Multimodal functional and still imaging of a transplanted human heart reanimated using Visible Heart® methodologies.

Background: Our research team obtained a human heart with the right lung attached from a recent transplantation patient via a research collaboration with LifeSource, a local organ procurement organization. The heart and lungs were not viable for transplant given the patient's medical history and were subsequently offered to the University of Minnesota for research purposes.

Methods: Using Visible Heart® methodologies, we reanimated the specimen en bloc and collected multimodal direct visualization from inside the cardiac chambers and great vessels of the functioning heart.

Identification of Radiofrequency Ablation Catheter Parameters That May Induce Intracardiac Steam Pops: Direct Visualization of Elicitation in Reanimated Swine Hearts.

Radiofrequency, a common ablation modality, is used clinically to terminate cardiac arrhythmias. With excessive heating, complications sometimes occur when the applied energy generates steam pops, which cause release of energy in the form of tissue and/or air emboli. In this study, we investigated numerous parameters potentially associated with intracardiac steam pops including (1) wattage, (2) catheter tip temperature, (3) catheter irrigation, (4) anatomic site, and (5) repeat ablations at a given site.

Determination of cryothermal injury thresholds in tissues impacted by cardiac cryoablation.

Despite widespread clinical use of cryoablation, there remain questions regarding dosing and treatment times which may affect efficacy and collateral injury. Dosing and treatment times are directly related to the degree of cooling necessary for effective lesion formation. Human and swine atrial, ventricular, and lung tissues were ablated using two cryoablation systems with concurrent infrared thermography.

Testing the Efficacy of Pharmacological Agents in a Pericardial Target Delivery Model in the Swine.

To date, many pharmacological agents used to treat or prevent arrhythmias in open-heart cases create undesired systemic side effects. For example, antiarrhythmic drugs administered intravenously can produce drops in systemic pressure in the already compromised cardiac patient. While performing open-heart procedures, surgeons will often either create a small port or form a pericardial cradle to create suitable fields for operation.

The novel in vitro reanimation of isolated human and large mammalian heart-lung blocs.

Background: In vitro isolated heart preparations are valuable tools for the study of cardiac anatomy and physiology, as well as for preclinical device testing. Such preparations afford investigators a high level of hemodynamic control, independent of host or systemic interactions. Here we hypothesize that recovered human and swine heart-lung blocs can be reanimated using a clear perfusate and elicit viable cardiodynamic and pulmonic function.

The Effects of Radiofrequency or Cryothermal Ablation on Biomechanical Properties of Isolated Human or Swine Cardiac Tissues.

Changes in cardiac tissue properties following the application of various ablation modalities may lead to the development of an array of associated complications. The application of either radio frequency (RF) or cryothermal ablations will alter the biomechanical properties of various cardiac tissues in a differential manner; in some cases, this may be attributable to increased incidences of cardiac tamponade, pulmonary vein stenosis, and/or atrial-esophageal fistula. Thus, a greater understanding of the underlying changes in tissue properties induced by ablative therapies will ultimately promote safer and more efficacious procedures.

Tissue properties of the fossa ovalis as they relate to transseptal punctures: a translational approach.

Objectives: This study focused on how catheter size affects transseptal puncture, what transseptal indication means, and whether the swine model is predictive for humans.

Background: Transseptal puncture is a common procedure that gains access to the left atrium, allowing percutaneous mitral valve repair, left atrial appendage closure, and left-sided ablations. The basic approach has not changed in many years; however, the frequency of transseptal punctures and the size of devices are increasing with emerging treatments.

Optimal contact forces to minimize cardiac perforations before, during, and/or after radiofrequency or cryothermal ablations.

Background: Catheter perforations remain a major clinical concern during ablation procedures for treatment of atrial arrhythmias and may lead to life-threatening cardiac tamponade. Radiofrequency (RF) ablation alters the biomechanical properties of cardiac tissue, ultimately allowing for perforation to occur more readily. Studies on the effects of cryoablation on perforation force as well as studies defining the perforation force of human tissue are limited.

The benefits of the Atlas of Human Cardiac Anatomy website for the design of cardiac devices.

This paper describes how the Atlas of Human Cardiac Anatomy website can be used to improve cardiac device design throughout the process of development. The Atlas is a free-access website featuring novel images of both functional and fixed human cardiac anatomy from over 250 human heart specimens. This website provides numerous educational tutorials on anatomy, physiology and various imaging modalities.