Disfunção endotelial venosa em pacientes com doença de Chagas sem insuficiência cardíaca / Venous endothelial dysfunction in Chagas' disease patients without heart failure

OBJETIVO: Analisar a função endotelial venosa em pacientes chagásicos sem insuficiência cardíaca. MÉTODOS: O grupo Chagas (G1) foi composto por quatorze mulheres e dois homens com idade de 46 ± 2,7 anos, e o grupo controle (G0), por sete mulheres e um homem, pareados em idade, peso, altura. A Técnica de Complacência da Veia Dorsal da Mão foi utilizada para avaliação da função endotelial venosa. Foram infundidas doses crescentes de fenilefrina para se obter pré-constrição de 70 por cento do basal; a seguir, foram administradas acetilcolina e nitroprussiato de sódio para avaliar as respostas de venodilatação, respectivamente, dependentes e independentes do endotélio. RESULTADOS: Não houve variação entre os valores hemodinâmicos nos grupos durante o experimento. A dose média de fenilefrina necessária para pré-constrição da veia foi significativamente maior no G1 (1116 ± 668,2 ng/ml), comparada à do G0 (103 ± 28 ng/ml) p = 0,05. A resposta de venodilatação máxima dependente do endotélio foi significativamente menor no grupo G1 (65,5 ± 8 por cento), comparada à do G0 (137 ± 20 por cento) p = 0,009. Não houve diferença nas respostas de venodilatação independente do endotélio entre os grupos. CONCLUSÃO: Pacientes com doença de Chagas sem insuficiência cardíaca apresentam disfunção endotelial venosa.

Papel da pressão arterial casual e do exercício e a influência de fatores clínicos sobre a hipertrofia ventricular esquerda na hipertensäo arterial / Role of Resting and Exercising Blood Pressure and Importance of Clinical Factors on Hypertensive Left Ventricular Hypertrop

PURPOSE--To evaluate the role of casual and exercise blood pressure as well as the importance of clinical factors on the presence and degree of left ventricular hypertrophy in hypertension. METHODS--Fifteen normotensives (control group) and 30 hypertensives, 14 of them with and 16 without left ventricular hypertrophy (groups with LVH and without LVH, respectively) were studied. LVH diagnosis was established when mass index was higher than 2 standard-deviations of the mean values calculated for each sex in control group. Resting, casual determined, and bicycle exercise systolic and diastolic blood pressures along with age, body surface area, sex and race distribution were compared between groups. In addiction, their relation with mass index as independent variables were also tested. RESULTS--Hypertensives in group with LVH had higher diastolic septal, posterior wall, and relative wall thicknesses. No significant statistical difference was observed neither in sex and race distribution, nor in age and body surface area between groups. Otherwise, there were significant differences in both resting and exercise blood pressure. In the entire population studied, left ventricular mass index significantly correlated with age (r=0,33, p=0,03) as well as with both casual (systolic - r=0,72, p=0,0001; diastolic - r=0,69, p=0,0001) and exercise (systolic - r=0,62, p=0,0001; diastolic - r=0,66, p=0,0001) blood pressures. However, linear regression analysis demonstrated that only resting systolic (p=0,0001) and exercise diastolic (p=0,0303) blood pressures were significant and independent determinants of mass index. CONCLUSION--Resting and exercising blood pressures are the main determinants of left ventricular hypertrophy in hypertension

Hipertensão arterial e arritmias ventriculares complexas: evoluçäo após tratamento de longo prazo da pressäo arterial / Hypertension and complex ventricular arrhythmias: evolution following a long-term blood pressure treatment

PURPOSE--To evaluate the effects of long-term antihypertensive treatment in the frequency as well as in the complexity of ventricular arrhythmias in arterial hypertension. METHODS--Twenty three patients, 14 males and 11 whites, with mean age of 46 years, were submitted to 24 hours ambulatory electrocardiographic monitoring and echocardiographic studies before and 9 months after antihypertensive treatment. RESULTS--There was no significant serum potassium level alteration, but significant reductions of both systolic (from 192 +/- 29mmHg to 161 +/- 25mmHg) and diastolic (from 122 +/- 17mmHg to 99 +/- 16mmHg) blood pressure. Left ventricular percent of fiber shortening significantly increased, even though only from 26 +/- 9 per cent to 30 +/- 9 per cent, and end-systolic wall stress did not change at all (before 258 +/- 94 10(3) dyn/cm2, after 255 +/- 101 10(3) dyn/cm2). Left ventricular mass index showed significant but also a discrete reduction from 211 +/- 75g/m2 to 196 +/- 70g/m2. Ambulatory electrocardiographic monitoring did not show any significant decrease in neither ventricular ectopic beats nor in couplets. Non-sustained ventricular tachycardia episodes remained unchanged too. Four out of 8 patients with more than 30 ventricular ectopic beats per hour reduced it by more than 70 per cent. On the other hand, the number of patients with couplets was reduced from 10 to 8 whilst those with non-sustained ventricular tachycardia increased from 5 to 7. Furthermore, in 7 patients reevaluated 24 months thereafter results were not expressively dissimilar. CONCLUSION--In hypertensive patients with either severe degree of left ventricular hypertrophy or myocardial dysfunction, long-term blood pressure treatment that produce no impressive changes in these abnormalities also do not modify complex ventricular arrhythmias, in spite of a great reduction in the increase blood pressure