BIOMECHANICS OF POSITIVE INTRATHORACIC PRESSURE AND ITS EFFECTS ON LEFT VENTRICULAR FILLING IN HEALTHY SUBJECTS

This study aims to explore the biomechanics of positive intrathoracic pressure and its effects on left ventricle (LV) filling in healthy subjects. 30 healthy subjects were enlisted to perform a Valsalva maneuver (VM) with a load of 40[Formula: see text]mmHg lasted 10[Formula: see text]s. LV filling parameters were measured by echocardiography at rest and at 10[Formula: see text]s during the VM. Compared with the at rest values, LV early inflow velocity (E) decreased significantly ([Formula: see text]), late inflow velocity (A) decreased insignificantly ([Formula: see text]), while the E/A ratio decreased significantly ([Formula: see text]) after 10[Formula: see text]s of the strain phase of the VM. LV septal early tissue velocity ([Formula: see text]) and lateral early tissue velocity ([Formula: see text]) of the mitral did not change ([Formula: see text]), while the [Formula: see text] ratio and the [Formula: see text] ratio decreased significantly ([Formula: see text] after 10[Formula: see text]s during the VM. Based on these results, biomechanical analysis suggests that the effects of positive intrathoracic pressure on the LV free wall impede LV diastolic motion, which may be one of the factors contributing to a decrease in E and the E/A ratio. Positive intrathoracic pressure also increases the flow resistance of the LV and pulmonary vasculature, which may contribute to a decrease in E, the [Formula: see text] ratio, and the [Formula: see text] ratio.

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The Mechanics of Left Ventricular Filling During the Strain Phase of the Valsalva Maneuver in Healthy Subjects

The American Journal of the Medical Sciences ◽

10.1097/maj.0b013e31826af7de ◽

2013 ◽

Vol 346 (3) ◽

pp. 187-189 ◽

Cited By ~ 5

Author(s):

Xiao-Yong Zhang ◽

Tie-Sheng Cao ◽

Li-Jun Yuan

Keyword(s):

Healthy Subjects ◽

Valsalva Maneuver ◽

Left Ventricular ◽

Left Ventricular Filling ◽

Ventricular Filling

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155 Assessment of Valsalva maneuver as a method for evaluation of patients with pseudonormalized left ventricular filling pattern

European Journal of Echocardiography ◽

10.1016/s1525-2167(03)90608-1 ◽

2003 ◽

Vol 4 ◽

pp. S12

Author(s):

S SHALABY ◽

W FARID ◽

A REDA ◽

A ELKERSH

Keyword(s):

Valsalva Maneuver ◽

Left Ventricular ◽

Left Ventricular Filling ◽

Filling Pattern ◽

Ventricular Filling

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P1748 Left atrial diastolic and systolic functions modulate the response to the standardised Valsalva maneuver in normal subjects

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.1107 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

R Musci ◽

G Teodone ◽

P Pollice ◽

A I Guaricci ◽

P Barbier

Keyword(s):

Heart Rate ◽

Healthy Subjects ◽

Left Atrial ◽

Valsalva Maneuver ◽

Velocity Ratio ◽

Normal Subjects ◽

Left Ventricular ◽

Volume Index ◽

Published Data ◽

Minimum Volume

Abstract Background Although the Valsalva maneuver (VM) is being advocated by current guidelines to identify with echocardiography patients with increased left ventricular (LV) filling pressures using a decrease in mitral E/A velocity > 0.5 as cutoff, there are limited published data for both patients and the normal response to the maneuver in healthy subjects. Purpose To assess LV and left atrial (LA) physiology during a standardized VM (VMs) in normal subjects. Methods The VMs was performed in 50 healthy subjects (M:F 38:12; age 40 ± 12 y.; HR 70 ± 11 bpm; BSA 1.81 ± 11 m2), instructed to forcefully exhale for 20 seconds without an initial deep breath into a tube connected to a sphygmomanometer, maintaining a 25-35 mmHg pressure. The VM was repeated 2 times at 5 minute intervals to record sequentially in the apical 4-chamber view: 1. LV and LA volumes; 2. Transmitral flow velocities. LA diastolic reservoir function (LAres) was calculated as: (maximum – minimum volume) / minimum volume x 100. Results. During the VMs, in all subjects LV indexed end-diastolic (-14 ± 7 ml/m2, -31 ± 15 %) and end-systolic (-6 ± 4 ml/m2, -31 ± 18 %) volumes, and stroke volume index (-9 ± 5 ml/m2, -30 ± 15 %) decreased similarly with unchanged LV ejection fraction %, and LA maximum and minimum volume indices both decreased (respectively -8 ± 6 ml/m2, -3 ± 3 ml/m2;-32 ± 25 %) with high variability. Mitral peak E velocity also decreased (-22 ± 13 cm/s, -27 ± 14 %) in all subjects, whereas peak A velocity change varied, such that a "pseudo-abnormal" decrease of E/A > 0.5 was seen in 18 subjects (37 %). At baseline, this subgroup had lower heart rate (66 ± 11 vs 73 ± 10 bpm, p= .026), higher LAres (193 ± 67 vs 145 ± 47 %, p= .006), lower peak A velocity (50 ± 12 vs 58 ± 12 cm/s, p= .04) and higher E/A (1.8±.6 vs 1.4±.3, p= .004). During VMs, LV and LA volumes decreased similarly in all subjects, but increase in heart rate was higher (12 ± 8 vs 6 ± 5 bpm, p= .023), and peak A wave increased instead of decreasing (20 ± 20 % vs -8 ± 18 %, p< .001) in the subjects with "pseudo-abnormal" decrease of E/A. During VMs, decrease in E/A was mainly determined (regression analysis, r: .76, p= .029) by baseline LAres (B= -.71) and change in LAres during VMs (B= -.47), whereas an increase in peak A velocity (r: .46, p= .031) was mainly determined by degree of HR increase (B= .41) and baseline LV EF (B= .3). Conclusions During VMs, a "pseudo-abnormal" decrease of the E/A velocity ratio is present in almost 40 % of normal subjects, and is determined by the interplay of the baseline diastolic compliance and the increase in systolic function of the LA during VM. These results may influence the accuracy of the VMs in the detection of increased LV filling pressures in patients.

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