- In this two-part series, we discuss the anatomical basis for arrhythmias arising above the semilunar valves. In this part (part I), we describe the relevant anatomy and technique for mapping and ablation of ventricular arrhythmias arising above either the pulmonic or the aortic valve. After an initial discussion of the underlying anatomy and characteristics of the substrate targeted for ablation above the semilunar valve, an approach for safe and effective ablation of supravalvar ventricular arrhythmias is presented.
- In this two-part series on arrhythmias occurring above the semilunar valve, we discuss the relevant underlying anatomy and the technique for mapping and ablation above the aortic and pulmonic valve. In part I, we focused on ventricular arrhythmias, and in this paper (part II), we discuss the anatomy and present knowledge of the substrate mapped and ablated above the aortic valve for atrial tachycardia in certain unusual accessory pathways. The background anatomy of the aortic valve has been discussed in part I of this series, to which the reader is referred.
- Superior vena caval (SVC) potentials are similar to pulmonary vein (PV) potentials. The concepts of multiple far-field electrograms and the use of perivenous pacing and specific site and simultaneous pacing described above are equally applicable to understanding the complex electrograms found within the SVC (Figure 1). Specific sites that require pacing to determine the components of a complex electrogram found in the SVC include the right atrium (RA), azygos vein, anomalous PVs draining into the SVC, and right upper PV; in some cases, an anomalous superior branch of the right inferior PV may be required.
- With the rapid evolution of atrial fibrillation ablation procedures, electrophysiologists have necessarily strived for simple and anatomic-based approaches. In all except the most straightforward procedures, however, questions regarding the significance of various potentials recorded on mapping and ablation catheters arise.1,2 Other articles in this series have described in detail the various approaches to atrial fibrillation ablation. In this article, the anatomic and electrophysiologic bases for pacing maneuvers used with a variety of ablation approaches are reviewed.