RESUMEN
Intravascular volumes and systemic and regional hemodynamic variables were measured before and after weight reduction in 12 patients with obesity and essential hypertension. These findings were compared with those in nine patients who did not have any weight loss. Reduction of mean arterial pressure significantly correlated with the fall in total body weight (r = 0.46, p less than 0.05). Total circulating and cardiopulmonary blood volumes were significantly reduced (p less than 0.05 and p less than 0.01, respectively), and these changes permitted a decreased venous return and cardiac output (p less than 0.01). This fall in cardiac output was directly related to a contracted total blood volume (r = 0.49, p less than 0.05) and decreased cardiopulmonary blood volume (r = 0.52, p less than 0.05). Patients who did not lose weight showed no changes in any of these hemodynamic measurements. In addition, weight loss was associated with reduced resting circulating levels of plasma norepinephrine (p less than 0.01), suggesting that diminished adrenergic function may also be related to weight reduction and its associated fall in arterial pressure.
Asunto(s)
Peso Corporal , Hemodinámica , Hipertensión/etiología , Obesidad/complicaciones , Presión Sanguínea , Dieta Reductora , Dieta Hiposódica , Femenino , Humanos , Hipertensión/fisiopatología , Hipertensión/terapia , Masculino , Norepinefrina/sangre , Obesidad/sangre , Obesidad/dietoterapia , Obesidad/fisiopatología , Renina/sangre , Ácido Úrico/sangreRESUMEN
Rebound hypertension occurred in two patients upon clonidine withdrawal. Treatment of the hypertensive crisis consists of both alpha- and beta-adrenergic receptor blockade, reserpine, or the reintroduction of clonidine. With effective control of pressure during the crisis, long-term antihypertensive therapy must be resumed.
Asunto(s)
Clonidina , Hipertensión/etiología , Síndrome de Abstinencia a Sustancias , Adulto , Anciano , Clonidina/administración & dosificación , Clonidina/uso terapéutico , Femenino , Humanos , Hipertensión/tratamiento farmacológico , MasculinoRESUMEN
The positive, preoperative recognition of a pressor kidney has many important ramifications, the most important being the ability to predict a reduction in blood pressure following surgical reconstruction or nephrectomy. One hundred forty hypertensive patients were selected for study for renal artery stenosis by measuring the differential plasma renin activity by either radioimmunoassay or bioassay. Bilateral renal vein renin determinations and renal arteriography were made consecutively in supine position and without stimulation of renin secretion. Unilateral or bilateral renal artery stenosis was found in 55 patients (39%). Twenty-eight of the 55 patients (51%) were treated surgically. Eighteen patients (64%) were cured of hypertension and seven (25%) were improved. All but one of the surgically treated patients had renal vein renin ratios of greater than 1.3 on the affected side over the unaffected or less-affected side. Increasing the ratio to greater than 1.5 or greater than 2.0 as a criterion for selection of patients for operation would not have decreased the failure rate. If used as the only criterion, increasing the ratios would have resulted in nonsurgical treatment of up to 50% of the patients cured or improved by surgery. Stimulation of renin secretion, although not used in this study, has been shown by others to more accurately identify a pressor kidney by increasing differential renal vein renin ratios. Although a combination of renin activity with renal plasma flow may lead to more accurate diagnosis, a careful clinical evaluation has not yet been replaced as the best method of selection of the patients for operation.