Dynamic deformation characteristics of porcine aortic valve leaflet under normal and hypertensive conditions

Choon Hwai Yap, Hee Sun Kim, Kartik Balachandran, Michael Weiler, Rami Haj-Ali, Ajit P. Yoganathan

Research output: Contribution to journalArticlepeer-review

54 Scopus citations

Abstract

Calcific aortic valve (AV) disease has a high prevalence in the United States, and hypertension is correlated to early onset of the disease. The cause of the disease is poorly understood, although biological and remodeling responses to mechanical forces, such as membrane tension, have been hypothesized to play a role. The mechanical behavior of the native AV has, therefore, been the focus of many recent studies. In the present study, the dynamic deformation characteristics of the AV leaflet and the effects of hypertension on leaflet deformation are quantified. Whole porcine aortic roots were trimmed and mounted in an in vitro pulsatile flow loop and subjected to normal (80/120 mmHg), hypertensive (120/160 mmHg), or severe hypertensive (150/190 mmHg) conditions. Local valve leaflet deformations were calculated with dual-camera photogrammetry method: by tracking the motion of markers placed on the AV leaflets in three dimensions and calculating their spatial deformations. The results demonstrate that, first, during diastole, high transvalvular pressure induces a stretch waveform which plateaus over the diastolic duration in both circumferential and radial directions. During systole, the leaflet stretches in the radial direction due to forward flow drag forces but compresses in the circumferential direction in a manner in agreement with Poisson's effect. Second, average diastolic and systolic stretch ratios were quantified in the radial and circumferential directions in the base and belly region of the leaflet, and diastolic stretch was found to increase with increasing pressure conditions.

Original languageEnglish
Pages (from-to)H395-H405
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume298
Issue number2
DOIs
StatePublished - 2010

Keywords

  • Dual-camera photogrammetry
  • Dynamic strain
  • Dynamic stretch
  • Hypertension

Fingerprint

Dive into the research topics of 'Dynamic deformation characteristics of porcine aortic valve leaflet under normal and hypertensive conditions'. Together they form a unique fingerprint.

Cite this