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Research Papers

Modeling Pathological Hemodynamic Responses to the Valsalva Maneuver

[+] Author and Article Information
Leszek Pstras

Nalecz Institute of Biocybernetics and
Biomedical Engineering,
Polish Academy of Sciences,
Ks. Trojdena 4,
Warsaw 02-109, Poland
e-mail: leszek.pstras@ibib.waw.pl

Karl Thomaseth

Institute of Electronics, Computer and
Telecommunication Engineering,
National Research Council,
c/o University of Padova (DEI),
Via G. Gradenigo 6/b,
Padova 35131, Italy
e-mail: karl.thomaseth@ieiit.cnr.it

Jacek Waniewski

Nalecz Institute of Biocybernetics and
Biomedical Engineering,
Polish Academy of Sciences,
Ks. Trojdena 4,
Warsaw 02-109, Poland
e-mail: jacek.waniewski@ibib.waw.pl

Italo Balzani

Department of Medicine,
Sant'Antonio Hospital,
Via Jacopo Facciolati 71,
Padova 35127, Italy
e-mail: italo.balzani@sanita.padova.it

Federico Bellavere

Rizzola Foundation Hospital,
Via Gorizia 1,
San Donà di Piave (Venezia) 30027, Italy
e-mail: bellavere@rizzola.it

1Corresponding author.

Manuscript received April 24, 2016; final manuscript received March 3, 2017; published online April 17, 2017. Assoc. Editor: C. Alberto Figueroa.

J Biomech Eng 139(6), 061001 (Apr 17, 2017) (9 pages) Paper No: BIO-16-1171; doi: 10.1115/1.4036258 History: Received April 24, 2016; Revised March 03, 2017

The Valsalva maneuver (VM) consisting in a forced expiration against closed airways is one of the most popular clinical tests of the autonomic nervous system function. When properly performed by a healthy subject, it features four characteristic phases of arterial blood pressure (BP) and heart rate (HR) variations, based on the magnitude of which the autonomic function may be assessed qualitatively and quantitatively. In patients with some disorders or in healthy patients subject to specific conditions, the pattern of BP and HR changes during the execution of the Valsalva maneuver may, however, differ from the typical sinusoidal-like pattern. Several types of such abnormal responses are well known and correspond to specific physiological conditions. In this paper, we use our earlier mathematical model of the cardiovascular response to the Valsalva maneuver to show that such pathological responses may be simulated by changing individual model parameters with a clear physiological meaning. The simulation results confirm the adaptability of our model and its usefulness for diagnostic or educational purposes.

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References

Figures

Grahic Jump Location
Fig. 1

Mean arterial blood pressure (MAP) and HR during a 40 mm Hg Valsalva maneuver. (a) and (b) Simulations performed with the original model for the reference patient with all model parameters fixed at their basal values; and (c) and (d) clinical data from a 71 yr old male with normal autonomic function.

Grahic Jump Location
Fig. 2

Electric analogy of the cardiovascular model, where R denotes resistances; P, pressures; C, capacities; and qr and ql, cardiac outputs from right and left heart ventricles, respectively. The meaning of subscripts is: aor, aorta; sa, systemic arteries; sc, systemic capillaries; sv, systemic veins; vc, vena cavae; pa, pulmonary arteries; pv, pulmonary veins; rh, right heart; lh, left heart; ra, right atrium; la, left atrium; and th, intrathoracic. Reproduced with permission from Pstras et al. [21]. Copyright 2016 by Oxford University Press.

Grahic Jump Location
Fig. 3

Mean arterial blood pressure (MAP) and heart rate (HR) during a 40 mm Hg Valsalva maneuver. (a) and (b) Simulations for the reference patient performed with the original model (dotted lines) and with the model adjusted to represent a subject with a heart failure (solid lines); and (c) and (d) clinical data from the literature (mean values from a group of ten men with left ventricular failure) [24].

Grahic Jump Location
Fig. 4

Right ventricular (dashed lines) and left ventricular (dotted lines) stroke volume as a function of atrial pressure in a normal heart (thin lines) and a failing heart (thick lines). The dots represent the steady-state conditions.

Grahic Jump Location
Fig. 5

Mean arterial blood pressure (MAP) and heart rate (HR) during a 40 mm Hg Valsalva maneuver. (a) and (b) Simulations for the reference patient performed with the original model (dotted lines) and with the model adjusted to represent partial autonomic dysfunction (solid lines); and (c) and (d) clinical data from a 79 yr old male with postural instability.

Grahic Jump Location
Fig. 6

Mean arterial blood pressure (MAP) and heart rate (HR) during a 40 mm Hg Valsalva maneuver. (a) and (b) Simulations for the reference patient performed with the original model (dotted lines) and with the model adjusted to represent a subject with α-adrenergic failure (solid lines); and (c) and (d) clinical data from a 69 yr old male with a sensory ataxia and fragile X syndrome.

Grahic Jump Location
Fig. 7

Mean arterial blood pressure (MAP) and HR during a 40 mm Hg Valsalva maneuver. (a) and (b) Simulations for the reference patient performed with the original model (dotted lines) and with the model adjusted to represent vagal withdrawal and reduced baroreflex sensitivity (solid lines); and (c) and (d) clinical data from a 75 yr old male with chronic obstructive pulmonary disease.

Grahic Jump Location
Fig. 8

Mean arterial blood pressure (MAP) and HR during a 40 mm Hg Valsalva maneuver. (a) and (b) Simulations for the reference patient performed with the original model (dotted lines) and with the model adjusted to represent a full autonomic dysfunction (solid lines); and (c) and (d) clinical data from a 61 yr old female with diabetic autonomic neuropathy.

Grahic Jump Location
Fig. 9

Mean arterial blood pressure (MAP) and HR during a 40 mm Hg Valsalva maneuver. (a) and (b) Simulations for the reference patient performed with the original model (dotted lines) and with the model adjusted to represent a low-compliant aorta and a partial baroreflex impairment (solid lines); and (c) and (d) clinical data from a 75 yr old male with an ascending aorta prosthesis and chronic obstructive pulmonary disease.

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