Data/hora: 10/06/2024 08:24:10

Provedor de dados: | Brazilian Journal of Medical and Biological Research
País: | Brazil
Título: | Pressure and time dependence of the cardiopulmonary reflex response in patients with hypertensive cardiomyopathy
Autores: | Otto,M.E.B.; Consolim-Colombo,F.M.; Rodrigues Sobrinho,C.R.M.; Krieger,E.M.
Data: | 2004-11-01
Ano: | 2004
Palavras-chave: | Baroreflex; Essential hypertension; Heart failure; Cardiopulmonary reflex; Baroreceptors.
Resumo: | The first minutes of the time course of cardiopulmonary reflex control evoked by lower body negative pressure (LBNP) in patients with hypertensive cardiomyopathy have not been investigated in detail. We studied 15 hypertensive patients with left ventricular dysfunction (LVD) and 15 matched normal controls to observe the time course response of the forearm vascular resistance (FVR) during 3 min of LBNP at -10, -15, and -40 mmHg in unloading the cardiopulmonary receptors. Analysis of the average of 3-min intervals of FVR showed a blunted response of the LVD patients at -10 mmHg (P = 0.03), but a similar response in both groups at -15 and -40 mmHg. However, using a minute-to-minute analysis of the FVR at -15 and -40 mmHg, we observed a similar response in both groups at the 1st min, but a marked decrease of FVR in the LVD group at the 3rd min of LBNP at -15 mmHg (P = 0.017), and -40 mmHg (P = 0.004). Plasma norepinephrine levels were analyzed as another neurohumoral measurement of cardiopulmonary receptor response to LBNP, and showed a blunted response in the LVD group at -10 (P = 0.013), -15 (P = 0.032) and -40 mmHg (P = 0.004). We concluded that the cardiopulmonary reflex response in patients with hypertensive cardiomyopathy is blunted at lower levels of LBNP. However, at higher levels, the cardiopulmonary reflex has a normal initial response that decreases progressively with time. As a consequence of the time-dependent response, the cardiopulmonary reflex response should be measured over small intervals of time in clinical studies.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004001100004
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2004001100004
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.37 n.11 2004
Fonte: | info:eu-repo/semantics/openAccess