Individual differences in the cardiovascular responses to tonic muscle pain: parallel increases or decreases in muscle sympathetic nerve activity, blood pressure and heart rate

Abstract

We recently showed that acute muscle pain, induced by bolus intramuscular injection of hypertonic saline, causes a sustained increase in muscle sympathetic nerve activity (MSNA) and a modest increase in blood pressure and heart rate. However, it is not known whether longlasting (tonic) pain, which more closely resembles chronic pain, causes a sustained increase in MSNA and blood pressure. We tested this hypothesis by recording MSNA in 12 healthy subjects. Tonic pain was induced for ∼60 min by slow intramuscular infusion of hypertonic saline (7%) into the ipsilateral tibialis anterior muscle. Pain was sustained at a tolerable level (5/10 to 6/10 on a visual analog scale). Seven subjects showed progressive increases in mean MSNA amplitude during tonic pain, increasing to 154 ± 17% (SEM) at 45 min and remaining essentially constant for the duration of the infusion. In these subjects, blood pressure and heart rate also increased. Conversely, for the other five subjects MSNA showed a progressive decline, with a peak fall of 67 ± 11% at 40 min; blood pressure and heart rate also fell in these subjects. We conclude that tonic muscle pain has long-lasting effects on the sympathetic control of blood pressure, causing a sustained increase in some subjects yet a sustained decrease in others. This may have implications for individual differences in the cardiovascular consequences of chronic pain.

Assessment of cardiac sympathovagal activity in the patients suffering from ankylosing spondylitis

“…The autonomic nervous system governs the cardiovascular system and this fact has resulted to various studies showing relations between autonomic dysfunction and chronic pain. [9,10] Since any alterations in the autonomic nervous system bring about the changes in the cardiovascular parameters such as BP and HR, therefore, VM and TTT were performed in this study to evaluate the autonomic reactivity. The increase in HR during exercise is due to the activation of the sympathetic nervous system with simultaneous suppression of the parasympathetic nervous system.…”

“…The autonomic nervous system governs the cardiovascular system and this principle has led to various studies showing relations between autonomic dysfunctions and chronic pain. [9,10] Since any alterations in the autonomic nervous system bring about the changes in the cardiovascular parameters such as blood pressure (BP) and HR, therefore, Valsalva maneuver (VM) and tilt-table test (TTT) were performed to evaluate the cardiac sympathovagal activities in the patients suffering from the AS.…”

Assessment of heart rate variability in the patients suffering with chronic pain of musculoskeletal origin

“…Since then a lot of work has been done in identifying correlations between HRV and chronic pain. [18,[22][23][24] Studies indicate that the involvement of the ANS at both the systemic and local levels is an important element of the pathogenesis of chronic musculoskeletal pain. It is also hypothesized that the treatment of chronic musculoskeletal disorders will improve the ANS balance which in turn will improve the cardiovascular functions.…”

“…Although some studies have been done on the association between chronic pain and autonomic changes, [18] the same study has not been done in the population of Eastern Uttar Pradesh, India, so for best of our knowledge is concern. Therefore, this study was conducted to evaluate the changes in the HRV of the male cases versus male controls and female cases versus female controls to understand the effects of chronic pain on the autonomic responses.…”

Os receptores TRPV₁ do córtex pré-frontal medial ventral modulam a atividade do barorreflexo cardíaco em ratos

“…Estes receptores são capazes de aumentar o disparo de tais neurônios durante processos inflamatórios e dolorosos, como na osteoartrite (Holzer, 1988, Han et al, 2012.O CPFMv, entre outras estruturas do SNC, além de modular a atividade cardiovascular (Resstel et al, 2004), está envolvido nas respostas cognitivas e emocionais relacionadas à dor, bem como na percepção da dor (Mohr et al, 2005, Wiech et al, 2006, sendo que a expressão dos receptores TRPV1 está aumentada no IL e PL em camundongos submetidos a um modelo de dor neuropática (Giordano et al, 2011). Estímulos dolorosos podem modificar a atividade do sistema nervoso simpático, resultando em alterações da PA, FC e fluxo sanguíneo, revelando a existência de um componente cardiovascular na resposta à dor (Fazalbhoy et al, 2012 …”