Goff, Ryan Patrick2014-07-072014-07-072014-04https://hdl.handle.net/11299/163755University of Minnesota Ph.D. dissertation. April 2014. Major: Biomedical Engineering. Advisor: Paul Anthony Iaizzo. 1 computer file (PDF); xiii, 177 pages.Atrial fibrillation (AF) remains as the most prevalent tachyarrhythmia, with a prevalence in the U.S., of 1% in the general population. The current therapeutic/treatment paradigm for the patient with atrial fibrillation, is to first attempt to restore normal rhythm via anti-arrhythmic pharmaceuticals. If this does not ameliorate the problem, or the patient does not well tolerate the drug side-effects, a transcatheter ablation is usually performed. The relatively recent introduction of cryoballoon based ablation has provided the electrophysiologist with an easier method of treating AF via pulmonary vein isolation. However, despite current clinical use research questions regarding anatomy, dosing, and device-tissue interactions have remained unanswered.Anatomical studies of the phrenic nerve, coronary sinus, left atria, and pulmonary vein anatomy were performed using high-resolution MRI and direct measurements on heart specimens. These novel anatomical studies may guide future device iterations and the computer based models used for numerical simulation. The amount of cooling required to injure and/or kill cardiac tissue, lung tissue, and the phrenic nerve was quantified using novel in-vitro models. These data may be used for procedural modeling and dosing optimization. Device-tissue interactions were studied using a functional, isolated heart-lung bloc model and a patent has been filed for this methodology. Using this model infrared imaging was performed to quantify the level of cooling being achieved by cryoballoon catheters. A separate study was performed using MRI to quantify ice dynamics and to our knowledge is the first cardiac cryoablation performed in an MR environment. This collection of work will aid the clinical, scientific, and engineering communities in further optimization of cardiac cryoablation.en-USAtrial FibrillationCardiac AblationCardiac anatomyCryoablationCryoballoonThermal InjuryThesis or Dissertation