Test design – Graz, cable car and Dachstein.

<p>Test design – Graz, cable car and Dachstein.</p

Absolute values of pulse oximetry (Graz vs. Dachstein).

<p>Absolute values of pulse oximetry (Graz vs. Dachstein).</p

Differences of biometrical data (HR, sBP, dBP and BRS) measured during the first period of rest R1.

<p>Differences of biometrical data (HR, sBP, dBP and BRS) measured during the first period of rest R1.</p

Analysis of differences between study locations, kind of stress and the interaction of study location*kind of stress (two factor repeated measurement ANOVA).

<p>Analysis of differences between study locations, kind of stress and the interaction of study location*kind of stress (two factor repeated measurement ANOVA).</p

Biometric data of the participants.

<p>Biometric data of the participants.</p

Intertwin correlation of average diameter, compliance and distensibility for monozygotic and ditzygotic twins in the sitting and in the supine positions without and with a 60 mmHg controlled Valsalva attempt.

<p>At right the significance levels of the correlation coefficients are shown (valid for monozygotes, n = 40, but almost identical for dizygotes, n = 42). Note higher correlation values for monozygotic twins (hinting for genetic factors). Note limited correlation of values sitting (measured at lower initial pressure).</p

Age and sex adjusted parameter estimates for additive hereditary (A), common environment (C) and unique environmental influences (E) of compliance, distensibility and full distension range (values averaged for both sides) by structural equation modeling.

<p>Age and sex adjusted parameter estimates for additive hereditary (A), common environment (C) and unique environmental influences (E) of compliance, distensibility and full distension range (values averaged for both sides) by structural equation modeling.</p

Baseline characteristics of study subjects.

<p>Baseline characteristics of study subjects.</p

Age and sex adjusted parameter estimates for additive hereditary (A), common environment (C) and unique environmental influences (E) of mean internal jugular vein diameter by structural equation modeling.

<p>Age and sex adjusted parameter estimates for additive hereditary (A), common environment (C) and unique environmental influences (E) of mean internal jugular vein diameter by structural equation modeling.</p

Heritability of the dimensions, compliance and distensibility of the human internal jugular vein wall - Fig 1

<p>Inner jugular vein diameters measured ultrasonographically in monozygotic (a) and dizygotic (b) A and B twins, in the sitting and in the supine body position, without and with a controlled 60 mmHg Valsalva. Antero-posterior and lateral diameters were averaged for the left and right sides for each person. Note very close mean values for two members of the twin pairs in both groups. Distensibilities computed for monozygotic (c) and dizygotic (d) A and B twins. Distensibilities for the left and right inner jugular veins measured between 0–60 mmHg Valsalva were averaged for each person.</p