Challenges in Cardiovascular Drug Discovery Despite the significant decline in cardiovascular disease mortality over the past several decades due to more effective medications and surgical procedures, cardiovascular diseases remain one of the leading causes of death and a major economic…
The autonomic nervous system plays a significant role in the genesis and maintenance of ventricular arrhythmias (VAs) and powerfully modulates the underlying substrate in a dynamic manner. Blockade of the sympathetic nervous system, whether through medications or neuraxial modulation, has…
Historical Perspective Open-heart surgery was commonly used in the past to treat refractory ventricular arrhythmias (VAs). The predominant population subjected to this management strategy was made up of patients with healed myocardial infarcts who experienced sustained ventricular tachycardia (VT). The…
Atrial Fibrillation The treatment of atrial fibrillation (AF) with antiarrhythmic medications have been limited by modest efficacies, proarrhythmic side effects, and systemic toxicities. Conversely, rate-control strategies leave patients in AF and do not address the impaired hemodynamics or symptoms associated…
The first invasive studies of cardiac electrophysiology (EP) in humans were performed epicardially. During its golden age (1970s to 1980s), electrical activation maps were acquired in the operating room by surgeons. These studies greatly advanced our understanding of the predominant…
Background: Why Develop a New Technique for Cardiac Ablation? Cardiac ablation using thermal energy is a mainstay of interventional electrophysiology (EP) today. Extremes of heat or cooling can be delivered through the tip of an invasive catheter, causing largely irreversible…
Introduction Radiofrequency ablation (RFA) has become the standard of care for catheter ablation of cardiac arrhythmias. Other ablative technologies, including cryoablation and lasers, are variably used depending on the anatomic features of the tissue being targeted. Common to all is…
Cryoablation Mechanism of Tissue Injury Cryoablation is the removal of heat that results in destruction of tissue. Cryotherapy was invented to treat cancers in the mid 19th century. Cryoablation causes tissue damage by direct and indirect mechanisms: the direct mechanism…
Radiofrequency (RF) current is the most common source of ablative energy used for the treatment of cardiac arrhythmias. Its origins began with electrosurgery and have since been refined to treat all cardiac arrhythmias. Over time, with greater understanding of resistive…
Areas of fibrosis that are common to many cardiac disease states predispose to reentry. Dense fibrosis can create areas of fixed conduction block that define parts of a reentry path (see Fig. 129.2A ). Alternatively, reentry circuits can be defined…