 6, 12, and 21 weeks after aortic banding. Myocardial morphological features and myocardial hydroxyproline concentration (HOP) were evaluated 2, 6, 12, and 21 weeks after surgery in additional animals. RESULTS: Aortic banding promoted early concentric LVH and a progressive increase in HOP. Under light microscopy, we observed myocyte hypertrophy and wall thickening of the intramural branches of the coronary arteries due to medial hypertrophy. Cardiac function was supranormal after 6 weeks (percentage of fractional shortening - EAo6: 70.3±10.8; C6: 61.3±5.4; p<0.05), and depressed in the last period. Diastolic dysfunction was detected after 12 weeks (ratio of early-to-late filling velocity - EAo12: 4.20±3.25; C12: 1.61±0.16; p<0.05). CONCLUSION: Ascending aortic stenosis promotes concentric LVH with myocardial fibrosis and minimal histological changes. According to the period of evaluation, cardiac function may be improved, normal, or depressed. The model is suitable and useful for studies on pathophysiology and treatment of the different phases of cardiac hypertrophy.

Influence of skeletal muscle mass on ventilatory and hemodynamic variables during exercise in patients with chronic heart failure

OBJECTIVE: To assess the influence of skeletal muscle mass on ventilatory and hemodynamic variables during exercise in patients with chronic heart failure (CHF). METHODS: Twenty-five male patients underwent maximum cardiopulmonary exercise testing on a treadmill with a ramp protocol and measurement of the skeletal muscle mass of their thighs by using magnetic resonance imaging. The clinically stable, noncachectic patients were assessed and compared with 14 healthy individuals (S) paired by age and body mass index, who underwent the same examinations. RESULTS: Similar values of skeletal muscle mass were found in both groups (CHF group: 3863 ± 874 g; S group: 3743 ± 540 g; p = 0.32). Significant correlations of oxygen consumption in the anaerobic threshold (CHF: r = 0.39; P= 0.02 and S: r = 0.14; P = 0.31) and of oxygen pulse also in the anaerobic threshold (CHF: r = 0.49; P = 0.01 and S: r =0.12; P = 0.36) were found only in the group of patients with chronic heart failure. CONCLUSION: The results obtained indicate that skeletal muscle mass may influence the capacity of patients with CHF to withstand submaximal effort, due to limitations in their physical condition, even maintaining a value similar to that of healthy individuals. This suggests qualitative changes in the musculature.

Lipid profile and cardiovascular risk in two Amazonian populations

OBJECTIVE: To compare the lipid profiles and coronary heart disease risks of 2 Brazilian Amazonian populations as follows: a riverside population (village of Vigia) and an urban population (city of Belém in the state of Pará). METHODS: Fifty individuals controlled for age and sex were assessed in each region, and the major risk factors for coronary heart disease were analyzed. RESULTS: According to the National Cholesterol Education Program (NCEP III) and using the Framingham score, both populations had the same absolute risk of events (Vigia = 5.4 ± 1 vs Belém = 5.7 ± 1), although the population of Vigia had a lower consumption of saturated fat (P<0.0001), a greater consumption of mono- and polyunsaturated fat (P<0.03), in addition to lower values for body mass index (25.4± 0.6 vs 27.6 ± 0.7 kg/m², P<0.02), of biceps skin fold (18.6 ± 1.1 vs 27.5 ± 1.3 mm, P<0.0001), of triceps skin fold (28.7 ± 1.2 vs 37.3 ± 1.7 mm, P<0.002), and of total cholesterol (205 ± 5 vs 223 ± 6 mg/dL, P< 0.03) and triglycerides (119 ± 9 vs 177 ± 18 mg/dL, P<0.005). Both populations did not differ in regard to HDL-C (46 ± 1 vs 46 ± 1 mg/dL), LDL-C (135 ± 4 vs 144 ± 5 mg/dL) and blood pressure (SBP 124 ± 3 vs 128 ± 3 mmHg; DBP 80 ± 2 vs 82 ± 2 mmHg). CONCLUSION: The riverside and urban populations of Amazonia had similar cardiovascular risks. However, the marked difference in the variables studied suggests that different strategies of prevention should be applied.

Pulmonary vein pulsatility in fetuses of diabetic mothers: prenatal Doppler echocardiographic study

OBJECTIVE: To verify the hypothesis that the pulmonary vein pulsatility index is higher in fetuses of diabetic mothers than it is in normal fetuses of nondiabetic mothers. METHODS: Twenty-four fetuses of mothers with either gestational or previous diabetes (cases), and 25 normal fetuses of mothers without systemic disease (control) were examined. Fetuses were examined through prenatal Doppler and color flow mapping. The pulmonary vein pulsatility index was obtained by placing the pulsed Doppler sample volume over the right superior pulmonary vein and applying the formula (systolic velocity - presystolic velocity)/mean velocity. RESULTS: The mean gestational age of the study fetuses was 30.3±2.7 weeks, and gestational age of the controls was 29±3.3 weeks, with no significant difference in gestational age between groups (p=0.14). Fetuses of diabetic mothers had a mean pulmonary vein pulsatility index of 1.6±1, and those of the control group had an index of 0.86±0.27. CONCLUSION: Fetuses of diabetic mothers had pulmonary vein pulsatility indexes (parameter easily obtained through Doppler echocardiography that may be related to fetal diastolic function) higher than those in fetuses of mothers with normal glycemia.

Distribuição dos escores de cálcio coronariano determinados pela tomografia ultra-rápida em 2.253 homens brancos assintomáticos

OBJETIVO: Descrever a distribuição dos escores de cálcio coronariano numa população de homens brasileiros brancos assintomáticos submetidos à avaliação pela tomografia ultra-rápida. MÉTODOS: Foram avaliados 2.253 homens de 22-88 anos, submetidos a exame tomográfico num aparelho ImatronR C150 para detecção do cálcio coronariano. Os dados foram separados em 7 faixas etárias: < 40 anos, 40-44 anos, 45-49 anos, 50-54 anos, 55-59 anos, 60-64 anos e >65 anos. RESULTADOS: A média e o desvio padrão da idade foram de 50,0 ± 9,7 anos. Em 48,8% dos casos ocorreu incidência de escore de cálcio coronário > zero, que apresentou distribuição não Gaussiana e mostrou grande variação para a mesma faixa etária. Houve correlação direta entre a idade e o escores de cálcio coronariano (r=0,4, p<0,01). Exceto na comparação entre os indivíduos nas faixas etárias 60-64 anos e, abaixo 55-60 anos e acima de 65 anos, quanto maior a faixa etária maiores as medianas dos escores de cálcio coronariano (p<0,0001). Os escores de cálcio coronariano estão relatados de acordo com os percentis 25,50,75 e 90 para as faixas etárias. CONCLUSÃO: Este estudo, primeiro a relatar a distribuição dos escores de cálcio coronariano em uma amostra de homens brasileiros brancos, pode ser útil para estratificação do risco de eventos coronarianos.

Letalidade por doenças isquêmicas do coração no Estado do Rio de Janeiro no período de 1999 a 2003

OBJETIVO: Estimar a letalidade nos procedimentos de doenças isquêmicas do coração (DIC) aguda e crônica e por revascularização miocárdica (RVM) e angioplastia coronariana (AC) nos hospitais cadastrados no SIH/SUS (Sistema de Informações Hospitalares/Sistema Único de Saúde) no Estado do Rio de Janeiro (ERJ), de 1999 a 2003. MÉTODOS: Os procedimentos considerados de RVM e de AC provieram do Datasus. As taxas foram padronizadas por sexo, idade e gravidade de doença, tendo como padrão todos os procedimentos de alta complexidade cardiovascular, realizados no ERJ em 2000. Os grupos de DIC são: angina, infarto agudo do miocárdio, outras DIC agudas e DIC crônicas. RESULTADOS: As letalidades por angina, IAM, outras DIC agudas e DIC crônicas foram de 2,8%, 16,2%, 2,9% e 3,9%, respectivamente, no ERJ. As taxas de letalidade, ajustadas por idade, sexo e grupo diagnóstico, nas RVM e AC foram elevadas, variando entre 1,9% e 12,8% nas RVM, e atingindo 3,2% nas AC, e de 2,3% e 11,1%, quando o tratamento clínico era realizado. CONCLUSÃO: As RVM e AC no tratamento das DIC no ERJ vêm aumentando progressivamente. A letalidade esteve acima do desejável, principalmente nas internações por DIC crônicas (5,4% e 1,7%, respectivamente). O tratamento clínico otimizado parece boa opção terapêutica, reservando-se as RVM e AC para os casos de pior prognóstico. A letalidade no IAM com tratamento clínico foi semelhante à existente quando não se utilizam trombolíticos (16,7%).