Radiofrequency ablation in a patient with tachycardia incorporating triple free wall accessory pathways and atrioventricular nodal reentrant tachycardia.
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Adult↗
Biomedical subjects
C C Cheng
Publications and source records attributed to C C Cheng.
Radiofrequency catheter ablation of sustained intraatrial reentrant tachycardia in a patient with mirror-image dextrocardia.
INTRODUCTION: There has been limited experience with radiofrequency catheter ablation in patients with dextrocardia. This report describes a 37-year-old man who had secundum type atrial septal defect, mirror-image dextrocardia, and drug-refractory atrial tachycardia, in whom catheter-mediated radiofrequency energy successfully eliminated the tachycardia without complication. METHODS AND RESULTS: On electrophysiologic study, the atrial tachycardia could be induced and terminated by atrial extrastimulation or rapid atrial pacing. Mixed resetting response pattern and manifest entrainment were also demonstrated. These findings suggested that the mechanism of atrial tachycardia might be related to reentry with an excitable gap. Because of the mirror-image dextrocardia, biplane fluoroscopy was adjusted to the right anterior oblique (RAO) 60 degrees and left anterior oblique (LAO) 30 degrees positions. Inducibility of the tachycardia was completely abolished after the sixth application of radiofrequency current (30 W). It was noted that the successful electrogram preceded the onset of P wave during atrial tachycardia by about 40 msec. CONCLUSION: This report presents another case in which radiofrequency catheter ablation was used in a patient with dextrocardia. Atrial tachycardia in patients with congenital heart disease may be difficult to control pharmacologically; however, the use of radiofrequency catheter ablation could be recommended as an alternative to medication and surgery.
Adult↗
Sustained atrial tachycardia in adult patients. Electrophysiological characteristics, pharmacological response, possible mechanisms, and effects of radiofrequency ablation.
BACKGROUND: Mechanisms and electropharmacological characteristics in adult patients with atrial tachycardia (AT) are not well described. We proposed that a combination of electropharmacological characteristics, recording of monophasic action potential, and effects of radiofrequency ablation could further determine the mechanisms and achieve a new classification in adults with various types of AT because they were important in regard to the correlation between mechanisms and pathophysiology, clinical syndrome, and responses to specific pharmacological or nonpharmacological therapies. METHODS AND RESULTS: Thirty-six patients (11 female, 25 male; mean age, 57 +/- 13 years) with AT were referred for electropharmacological studies and radiofrequency ablation. Resetting response pattern, entrainment phenomenon, recording of monophasic action potential, serial drug test, response to Valsalva maneuver, endocardial mapping technique, and radiofrequency ablation were performed. Seven patients had automatic AT provocable with isoproterenol; neither initiation nor termination was related to programmed electrical stimulation. The other 29 patients had AT initiated or terminated by electrical stimulation and mechanisms related to triggered activity or reentry; nine of them needed isoproterenol to facilitate initiation of AT, associated with delayed afterdepolarization in monophasic action potential. All responded to adenosine (15 to 60 micrograms/kg) and Valsalva maneuver. Dipyridamole terminated AT and decreased the slope of afterdepolarization. Afterdepolarization was not found in the patients with automatic or reentrant AT. In 40 of 41 (98%), AT was ablated successfully, with late recurrence in 2 of 40 (5%) (follow-up, 18 +/- 4 months). CONCLUSIONS: This study demonstrates the diverse mechanisms and electropharmacological characteristics of AT in adults. Furthermore, radiofrequency ablation of various types of AT could achieve high success and low recurrence rates.
Adult↗
Incidence, significance, and pharmacological responses of catheter-induced mechanical trauma in patients receiving radiofrequency ablation for supraventricular tachycardia.
BACKGROUND: Catheter-induced mechanical trauma is unfavorable during electrophysiological study. However, its incidence, significance, and pharmacological responses in patients receiving radiofrequency ablation for supraventricular tachycardia have not been investigated. METHODS AND RESULTS: A prospective study was performed in 666 consecutive patients with documented, symptomatic supraventricular tachycardia. All had been referred for electrophysiological study and radiofrequency ablation. Catheter-induced mechanical trauma was defined by either disappearance of or change in preexcitation pattern induced by the electrode catheters or noninducibility of tachycardia after the electrode catheter-induced termination of tachycardia, confirmed by electrophysiological study. Adenosine, isoproterenol, and atropine were serially administered 1 hour after the mechanical trauma to study pharmacological response. "Rescue" radiofrequency ablation was defined as delivery of radiofrequency energy just at the presumed ablation site immediately after the mechanical trauma. Of the 666 patients, 254 had atrioventricular (AV) nodal reentrant tachycardia, 367 patients had accessory pathways, 30 patients had atrial tachycardia, and 15 had atrial flutter. Catheter-induced mechanical trauma occurred in 17 patients (2.6%): 4 patients had AV nodal reentrant tachycardia, 9 had accessory pathways, and 4 had atrial tachycardia. Five patients had such episodes during the placement of electrode catheters and 12, during mapping and ablation procedures. Of the 4 patients with AV nodal reentrant tachycardia, 3 had mechanical trauma on the retrograde fast pathway and 1, on the antegrade slow pathway. In the 9 patients with accessory pathways, those pathways were located in the left free wall in 4 patients, right free wall in 1, right posteroseptum in 1, and right anteroseptum in 3. Atrial tachycardia was more easily traumatized than AV nodal reentrant tachycardia (P < .01) and than accessory pathways (P < .01). The clinical courses of mechanical trauma were variable: 1 patient had spontaneous recovery within 1 week, 5 patients had recurrence of tachycardia within 3 months, and the rest have been free of tachycardia from 3 to 35 months. The recurrence rate was higher in patients with mechanical trauma than in those without (33.3% versus 3.5%, P < .0001) despite rescue radiofrequency ablation given in 7 patients. Pharmacological agents were generally unable to revive the traumatized tissues, and recurrence was unpredictable. CONCLUSIONS: Catheter-induced mechanical trauma was not common in patients receiving radiofrequency ablation for supraventricular tachycardia. Their clinical courses were variable, and pharmacological manipulation offered little assistance. More than half of the patients had long-term cures. However, the recurrence rate was, on the whole, significantly high despite rescue radiofrequency ablation. There is a need for great caution in the placement of electrode catheters in every patient during electrophysiological study and radiofrequency ablation.
Adenosine↗
Atrial pacing-induced reverse alternating Wenckebach periods. A common electrophysiologic phenomenon in patients with dual atrioventricular nodal pathways.
Reverse alternating Wenckebach periods (RAWP) have rarely been described, and the significance of dual AV nodal pathways in atrial pacing-induced RAWP is unknown. Forty-five of 50 consecutive patients (M/F = 23/27, mean age 40 +/- 5 years) with common type AV nodal reentrant tachycardia had discontinuous antegrade conduction curves. Atrial pacing revealed that pattern A RAWP (23 patients) had the fourth paced beat conducted over the fast pathway, and pattern B (18 patients) over the slow pathway. Four patients had both pattern A and B RAWP during different pacing cycle lengths. All episodes of atrial pacing-induced RAWP emerged from (or started as) 3:2 AH block, which thereafter were followed by runs of 2:1 AH block. Comparisons between patterns A and B showed (1) maximal atrial pacing cycle length with RAWP was longer in pattern A; (2) A2H2-A1H1 and A4H4-A1H1 were significantly greater in pattern B; (3) A2H2-A4H4 and H2A4/A2H2 were significantly greater in pattern A. It is concluded that atrial pacing-induced RAWP is a common electrophysiologic phenomenon in patients with dual AV nodal pathways. Furthermore, intermittent slow pathway conduction associated with different AnHn and HnAn+2 parameters helped the interpretation of different conduction patterns.
Adult↗
Design of antineoplastic agents on the basis of the "2-phenylnaphthalene-type" structural pattern. 2. Synthesis and biological activity studies of benzo]b]naphtho[2,3-d]furan-6,11-dione derivatives.
Based on the "2-phenylnaphthalene-type" structural pattern hypothesis developed in our laboratory, a number of benzo[b]naphtho[2,3-d]furan-6,11-diones were designed, synthesized, and evaluated in vitro for their inhibitory action against the growth of human promyelocytic leukemia cells (HL-60), small-cell lung cancer (SCLC), SCLC cells resistant to cisplatin (SCLC/CDDP), National Cancer Institute's disease-oriented primary antitumor 60 cell-line panel, and drug-stimulated topoisomerase II-mediated DNA cleavages. Many compounds designed were found to possess potent activity in one or more of the biological tests. In general, activity found in one of the cell lines tested is often echoed in other cell lines and many also expressed substantial inhibitory activity against topoisomerase II-mediated cleavage activities. One of these compounds, 3-[2-(dimethylamino)ethoxy]-1-hydroxybenzo[b]naphthol[2,3-d]furan- 6,11-dione (8j), exhibited strong inhibitory activity throughout the entire series of test panel. Thus, it appears that the proposed structural pattern hypothesis has received substantial support through experimental verification.
Antineoplastic Agents↗
Effects of radiofrequency ablation of supraventricular reentrant tachycardia on left ventricular systolic dysfunction.
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Adult↗
Selective radiofrequency catheter ablation of fast and slow pathways in 100 patients with atrioventricular nodal reentrant tachycardia.
One hundred patients received selective radiofrequency ablation of retrograde fast pathway (32 patients, group I) or slow pathway (68 patients, group II) to treat drug-refractory atrioventricular nodal reentrant tachycardia. In group I, a mean of 6 +/- 3 radiofrequency pulses eliminated the retrograde fast pathway. Thirty patients were free of symptoms and were not receiving antiarrhythmic drugs; two patients had accidental atrioventricular block. One patient had recurrent tachycardia and received a repeated ablation (slow pathway ablation). In group II, a mean of 9 +/- 4 radiofrequency pulses eliminated the slow pathway in 68 patients. All patients were free of symptoms and were not receiving antiarrhythmic drugs. One patient had recurrent tachycardia and received a repeated ablation. Serial follow-up electrophysiologic studies (immediate [20 to 30 minutes], early [5 to 7 days], and late [3 to 6 months]) showed that selective ablation of retrograde fast pathway was associated with nonspecific injury on the antegrade fast pathway (increase of AH interval) without effects on the slow pathway. Selective ablation of slow pathway was associated with nonspecific injury on the retrograde fast pathway in 15 patients (22%), but the antegrade fast pathway conduction parameters did not change significantly. Thus retrograde and antegrade fast pathway may be anatomically similar or have different sensitivities to radiofrequency energy, and slow pathway may be anatomically distinct from fast pathway. We conclude that (1) selective radiofrequency ablation of retrograde fast or slow pathway could cure atrioventricular nodal reentrant tachycardia with a high success rate (98%) and a low recurrence rate (2%) during a follow-up period of 6 to 18 months, but fast pathway ablation was associated with accidental atrioventricular block (5%), and (2) serial follow-up electrophysiologic studies elucidated the possible mechanisms of cure in atrioventricular nodal reentrant tachycardia.
Adolescent↗
Reappraisal of radiofrequency ablation of multiple accessory pathways.
Complete electrophysiologic study and radiofrequency ablation were performed in 145 consecutive patients with Wolff-Parkinson-White syndrome. Presence of multiple accessory atrioventricular pathways was documented in 20 patients (13.8%); 17 had two, two had three, and one had four accessory pathways. Location of accessory pathways was posteroseptal in 18, left free wall in 15, right free wall in nine, and right midseptal in two. Of the 44 pathways, 36 were found during baseline electrophysiologic study and eight were found after successful ablation of the initially attempted pathways. After delivery 20 +/- 23 pulses (per patient) of radiofrequency energy (37 +/- 6 W, 70 +/- 30 seconds), 43 accessory pathways were ablated successfully without complications. Duration of the procedure (4.5 +/- 1.7 vs 3.7 +/- 1.6 hours, p < 0.05) and radiation exposure time (53 +/- 30 vs 38 +/- 18 minutes, p < 0.05) were longer in patients with multiple pathways, whereas the success rate (95% vs 95%, p > 0.05) and incidence of recurrent conduction (11% vs 11%, p > 0.05) were similar in patients with single or multiple accessory pathways. These findings confirmed that multiple accessory pathways were common in patients with Wolff-Parkinson-White syndrome, and these pathways could be ablated successfully by radiofrequency energy with a success rate comparable to that of a single accessory pathway.
Adult↗
Usefulness of serial follow-up electrophysiologic studies in predicting late outcome of radiofrequency ablation for accessory pathways and atrioventricular nodal reentrant tachycardia.
A total of 408 patients received radiofrequency catheter ablation for paroxysmal supraventricular tachycardia, and 326 patients underwent serial follow-up electrophysiologic studies (early and late) after initially successful radiofrequency catheter ablation of accessory pathways (group 1, 186 patients with Wolff-Parkinson-White syndrome) and slow atrioventricular (AV) nodal pathways (group 2, 140 patients with AV nodal reentrant tachycardia). Among the patients in group 1, early (4 +/- 1 days) and late (129 +/- 14 days) studies found recurrent conduction through the accessory pathways in 12 and 16 patients, respectively. During a follow-up period of 21 +/- 7 months, recurrence of accessory pathway-mediated tachyarrhythmias was noted in six patients. Of these six patients, all had tachycardia inducible in the late study but not in the early study. Among the patients in group 2, four had recurrence of AV nodal reentrant tachycardia during a follow-up of 16 +/- 6 months. Of the four patients, one had tachycardia inducible in the early (4 +/- 1 days) study and three in the late (130 +/- 12 days) study. The results demonstrated that the early study was not as sensitive as the late follow-up electrophysiologic study in predicting late outcome of radiofrequency ablation, but both the early and late studies had a high total predictive accuracy (> 90%) in groups 1 and 2. Furthermore, only 4 of the 326 patients had initial evidence of recurrent tachycardia activated by programmed electrical stimuli during follow-up studies, suggesting that follow-up electrophysiologic studies in asymptomatic patients are not warranted.
Adult↗
Clinical features and electrophysiologic characteristics of accessory atrioventricular pathways and atrioventricular nodal reentrant tachycardia: comparative study between young and elderly patients.
Information focused on elderly patients with paroxysmal supraventricular tachycardia, and a comparative study between the elderly and younger patients was limited. The aim of this study was to investigate the clinical features and electrophysiologic characteristics in elderly patients (> or = 65 years of age) with accessory atrioventricular pathway-mediated tachyarrhythmia or atrioventricular nodal reentrant tachycardia. Electrophysiologic studies of 45 elderly patients with accessory pathway-mediated tachyarrhythmia and 47 elderly patients with atrioventricular nodal reentrant tachycardia were performed. When compared with younger patients, the elderly patients had a similar incidence of critical clinical manifestation, higher incidence of other cardiac disease or systemic disease, similar inducibility of tachycardia, greater baseline electrophysiologic parameters (sinus node, atrioventricular node, atrium and ventricle), and poorer properties of accessory pathways and dual atrioventricular nodal pathways. These results suggest that conduction properties of accessory pathways and dual atrioventricular nodal pathways were poorer in elderly patients, but similar critical manifestations and tachycardia events were found in elderly and younger patients.
Adolescent↗
Radiofrequency ablation of posteroseptal accessory pathways in patients with abnormal coronary sinus.
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Adult↗
A structure-activity relationship study of batracylin analogues.
A number of isoindolo[1,2-b]quinazolines and some benzo[4,5]isoquinolino[1,2-b]quinazolines as structural modification analogues of the antitumor compound batracylin were synthesized and evaluated against HL-60 cell growth and in topoisomerase II-mediated DNA cleavage assays. Of the compounds studied, 10,12-dihydro-7,8-methylenedioxyisoindolo[1,2-b]quinazolin-1 2(10H)-one (1d), 2-amino-10,12-dihydroisoindolo[1,2-b]quinazolin-12(10H)-one (1p), and 2-amino-7,8-methylenedioxy-10,12-dihydroisoindolo[1,2-b] quinazolin-12(10H)-one (1ab) exhibited good inhibitory activities against HL-60 cell lines as well as induction of topo II-mediated DNA cleavage activities.
Antineoplastic Agents↗
Serial electrophysiological studies in the late outcome of radiofrequency ablation for accessory atrioventricular pathway-mediated tachyarrhythmias.
Assessment of radiofrequency ablation for accessory pathway-mediated tachyarrhythmias is evaluated by a variety of methods in different institutes. However, the predictive values of these methods are not known. Therefore, serial electrocardiograms (12-lead, 24-h Holter monitoring), reviews of symptoms, and electrophysiological studies (immediate, early, late) were used in this institute to evaluate and predict late outcome in 150 patients with 174 accessory pathways. Late electrophysiological study (130 +/- 11 days after ablation) detected a larger proportion of patients (11.1%) with late ablation failure than immediate (1.3%), or early (7.0%) electrophysiological study, or serial electrocardiograms (1.4%), or reviews of symptoms (1.4%); it showed that patients with concealed accessory pathways (11.4%), energy delivered to the ventricular sites of left concealed accessory pathways (23.3%), and those without a recordable accessory pathway activation potential (14.8%) had a higher incidence of recurrent conduction, and also provided the most accurate information for predicting late outcome with higher sensitivity (100%) and predictive accuracy (100%) than other tests. It is concluded that the value of serial electrocardiograms, symptom review, immediate and early electrophysiological studies should be downgraded, and that the late electrophysiological study has a high predictive value for late outcome and helps understanding of the residual changes in accessory pathways after initially successful ablation.
Adolescent↗
Radiofrequency catheter ablation of sustained intra-atrial reentrant tachycardia in adult patients. Identification of electrophysiological characteristics and endocardial mapping techniques.
BACKGROUND: Information about electrophysiological characteristics and radiofrequency ablation of intra-atrial reentrant tachycardia has not been reported before. We proposed that induction and termination of intra-atrial reentrant tachycardia by atrial extrastimuli or rapid atrial pacing and resetting the response pattern by atrial extrastimuli during intra-atrial reentrant tachycardia could ensure the mechanism of reentry and that the earliest site of endocardial activation and concealed entrainment pace mapping with the shortest stimulus-P wave interval could localize a critical area responsible for intra-atrial reentrant tachycardia and radiofrequency ablation. METHODS AND RESULTS: Seven patients with refractory atrial tachycardia were referred for electrophysiological studies and radiofrequency ablation. Electrophysiological studies and endocardial mapping found (1) 10 atrial foci with atrial tachycardia cycle length of 406 +/- 41 ms; (2) atrial tachycardia had induction and termination by atrial extrastimuli (8 of 10) or rapid atrial pacing (10 of 10); (3) atrial tachycardia had increasing (6 of 10) or mixed (flat and increasing, 4 of 10) resetting response pattern, with resetting interval of 57 +/- 13 ms (14 +/- 4% of atrial tachycardia cycle length); (4) exit sites of atrial tachycardia in right atrial free wall (6 of 10), right atrial septum (3 of 10), and midposterior left atrium (1 of 10); and (5) earliest activation site had timing relative to P wave by -37 +/- 7 ms, and concealed entrainment pace mapping had shortest stimulus-P interval 23 +/- 3 ms. By the endocardial activation pace-mapping technique, radiofrequency energy (8 +/- 1 pulses, 31 +/- 3 W, 101 +/- 11 seconds) successfully eliminated the 10 atrial foci without recurrence (follow-up, 16 +/- 5 months). CONCLUSIONS: Mechanism of intra-atrial reentrant tachycardia could be confirmed by the electrophysiological characteristics, and radiofrequency ablation energy delivered to a critical area in the atrial reentrant circuit is safe and effective for the treatment of intra-atrial reentrant tachycardia.
Aged↗
Aspergillosis of the paranasal sinuses.
The CT appearances of 13 cases of pathologically proven aspergillosis involving paranasal sinuses were reviewed. Symptoms included rhinorrhea, nasal obstruction, headache, facial pain and foul smell from the nose. At operation, these lesions appeared yellowish, brownish, grey or black in colour, and contained dirty or muddy material. Microscopic examination of the tissue removed showed an Aspergillus ball with chronic inflammation but without invasion of the nasal or sinus mucosa in 6 cases, and tissue invasion with necrosis and inflammation in 7. The structures involved, in order of frequency, were: maxillary sinus, nasal cavity, ethmoid sinus, orbit and cavernous sinus. The orbit was involved in 2 cases, therefore categorized as invasive; the other 11 cases were non-invasive as judged by CT. Calcification was seen in the lesions of 9 cases. In most cases the adjacent bony structures showed areas of erosion and sclerosis. Aspergillosis should be suspected in the presence of a mass in the paranasal sinuses or nasal cavity with calcification within it, which may not appear solid or dense and is separate from the walls of the sinus.
Aged↗
Structural modification study of anthracyclinones: synthesis and biological activity of several derivatives of eta-pyrromycinone.
On the basis of the N-O-O triangular pharmacophore hypothesis postulated earlier in our laboratory, selected side chains with or without the nitrogen atom at the strategic position were incorporated to eta-pyrromycinone, one of the anthracyclinones derived from the antibiotic cinerubins. Since none of the anthracyclinones (the aglycones of anthracyclines) were reported to have antineoplastic activity, the validity of the proposed hypothesis could be tested. Results indicated that a compound designed in this manner, 1,4-bis[2-(2,2-dimethyloxazolidin-3-yl)ethylamino]-1,4-didehydr oxy-eta- pyrromycinone (9c) possessed both in vitro and in vivo antineoplastic activity comparable to that of mitoxantrone. The structure-activity relationship of this class of compounds is discussed.
Animals↗
Identification of the mixed disulfide of glutathione and cysteinylglycine in bile: dependence on gamma-glutamyl transferase and responsiveness to oxidative stress.
Biliary excretion of glutathione disulfide (GSSG) is used as an index of oxidative stress. Analysis of endogenous thiols and disulfides in rat bile by reverse phase high performance liquid chromatography with electrochemical detection revealed an unknown disulfide which eluted immediately after GSSG. This disulfide was tentatively identified as the mixed disulfide of glutathione (GSH) and cysteinylglycine (Cys-Gly), based on its coelution on a reverse phase column with the synthetic GS-Cys-Gly. GS-Cys-Gly was also detected in bile of other species. On analyzing species differences in biliary excretion of GSH-related thiols and disulfides, it was concluded that biliary excretion of GS-Cys-Gly was related to the excretion of both GSSG and Cys-Gly, which is formed from GSH by gamma-glutamyltransferase (gamma-GT)-catalyzed hydrolysis. Species with low hepatic gamma-GT (i.e., hamsters and mice) excreted little Cys-Gly in bile. These animals excreted negligible amounts of GS-Cys-Gly even when biliary excretion of GSSG was markedly increased by paraquat-induced oxidative stress. Rats and guinea pigs, which have high hepatic gamma-GT activities, excreted large amounts of both Cys-Gly and GS-Cys-Gly. Treatment of rats with acivicin, an inhibitor of gamma-GT, decreased the biliary excretion of both Cys-Gly and GS-Cys-Gly. Paraquat treatment of rats resulted in an increase in GSSG excretion with concomitant increase of GS-Cys-Gly excretion. Rabbits, which also have high hepatic gamma-GT activity, excreted little GS-Cys-Gly into bile.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗