Brachial Artery Elastic Mechanics in Patients With Heart Failure

Abstract

Abstract-Studies of arterial elasticity in patients with heart failure (HF) have produced varying results. In addition, the direct effects of smooth muscle relaxation on arterial wall mechanics in these patients have not been well characterized. Nineteen patients with New York Heart Association class II to IV HF and 17 age-and size-matched normal subjects were studied by using a recently validated technique for measuring brachial arterial wall mechanics over a wide pressure range. The left brachial artery was imaged through a water-filled blood pressure cuff by use of an ultrasound wall-tracking system at baseline and after 0.4 mg sublingual nitroglycerin (NTG). Simultaneous radial artery pressure waveforms were recorded by tonometry. Transmural pressure (TP) was reduced by increasing water pressure in the cuff. Baseline area, compliance, and pulse wave velocity versus TP curves were similar in the normal subjects and the patients with HF. The incremental elastic modulus versus TP curve tended to be lower in the patients with HF. The wall-to-lumen ratio was increased in HF (Pϭ0.05). NTG significantly shifted the area versus TP (PϽ0.001) and compliance versus TP (PϽ0.05) curves upward and the pulse wave velocity versus TP (PϽ0.05) curve downward in both groups. NTG also significantly (PϽ0.001) shifted the stress versus strain curve to the right in both groups but did not alter the incremental elastic modulus versus TP curve. We conclude that the brachial arterial wall-to-lumen ratio is increased in HF. This finding occurs together with a trend toward reduced arterial stiffness such that overall mechanical behavior of the brachial artery is preserved. Smooth muscle relaxation with NTG produces similar improvements in brachial arterial wall mechanics in normal subjects and in patients with HF.

Renal Advances in Ultrasound Elasticity Imaging: Measuring the Compliance of Arteries and Kidneys in End-Stage Renal Disease

“…Both in vivo measurements presented in this study, as well as a large body of previous literature [4,16,19,31] , suggest that the nonlinear change in arterial elastic modulus with changing transmural pressures can be modeled as an exponential function. The reconstructed elastic moduli were fi t to a straight line assuming a purely exponential model; i.e., E = E o e ␣ , where ␣ is a dimensionless constant describing the degree of nonlinearity.…”

“…Arterial pathologies are often associated with decreased compliance [14,17] . In previous reports on arterial elasticity over a wide range of intraluminal pressures [18,19] , the compliance was inferred from geometric changes such as artery diameter and lumen cross-section based on a numerical model [20] . However, the precision of speckle tracking offers the possibility of being able to detect subtle underlying structural changes within the vascular wall and measure the corresponding intramural changes in elastic properties with unprecedented resolution, precision and accuracy [21] .…”

Flow Characteristics in Elastic Arteries Using a Fluid-Structure Interaction Model

“…The flow waveform obtained from experimental data with applications of long wavelength approximation theory. [20,23,[36][37][38] . The FSI modeling results showed a good agreement with published data.…”

Impaired brachial artery endothelium-dependent and -independent vasodilation in men with erectile dysfunction and no other clinical cardiovascular disease

“…Arterial diameter was recorded over time, as previously shown (23,24). Endothelium-dependent, flow-mediated vasodilation (FMD) was produced by releasing a blood pressure tourniquet around the wrist, which was inflated for 5 min at a pressure of 250 mm Hg (25,26).…”