Reflex and mechanical circulatory effects of graded Valsalva maneuvers in normal man

Pi, Korner; Tonkin, A.; Uther, John B.

doi:10.1152/jappl.1976.40.3.434

Cited by 180 publications

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“…3 There are four phases to the Valsalva manoeuvre. 4 Phase 1, the initiation of Valsalva, creates a rise in arterial pressure as blood is squeezed from the thoracic aorta. In phase 2, the raised intrathoracic pressure reduces venous return via the vena cava causing a fall in mean arterial pressure (mAP), but still remaining higher than the resting mAP because a reflex tachycardia and peripheral vasoconstriction limits the fall in mAP.…”

Section: Discussionmentioning

confidence: 99%

Pulsatile ocular blood flow: the effect of the Valsalva manoeuvre in open angle and normal tension glaucoma: a case report and prospective study

Khan

Hughes²,

Tom³

et al. 2002

British Journal of Ophthalmology

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Aim: A case of severe normal tension glaucoma is reported in a trumpet player, along with a study investigating the association between glaucoma and raised intrathoracic pressure, using measurements of pulsatile ocular blood flow (POBF). Methods: Three patient groups were studied; normals (n = 34), untreated primary open angle glaucoma (POAG) (n = 20), and untreated normal tension glaucoma (NTG) (n = 22), with a total of 76 patients who underwent measurements of POBF using the OBF pneumotonometer at rest and while forcibly exhaling through a mouthpiece connected to a mercury manometer (30 mm Hg) (Valsalva manoeuvre). Results: POBF fell during Valsalva in all groups with the greatest predictor being the resting value of POBF. There was no evidence of significant differences in the mean change in POBF occurring during the Valsalva manoeuvre for the three groups studied before or after adjusting for the sex, the resting POBF, and the resting IOP of the patients (p = 0.294 and p = 0.542, respectively). However, statistically significant associations were found between the change in POBF and sex (p = 0.049), resting POBF (p<0.0001) and resting IOP (p = 0.032). Males had a greater drop, on average, in POBF during Valsalva manoeuvre than females after adjusting for the other factors. Additionally, there was a significant difference in the mean change in IOP during Valsalva for the three groups (p = 0.002), with the difference occurring between the normal and POAG groups (p<0.005). The POAG group had, on average, a drop in IOP during Valsalva, while the other two groups had an increase in IOP. Also noted was a significant difference in the distributions of the risk factors among the three groups (p = 0.002). Conclusions: This study demonstrates no difference between groups with respect to resting or Valsalva POBF, but does demonstrate a possible trend with respect to IOP, with a drop in IOP occurring during Valsalva in the POAG group. There is, however, much variability in the data left unexplained by our models. Thus, unfortunately, we cannot advise our trumpet player whether his NTG is directly related to his trumpet playing.A 60 year old man presented with optic disc cupping, and visual field defects (right eye; vertical cup:disc ratio 0.4, mean defect −3.55 dB, left eye; vertical cup:disc ratio 0.7 with an inferior notch, mean defect −16.26 dB). Intraocular pressures were 17 mm Hg in each eye and mean resting pulsatile ocular blood flow (POBF) at rest was right eye 947 µl/min; left eye 812 µl/min. He reported that he was a professional trumpet player and inquired whether he could continue playing for 5 hours each day. While trumpet blowing the following single readings were obtained, right eye 515 µl/min; left eye 849 µl/min.The playing of high resistance wind instruments such as the trumpet involves expiration against resistance, mimicking the Valsalva manoeuvre. We designed this study to investigate the effect of the Valsalva manoeuvre upon POBF in normal patients, and untreated patients with primary open angle gl...

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Section: Discussionmentioning

confidence: 99%

Pulsatile ocular blood flow: the effect of the Valsalva manoeuvre in open angle and normal tension glaucoma: a case report and prospective study

Khan

Hughes²,

Tom³

et al. 2002

British Journal of Ophthalmology

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“…Skin blood flow was measured during a 30-s interval before each VM (baseline) and the last 5 s of the VM; the latter corresponds to the late phase II (phase IIb) of the VM (17,19,22). Data during this phase of the VM were analyzed because of sustained decreases in arterial blood pressure after ganglionic blockade (24).…”

Section: Subjectsmentioning

confidence: 99%

Evidence of a myogenic response in vasomotor control of forearm and palm cutaneous microcirculations

Durand

Zhang²,

Cui

et al. 2004

Journal of Applied Physiology

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Evidence of a myogenic response in vasomotor control of forearm and palm cutaneous microcirculations. J Appl Physiol 97: 535-539, 2004. First published April 16, 2004 10.1152/japplphysiol.01299.2003.-Previous investigations of autoregulatory mechanisms in the control of skin blood flow suffer from the possibility of interfering effects of the autonomic nervous system. To address this question, in 11 subjects cutaneous vascular responses were measured during acute changes in perfusion pressure (using Valsalva maneuver; VM) before and after ganglionic blockade via systemic trimethaphan infusion. Cutaneous vascular conductance at baseline (CVC base) and during the last 5 s of the VM (CVC VM) were measured from forearm (nonglabrous) and palm (glabrous) skin. During the VM without ganglionic blockade, compared with CVCbase, CVCVM decreased significantly at the palm [0.79 Ϯ 0.17 to 0.55 Ϯ 0.17 arbitrary units (AU)/mmHg; P ϭ 0.002] but was unchanged at the forearm (0.13 Ϯ 0.02 to 0.16 Ϯ 0.02 AU/mmHg; P ϭ 0.50). After ganglionic blockade, VM induced pronounced decreases in perfusion pressure, which resulted in significant increases in CVC VM at both forearm (0.19 Ϯ 0.03 to 0.31 Ϯ 0.07 AU/mmHg; P ϭ 0.008) and palm (1.84 Ϯ 0.29 to 2.76 Ϯ 0.63 AU/mmHg; P ϭ 0.003) sites. These results suggest that, devoid of autonomic control, both glabrous and nonglabrous skin are capable of exhibiting vasomotor autoregulation during pronounced reductions in perfusion pressure. autoregulation; skin blood flow; Valsalva maneuver CUTANEOUS TISSUE HAS RELATIVELY low metabolic requirements, and control of skin blood flow is primary influenced by thermal factors (e.g., local and internal temperatures). Skin blood flow can also be modulated by nonneurally mediated events, one of which may be vascular cutaneous autoregulation. Vascular autoregulation serves to maintain blood flow and nutrient supply when perfusion pressure is altered. In addition, autoregulatory responses attenuate large changes in capillary pressure that otherwise would occur during changes in perfusion pressure (15).Cutaneous blood flow during normothermic conditions is in excess of that required to provide for its metabolic demand. Given this, the requirement to autoregulate blood flow through this vascular bed during relatively small changes in perfusion pressure would be less critical relative to other vascular beds. Such a response is likely advantageous given that precise autoregulation of cutaneous vasculature would oppose thermally induced cutaneous vasoconstriction and vasodilation, which are necessary to maintain temperature homeostasis (21).The venoarteriolar response is an example of a vascular autoregulatory mechanism that has been identified and widely investigated in human skin (3,7,9,13,23). However, the stimulus for this response is a change in venous pressure regardless of whether perfusion pressure changes or remains constant. This response also requires an intact local neural network (3,7,10,13,23), which is in contrast to traditional myogenic vascular autor...

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“…1,2 One circumstance that has been studied extensively is the Valsalva maneuver (VM), defined as a forced expiratory blow against a closed glottis. 1,3 Valsalva maneuvers are performed both voluntarily and involuntarily during daily life under many conditions such as coughing, defecation, and heavy weightlifting.…”

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confidence: 99%

“…5,6 Under experimental conditions, phasic changes in blood pressure (BP) and other cardiovascular variables during the VM have been well characterized to examine the integrity of autonomic function. 2,7 However, owing to the relative inaccessibility of the cerebral circulation and the limitations in technology for the measurement of cerebral blood flow (CBF) with high temporal resolution, changes in cerebral hemodynamics during the VM have rarely been studied.…”

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confidence: 99%

Cerebral Hemodynamics During the Valsalva Maneuver

Zhang

Crandall

Levine

2004

Stroke

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Background and Purpose-The aim of this study was to differentiate the mechanical effects of the Valsalva maneuver (VM) from the effects of changes in autonomic neural activity on cerebral hemodynamics in humans. Methods-Nine healthy subjects performed the VM before and after autonomic ganglionic blockade with trimethaphan.Blood pressure (BP) was measured in the radial artery with an indwelling catheter or at the finger by Finapres. Cerebral blood flow (CBF) velocity was measured in the middle cerebral artery with transcranial Doppler; end-tidal CO 2 was measured by mass spectrometry. Results-Before blockade, during phase II of the VM, BP was reduced by 27% and CBF velocity was reduced by 33%(magnitude of changes during phase II divided by baseline measurements before the VM, PϽ0.05). Cerebrovascular conductance index (CVCI) increased by 21%. During phase IV, overshoot of CBF velocity was proportionately greater than that of BP (46% versus 30%). After blockade, during phase II, BP fell to a much greater degree by 50%, while CBF velocity decreased even more by 60% associated with an increase in CVCI by 33%. During phase IV, despite the absence of BP overshoot, CBF velocity still increased by 55% and CVCI by 33%. Both were significantly greater than before blockade. Conclusions-After ganglionic blockade, cerebral autoregulation is unable to prevent the substantial fall in CBF induced by the marked reduction in BP during the VM. Enhanced phase IV increases in both CBF velocity and CVCI reflect the intrinsic characteristics of cerebral hyperemic responses, which are likely modified in part by the removal of vasoconstrictor effects of autonomic neural activity elicited during the VM.

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Reflex and mechanical circulatory effects of graded Valsalva maneuvers in normal man

Cited by 180 publications

References 0 publications

Pulsatile ocular blood flow: the effect of the Valsalva manoeuvre in open angle and normal tension glaucoma: a case report and prospective study

Pulsatile ocular blood flow: the effect of the Valsalva manoeuvre in open angle and normal tension glaucoma: a case report and prospective study

Evidence of a myogenic response in vasomotor control of forearm and palm cutaneous microcirculations

Cerebral Hemodynamics During the Valsalva Maneuver

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