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Augmentation index assessed by applanation tonometry is elevated in Marfan Syndrome.

Payne RA, Hilling-Smith RC, Webb DJ, Maxwell SR, Denvir MA - J Cardiothorac Surg (2007)

Bottom Line: PP was not associated with aortic root size.However, when an independent GTF was used to derive carotid waves from radial waves, no differences were found in the degree of error between MFS and controls.Differences between MFS and controls in the nature of the peripheral-to-central GTF are present, although have little effect on the pulse contour.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK. r.payne@ed.ac.uk

ABSTRACT

Background: To examine whether augmentation index (AIx) is increased in Marfan syndrome (MFS) and associated with increased aortic root size, and whether a peripheral-to-central generalised transfer function (GTF) can be applied usefully in MFS.

Methods: 10 MFS patients and 10 healthy controls (matched for sex, age and height) were studied before and after 400 microg sub-lingual GTN. Arterial waveforms were recorded using applanation tonometry. AIx and pulse pressure (PP) were determined for the radial and carotid arteries. Pulse wave velocity (PWV) was measured between carotid and femoral arteries. GTFs were generated to examine the relationship between radial and carotid waveforms.

Results: AIx was greater in MFS compared to controls at radial (mean -31.4 (SD 14.3)% v -50.2(15.6)%, p = 0.003) and carotid (-7.6(11.2)% v -23.7(12.7)%, p = 0.004) sites. Baseline PP at all measurement sites, and PWV, did not differ between subject groups. Multivariate analysis demonstrated that PWV and carotid AIx were positively correlated with aortic root size (p < 0.001 and p = 0.012 respectively), independent of the presence of MFS. PP was not associated with aortic root size. GTN caused similar decreases in AIx in both controls and patients. Significant differences were found in GTFs between MFS and control subjects, which changed following GTN administration. However, when an independent GTF was used to derive carotid waves from radial waves, no differences were found in the degree of error between MFS and controls.

Conclusion: AIx is sensitive to the vascular abnormalities present in MFS, and may have a role as an adjunct to measurement of central PP and PWV. Differences between MFS and controls in the nature of the peripheral-to-central GTF are present, although have little effect on the pulse contour.

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Correlation between aortic root size and haemodynamic measures. Black circles, Marfan syndrome patients; white circles, controls. Aortic root measurements are those at sinus of Valsalva, not adjusted for body surface area. AIx, augmentation index.
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Figure 1: Correlation between aortic root size and haemodynamic measures. Black circles, Marfan syndrome patients; white circles, controls. Aortic root measurements are those at sinus of Valsalva, not adjusted for body surface area. AIx, augmentation index.

Mentions: Baseline haemodynamic parameters (Table 2) demonstrated no differences in resting heart rate, brachial systolic or diastolic blood pressure, or mean arterial pressure. Baseline brachial and carotid pulse pressure were not different between the two groups. dP/dtMAX was not found to be significantly different between controls and MFS subjects when measured at either the carotid (p = 0.10) or radial artery (p = 0.27). Multivariate analysis was performed to ascertain the principal determinants of carotid AIx and PWV (Table 3). MFS was the strongest independent determinant of variation in carotid AIx, followed by age and height. Age and mean arterial pressure were the strongest independent determinants of PWV, although the presence of MFS nonetheless had an independent (albeit weak) association. Multivariate analysis revealed that both aortic PWV and baseline carotid AIx were positively correlated with aortic root size (Table 3, Figure 1), independent of the presence or absence of MFS, although this was not evident if aortic root size was corrected for body surface area. Age, sex, mean arterial pressure and carotid pulse pressure were not significantly associated with aortic root size.


Augmentation index assessed by applanation tonometry is elevated in Marfan Syndrome.

Payne RA, Hilling-Smith RC, Webb DJ, Maxwell SR, Denvir MA - J Cardiothorac Surg (2007)

Correlation between aortic root size and haemodynamic measures. Black circles, Marfan syndrome patients; white circles, controls. Aortic root measurements are those at sinus of Valsalva, not adjusted for body surface area. AIx, augmentation index.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2169245&req=5

Figure 1: Correlation between aortic root size and haemodynamic measures. Black circles, Marfan syndrome patients; white circles, controls. Aortic root measurements are those at sinus of Valsalva, not adjusted for body surface area. AIx, augmentation index.
Mentions: Baseline haemodynamic parameters (Table 2) demonstrated no differences in resting heart rate, brachial systolic or diastolic blood pressure, or mean arterial pressure. Baseline brachial and carotid pulse pressure were not different between the two groups. dP/dtMAX was not found to be significantly different between controls and MFS subjects when measured at either the carotid (p = 0.10) or radial artery (p = 0.27). Multivariate analysis was performed to ascertain the principal determinants of carotid AIx and PWV (Table 3). MFS was the strongest independent determinant of variation in carotid AIx, followed by age and height. Age and mean arterial pressure were the strongest independent determinants of PWV, although the presence of MFS nonetheless had an independent (albeit weak) association. Multivariate analysis revealed that both aortic PWV and baseline carotid AIx were positively correlated with aortic root size (Table 3, Figure 1), independent of the presence or absence of MFS, although this was not evident if aortic root size was corrected for body surface area. Age, sex, mean arterial pressure and carotid pulse pressure were not significantly associated with aortic root size.

Bottom Line: PP was not associated with aortic root size.However, when an independent GTF was used to derive carotid waves from radial waves, no differences were found in the degree of error between MFS and controls.Differences between MFS and controls in the nature of the peripheral-to-central GTF are present, although have little effect on the pulse contour.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK. r.payne@ed.ac.uk

ABSTRACT

Background: To examine whether augmentation index (AIx) is increased in Marfan syndrome (MFS) and associated with increased aortic root size, and whether a peripheral-to-central generalised transfer function (GTF) can be applied usefully in MFS.

Methods: 10 MFS patients and 10 healthy controls (matched for sex, age and height) were studied before and after 400 microg sub-lingual GTN. Arterial waveforms were recorded using applanation tonometry. AIx and pulse pressure (PP) were determined for the radial and carotid arteries. Pulse wave velocity (PWV) was measured between carotid and femoral arteries. GTFs were generated to examine the relationship between radial and carotid waveforms.

Results: AIx was greater in MFS compared to controls at radial (mean -31.4 (SD 14.3)% v -50.2(15.6)%, p = 0.003) and carotid (-7.6(11.2)% v -23.7(12.7)%, p = 0.004) sites. Baseline PP at all measurement sites, and PWV, did not differ between subject groups. Multivariate analysis demonstrated that PWV and carotid AIx were positively correlated with aortic root size (p < 0.001 and p = 0.012 respectively), independent of the presence of MFS. PP was not associated with aortic root size. GTN caused similar decreases in AIx in both controls and patients. Significant differences were found in GTFs between MFS and control subjects, which changed following GTN administration. However, when an independent GTF was used to derive carotid waves from radial waves, no differences were found in the degree of error between MFS and controls.

Conclusion: AIx is sensitive to the vascular abnormalities present in MFS, and may have a role as an adjunct to measurement of central PP and PWV. Differences between MFS and controls in the nature of the peripheral-to-central GTF are present, although have little effect on the pulse contour.

Show MeSH
Related in: MedlinePlus