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Evaluating diastolic function in children remains a topic of clinical discussion and a gold standard measurement technique is still lacking. Wave intensity analysis can provide insight into ventricular filling mechanisms and ventriculo-vascular coupling, and it can be derived directly from cardiovascular magnetic resonance (CMR) imaging data, specifically from routine phase-contrast flow acquisitions, by defining wave intensity in terms of simultaneous changes of velocity and fractional changes of area. This method was applied to a group of 53 cases (12 healthy controls, 12 congenital aortic stenosis, 11 hypertrophic cardiomyopathy, 8 restrictive cardiomyopathy, 10 dilated cardiomyopathy). All patients also had full CMR and echocardiographic examinations. A new wave intensity parameter FCW/FEW was defined (=ratio of peak forward compression wave in early systole, typically associated with ventricular dP/dt, and peak forward expansion wave at end systole, associated with diastolic time constant τ) and compared with accepted indicators of diastolic dysfunction, i.e. left atrium area from CMR, E/A ratio, E/E’ ratio and E-wave deceleration time (DT) from echo. Differences between cohorts were firstly appreciated in terms of ejection fraction and aortic distensibility. Receiver operating characteristic (ROC) curves then revealed that FCW/FEW, LA area and E/E’ ratio were overall good, statistically significant discriminators between controls and patients with presumed compromised diastolic function, while E/A and DT failed to differentiate (Fig. 1, Table 1). This study proposes CMR-derived wave intensity analysis as an additional medium to non-invasively investigate diastolic function in children, contributing to a point of on-going clinical debate. Parameter AUC p Value FCW/FEW 0.881

Background: It is widely believed that changes in the magnitude and timing of reflected waves reaching the heart result in deleterious cardiovascular effects. Inherent in this is the assumption that waves propagate well in the backward direction. There is limited information regarding retrograde travel of the reflected wave from an imposed occlusion. We investigated this. Methods: In this study, 20 subjects (age 31–83 years), underwent invasive measurement of pressure & Doppler velocity with sensor-tipped intra-arterial wires placed in the aorta, iliac artery and femoral artery. An external cuff was inflated to occlude one femoral artery, creating a site of total reflection and the effect of this assessed. Separated wave intensity analysis was used to identify and quantify incident and reflected waves. Wave reflection index (WRI) expresses the backward compression wave as a percentage of the incident forward compression wave. Results: The additional reflection (evident by statistically significant increase in WRI and earlier arrival of the reflected wave) generated in the femoral artery by femoral occlusion was not visible in the proximal aorta. Furthermore, the reflected wave in the proximal aorta occurred in systole in all subjects, much earlier than is widely proposed. Conclusion: A reflection arising from an occlusion is wholly attenuated by the time it reaches the proximal aorta. This lack of retrograde travel could account for the limited reflection in the proximal aorta and prompts review of our understanding of the mechanisms underlying blood pressure augmentation.

It has been reported that augmentation index (AIx) increases with age, but that the increase is more prominent in younger subjects [1], and may even decrease with age in individuals over 50yrs [2]. We undertook a meta-analysis of the published literature of 9,551 individuals (5,659 male), aged 4 to 91 years (mean 54.2 years) and undertook meta-regression to further investigate the relationship of AIx with age. AIx increased with age (0.51 (0.41, 0.61) %/yr; coefficient (95% CI); adjusted r2=59.97%; p

Background: The Valsalva manoeuvre (VM) is a physiological manoeuvre capable of generating profound changes in venous return. Although its physiology has been extensively described, the predominant focus has been on dynamic effects on cardiac preload with subsequent impact on cardiac output. However, analysis of the dramatic changes seen in arterial pressure and flow during this manoeuvre offers valuable insight into arterial function. Methods: In 11 patients (9male, mean age 64 years), invasive measurement of pressure & Doppler flow velocity were made in the proximal aorta using sensor-tipped intra-arterial wires. Whilst recording, patients performed a controlled VM by blowing into a syringe. Calculation of pressure, aortic reservoir function and wave intensity were performed offline. Results: Peak systolic blood pressure fell on average by 24% during sustained VM (157±43mmHg to 122±48mmHg, p