The two broad, long term objectives of this proposed research are to use electrophysiological techniques to improve our understanding of the mechanisms responsible for atrial fibrillation (AF) in patients and to develop an improved basis for its treatment.
The specific aims of this research plan are to study patients 1) during open heart surgery a) to map the sequence of atrial activation simultaneously in both atria i) during spontaneous AF of various types (paroxysmal, persistent, or permanent) and duration (recent onset, weeks, months, or years); ii) during overdrive pacing or programmed atrial stimulation during AF from a site or sites close to or within an area of regular rhythm of very short cycle length; iii) following cardioversion of AF to sinus rhythm; iv) during atrial pacing from selected atrial sites during sinus rhythm in patients with or without a history of AF; b) during AF, to identify and characterize areas of very regular but very short cycle length, thought to drive the atria creating fibrillatory conduction; c) to characterize the atrial effective refractory period during sinus rhythm from selected sites in both atria in patients with various forms and durations of AF, and compare that with patients with normal atria and no history of AF; and d) to obtain Fast Fourier Transform (FFT) analysis of atrial electrograms recorded during intraoperative activation mapping to identify and help characterize the presence of a region with a regular rhythm of very short cycle length; and 2) in the postoperative period to use temporary atrial epicardial wire electrodes in patients with new onset AF a) to record atrial electrograms and obtain FFT analysis of these atrial electrograms to identify and help characterize the presence of a regular rhythm of very short cycle length; and b) to perform overdrive pacing from an area demonstrating a regular rhythm of very short cycle length to try to terminate the AF. ? ?
|Lee, Seungyup; Sahadevan, Jayakumar; Khrestian, Celeen M et al. (2015) Simultaneous Biatrial High-Density (510-512 Electrodes) Epicardial Mapping of Persistent and Long-Standing Persistent Atrial Fibrillation in Patients: New Insights Into the Mechanism of Its Maintenance. Circulation 132:2108-17|
|Sahadevan, Jayakumar; Ryu, Kyungmoo; Matsuo, Kunihiro et al. (2011) Characterization of atrial activation (A-A) intervals during atrial fibrillation due to a single driver: do they reflect atrial effective refractory periods? J Cardiovasc Electrophysiol 22:310-5|
|Ryu, Kyungmoo; Sahadevan, Jayakumar; Khrestian, Celeen M et al. (2009) Frequency analysis of atrial electrograms identifies conduction pathways from the left to the right atrium during atrial fibrillation-studies in two canine models. J Cardiovasc Electrophysiol 20:667-74|
|Vitebskiy, Sergey A; Khrestian, Celeen M; Waldo, Albert L (2007) Termination of a tachyarrhythmia by flunarizine is not a specific marker for a triggered mechanism. Heart Rhythm 4:1544-52|
|Ryu, Kyungmoo; Li, Li; Khrestian, Celeen M et al. (2007) Effects of sterile pericarditis on connexins 40 and 43 in the atria: correlation with abnormal conduction and atrial arrhythmias. Am J Physiol Heart Circ Physiol 293:H1231-41|
|Ryu, Kyungmoo; Sahadevan, Jayakumar; Khrestian, Celeen M et al. (2006) Use of fast fourier transform analysis of atrial electrograms for rapid characterization of atrial activation-implications for delineating possible mechanisms of atrial tachyarrhythmias. J Cardiovasc Electrophysiol 17:198-206|
|Ryu, Kyungmoo; Ghanem, Raja N; Khrestian, Celeen M et al. (2005) Comparative effects of single- and linear triple-site rapid bipolar pacing on atrial activation in canine models. Am J Physiol Heart Circ Physiol 289:H374-84|
|Ryu, Kyungmoo; Shroff, Sunil C; Sahadevan, Jayakumar et al. (2005) Mapping of atrial activation during sustained atrial fibrillation in dogs with rapid ventricular pacing induced heart failure: evidence for a role of driver regions. J Cardiovasc Electrophysiol 16:1348-58|
|Sahadevan, Jayakumar; Ryu, Kyungmoo; Peltz, Leora et al. (2004) Epicardial mapping of chronic atrial fibrillation in patients: preliminary observations. Circulation 110:3293-9|
|Waldo, Albert L (2004) From bedside to bench: entrainment and other stories. Heart Rhythm 1:94-106|
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