Exercise stress testing before and after successful multivessel percutaneous transluminal coronary angioplasty

Controversy exists regarding the diagnostic accuracy, optimal technique, and timing of exercise testing after percutaneous coronary intervention. The objectives of the present study were to analyze variables and the power of exercise testing to predict restenosis or a new lesion, 6 months after the procedure. Eight-four coronary multi-artery diseased patients with preserved ventricular function were studied (66 males, mean age of all patients: 59 ± 10 years). All underwent coronary angiography and exercise testing with the Bruce protocol, before and 6 months after percutaneous coronary intervention. The following parameters were measured: heart rate, blood pressure, rate-pressure product (heart rate x systolic blood pressure), presence of angina, maximal ST-segment depression, and exercise duration. On average, 2.33 lesions/patient were treated and restenosis or progression of disease occurred in 46 (55 percent) patients. Significant increases in systolic blood pressure (P = 0.022), rate-pressure product (P = 0.045) and exercise duration (P = 0.003) were detected after the procedure. Twenty-seven (32 percent) patients presented angina during the exercise test before the procedure and 16 (19 percent) after the procedure. The exercise test for the detection of restenosis or new lesion presented 61 percent sensitivity, 63 percent specificity, 62 percent accuracy, and 67 and 57 percent positive and negative predictive values, respectively. In patients without restenosis, the exercise duration after percutaneous coronary intervention was significantly longer (460 ± 154 vs 381 ± 145 s, P = 0.008). Only the exercise duration permitted us to identify patients with and without restenosis or a new lesion.

Assessment of the cardiovascular effects of electroconvulsive therapy in individuals older than 50 years

To evaluate the impact of electroconvulsive therapy on arterial blood pressure, heart rate, heart rate variability, and the occurrence of ischemia or arrhythmias, 38 (18 men) depressive patients free from systemic diseases, 50 to 83 years old (mean: 64.7 ± 8.6) underwent electroconvulsive therapy. All patients were studied with simultaneous 24-h ambulatory blood pressure and Holter monitoring, starting 18 h before and continuing for 3 h after electroconvulsive therapy. Blood pressure, heart rate, heart rate variability, arrhythmias, and ischemic episodes were recorded. Before each session of electroconvulsive therapy, blood pressure and heart rate were in the normal range; supraventricular ectopic beats occurred in all patients and ventricular ectopic beats in 27/38; 2 patients had non-sustained ventricular tachycardia. After shock, systolic, mean and diastolic blood pressure increased 29, 25, and 24 percent (P < 0.001), respectively, and returned to baseline values within 1 h. Maximum, mean and minimum heart rate increased 56, 52, and 49 percent (P < 0.001), respectively, followed by a significant decrease within 5 min; heart rate gradually increased again thereafter and remained elevated for 1 h. Analysis of heart rate variability showed increased sympathetic activity during shock with a decrease in both sympathetic and parasympathetic drive afterwards. No serious adverse effects occurred; electroconvulsive therapy did not trigger any malignant arrhythmias or ischemia. In middle-aged and elderly people free from systemic diseases, electroconvulsive therapy caused transitory increases in blood pressure and heart rate and a decrease in heart rate variability but these changes were not associated with serious adverse clinical events.

Effect of sexual steroids on the calcium content of aortic atherosclerotic plaque of oophorectomized rabbits

We determined the effect of conjugated equine estrogen plus medroxyprogesterone acetate on calcium content of aortic atherosclerotic lesions in oophorectomized adult New Zealand rabbits submitted to a cholesterol rich diet. Five groups of 10 animals each were studied: G1 = control, G2 = cholesterol diet only, G3 = diet plus conjugated equine estrogen (0.625 mg/day); G4 and G5 = diet, conjugated equine estrogen (0.625 mg/day) plus medroxyprogesterone acetate (5 and 10 mg/day, respectively). Mean weight varied from 2.7 ± 0.27 to 3.1 ± 0.20 kg (P = 0.38) between groups at the beginning and 3.1 ± 0.27 to 3.5 ± 0.20 kg (P = 0.35) at the end of the experiment. Cholesterol and triglyceride levels were determined at the time of oophorectomy, 21 days after surgery (time 0), and at the end of follow-up of 90 days. The planimetric method was used to measure plaque and caryometric method for histopathologic examination of the aorta. Calcium content was determined by the method of von Kossa. A similar increase in cholesterol occurred in all treated groups without differences between them at the end of the study. Groups G4 and G5 had smaller areas of atherosclerotic lesions (2.33 ± 2.8 and 2.45 ± 2.1 cm², respectively) than the groups receiving no progestogens (G2: 5.6 ± 4 and G3: 4.6 ± 2.8 cm²; P = 0.02). The relation between lesion area and total aorta area was smaller in groups treated with combined drugs compared to the groups receiving no progesterone (G4: 14.9 ± 13 and G5: 14.2 ± 13.4 vs G2: 35.8 ± 26 and G3: 25 ± 8 cm², respectively; P = 0.017). Oral conjugated equine estrogen (0.625 mg/day) plus medroxyprogesterone acetate (5 or 10 mg/day) provoked a greater reduction in atherosclerotic plaque area and calcium content in treated groups, suggesting a dose-dependent effect.

Avaliação de reserva de fluxo coronariano e miocárdico pela ecodopplercardiografia transtorácica e ecocardiografia com contraste miocárdico em pacientes com lesão na artéria coronária descendente anterior / Detection of left anterior descending coronary artery obstruction by real time myocardial contrast echocardiography with adenosine. A head to head comparison with transthoracic doppler

Embora a ecocardiografia com perfusão miocárdica em tempo real (EPTR) permita detectar doença arterial coronária (DAC), sua correlação com reserva de fluxo coronário (RFC) obtida pelo estudo Doppler não foi demonstrada. Objetivo: Comparar a RFC obtida pela EPTR e pelo Doppler no território da artéria coronária descendente anterior (ADA) em pacientes com suspeita de DAC. Métodos: Avaliamos prospectivamente 44 pacientes (18 homens, 57 +- 13 anos) com EPTR em repouso e durante infusão de adenosi na 140 mcg/kg/min. Quantificação do pico de intensidade miocárdica (A), velocidade das microbolha (B) e RFC pela EPTR foi realizada utilizando software específico (Q-lab-Philip Medical Systems).A RFC foi obtida pelo Doppler como a relação entre a velocidade de pico diastólica durante hiperemia e no estado basal. Todos os pacientes foram submetidos à angiografia quantitativa dentro de 7 dias. Valores de 1,7 e 2,4 de RFC pela EPTR e pelo Doppler foram utilizados para identificação DAC (estenoses >50 por cento) na ADA. Resultados: A exeqüibilidade foi de 84 por cento para aquisição adequada dos fluxos Doppler da ADA e 86 por cento para a quantificação da reserva de fluxo pela EPTR. A sensibilidade e a especificidade e acurácia para de detecção de obstrução coronariana ou não no território da ADA baseado nas análises de reservas de fluxo foram respectivamente de 96 por cento,87 por cento e 93 por cento para o Doppler da ADA, de 94 por cento, 86 por cento e 89 por cento para o índice de fluxo miocárdico (AxB) e de 75 por cento, 81 por cento e 77 por cento para a velocidade de fluxo miocárdico (B). Pela análise de regressão logística, o estudo com Doppler da ADA foi o parâmetro que melhor diferenciou os pacientes com e sem lesão na ADA (Odds Ratio 0,01 - intervalo de confiança de 95 por cento de 0,001 a 0,136).Conclusão: A avaliação da RFC e miocárdio, tanto pelo Doppler da ADA quanto pela EPTR foram capazes de diferenciar precisamente os indivíduos com lesão na ADA. No entanto, a acurácia diagnóstica pelo Doppler da ADA foi superior aos outros parâmetros analisados.

Temperature, air pollution, and mortality from myocardial infarction in São Paulo, Brazil

An increase in daily mortality from myocardial infarction has been observed in association with meteorological factors and air pollution in several cities in the world, mainly in the northern hemisphere. The objective of the present study was to analyze the independent effects of environmental variables on daily counts of death from myocardial infarction in a subtropical region in South America. We used the robust Poisson regression to investigate associations between weather (temperature, humidity and barometric pressure), air pollution (sulfur dioxide, carbon monoxide, and inhalable particulate), and the daily death counts attributed to myocardial infarction in the city of São Paulo in Brazil, where 12,007 fatal events were observed from 1996 to 1998. The model was adjusted in a linear fashion for relative humidity and day-of-week, while nonparametric smoothing factors were used for seasonal trend and temperature. We found a significant association of daily temperature with deaths due to myocardial infarction (P < 0.001), with the lowest mortality being observed at temperatures between 21.6 and 22.6ºC. Relative humidity appeared to exert a protective effect. Sulfur dioxide concentrations correlated linearly with myocardial infarction deaths, increasing the number of fatal events by 3.4 percent (relative risk of 1.03; 95 percent confidence interval = 1.02-1.05) for each 10 µg/m increase. In conclusion, this study provides evidence of important associations between daily temperature and air pollution and mortality from myocardial infarction in a subtropical region, even after a comprehensive control for confounding factors.

Antagonism of the acute hemodynamic effects of captopril in decompensated congestive heart failure by aspirin administration

The concomitant use of angiotensin-converting enzyme inhibitors and aspirin may cause pharmacological antagonism. Hence we examined the effect of aspirin on the neurohormonal function and hemodynamic response to captopril in heart failure patients. Between April 1999 and August 2000, 40 patients were randomized into four equal groups: 1) captopril, 2) aspirin, 3) captopril-aspirin: captopril was given alone on the first day, followed by aspirin on the remaining days, and 4) aspirin-captopril: aspirin was given alone on the first day, followed by captopril on the remaining days. Hemodynamic, norepinephrine and prostaglandin measurements were performed pre- and post-medication for 4 days. Captopril (50 mg) was given orally every 8 h and 300 mg aspirin was given on the first day, and 100 mg/day thereafter. In the captopril group and only on the first day of captopril-aspirin, captopril produced increases in cardiac index (2.1 + or - 0.6 to 2.5 + or - 0.5 l min-1 m-2, P<0.0001), and reduced peripheral vascular resistance (1980 + or - 580 to 1545 + or - 506 dyn s-1 cm-5/m2, P<0.0001) and pulmonary wedge pressure (20 + or - 4 to 15 + or - 4 mmHg, P<0.0001). In contrast, aspirin alone or associated with captopril showed no significant hemodynamic changes. Norepinephrine decreased (P<0.02) only in the captopril group. Prostaglandin levels did not differ significantly among groups. Thus, aspirin compromises the short-term hemodynamic and neurohormonal effects of captopril in patients with acute decompensated heart failure

Etofibrate but not controlled-release niacin decreases LDL cholesterol and lipoprotein (a) in type IIb dyslipidemic subjects

Etofibrate is a hybrid drug which combines niacin with clofibrate. After contact with plasma hydrolases, both constituents are gradually released in a controlled-release manner. In this study, we compared the effects of etofibrate and controlled-release niacin on lipid profile and plasma lipoprotein (a) (Lp(a)) levels of patients with triglyceride levels of 200 to 400 mg/dl, total cholesterol above 240 mg/dl and Lp(a) above 40 mg/dl. These patients were randomly assigned to a double-blind 16-week treatment period with etofibrate (500 mg twice daily, N = 14) or niacin (500 mg twice daily, N = 11). In both treatment groups total cholesterol, VLDL cholesterol and triglycerides were equally reduced and high-density lipoprotein cholesterol was increased. Etofibrate, but not niacin, reduced Lp(a) by 26 percent and low-density lipoprotein (LDL) cholesterol by 23 percent. The hybrid compound etofibrate produced a more effective reduction in plasma LDL cholesterol and Lp(a) levels than controlled-release niacin in type IIb dyslipidemic subjects

Detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured atherosclerotic plaques

This paper reports what is apparently the first observation of Mycoplasma pneumoniae in association with Chlamydia pneumoniae in thrombosed ruptured atheromas. We performed electron microscopy and in situ hybridization in specimens from three patients who died of acute myocardial infarction. These patients had typical symptoms of acute ischemic syndrome. Mycoplasmas were present mainly in the lipid core of the ruptured thrombosed plaque. Vulnerable atheromas are rich in cholesterol and may favor the growth of mycoplasmas, the only microorganisms that require cholesterol for survival. We suggest that the association of Mycoplasma pneumoniae and Chlamydia pneumoniae may increase the virulence of these microorganisms, favoring proliferation, plaque inflammation and possibly plaque rupture

Pharmacokinetics and pharmacodynamics of propranolol in hypertensive patients after sublingual administration: systemic availability

The bioavailability of propranolol depends on the degree of liver metabolism. Orally but not intravenously administered propranolol is heavily metabolized. In the present study we assessed the pharmacokinetics and pharmacodynamics of sublingual propranolol. Fourteen severely hypertensive patients (diastolic blood pressure (DBP) =115 mmHg), aged 40 to 66 years, were randomly chosen to receive a single dose of 40 mg propranolol hydrochloride by sublingual or peroral administration. Systolic (SBP) and diastolic (DBP) blood pressures, heart rate (HR) for pharmacodynamics and blood samples for noncompartmental pharmacokinetics were obtained at baseline and at 10,20,30,60 and 120 min after the single dose. Significant reductions in BP and HR were obtained, but differences in these parameters were not observed when sublingual and peroral administrations were compared as follows: SBP (17 vs 18 percent, P=NS), DBP (14 vs 8 percent, P=NS) and HR (22 vs 28 percent, P=NS), respectively. The pharmacokinetic parameters obtained after sublingual or peroral drug administration were: peak plasma concentration (CMAX): 147 + 72 vs 41 + 12 nl/ml, P<0.05; time to reach CMAX (TMAX): 34 + 18 vs 52 + 11 min, P<0.05; biological hall-life (t1/2b): 0.91 + 0.54 vs 2.41 + 1.16 h, P<0.05; area under the curve (AUCT): 245 + 134 vs 79 + 54 ng h(-1) ml(-1), P<0.05; total body clearance (CLT/F):44 + 23 vs 26 + 12 ml min(-1) kg(-1), P=NS. Systemic availability measured by the AUCT ratio indicates that extension of bioavailability was increased 3 times by the sublingual route. Mouth paresthesia was the main adverse effect observed after sublingual administration. Sublingual propranolol administration showed a better pharmacokinetic profile and this route of administration may be an alternative for intravenous or oral administration.

Efeito da cirurgia de revascularizaçäo miocárdica sobre os episódios isquêmicos assintomáticos / Effect of coronary artery bypass graft surgery on ischemic asymptomatic episodes

OBJETIVO - Avaliar o efeito da cirurgia de revascularizaçäo miocárdica (CRM) sobre episódios isquêmicos assintomáticos (EIA). MÉTODOS - Foram estudados 28 homens, com angina estável (idade média 57,3ñ9,6) anos sem condiçöes relacionadas a alteraçöes de microcirculaçäo e que, após retirada da medicaçäo, apresentaram EIA à eletrocardiografia ambulatorial (ECGA). No pré-operatório e 4 meses após a cirurgia foram analisados os comportamentos dos EIA, segundo sua freqüência, e o de suas freqüências cardíacas (FC). A revascularizaçäo miocárdica foi completa em 75 'por cento' dos casos. RESULTADOS - O número dos EIA foi reduzido de 162 (9 sintomáticos) no pré-operatório para, apenas, 4 no pós-operatório (p<0,05). Nos dois pacientes com EIA no operatório, estudo cinecoronariográfico confirmou obstruçäo de enxertos aortocoronários. A análise das FC no início e pico dos EIA sugeriram envolvimento de mecanismo de reduçÝo de oferta e aumento de consumo de oxigênio pelo miocárdio. CONCLUSÄO - A CRM eliminou os episódio isquêmicos relacionados ou näo ao aumento da FC. Quando os EIA encontram-se presentes após CRM, devemos considerar a possibilidade de oclusäo de enxerto.

Apolipoprotein and lipid abnormalities in chronic liver failure

Total serum lipids, as well as apolipoproteins A-I (apo A-I) and B (apo B), were determined in 74 patients with chronic liver failure without cholestasis and in 82 normal subjects. The VLDL, LDL and HDL lipid fractions were reduced in the liver failure group by 36 percent, 24 percent and 46 percent, respectively (P<0.001). Apolipoproteins A-I and B were also reduced by 26 percent and 25 percent, respectively (P<0.001). However, the reduction of HDL cholesterol (HDLc) was more pronounced than that of apo A-I and HDLc:apo A-I ratio was significantly lower in the liver failure group. After separating these patients into groups with plasma albumin lower than 3.0, between 3.0 and 3.5, and higher than 3.5 g/dl, the HDLc:apo A-I ratio was proportional to plasma albumin, but the correlation was not statistically significant. When these patients were separated by the Child classification of liver function, there was a correlation between the HDLc:apo A-I ratio and liver function. The differences in the HDLc:apo A-I ratio between the Child groups B and C, and A and C were statistically significant (P<0.05). We conclude that there is a more pronounced reduction in HDL cholesterol than in apo A-I in liver failure patients. Therefore, the HDLc:apo A-I ratio is a marker of liver function, probably because there is a decreased lecithin-cholesterol acyltransferase production by the diseased liver.

Tratamento medicamentoso da doença arterial coronária estável em centros de atendimento primário e terciário / Clinical therapheutics for stable coronary artery disease. Differences between primary and tertiary medical care centers

OBJETIVO - Observar a distribuição das drogas em pacientes com doença arterial coronária (DAC) estável, em centros de atendimento (CA) primário e terciário. MÉTODOS - Foram analisados, 300 pacientes, consecutivos, no ambulatório do Grupo de Coronariopatias do INCOR com diagnóstico de DAC, idades entre 31 a 80 (58,5ñ8,0) anos, sendo 205 (68 por cento) do sexo masculino e 95 (32 por cento) do feminino e estudadas as características clínicas e hemodinâmicas. Avaliaram-se as drogas utilizadas, inicialmente, nos CA primários (comunitários) e, posteriormente, no CA terciário. RESULTADOS - As drogas mais utilizadas nos CA primários foram os ß-bloqueadores (50 por cento dos pacientes), nitratos (48 por cento), bloqueadores dos canais de cálcio (46 por cento), ácido acetil-salicílico (44 por cento), diuréticos (30 por cento) e os inibidores da enzima de conversão de angiotensina (ECA), em 11 'por cento' dos pacientes. No CA terciário as drogas mais utilizadas foram o ácido acetil-salicílico (76 por cento dos casos), nitratos (55 por cento), diuréticos (49 por cento), inibidores da ECA (42 por cento), os antagonistas dos canais de cálcio (37 por cento ) e os betabloqueadores (35 por cento dos pacientes). Os ß-bloqueadores foram mais prescritos em CA primário, p=0,02, já os inibidores da ECA, p<0,0001, o ácido acetil-salicílico, p<0,0001 e os diuréticos, p=0,002, foram mais prescritos no CA terciário. CONCLUSÄO - O tratamento farmacológico preconizado para a DAC estável deve ser otimizado em ambos os CA, dando prioridade às drogas que modificam a história natural da doença, como os betabloqueadores, antiagregantes plaquetários, e os inibidores da ECA nos pacientes com disfunção ventricular esquerda.

Slow coronary run-off in patients with angina pectoris: clinical significance and thallium-201 scintigraphic study

To determine whether or not slow coronary flow (SF) depends on hemodynamic variables, we studied 17 patients (15 men, mean age = 47.8 years) with SF at coronariography. Exercise thallium-201 myocardial scintigraphy revealed perfusion abnormalities in 13 (76.4 per cent) patients. We then selected 89 individuais submitted to cinecoronariography for comparison: 15 were normal and 74 had heart disease. The coronary flow velocity was evaluated by the number of heart beats (HB) needed for coronary artery dye filling. The patients in the SF group had normal hemodynamic variables which were significantly different from those of patients with heart disease (P = 0.001). Patients with heart disease needed no more than 4 HB to fill their arteries, in contrast to 6.88 ñ 1.68 (5 to 11) in the SF group (P<0.OOO1). Thus, in our patients with myocardial scintigraphy suggesting ischemia, SF was found to be an event which did not depend on hemodynamic factors.

Beneficial effect of long-term use of a beta-blocker in patients before acute myocardial infarction

The outcome of 38 beta-blocker users (group BB, 28 men and 10 women with a mean age of 56 ñ 4 years) was compared to that of 100 non-users (group NU, 69 men and 31 women with mean age of 57 ñ 8 years) after acute myocardial infarction (AMI). The two groups were compared in terms of electrocardiographic (EKG) location of the AMI (anterior, inferior and lateral), EKG Q and non-Q wave infarction, clincial functional class of Forrester, serum cratine phosphokinase MB fraction (CKMB) peak release and intrahospital mortality.There were no differences between groups concerning sex or severity of coronary artery disease bath arterial hypertension was 3-fold more prevalent group BB. The EKG location of the AMI was similar int he two groups. Non-Q infarction was significantly more prevalent in group BB (37 percent) than in group NU (5 percent). The incidence of clinical functional class IV of Forrester and the serum CKMB peaks were significantly lower in goup BB (2.6 percent vs 16.0 percent and 53 ñ 3 vs 68 ñ 9 UI/1, respectively. Intrahospital mortality was also significantly lower in group BB (2.6 percent) than in group NU (10 percent). These data suggest the beneficial effect of previous long-term use of beta-blockers as indicated by a lower incidence of cardiogenic shock and a significant decrease in intrahospital mortality after AMI

Acute effects of dobutamine and dopamine on renal and respiratory functions in patients on prolonged mechanical ventilation

Its is known that positive pressure mechanical ventilation (PPMV) decreases diuresis and increases extravascular water, thereby impairing pulmonary gas exhange. Sympathomimetic amines are commonly used to relieve these effects. To compare the effects of dobutamine (DT) and dopamine (DP) on renal and pulmonary function, we studied 30 patients submitted to continuous PPMV for a least 72 h. All were in stable hemodynamic conditions.patients had pulmonary insufficiency of different etiology. The drugs were randomly administered by continuous intravenous infusion at the dose of 4 to 6 *g kg-1 min-1 for 3 h. An interval of 60 min was allowed to elapse between treatments. A significant increases in arterial pressure and heart rate occurred with both drugs (P,0.05). DP increased urinary flow by 93.7% (1.6ñ0.1 to 3.1 ñ0.4 ml/min; P,0.05) and Na excretion fraction (NaEF) by 35.5% (P,0.05).In contrast, DT reduced NaEF by 58.9%(P,0.05) and had effect on urinary flow. Neither drug altered cretinine clearance.The alveolo-arterial O2 difference (a-aO2D), which was 370ñ20 mmHg during the control period, increased to 394 ñ 20 mmHg after DP and decreased to 355 ñ 22 mmHg after DT, the difference being statistically significant (P,0.05). Pulmonary shunt (%) and the venous pO2 (mmHg) did not change during the infusion of DP or DT.In conclusion, an acute increase in salt and water excretion does not necessarily lead to an immediate reduction in pulmonary "shunt". DT deserves further investigation since it may increase paO2 in the absence of ventricular failure