New Paradigm of Defibrillation: Towards Painless Therapy

Sudden cardiac death: SCD) causes approximately 300,000 - 400,000 deaths a year in the United States. It usually starts as ventricular tachycardia: VT) and then degenerates into ventricular fibrillation: VF). Implantable cardioverter defibrillator: ICD) therapy is the only reliable treatment of VT/VF and has been shown to effectively reduce mortality by many clinical trials. However, high-voltage ICD shocks could result in myocardial dysfunction and damage. The majority of patients receiving ICD therapy have a history of coronary disease; their hearts develop myocardium infarction, which could provide a substrate for reentrant tachy-arrhythmias. Other than lethal ventricular tachycardia, atrial fibrillation: AF) became the most common arrhythmia by affecting 2.2 to 5.6 millions of Americans. The complications of AF include an increased rate of mortality, heart failure, stroke, etc. In this dissertation, we explore mechanisms of sustained ventricular and atrial tachyarrhythmias and the mechanisms of defibrillation using the conventional high-voltage single shock. Through the use of novel fluorescent optical mapping techniques and several animal models of ventricular and atrial arrhythmias, we develop and validate several novel low-voltage defibrillation therapies for atrial and ventricular arrhythmias. Several important previous studies on mechanisms of arrhythmia maintenance and termination using mathematical and experimental models are overviewed in Chapter 2. A study on multiple monophasic shocks improving electrotherapy of ventricular tachycardia in rabbit model of chronic infarction is presented in Chapter 3. Ventricular arrhythmias and low-voltage defibrillation therapy are studied in a more clinically-relevent in vivo canine model of healing myocardial infarction in Chapter 4. Finally, Chapter 5 presents a novel multi-stage low-energy defibrillation therapy for atrial fibrillation in in vivo canine hearts.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biomedical Engineering

Year dc:date.available

2011

Author dc:creator

• Li, Wenwen

Contributors dc:contributor

• Igor Efimov

• Biomedical Engineering
• Atrial Fibrillation
• Defibrillation
• Low-voltage
• Multiple Pulse
• Multi-stage
• Ventricular Tachycardia

Language dc:language

English (en)

DOI

https://doi.org/10.7936/K798851B

OAI identifier oai:identifier

oai:openscholarship.wustl.edu:etd-1607