Pulmonary vein dissection during mapping of atrial fibrillation.
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Atrial Fibrillation↗
Biomedical subjects
W C Yu
Publications and source records attributed to W C Yu.
Pulmonary vein dilation in patients with atrial fibrillation: detection by magnetic resonance imaging.
INTRODUCTION: The positive relationship between left atrial (LA) size and atrial fibrillation (AF) is well recognized; however, there is little information on the association of pulmonary vein (PV) diameter and AF. The purpose of this study was to investigate by magnetic resonance angiography the change of PV and LA size in patients with no history of AF, patients with paroxysmal AF (PAF), and patients with chronic AF (CAF). METHODS AND RESULTS: The study included 47 patients. Group I included 15 patients with normal sinus rhythm and no history of documented AF. Group II included 24 patients with drug-refractory PAF who underwent electrophysiologic study and radiofrequency ablation of PV foci. Group III included 8 patients with CAF who were converted to sinus rhythm by external electrical cardioversion. Age and concomitant heart diseases were similar among the three groups. We measured the diameter of each PV at its junction with the LA in addition to LA dimensions by gadolinium-enhanced magnetic resonance angiography with three-dimensional reconstruction. Significant dilation of both superior PVs (P < 0.01) and transverse diameter of LA (P < 0.01) was seen in the three groups. There were no significant changes of both inferior PVs, corrected PV (PV/LA) diameter, or longitudinal diameter of LA among the three groups. Only 28% patients showed arrhythmogenic foci from the largest PV. CONCLUSION: Significant dilation of both superior PVs with simultaneous LA enlargement was demonstrated i
Aged↗
Acquired pulmonary vein stenosis after radiofrequency catheter ablation of paroxysmal atrial fibrillation.
INTRODUCTION: Elimination of the initiating focus within the pulmonary vein (PV) using radiofrequency (RF) catheter ablation is a new treatment modality for treatment of drug-refractory atrial fibrillation. However, information on the long-term safety of RF ablation within the PV is limited. METHODS AND RESULTS: In 102 patients with drug-refractory atrial fibrillation and at least one initiating focus from the PV, series transesophageal echocardiography was performed to monitor the effect of RF ablation on the PV. There were 66 foci in the right upper PV and 65 foci in the left upper PV. Within 3 days of ablation, 26 of the ablated right upper PVs (39%) had increased peak Doppler flow velocity (mean 130+/-28 cm/sec, range 106 to 220), and 15 of the ablated left upper PVs (23%) had increased peak Doppler flow velocity (mean 140+/-39 cm/sec, range 105 to 219). Seven patients had increased peak Doppler flow velocity in both upper PVs. No factor (including age, sex, site of ablation, number of RF pulses, pulse duration, and temperature) could predict PV stenosis after RF ablation. Three patients with stenosis of both upper PVs experienced mild dyspnea on exertion, but only one had mild increase of pulmonary pressure. There was no significant change of peak and mean flow velocity and of PV diameter in sequential follow-up studies up to 16 (209+/-94 days) months. CONCLUSION: Focal PV stenosis is observed frequently after RF catheter ablation applied within the vein, but usually is without clinical significance. However, ablation within multiple PVs might cause pulmonary hypertension and should be considered a limiting factor in this procedure.
Adult↗
Mechanisms of transition between double paroxysmal supraventricular tachycardias.
INTRODUCTION: Coexistence of double tachycardias in one patient has been infrequently reported. Furthermore, the mechanisms of transition between double paroxysmal supraventricular tachycardias have not been well studied. METHODS AND RESULTS: Thirty-five patients with two paroxysmal supraventricular tachycardias were studied. Group IA consisted of 3 patients with spontaneous transition between AV reciprocating tachycardia (AVRT) and AV nodal reentrant tachycardia (AVNRT). Group IB consisted of 13 patients without spontaneous transition between AVRT and AVNRT. Group IIA consisted of 5 patients with spontaneous transition between AVNRT and atrial tachycardia (AT). Group IIB consisted of 14 patients without spontaneous transition between AVNRT and AT. The absolute values of differences between the two tachycardia cycle lengths were significantly smaller in patients with than in those without transition between the two tachycardias (25+/-8 msec vs 90+/-46 msec, P < 0.05, IA vs IB; 21+/-25 msec vs 99+/-57 msec, P < 0.01, IIA vs IIB). The cutoff point of 25 msec had 80% positive predictive value for transition between the two tachycardias. Transition between two tachycardias occurred due to a spontaneous premature atrial complex (30%), conduction block at one limb of tachycardia (20%), or tachycardia-induced tachycardia (50%). Absence of transition between two tachycardias might be explained by the absence of a spontaneous premature atrial complex, longer cycle length of the first tachycardia, larger difference between two tachycardia cycle lengths, or induction of each tachycardia under different situations. CONCLUSION: Double supraventricular tachycardias with similar tachycardia cycle lengths are vulnerable to transition between different tachycardias.
Adolescent↗
Role of right middle pulmonary vein in patients with paroxysmal atrial fibrillation.
INTRODUCTION: Elimination of the ectopic foci from pulmonary veins (PVs) has proved to be a curative therapy for focal atrial fibrillation (AF). However, information about the importance of the right middle PV (RMPV) in initiation of AF and radiofrequency ablation of AF is limited. METHOD AND RESULTS: Forty-three patients (34 men and 9 women; age 65+/-12 years) with drug-refractory paroxysmal AF underwent electrophysiologic study and catheter ablation for treatment of AF. Three-dimensional magnetic resonance angiography (MRA) of the PVs and left atrium (LA) was performed to determine the anatomic patterns of RMPV. Diameter of PV ostium was measured at the junction of the LA and each PV. MRA findings showed the following: (1) 36 (84%) of 43 patients had a discrete RMPV; (2) there are three drainage patterns of RMPV, including joining the proximal part (<1 cm from the ostium) of the right superior PV (RSPV), joining the right inferior PV (RIPV), and a separate RMPV ostium in the LA wall; and (3) the ostial diameter of RMPV was significantly smaller than RSPV and RIPV (P < 0.01). Electrophysiologic studies demonstrated that five AF foci arose from RMPV. The coupling interval between the ectopic beat of AF and sinus beat was longer in RMPV than RSPV (262+/-45 msec vs 212+/-47 msec; P = 0.043). All AFs from RMPV were ablated successfully. PV stenosis or AF recurrence from RMPV was not found during follow-up of 10+/-4 months. CONCLUSION: RMPV was detected by MRA in >80% of paroxysmal AF patients. Ectopy from RMPV can initiate AF, and radiofrequency ablation of RMPV foci is feasible and safe.
Adult↗
Serum vascular endothelial growth factor predicts venous invasion in hepatocellular carcinoma: a prospective study.
OBJECTIVE: To evaluate the correlation between serum vascular endothelial growth factor (VEGF) level and the clinicopathologic features in patients with hepatocellular carcinoma (HCC). SUMMARY BACKGROUND DATA: VEGF is an important angiogenic factor regulating tumor angiogenesis. A high serum VEGF level has been shown to be associated with tumor progression and metastasis in several human cancers, but its significance in HCC is unclear. The correlation between serum VEGF level and tumor pathologic features in patients with HCC has not been studied before. METHODS: Preoperative serum samples and tumor specimens were prospectively collected in 100 patients undergoing resection of HCC. Serum VEGF level was measured by enzyme-linked immunosorbent assay, and tumor VEGF expression was assessed by immunohistochemical study. Histopathologic examination was performed by a pathologist without prior knowledge of the serum VEGF level or tumor VEGF expression. RESULTS: Preoperative serum VEGF levels ranged from 15 to 1,789 pg/mL (median 269). When serum VEGF levels were compared between groups categorized by different clinicopathologic variables, significant correlation was found between a high serum VEGF level and absence of tumor capsule, presence of intrahepatic metastasis, presence of microscopic venous invasion, and advanced stage. There was a positive correlation between the serum VEGF level and tumor expression of VEGF as well as platelet count. When the 75th percentile serum VEGF level (500 pg/mL) was used as a cutoff level, the frequency of venous invasion in patients with a high serum VEGF level was significantly greater compared with patients with a low serum VEGF level. By multivariate analysis, a serum VEGF level of more than 500 pg/mL and tumor size more than 5 cm were independent preoperative factors predictive of microscopic venous invasion. During a median follow-up of 11.6 months, 48% of patients with a serum VEGF level of more than 500 pg/mL and 27% of those with a serum VEGF level of 500 pg/mL or less developed postoperative recurrence. CONCLUSIONS: These results show that a high preoperative serum VEGF level is a predictor of microscopic venous invasion in HCC, suggesting that the serum VEGF level may be useful as a biologic marker of tumor invasiveness and a prognostic factor in HCC.
Adult↗
Initiation of atrial fibrillation by ectopic beats originating from the superior vena cava: electrophysiological characteristics and results of radiofrequency ablation.
BACKGROUND: The superior vena cava (SVC) has cardiac musculature extending from the right atrium. However, no previous study in humans has given details regarding the ectopic foci that initiate paroxysmal atrial fibrillation (PAF), which may originate from the SVC. METHODS AND RESULTS: A total of 130 patients with frequent attacks of PAF initiated by ectopic beats were included. Eight patients (6%) had spontaneous AF initiated by a burst of rapid ectopic beats from the SVC (located 19+/-7 mm above the junction of the SVC and right atrium), which was confirmed by multiplane angiographic and intracardiac echocardiographic visualization and was marked by a sharp SVC potential preceding atrial activity. During initial repetitive discharges, the group with SVC ectopy had a higher incidence of intravenous conduction block than the group with pulmonary vein ectopy (75% versus 37%; P=0.03). The activation time of the earliest intracardiac ectopic activities relative to ectopic P wave onset was significantly shorter in the SVC ectopy than the pulmonary vein ectopy group (37+/-15 versus 84+/-32 ms; P<0. 001). After 5+/-3 applications of radiofrequency energy, AF was eliminated. SVC angiography after ablation revealed a local indentation of the venous wall in one patient. Two patients manifested coexisting sinus rhythm and a "focal" fibrillating activity confined inside the SVC after radiofrequency ablation. During a follow-up period of 9+/-3 months, all 8 patients were free of antiarrhythmic drugs, without tachycardia recurrence or symptoms of SVC obstruction. CONCLUSIONS: Ectopic beats initiating PAF can originate from the SVC. A radiofrequency current delivered to eliminate these ectopies is a highly effective and safe way to prevent PAF.
Adult↗
Pulmonary vein morphology in patients with paroxysmal atrial fibrillation initiated by ectopic beats originating from the pulmonary veins: implications for catheter ablation.
BACKGROUND: Successful ablation of ectopic beats originating from the pulmonary veins (PV) could eliminate paroxysmal atrial fibrillation (PAF). However, information about the structure of the PV in patients with PAF that is initiated by PV ectopic beats has not been reported. METHODS AND RESULTS: We studied the morphology of the PVs and measured their diameters in 3 groups of patients. Group I included 52 patients (aged 66+/-14 years; 44 men) with focal atrial fibrillation (AF) from the PVs. Group II included 8 patients (aged 50+/-10 years; 3 men) with focal AF from the superior vena cava or cristal terminalis. Group III included 23 control patients (aged 55+/-16 years; 17 men). Of the control patients, 11 had AV node and 12 had AV reentrant tachycardia. After an atrial transseptal procedure, selective PV angiography using a biplane system with a right anterior oblique view of 30 degrees, a left anterior oblique view of 60 degrees, and a cranial angle of 20 degrees was performed. The ostial and proximal portions of the right and left superior PVs (RSPV and LSPV) were significantly dilated in group I patients compared with those in groups II and III. Furthermore, the ostia of the RSPV and LSPV were significantly dilated in group II compared with group III patients. However, the mean diameters of the inferior PVs were similar between the 3 groups. Comparisons of the individual PV diameters among the 3 subgroups of group I (which was divided according to where the ectopic focus was located) showed nonselective dilatation of the PV. CONCLUSIONS: Nonspecific dilatation of the ostia and proximal portion of superior PVs were found in patients with PAF initiated by ectopic beats from the superior PVs.
Adult↗
Effect of verapamil on long-term tachycardia-induced atrial electrical remodeling.
BACKGROUND: The effect of verapamil on long-term tachycardia-induced atrial electrical remodeling has not been reported. METHODS AND RESULTS: Forty-eight dogs were randomly divided into verapamil and control groups. The dogs in the verapamil group received verapamil 120 mg every day, those in the control group did not receive verapamil. Atrial effective refractory period (AERP), inducibility of atrial fibrillation (AF), and duration of AF were assessed before and after complete atrioventricular junction ablation with 1-day, 1-week, or 6-week rapid atrial pacing (780 bpm). AERP shortening, AERP dispersion, AERP maladaptation, and inducibility of AF after 1-day pacing was significantly attenuated by verapamil. However, verapamil did not have any significant effect on these parameters in the dogs with 1-week or 6-week pacing. Verapamil did not have any significant effect on the conduction velocity in the dogs with 1-day, 1-week, or 6-week pacing. Before rapid atrial pacing, verapamil significantly prolonged the duration of AF. In the dogs with 1-day pacing, the duration of AF measured immediately after termination of pacing was similar between the control and verapamil groups. However, in the dogs with 1-week or 6-week pacing, the duration of AF after pacing was significantly longer in the verapamil group. CONCLUSIONS: Verapamil cannot prevent long-term (1 and 6 weeks, respectively) tachycardia-induced changes of atrial electrophysiological properties. Furthermore, verapamil increases the duration of AF in the dogs either before or after long-term rapid atrial pacing.
Adaptation, Physiological↗
Effect of phenylephrine on focal atrial fibrillation originating in the pulmonary veins and superior vena cava.
OBJECTIVES: This study was aimed at evaluating the effects of phenylephrine infusion on the occurrence of focal atrial fibrillation (AF). BACKGROUND: Paroxysmal AF can be initiated by ectopic atrial beats originating in the pulmonary vein (PV) or superior vena cava (SVC). The effect of change in autonomic tone on this focal AF is unknown. METHODS: This study included 12 patients with frequent bursts of AF documented by 24-h Holter monitoring. The number and coupling interval of spontaneous ectopic activity and bursts of AF were evaluated for 1 min before and after phenylephrine (2 to 3 microg/kg) injection. RESULTS: After detailed mapping, four patients had a focus located in the left superior PV, six in the right superior PV and two in the SVC. In 10 patients with AF foci originating in the PVs, the frequency of ectopic activity (19.5 +/- 27.4 vs. 11.4 +/- 22.9 beats/min, p = 0.059) was reduced as well as AF bursts (14 +/- 3 vs. 1.8 +/- 2.7 bursts/min, p = 0.005) before versus after phenylephrine injection; the minimal coupling interval of ectopic activity and AF bursts became longer compared with baseline. The maximal percent increase in sinus cycle length after phenylephrine injection was significantly greater in patients with complete suppression of AF compared with those with partial suppression (43 +/- 19 vs. 14 +/- 5%, p = 0.01). However, no significant effect of phenylephrine on AF originating in the SVC was found. CONCLUSIONS: Change in autonomic tone induced by phenylephrine injection was effective in suppressing focal AF originating in the PVs but not in the SVC.
Aged↗
Editorial comment: can we avoid pulmonary vein stenosis following ablation of atrial fibrillation?
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Animals↗
Differentiating the ligament of Marshall from the pulmonary vein musculature potentials in patients with paroxysmal atrial fibrillation: electrophysiological characteristics and results of radiofrequency ablation.
It was reported that paroxysmal atrial fibrillation (PAF) can be initiated by ectopic atrial beats originating from the pulmonary vein (PV) or left atrial tract (LAT) within the ligament of Marshall (LOM). The aim of this study was to differentiate the LAT from the PV potentials, and to investigate the results of radiofrequency ablation guided by these potentials. Ten patients (age 60 +/- 12 years) with PAF who had a recording of double potentials (DPs) in or around the left PV were included. Group I had five patients with the second deflection of DPs (D2) due to activation of the LAT, and Group II had five patients with D2 due to activation of the PV musculature. There were no significant difference in the isoelectric interval between DPs, the activation time, and amplitude of D2 between Groups I and II. During distal coronary sinus (CS) pacing, the CS ostium (CSO) to D2 interval was shorter compared with that during sinus rhythm in Group I (39 +/- 19 vs 71 +/- 25 ms, P = 0.04), but was longer in Group II (96 +/- 16 vs 44 +/- 19 ms, P = 0.04). During ectopic activation, three patients in Group I, but no Group II patients, had transformation of recorded DPs into triple potentials. Radiofrequency ablation guided by the earliest activation of the LAT potential was performed with transient suppression of PAF, but ablation guided by the earliest activation of the PV potentials had a high success rate in eliminating PAF. In conclusion, differentiating the LAT from the PV potentials for initiation of PAF is feasible by an electrophysiological approach, and may be important for radiofrequency ablation of PAF.
Action Potentials↗
Impact of transisthmus linear ablation of typical atrial flutter on coronary sinus activation time.
Complete or incomplete bidirectional isthmus conduction block after linear ablation of atrial flutter is difficult to interpret without detailed multiple electrodes mapping along the tricuspid annulus and the low right atrial isthmus area. The influence of isthmus block on the intraatrial septal and coronary sinus activation has not been assessed by endocardial mapping. This study was designed to analyze the intraartial and interatrial activation times in a retrospective fashion to investigate (1) whether isthmus conduction block can change the coronary sinus activation sequence during low lateral right atrial pacing, and (2) the correlation between change of coronary sinus activation time and isthmus conduction block. Sixty-five consecutive patients (mean age, 57 +/- 18 years) with clinically documented typical atrial flutter were studied. A 20-pole "Halo" catheter was placed around the tricuspid annulus including the entire low right atrial isthmus to verify complete bidirectional isthmus block. Activation time from ostium to distal coronary sinus (OCS-->DCS), and interatrial septum and isthmus activation times during right atrial pacing were analyzed and compared before and after incomplete or complete isthmus block. Complete bidirectional isthmus block was achieved in 50 (77%) patients. During low lateral right atrial pacing, linear ablation at low right atrial isthmus results in a significant delay of activation in all coronary sinus recording sites with greater extent at the ostium area without influence on interatrial septum activation in complete and incomplete isthmus conduction block. The difference of the OCS-->DCS interval before and after ablation, delta (OCS-->DCS), was well correlated with results of isthmus conduction block and significantly longer in patients with complete than those with incomplete isthmus block (34 +/- 11 vs 11 +/- 8 ms, P < 0.001), thereby allowing a value of 20 ms as a discriminative parameter to differentiate incomplete (< 20 ms) from complete (> or = 20 ms) isthmus counterclockwise conduction block with a sensitivity of 96% and a specificity of 88%. In conclusion, creation of a line of block at the inferior vena cava-tricuspid annulus isthmus could change coronary sinus activation sequence during low lateral right atrial pacing in sinus rhythm. The change of coronary sinus activation time after linear ablation, delta (OCS-->DCS), was well correlated with isthmus conduction block by using a value > or = 20 ms to discern complete counterclockwise isthmus block.
Adolescent↗
Tachycardia induced changes of atrial electrophysiological properties.
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Animals↗
Ventricular tachycardia in a patient with primary hyperparathyroidism.
We present a case of primary hyperparathyroidism with hypercalcemia in a patient who had spontaneous attacks of ventricular tachycardia. Right ventricular burst pacing reproducibly induced ventricular tachycardia in the electrophysiological laboratory after intravenous administration of calcium-gluconate, and verapamil could terminate the tachycardia. After resection of the parathyroid adenoma, the calcium level was restored to normal, and ventricular tachycardia did not occur again during the follow-up period.
Adenoma↗
Prevention of the initiation of atrial fibrillation: mechanism and efficacy of different atrial pacing modes.
Several atrial pacing modes have been reported to be effective in the prevention of atrial fibrillation (AF); they included biatrial pacing, dual site right atrial pacing, Bachmann's bundle (BB) pacing, and coronary sinus pacing. However, the relative efficacy and electrophysiological mechanisms of these pacing modes in the prevention of AF are not clear. In 15 patients (age 54 +/- 14 years) with paroxysmal AF, P wave duration, effective refractory period, and atrial conduction time were determined with six different atrial drive pacings, that were right atrial appendage (RAA), BB, right posterior interatrial septum (RPS), distal coronary sinus (DCS), RAA plus RPS simultaneously (DSA), and RAA plus DCS simultaneously (BiA). All these patients consistently had AF induced with early RAA extrastimulation coupling to RAA drive pacing. No patient had AF induced with RAA extrastimulation coupled to BB, RPS, or DCS drive pacing, but seven and eight patients had AF induced with RAA extrastimulation coupled to DSA and BiA drive pacing, respectively. The P wave duration was longest during RAA pacing, and became shorter during other atrial pacing modes. Analysis of electrophysiological change showed that early RAA extrastimulation coupled to RAA drive pacing caused the longest atrial conduction delay among these atrial pacing modes; BB, RPS, and DCS drive pacing caused a greater reduction of this conduction delay than DSA and BiA drive pacing. In addition, the effective refractory periods of RAA determined with BB, RPS, and DCS drive pacing were similar and longer than that determined with DSA and BiA drive pacing. In patients with paroxysmal AF, this arrhythmia was readily induced with RAA extrastimuli coupled to RAA drive pacing. BB, RPS, and DCS pacing were similar and more effective than DSA and BiA pacing in preventing AF.
Adolescent↗
Atrial tachycardias originating from the atrial septum: electrophysiologic characteristics and radiofrequency ablation.
INTRODUCTION: The characteristics of atrial tachycardia (AT) have varied widely among different reports. The anatomic locations of ATs may bias the results. We propose that septal ATs and free-wall ATs have different characteristics. METHODS AND RESULTS: One hundred forty-one patients with AT underwent electropharmacologic study, endocardial mapping, and radiofrequency ablation. Forty-nine (34.7%) patients had septal AT originating from the anteroseptal, mid-septal, and posteroseptal areas. Tachycardia cycle length was similar between septal AT and free-wall AT (367 +/- 46 msec vs 366 +/- 58 msec, P > 0.05). More patients with septal AT required isoproterenol to facilitate induction (44.9% vs 31.5%, P <.0.05). Septal AT was more sensitive to adenosine than free-wall AT (84.4% vs 67.8%, P < 0.05). Only posteroseptal AT showed a positive P wave in lead V1 and negative P wave in all the inferior leads (II, III, aVF). Radiofrequency catheter ablation had a comparable success rate for septal AT and free-wall AT (96% vs 95%) without impairment of AV conduction. During follow-up of 49 +/- 13 months (range 17 to 85), the recurrence rate was similar for septal AT and free-wall AT (3.2% vs 4.6%, P = 0.08). CONCLUSION: Septal AT has electrophysiologic characteristics that are distinct from those of free-wall AT. Catheter ablation of the septal AT is safe and effective.
Adult↗
Predicting the arrhythmogenic foci of atrial fibrillation before atrial transseptal procedure: implication for catheter ablation.
INTRODUCTION: Use of endocardial atrial activation sequences from recording catheters in the right atrium, His bundle, and coronary sinus to predict the location of initiating foci of atrial fibrillation (AF) before an atrial transseptal procedure has not been reported. The purpose of the present study was to develop an algorithm using endocardial atrial activation sequences to predict the location of initiating foci of AF before transseptal procedure. METHODS AND RESULTS: Seventy-five patients (60 men and 15 women, age 68 +/- 12 years) with frequent episodes of paroxysmal AF were referred for radiofrequency ablation. By retrospective analysis, characteristics of the endocardial atrial activation sequences of right atrial, His-bundle, and coronary sinus catheters from the initial 37 patients were correlated with the location of initiating foci of AF, which were confirmed by successful ablation. The endocardial atrial activation sequences of the other 38 patients were evaluated prospectively to predict the location of initiating foci of AF before transseptal procedure using the algorithm derived from the retrospective analysis. Accuracy of the value <0 msec (obtained by subtracting the time interval between high right atrium and His-bundle atrial activation during atrial premature beats from that obtained during sinus rhythm) for discriminating the superior vena cava or upper portion of the crista terminalis from the pulmonary vein (PV) foci was 100%. When the interval between atrial activation of ostial and distal pairs of the coronary sinus catheter of the atrial premature beats was <0 msec, the accuracy for discriminating left PV foci from right PV foci was 92% in the 24 foci from the left PVs and 100% in the 19 foci from the right PVs. CONCLUSION: Endocardial atrial activation sequences from right atrial, His-bundle, and coronary sinus catheters can accurately predict the location of initiating foci of AF before transseptal procedure. This may facilitate mapping and radiofrequency ablation of paroxysmal AF.
Adult↗