The cardiovascular applications group in the Rollins research group currently includes three graduate students (Fleming, Jenkins, Peterson), one post-doctoral researcher, and two undergraduate researchers (Jenkins and Tsai). The cardiovascular applications groups collaborates with investigators at Case School of Medicine (Dr. Michiko Watanabe), the Cleveland Clinic Foundation (Dr. Yuanna Cheng), Washington University (Dr. Igor Efimov), and MetroHealth Medical Center (Dr. Kara Quan). These investigators are experts in developmental cardiology and cardiac electrophysiology.
Research Projects
OCT Imaging of the Embryonic Heart
Abnormalities that occur during cardiac looping in the early embryo are responsible for congenital heart disease. To date researchers have had to rely upon bioassays, video microscopy and mathematical models to investigate the mechanisms underlying development during looping. Direct observation of looping has been problematic due to the diminutive size (< 2 mm) of the heart and the inability to measure the small and rapid events that influence heart development. Optical coherence tomography (OCT) is a noninvasive imaging tool with the spatiotemporal resolution and field of view to observe both structure and function during the critical time period of looping. Using OCT technology, preload, afterload, and effects of blood flow on the morphological and mechanical changes that occur throughout the looping process can be examined more closely and serve as a baseline for future work that will define environmental, genetic and mechanical factors that impinge on the developing heart and can result in congenital defects.
Imaging Arrhythmogenic Tissue
The structure of the myocardium is important to both electrical conduction and mechanical contractility. Due to the anisotropic nature of myocytes, cell-to-cell coupling and fiber orientation (alignment of myocytes) directly influence the wavefront propagation, force generation and efficiency of contraction. Abnormal fiber orientation caused by a disease such as infarction or hypertrophic cardiomyopathy is a substrate for arrhythmia that may result in sudden cardiac death.
We have developed an automated algorithm for quantifying fiber orientation parallel to the surface within intact heart preparations.
OCT Imaging of Cardiac Ablation
Catheter ablation using radiofrequency (RF) energy is commonly used as a non-pharmacological strategy in clinical electrophysiology to destroy or block abnormal conduction pathways to treat cardiac arrhythmias. However, there is no mechanism to visualize lesion formation. RF ablation therapy is a standard of care and would benefit significantly from a high-resolution, real-time, image-based monitoring technology. We have shown that thermal lesions produced by both RF and High Intensity Focused Ultrasound (HIFU) appear highly scattering (‘white’) within OCT images. Ablation lesions are readily distinguished from viable tissue.
Cardiovascular Application References
Jenkins, M., R.S. Wade, Y. Cheng, A.M. Rollins, and I.R. Efimov, Optical Coherence Tomography Imaging of the Purkinje Network. JCE, 2005. 16(5): p. 559-560.
Jenkins, M.W., F. Rothenberg, D. Roy, V. Nikolski, D.L. Wilson, I.R. Efimov, and A.M. Rollins. 4D optical coherence tomography of the embryonic heart using gated reconstruction. in BiOS, Photonics West, SPIE. 2005. San Jose, CA.
Ford, M., Y. Zhou, H. Wang, C.X. Deng, and A.M. Rollins. Conference Presentation : Optical Coherence Tomography monitoring of cardiac ablation by high intensity focused ultra sound. in SPIE. 2005. San Jose.
Huprikar, N., M.W. Jenkins, Y. Cheng, and A.M. Rollins. Imaging of Myocardial Infarcts using OCT. in BMES National Conference. 2004. Philadelphia, PA.
Gupta, M., A. Rollins, J. Izatt, and I. Efimov, Imaging of the atrioventricular node using optical coherence tomography. J Cardiovasc Electrophysiol, 2002. 13: p. 95.
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