RESUMO
OBJECTIVE: To determine the effects of exercise training on sympathetic nerve activity in heart failure patients. METHODS: A systematic review was performed. An electronic search of MEDLINE, ProQuest, SciELO, SPORTDiscus, Rehabilitation and Sport Medicine Source, Cumulative Index to Nursing and Allied Health Literature, Tripdatabase, Science Direct and PEDrO was performed from their inception to February 2017. Clinical trials and quasi-experimental studies were considered for primary article selection. The studies should include patients diagnosed with chronic heart failure that performed exercise training for at least 4 weeks. Sympathetic nerve activity should be measured by microneurography before and after the intervention. The Cochrane Collaboration's Risk of Bias Tool was used to evaluate risk of bias, and the quality of evidence was rated following the GRADE approach. Standardized mean differences (SMD) were calculated for control and experimental groups. Meta-analysis was performed using the random effects model. RESULTS: Five trials were included. Overall, the trials had moderate risk of bias. The experimental group indicated a significant decrease in the number of bursts per minute (SMD -2.48; 95% CI -3.55 to -1.41) when compared to the control group. Meanwhile, a significant decrease was also observed in the prevalence of bursts per 100 beats in the experimental group when compared to the control group (SMD -2.66; 95% CI -3.64 to -1.69). CONCLUSION: Exercise training could be effective in reducing sympathetic nerve activity in patients with heart failure. The quality of evidence across the studies was moderate. Future studies are necessary to confirm these results.
Assuntos
Exercício Físico/fisiologia , Insuficiência Cardíaca , Doença Crônica , HumanosRESUMO
La regulación fisiológica de la función vascular es esencial para la salud cardiovascular y depende de un adecuado control de mecanismos moleculares desencadenados por células endoteliales en respuesta a estímulos mecánicos y químicos inducidos por flujo sanguíneo. La disfunción endotelial es uno de los principales factores de riesgo de enfermedad cardiovascular, donde un desequilibrio entre la síntesis de moléculas vasodilatadoras y vasoconstrictoras constituye uno de sus principales mecanismos. En este contexto, el estrés de flujo es uno de los estímulos más importantes para mejorar la función vascular, gracias a que la mecanotransducción endotelial generada por la estimulación de diversos mecanosensores endoteliales induce la generación de estímulos intracelulares que culmina con un incremento en la biodisponibilidad de moléculas vasodilatadoras como el óxido nítrico y, a largo plazo, con la inducción de mecanismos angiogénicos. Estos mecanismos permiten proporcionar el sustento fisiológico a los efectos del ejercicio físico sobre la salud vascular. En la presente revisión se discuten los mecanismos moleculares implicados en la respuesta vascular modulada por estrés de flujo inducido por ejercicio y su impacto en la reversión del daño vascular asociado a las enfermedades cardiovasculares más prevalentes en nuestra población.
The physiological regulation of vascular function is essential for cardiovascular health and depends on adequate control of molecular mechanisms triggered by endothelial cells in response to mechanical and chemical stimuli induced by blood flow. Endothelial dysfunction is one of the major risk factors for cardiovascular disease, where an imbalance between synthesis of vasodilator and vasoconstrictor molecules is one of its main mechanisms. In this context, the shear stress is one of the most important mechanical stimuli to improve vascular function, due to endothelial mechanotransduction, triggered by stimulation of various endothelial mechanosensors, induce signaling pathways culminating in increased bioavailability of vasodilators molecules such as nitric oxide, that finally trigger the angiogenic mechanisms. These mechanisms allow providing the physiological basis for the effects of exercise on vascular health. In this review it is discussed the molecular mechanisms involved in the vascular response induced by shear stress and its impact in reversing vascular injury associated with the most prevalent cardiovascular disease in our population.
Assuntos
Humanos , Doenças Cardiovasculares/fisiopatologia , Exercício Físico/fisiologia , Hemodinâmica , Estresse FisiológicoRESUMO
The physiological regulation of vascular function is essential for cardiovascular health and depends on adequate control of molecular mechanisms triggered by endothelial cells in response to mechanical and chemical stimuli induced by blood flow. Endothelial dysfunction is one of the major risk factors for cardiovascular disease, where an imbalance between synthesis of vasodilator and vasoconstrictor molecules is one of its main mechanisms. In this context, the shear stress is one of the most important mechanical stimuli to improve vascular function, due to endothelial mechanotransduction, triggered by stimulation of various endothelial mechanosensors, induce signaling pathways culminating in increased bioavailability of vasodilators molecules such as nitric oxide, that finally trigger the angiogenic mechanisms. These mechanisms allow providing the physiological basis for the effects of exercise on vascular health. In this review it is discussed the molecular mechanisms involved in the vascular response induced by shear stress and its impact in reversing vascular injury associated with the most prevalent cardiovascular disease in our population.
