[Hemodynamic effects of low doses of chlorthalidone in patients with mild systemic arterial hypertension]. / Efeitos hemodinâmicos de baixas doses de clortalidona em pacientes com hipertensão arterial sistêmica leve.

ABSTRACT

PURPOSE: To evaluate the hemodynamic effects of low doses of chlorthalidone (CHT) in patients with systemic arterial hypertension (SAH). METHODS: Eight patients with mild SAH, mean age of 52 +/- 8.9 years, 7 men, were studied. Clinical evaluation, systolic (SBP) and diastolic (DBP) blood pressure and heart rate (HR), in supine and standing positions, were obtained before and every two weeks, first two in placebo, during 12 weeks. Laboratory data, hemogram, sodium, potassium, urea, creatinine, glucose, hepatic aminotransferases and urinalysis, were done and at end of study. Hemodynamic monitorization was performed by Swan-Ganz catheter in pulmonary artery to obtain RAP and PAWP, in mmHg. Cardiac output (CO) was obtained by thermodilution method. Systemic vascular resistance (SVR) arose from variables above. Hemodynamic variables were measured at 2nd and 12th weeks during treatment with 50mg of chlorthalidone each 48 h. RESULTS: A significant reduction of SBP (p = 0.005 and p = 0.003), DBP (p < 0.0001 and p < 0.0001), respectively in supine and standing positions. HR did not show statistical difference. At hemodynamic monitoring was observed a significative reduction of SVR (p < 0.02), but not with CO. CONCLUSION: Chlorthalidone in low dosis was effective to treat mild SAH, basically by lowering SVR.