Patrick D. Wolf, Ph.D. (Duke)

Assistant Professor of Biomedical Engineering

Research Interest: Instrumentation for the Diagnosis and Treatment of Cardiac Arrhythmias

EXPERIMENTAL CARDIAC ELECTROPHYSIOLOGY

Cardiac electrophysiology is the study of the heart's electrical system. This system initiates and propagates the signal that culminates in a synchronous mechanical contraction of the heart muscle. A number of cardiac pathologies can lead to rapid uncontrolled beats that compromise the mechanical function and can degrade into fibrillation and sudden cardiac death. Recently, two interventional therapies have become available to treat these life threatening tachyarrhythmias. These new techniques are catheter ablation and automatic implantable cardioverter/defibrillator (AICD) implantation. Ablation therapy is performed in the Clinical Electrophysiology (EP) Laboratory and is effective for most forms of atrial tachycardia. During an EP procedure, catheters with electrodes located at the tip are inserted through the vascular system into the heart under fluoroscopic guidance. Signals from the edocardial (inside) surface of the heart are recorded and used to map the spread of electrical activation. This endocardial mapping is used to locate the tissue responsible for generating or sustaining the tachyarrhythmia. Once located the tissue is ablated or destroyed using radio frequency (RF) energy delivered through the same electrodes used for recording. For treating life threatening ventricular tachycardia, the physician can implant an AICD. These devices do not prevent arrhythmias but terminate them once they have started by delivering appropriately timed shocks to the heart. Hopefully, as the understanding of these rhythms increases and technology advances, ablation therapy will be used to prevent these rhythms as well.

Dr. Wolf's research is based around the diagnostic and therapeutic instrumentation described above. On the diagnostic side, endocardial mapping techniques are being improved by developing better electrodes and electrode arrays for acquiring the heart's electrical signals and better amplifiers and software for processing and interpreting the signals. Research is also being conducted on ways of improving the imaging systems currently used to direct the positioning of catheters within the heart. The improved systems would allow three dimensional reconstruction of the catheter locations within the heart. New methods of visualizing the experimental results using state of the art computer graphics are being developed to present the recorded electrical data in a true three dimensional format. On the therapeutic side, ways of improving cardioversion, defibrillation and ablation are being developed. Some of this research includes development of improved animal models of ventricular tachycardia and atrial fibrillation, improved shock timing for cardioversion and defibrillation, and improved RF ablation techniques.

aa Dr. Wolf collaborates closely with the Clinical Electrophysiology Lab in the hospital and works closely with clinicians to develop and test new instrumentation. Developing and testing takes place in a state of the art cardiac mapping laboratory. This laboratory has all of the equipment needed for in vivo testing of the instrumentation and the techniques. This facility is also used to provide experimental data for the members of the Department involved in modeling cardiac electrical activity. This combination of clinical input, sophisticated laboratory facilities, and faculty interaction provides a stimulating environment for research on the next generation of antiarrhythmic therapies.