Eng. sanit. ambient. 329Aval. da qualidade da água e autodepuração do Ribeirão do Meio, Leme (SP) Vol.13 -Nº 3 -jul/set 2008, 329-338

No abstract

Abstract-Normotensive and hypertensive subjects with and without left ventricular (LV) hypertrophy (LV mass index[LVMI] Ͼ51 g/m 2.7 ) were examined by conventional echocardiography and tissue Doppler imaging of mitral annulus motion. The subgroups included nonobese normotensive subjects (nϭ16; age 51Ϯ9 years; 11 female; systolic blood pressure [SBP] 109Ϯ11 mm Hg, body mass index [BMI] 24Ϯ2.7 kg/m 2 ; LVMI 32Ϯ5.5 g/m 2.7 ), nonobese hypertensive subjects without LV hypertrophy (nϭ16; age 54Ϯ12 years; 12 female; SBP 166Ϯ15 mm Hg; BMI 25Ϯ2.7 kg/m 2 ; LVMI 42Ϯ5.5 g/m 2.7 ), and hypertensive subjects with LV hypertrophy (nϭ22; age 56Ϯ10 years; 10 female; SBP 181Ϯ19 mm Hg; BMI 26Ϯ2.3 kg/m 2 ; LVMI 69Ϯ16 g/m 2.7 ). Ejection fraction was comparable among the subgroups, but midwall fractional shortening was reduced in hypertensive subjects with LV hypertrophy (Ϸ26%). Isovolumic relaxation time was increased in subjects with LV hypertrophy, whereas mitral wave A velocity was increased in hypertensive subjects with and without LV hypertrophy. Tissue Doppler imaging mitral annulus systolic (S M ) and diastolic (E M ) velocities were reduced in subjects with and without LV hypertrophy compared with normotensive subjects. There was a positive correlation between S M and E M (rϭ0.68; PϽ0.0001) and negative correlations between these 2 variables and LVMI (S M , rϭϪ0.41; Pϭ0.002; E M , rϭϪ0.56; PϽ0.0001). Thus, reductions in mitral annulus systolic and diastolic velocities parallel increases in LV mass in hypertensive subjects, beginning at LV mass within the clinically defined normal values. The poorer prognosis of hypertensive subjects with major increases in LV mass has been, in part, attributed to myocardial dysfunction, 3,4 but it remains unknown whether hypertensive subjects without clinically defined LV hypertrophy have subtle abnormalities of myocardial function. Echocardiographic indices derived from LV chamber dimensions and Doppler measurements of flow velocities have been used routinely for the assessment of systolic and diastolic function. However, such indices have been proved to be generally nonspecific and insensitive for the detection of minor abnormalities of cardiac relaxation and contraction. [5][6][7][8][9][10][11][12] Tissue Doppler imaging (TDI) has been advocated as a reliable, rapid, and efficient method to assess myocardial function. 13 TDI derived from early systolic and diastolic velocities of the mitral annulus longitudinal motion have been shown to correlate with contractile and relaxing activities of LV subendocardial layers. 14 -17 Several studies have shown the usefulness of TDI mitral annulus motion velocities for the detection of LV subclinical myocardial dysfunction in patients with cardiomyopathy. 18 -21 In hypertensive patients with LV hypertrophy, TDI mitral annulus systolic and diastolic velocities have been shown to be reduced. [22][23][24] However, a comprehensive TDI approach has not been reported in hypertensive subjects without or with minor increases in LV mass. The present study e...

Neste trabalho foram avaliadas as águas fluviais da bacia hidrográfica do córrego São Simão (SP). Para isso, seis pontos de coleta foram estabelecidos e realizaram-se doze coletas de água durante os meses de março, maio, junho, julho, agosto, setembro, outubro, novembro e dezembro de 2005, e janeiro, fevereiro e março de 2006, analisando as seguintes variáveis: vazão, temperatura, turbidez, pH, condutividade, oxigênio dissolvido, alcalinidade, cloreto e sólidos totais em suspensão. A simulação do processo de autodepuração foi realizada com o uso do modelo de Streeter-Phelps, o qual relaciona a variação do déficit de oxigênio dissolvido com o perfil longitudinal do rio. As características do córrego São Simão próximo à sua nascente até a cidade de São Simão permitem concluir que há pouca interferência na sua qualidade. Porém, a falta de tratamento para o esgoto doméstico na cidade de São Simão piora a qualidade da água e intensifica o processo de degradação do córrego São Simão. O modelo de Streeter & Phelps permitiu identificar as zonas de autodepuração do córrego São Simão e indicou a necessidade de tratamento de esgotos em nível primário, com eficiência de 30%. Palavras-chave: Avaliação da qualidade da água; esgotos domésticos; modelagem matemática de autodepuração.