Biomedical subjects

F Bogun

Publications and source records attributed to F Bogun.

39 records · Page 3Linked to original sources

PubMed1995

Radiofrequency ablation of idiopathic left anterior fascicular tachycardia.

INTRODUCTION: A 45-year-old man with idiopathic ventricular tachycardia (VT) having a right bundle branch block configuration with right-axis deviation underwent an electrophysiologic test. METHODS AND RESULTS: Mapping demonstrated a site on the anterobasal wall of the left ventricle where there was an excellent pace map and an endocardial activation time of -20 msec, but radiofrequency catheter ablation at this site was unsuccessful. At a nearby site, a presumed Purkinje potential preceded the by 30 msec during VT and sinus rhythm, and catheter ablation was effective despite a poor pace map and an endocardial ventricular activation time of zero. CONCLUSION: Idiopathic VT with a right bundle branch configuration and right-axis deviation may originate in the area of the left anterior fascicle. A potential presumed to represent a Purkinje potential may be more helpful than endocardial ventricular activation mapping or pace mapping in guiding ablation of this type of VT.

Catheter Ablation↗

PubMed1995

Assessment of pacing maneuvers used to validate anterograde accessory pathway potentials.

Four pacing maneuvers have been proposed to validate an anterograde accessory pathway potential (APP): (1) atrial pacing to induce complete block between the atrial electrogram and the APP; (2) ventricular pacing to advance the APP without altering the timing of the atrial electrogram; (3) atrial pacing to induce complete block between the APP and the ventricular electrogram; and (4) ventricular pacing to advance the ventricular electrogram without altering the timing of the APP. The purpose of this study was to assess these validation techniques by applying them to electrograms that simulated APPs but which were known to be atrial in origin. In 32 patients undergoing an electrophysiology procedure, a split atrial electrogram containing two components separated by at least 30 msec (mean 54 +/- 15 msec) was recorded. Using an atrial extrastimulus technique, complete block between the two components of the atrial electrogram (criterion 1) could never be induced, but complete block between the second component of the atrial electrogram and the ventricular electrogram (criterion 3) consistently was induced. Using a ventricular extrastimulus technique, the second component of the atrial electrogram consistently could be advanced by 10 to 40 msec without altering the timing of the first component (criterion 2). In addition, with ventricular pacing, the ventricular electrogram consistently was advanced without altering the timing of the two components of the atrial electrogram (criterion 4). In conclusion, among the four pacing maneuvers used to validate an anterograde APP, the only one that may be specific for an APP is the ability to induce complete block between the atrial electrogram and the APP.

Adult↗

PubMed1993

Local calcification as a determinant of the outcome of excimer laser coronary angioplasty: an in vitro study.

BACKGROUND: Calcification influences the outcome of various angioplasty techniques in the treatment of coronary artery disease. During angioscopic in vitro studies, we observed that dissections and perforations not caused by vessel bending frequently occurred at the boundary areas of plaque and adjacent vessel wall. This study investigated whether this is related to the distribution of calcific deposits. METHODS: Postmortem excimer laser coronary angioplasty (308-nm XeCl) was performed in 51 stenotic coronary arteries. Twenty-three segments were further examined; these consisted of 11 perforations, six dissections, three segments with no ablative effect after the application of 20,000 laser impulses, and three successfully passed stenoses without complications. X-ray diffraction analysis and scanning electron microscopy were performed to detect calcium deposits and their spatial relationship to perforations and dissections. RESULTS: X-ray diffractions analysis detected calcifications in 21 of 23 specimens. Postmortem angiography revealed calcifications only on 11 of 23 segments. Three of 11 perforations were located at the plaque border, as were three of six dissections. In all six complications at the plaque border, x-ray diffraction analysis revealed that the plaque border was identical with a border of calcium deposits. Eight of 11 perforations and three of six dissections could be explained by axis divergence between the laser catheter and the vessel orientation. CONCLUSIONS: Contributing factors for perforations and dissections during excimer laser coronary angioplasty are axis divergence and the distribution of plaque calcification. More sensitive methods are needed to detect local vessel wall calcium in vivo.

Angioplasty, Balloon, Coronary↗