Slow pathway ablation in patients with documented but noninducible paroxysmal supraventricular tachycardia

Symptom burden guiding invasive electrophysiological study in paroxysmal supraventricular tachycardia: The believe SVT registry

BACKGROUND AND OBJECTIVE

Patients with palpitations clinically suggestive of paroxysmal supraventricular tachycardia (PSVT) are often managed conservatively until ECG-documentation of the tachycardia, leading to high impact on life quality and healthcare resource utilization. We evaluated results of electrophysiological study (EPS), and ablation when appropriate, among these patients, with special focus on gender differences in management.

METHODS

BELIEVE SVT is a European multicenter, retrospective registry in tertiary hospitals performing EPS in patients with palpitations, without ECG-documentation of tachycardia or preexcitation, and considered highly suggestive of PSVT by a cardiologist or cardiac electrophysiologist. We analyzed clinical characteristics, results of EPS and ablation, complications, and clinical outcomes during follow-up.

RESULTS

Six-hundred eighty patients from 20 centers were included. EPS showed sustained tachycardia in 60.9% of patients, and substrate potentially enabling AVNRT in 14.7%. No major/permanent complications occurred. Minor/transient complications were reported in 0.84% of patients undergoing diagnostic-only EPS and 1.8% when followed by ablation. During a 3.4-year follow-up, 76.2% of patients remained free of palpitations recurrence. Ablation (OR: 0.34, P < .01) and male gender (OR: 0.58, P = .01) predicted no recurrence. Despite a higher female proportion among patients with recurrence, (77.2% vs 63.5% among those asymptomatic during follow-up, P < .01), 73% of women in this study reported no recurrence of palpitations after EPS.

CONCLUSIONS

EPS and ablation are safe and effective in preventing recurrence of nondocumented palpitations clinically suggestive of PSVT. Despite a lower efficacy, this strategy is also highly effective among women and warrants no gender differences in management.

Clinical impact of "pure" empirical catheter ablation of slow-pathway in patients with non-ECG documented clinical on-off tachycardia

Background

Catheter ablation of slow-pathway (CaSP) has been reported to be effective in patients with dual atrioventricular nodal conduction properties (dcp-AVN) and clinical ECG documentation but without the induction of tachycardia during electrophysiological studies (EPS). However, it is unknown whether CaSP is beneficial in the absence of pre-procedural ECG documentation and without the induction of tachycardia during EPS. The aim of this study was to evaluate long-term results after a “pure” empirical CaSP (peCaSP).

Methods

334 consecutive patients who underwent CaSP (91 male, 47.5 ± 17.6 years) were included in this study. Sixty-three patients (19%) who had no pre-procedural ECG documentation, and demonstrated dcp-AVN with a maximum of one echo-beat were assigned to the peCaSP group. The remaining 271 patients (81%) were assigned to the standard CaSP group (stCaSP). Clinical outcomes of the two groups were compared, based on ECG documented recurrence or absence of tachycardia and patients’ recorded symptoms.

Results

CaSP was performed in all patients without any major complications including atrioventricular block. During follow-up (909 ± 435 days), 258 patients (77%) reported complete cessation of clinical symptoms. There was no statistically significant difference in the incidence of AVNRT recurrence between the peCaSP and stCaSP groups (1/63 [1.6%] vs 3/271 [1.1%], P = 0.75). Complete cessation of clinical symptoms was noted significantly less frequently in patients after peCaSP (39/63 [62%] vs 219/271 [81%], P = 0.0013). The incidence of non-AVNRT atrial tachyarrhythmias (AT) was significantly higher in patients after peCaSP (5/63 [7.9%] vs 1/271 [0.4%], P = 0.0011).

Conclusion

A higher incidence of other AT and subjective symptom persistence are demonstrated after peCaSP, while peCaSP improves clinical symptoms in 60% of patients with non-documented on–off tachycardia.

Correlation between the sudden jump-like increases of the atrio-Hisian interval induced during burst atrial pacing and during programmed atrial stimulation in patients with atrioventricular nodal reentrant tachycardia

Purpose

To study the correlation between the sudden prolongations of the atrio-Hisian (AH) interval with ≥50 ms during burst and programmed atrial stimulation, and to define whether the AH jump during burst atrial pacing is a reliable diagnostic criterion for dual AV nodal physiology.

Methods

Retrospective data on 304 patients with preliminary ECG diagnosis of AV nodal reentrant tachycardia (AVNRT), confirmed during electrophysiological study, was analyzed for the presence of AH jump during burst and programmed atrial stimulation, and for correlation between the pacing modes for inducing the jump. Wilcoxon signed-ranks test and Spearman's bivariate correlation coefficient were applied, significant was P-value <0.05.

Results

The population was aged 48.5 ± 15.7 (12-85) years; males were 38.5%. AH jump occurred during burst atrial pacing in 81% of the patients, and during programmed stimulation – in 78%, P = 0.366. In 63.2% AH jump was induced by both pacing modes; in 17.8% – only by burst pacing; in 14.8% – only by programmed pacing; in 4.2% there was no inducible jump. There was negative correlation between both pacing modes, ρ = –0.204, Р<0.001.

Conclusion

Burst and programmed atrial stimulation separately prove the presence of dual AV nodal physiology in 81 and 78% of the patients with AVNRT, respectively. There is negative correlation between the two pacing modes, allowing the combination of the two methods to prove diagnostic in 95.8% of the patients.

Occurrence of primarily noninducible atrioventricular nodal reentry tachycardia after radiofrequency delivery in the slow pathway region during empirical slow pathway modulation

BACKGROUND

The first-line therapy for atrioventricular nodal reentry tachycardia (AVNRT) is catheter-based slow pathway modulation. If AVNRT is not inducible during an electrophysiological study, an empirical slow pathway modulation (ESPM) may be considered in patients with dual atrioventricular nodal physiology and/or a typical electrocardiogram (ECG).

METHODS

We screened 149 symptomatic patients who underwent ESPM in our department between 1993 and 2013. All patients fulfilled the following criteria: (1) either dual atrioventricular nodal (AVN) physiology with up to 2 AVN echo beats or characteristic ECG documentation or both, (2) noninducibility of AVNRT by programmed stimulation, and (3) completion of a telephone questionnaire for long-term follow-up. Out of this population we retrospectively investigated 13 patients who were primarily noninducible but in whom an AVNRT occurred during or after radiofrequency (RF) delivery.

RESULTS

When AVNRT occurred, the procedure lost its empirical character, and RF delivery was continued until the procedural endpoint of noninducibility of AVNRT. This endpoint was reached in all but one patient (92%). After a follow-up of 73 ± 15 months, this patient was the only one who reported no benefit from the procedure.

CONCLUSIONS

Out of 149 initially noninducible patients, a considerable number (9%) exhibited AVNRT during or after RF delivery. These patients crossed over from empirical to controlled slow pathway modulation resulting in a good clinical outcome. Our observations should encourage electrophysiologists to repeat programmed stimulation even after initial empirical RF delivery to retest for inducibility.

Empiric slow pathway ablation in non-inducible supraventricular tachycardia

BACKGROUND

The data supporting the practice of empiric slow pathway ablation (ESPA) in patients with documented supraventricular tachycardia (SVT) who are non-inducible at electrophysiology study (EPS) is limited. The aim of this study is to assess the efficacy of ESPA in adults.

METHODS

A multi-center cohort study of patients who had ESPA between January 2008 and October 2013 was performed. Patients were identified by screening sequential SVT ablation procedures.

RESULTS

Forty-three (5%) out of 859 SVT ablation procedures were identified as ESPA. The median age was 53 (IQR: 24) years; 63% were female. All patients had pre-EPS documentation of SVT (either strip or ECG). In 23 (53.5%) cases, pre-EPS ECG showed short RP tachycardia. Thirty-two (74.4%) patients had dual atrioventricular nodal physiology (DAVNP) plus echo beats. Junctional rhythm (JR) as procedural endpoint was noted in 39 (90.7%) patients. In 18 (41.9%) patients, the abolishment of DAVNP was achieved. No complications were encountered. A median follow-up of 17 months (range: 6 to 31 months) revealed 83.7% (36 of 43) success rate, defined as the absence of pre-procedural symptoms and any documented sustained arrhythmia. As compared to patients with recurrence (n=7), patients with no recurrence (n=36) had significantly higher prevalence of clinical short RP tachycardia (61.1% vs. 14.3%, p=0.038), and EPS finding of DAVNP plus echo beats (80.6% vs. 42.9%, p=0.034).

CONCLUSIONS

ESPA is a reasonable approach in patients with documented SVT, in particular in short RP tachycardia, who are not inducible at EPS. Larger studies are required to assess this practice.

Multiple multisite low-temperature and low-power radiofrequency currents for the induction of atrioventricular nodal reentry tachycardia in non-inducible patients

AIMS

Some patients with documented episodes of paroxysmal supraventricular tachycardia (PSVT) do not have inducible tachycardia during the electrophysiological study. In this study, we describe how multiple low-temperature, low-power radiofrequency (RF) currents in the atrioventricular (AV) junction region can increase the rate of the induction of atrioventricular nodal reentrant tachycardia (AVNRT) in non-inducible cases.

METHOD

We enrolled 31 consecutive patients (mean age = 50.9 ± 11.9 years; 5 [16.1 %] male) who presented with documented clinical PSVT in superficial electrocardiography but had non-inducible arrhythmia in the electrophysiology laboratory despite applying different stimulation protocols. We delivered low-power (25 W), low-temperature (45 °C) RF currents into the AV junction region to induce AVNRT.

RESULTS

Arrhythmia was induced in 20 (64.5 %) patients, and it was non-sustained in 3 (9.6 %) patients. RF current was delivered into the posterior region near the coronary sinus ostium and midseptal region. RF ablation target in inducible patients was the non-inducibility of the AVNRT at the end of the procedure, while the target in the non-inducible patients was slow pathway ablation with no antegrade conduction over the slow pathway. During the follow-up period, none of the patients (either with inducible or non-inducible arrhythmia) had recurrence of AVNRT.

CONCLUSION

Multiple low-power, low-temperature RF current application into the AV junction region is a more effective method for the induction of AVNRT in comparison with a single current use into the slow pathway.

Approaches to empiric ablation of slow pathway: results from the Canadian EP web survey

AIM

Dual atrioventricular nodal physiology (DAVNP) is a frequent finding in patients with suspected or documented supraventricular tachycardia (SVT). Empiric slow pathway ablation (ESPA) is sometimes performed in patients with DAVNP without inducible SVT at the time of electrophysiological study. Evidence to guide this practice in the adult population is limited. This study was aimed to assess the practice of ESPA by adult electrophysiologists in Canada.

METHODS

All Canadian interventional electrophysiologists (n = 81) were invited to complete a web-based questionnaire assessing their practice of ESPA in patients with suspected and documented SVT. Operator experience, reimbursement models, diagnostic, and treatment decisions regarding ESPA were assessed with case scenarios.

RESULTS

Forty-one responses (50 %) were obtained. Ninety-five percent of the responders stated that the evidence for ESPA is lacking or limited. Responders were more likely to perform ESPA in the setting of non-inducible SVT when there was documentation of the clinical arrhythmia (64 vs. 31 % (p = 0.017)). The threshold to perform ESPA was highly variable. Longer time in practice (r = 0.38, p = 0.017) and less perceived complications with ESPA (r = 0.31, p = 0.05) were correlated with the practice of ESPA, whereas length of ablation waiting lists (r = -0.15, p = 0.38), number of procedures performed per day (r = 0.11, p = 0.51) and type of reimbursement (p = 0.24) were not associated with the practice of ESPA. The perceived complication rate with ESPA was <1 %.

CONCLUSION

Variability in the practice of ESPA in cases of non-inducible SVT exists. Documentation of the clinical arrhythmia, operator experience, and perceived low complication rates positively influence this practice.

Decremental Ramp Atrial Extrastimuli Pacing Protocol for the Induction of Atrioventricular Nodal Re-entrant Tachycardia and Other Supraventricular Tachycardias

AIM

The primary aim of this study was to evaluate the utility of decremental ramp atrial extrastimuli pacing protocol (PRTCL) for induction of atrioventricular nodal re-entrant tachycardia (AVNRT), and other supraventricular tachycardias (SVTs), compared to standard (STD) methods.

METHODS

The study cohort of 121 patients (age 57.51 +/- 14.02 years) who presented with documented SVTs and/or symptoms of palpitations and dizziness, and underwent invasive electrophysiological evaluation was divided into Group I (AVNRT, n = 42) and Group II (Control, n = 79). The PRTCL involved a train of six atrial extrastimuli, delivered in a decremental ramp fashion. The STD methods included continuous burst and rapid incremental pacing up to atrioventricular (AV) block cycle length, and single and occasionally double atrial extrastimuli. Prolongation in the Atrio-Hisian (Delta-AH) intervals achieved by both methods were compared, as were induction frequencies.

RESULTS

In Group I, three categories of responses--(1) induction of AVNRT, (2) induction of echo beats only, and (3) none--were observed in 29 (69%), 11 (26%), and 2 (5%) patients with the PRTCL, when compared with 14 (33%), 16 (38%), and 12 (29%) patients with STD methods in the baseline state without the use of pharmacological agents. The Delta-AH intervals for each of these three categories were larger using PRTCL versus STD methods; 293.3 +/- 95.2 ms versus 192.9 +/- 61.4 ms (P < 0.005), 308.6 +/- 68.5 ms versus 189. 9 +/- 64.9 ms (P < 0.0005), and 203.0 +/- 86.3 ms versus 145.8 +/- 58.9 ms (P = NS), respectively. In Group II, in one patient with dual AV nodal physiology but no clinical tachycardia, the PRTCL induced nonsustained (12 beats) AVNRT. Additionally, in this group, both PRTCL and STD methods induced atrial tachycardia in two patients and orthodromic AV re-entrant tachycardia in one patient.

CONCLUSION

Decremental ramp atrial extrastimuli pacing PRTCL demonstrates a superior response for induction of typical AVNRT as compared to STD techniques. Because of easy and reliable induction of AVNRT and echo beats by the PRTCL, we recommend it as a method to increase the likelihood of induction of AVNRT. For induction of other SVTs, the PRTCL and the STD methods are comparable.

Slow pathway ablation in children with documented reentrant supraventricular tachycardia not inducible during invasive electrophysiologic study

Radiofrequency catheter ablation (RFA) has become the procedure of choice for permanent therapy of atrioventricular nodal reentrant tachycardia (AVNRT). This report presents our experience with atrio-ventricular node (AVN) modification in patients with documented narrow complex reentrant SVT, but no evidence for an accessory pathway, and no inducible tachyarrhythmia during invasive electrophysiology (EP) study.

METHODS

The study population consists of nine children, age range 6-13 years (median 9) with previously documented SVT who had no tachyarrhythmia inducible during EP study (at baseline and following isoprenaline infusion). Eight of the 9 EP studies were performed under general anesthesia, and one under conscious sedation. An accessory pathway was excluded in all patients by appropriate atrial and ventricular extrastimulus pacing techniques. Eight of the nine patients had dual AV nodal physiology, and one had single AV nodal echo beats. The slow AV nodal pathway was empirically ablated, by applying RF lesions in the right inferoseptal AV groove, achieving catheter tip temperature of 50 degrees C. The appearance of an accelerated junctional rhythm during RF application was deemed to denote a successful application site. AV conduction during RF application was confirmed by incremental atrial pacing. The catheter position, and its relation to the compact AV node was constantly monitored using the LocaLisa navigation system. The end-point was absence of dual AVN physiology, and/or AV nodal echo beats.

RESULTS

Successful slow pathway ablation was achieved in all patients. One patient appeared to have two separate slow pathways with different locations and two AH-jumps, which were both successfully ablated. None of the patients had evidence of temporary or permanent AV block at follow-up (median duration 9 months, range 4 to 36 months); none has had recurrence of symptoms or documented tachyarrhythmia.

CONCLUSIONS

In children with structurally normal hearts, a previously documented SVT, absence of an accessory pathway and noninducibility of SVT during EP study, empirical slow pathway ablation appears to be justified.

Junctional Rhythm-A Suitable Surrogate Endpoint in Catheter Ablation of Atrioventricular Nodal Reentry Tachycardia?

INTRODUCTION

Current AHA/ACC guidelines state that junctional rhythm (JR) is an acceptable endpoint in patients undergoing radiofrequency ablation (RFA) for narrow complex tachycardia in the presence of dual AV nodal physiology, but in the absence of inducible AVNRT. Only limited data are available on the utility of JR as a marker of successful slow pathway ablation. We sought to further characterize the sensitivity, specificity, and predictive value of JR in AVNRT ablation.

METHODS

A retrospective analysis was performed of 387 consecutive patients with documented narrow complex tachycardia referred for ablation, with dual AV nodal physiology and inducible AVNRT at electrophysiological study. RFA of slow pathway was performed, with the presence or absence of JR recorded for each application and inducibility tested using atrial stimulation protocol and isoproterenol.

RESULTS

Successful ablation was achieved in 385 of 387 patients using a total of 1,861 applications of radiofrequency energy. JR occurred in 692 applications, giving a sensitivity and specificity of JR as an indicator of successful ablation of 99.5% and 79.1% and a positive predictive value of 55.5%.

CONCLUSIONS

This study confirms that successful ablation of slow pathway seldom occurs in the absence of JR. Although JR almost invariably occurs with successful ablation, its lack of specificity and low positive predictive value questions the use of it as an endpoint in AVNRT ablations, and the guidelines should reflect this.

Long-term efficacy of slow-pathway catheter ablation in patients with documented but noninducible supraventricular tachycardia

BACKGROUND

The long-term efficacy of radiofrequency catheter ablation of slow pathway in patients with dual atrioventricular node pathway and a documented but noninducible paroxysmal supraventricular tachycardia (PSVT) is not entirely clear.

METHODS

Forty nine patients (Group A) with documented but noninducible PSVT and dual atrioventricular node pathway were prospectively studied. Programmed electrical stimulation induced a single atrioventricular node echo beat in 13 patients, and double echo beats in 9 at baseline or during isoproterenol infusion. Clinical and electrophysiological characteristics of Group A patients were compared with that of age- and gender-matched patients with dual atrioventricular node pathway but inducible PSVT (Group B).

RESULTS

There was no significant difference in the electrophysiological properties of the fast and slow pathways between the two groups. Catheter ablation eliminated the slow pathway in all patients. There was no recurrence of PSVT in either Group A or Group B during the follow-up of 38 +/- 5 months.

CONCLUSIONS

In patients with dual atrioventricular node pathway and a documented but noninducible PSVT, catheter ablation of slow pathway is highly effective in preventing tachycardia in long term.

Registro Español de Ablación con Catéter. III Informe Oficial de la Sección de Electrofisiología y Arritmias de la Sociedad Española de Cardiología (2003)

INTRODUCTION

The results of the Third Spanish Catheter Ablation Registry, developed by the Working Group on Electrophysiology and Arrhythmias, are presented for the third consecutive year (2003).

MATERIAL AND METHOD

In contrast to previous years, data were collected in two different ways at the discretion of the participating center. Retrospective were obtained with a standard questionnaire, as in previous years. Prospective data were obtained from a database of records completed after each ablation was performed. Results and complications are presented according to different arrhythmic substrates.

RESULTS

Thirty-nine centers participated in the registry (25 supplied prospective data and 14 retrospective data), representing more than 80% of all electrophysiological laboratories in Spain. A total number of 4354 ablations were recorded (111 procedures per center, 2723 from the prospective registry and 1631 from the retrospective one). The substrate most frequently treated was AV nodal reentry tachycardia (31.6%, 98% success), followed by accessory pathways (26%, 89% success) and atrial macro-reentry tachycardia (23%, 90% success). The incidence of complications was 1.7% and mortality was 0.11%. With the prospective registry we obtained more comprehensive information individualized for each procedure (age, sex, underlying cardiomyopathy, anticoagulation, sedation, type of catheter, etc.).

CONCLUSIONS

The high rate of participation in the registry and the consistency of the results with previous years help to consolidate the registry as a reference for the rest of the scientific community. The results from the prospective registry showed better-quality information and more detailed reporting of results and complications.

Is electrical stimulation during administration of catecholamines required for the evaluation of success after ablation of atrioventricular node re-entrant tachycardias?

OBJECTIVES

The purpose of this study was to answer the question of whether stimulation after administration of catecholamines is mandatory for identifying unsuccessful ablations of atrioventricular node re-entrant tachycardia (AVNRT).

BACKGROUND

The success of radiofrequency (RF) catheter ablation in AVNRT is confirmed in many centers by noninducibility of tachycardias during stimulation after the administration of catecholamines.

METHODS

A total of 131 patients (81 women and 50 men; mean age 53.6 +/- 13.7 years [range 20 to 77]) were studied. Electrical stimulation was performed without and with the beta-adrenergic amine Orciprenaline (metaproterenol) before and after RF catheter ablation.

RESULTS

In 100 patients (76.3%; confidence interval [CI] 68.1% to 83.3%) an AVNRT was inducible without administration of Orciprenaline. Thirty minutes after the initially successful ablation in 95 patients, tachycardia was inducible in none of these patients, not even after Orciprenaline administration. In the 31 patients (23.7%; CI 16.7% to 31.9%) in whom there was no tachycardia inducible before ablation, Orciprenaline was given, and the stimulation protocol was repeated. In only five patients (3.8%; CI 1.3% to 8.7%) was there still no tachycardia inducible. After an initially successful ablation in the 26 patients who had inducible tachycardias with Orciprenaline before ablation, no tachycardia could be re-induced. After Orciprenaline, the tachycardia was inducible again in only one patient.

CONCLUSIONS

Only patients who require catecholamines for tachycardia induction before ablation need catecholamines for control of the success of the ablation of AVNRT.

Simplified "ATP test" for noninvasive diagnosis of dual AV nodal physiology and assessment of results of slow pathway ablation in patients with AV nodal reentrant tachycardia

INTRODUCTION

We recently reported that administration of adenosine triphosphate (ATP) during sinus rhythm identifies dual AV nodal physiology (DAVNP) in 76% of patients with inducible sustained AV nodal reentrant tachycardia (AVNRT) at electrophysiologic (EP) study. In that report, however, the ATP test was considered positive for DAVNP only when the results were reproducible at a given dose of ATP. The aim of the present study was to assess the value of a simplified ATP test for noninvasive diagnosis of DAVNP and abolition or modification of the slow pathway (SP) after radiofrequency ablation (RFA) in patients with inducible sustained AVNRT.

METHODS AND RESULTS

The value of a single dose of ATP was studied in 105 patients with inducible sustained AVNRT and in 31 control patients before placement of EP catheters in the cardiac chambers. ATP (10 to 60 mg, in 10-mg increments) was injected during sinus rhythm until ECG signs of DAVNP (> or = 50 msec increase or decrease in PR interval in two consecutive beats, or occurrence of > or = 1 AV nodal echo beat) or > or = second-degree AV block was observed. DAVNP was observed in only 1 (3.2%) control patient. The test could be completed in 96 study patients. DAVNP was found by ATP test in 72 (75%) patients, whereas it was diagnosed by EP criteria in 82 (85%) patients. DAVNP by ATP test disappeared in 27 (96%) of 28 patients who underwent SP abolition and in 18 (60%) of 30 patients who underwent SP modification. In the 12 patients with persistent DAVNP determined by ATP test after SP modification, the number of beats conducted over the SP was significantly reduced (from 6.3+/-3.3 to 2.5+/-2.2 beats; P = 0.002).

CONCLUSION

A single administration of ATP during sinus rhythm (at a given dose) enables noninvasive diagnosis of DAVNP in a high percentage of patients with inducible AVNRT and reliably confirms the results of RFA of the SP.

[Typical AV nodal reentry tachycardia in 4 anterograde AV nodal pathways. Successful high frequency ablation of slow AV nodal pathways]

CASE REPORT

A 26-year-old patient was referred to our department for electrophysiologic evaluation of recurrent paroxysmal tachycardias with narrow QRS-complexes (< 120 ms). Three jumps in the AV-nodal conduction curve were detected during programmed atrial extrastimulation in sinus rhythm and at a cycle length of 600 ms indicating of 4 antegrade conducting AV-nodal pathways. After intravenous application of orciprenaline an AV-nodal re-entrant-tachycardia (AVNRT) of the common type was induced with a cycle length of 290 ms. During tachycardia, antegrade conduction occurred via one of the slow conducting pathways, retrograde conduction via the fast pathway ("slow-fast"-AVNRT). Application of radiofrequency energy was able to ablate all slowly conducting AV-nodal pathways at one site in the infero-posterior region of Koch's triangle. During control stimulation with and without orciprenaline no AH-jump or inducible tachycardia was found.

CONCLUSION

This case shows the rare finding of 4 antegrade AV-nodal pathways in a patient with the common type of AVNRT. Application of radiofrequency current was able to ablate all slow conducting AV-nodal pathways successfully.

Cycling of inducibility of paroxysmal supraventricular tachycardia in women and its implications for timing of electrophysiologic procedures

Arrhythmias in women may be affected by phases of the menstrual cycle. This study was designed to determine the prevalence of perimenstrual clustering of spontaneous episodes of paroxysmal supraventricular tachycardia (SVT) in women. It also tested the hypothesis that women with this temporal pattern of events have an altered probability of induction of paroxysmal SVT during electrophysiologic testing at higher estrogen states (midcycle or with estrogen replacement therapy) than at low estrogen states (perimenstrual or without estrogen replacement). A structured history of the relation of spontaneous paroxysmal SVTs to phases of the menstrual cycle was obtained prospectively among 42 women referred during a 3-year period. Patients with cyclical patterns of spontaneous tachycardias, who had had negative electrophysiologic studies at midcycle or while receiving estrogen replacement therapy, had repeat procedures (1) when premenstrual or at the onset of menses, or (2) after stopping estrogen replacement therapy. Seventeen of 42 consecutive female patients (40%) had histories of perimenstrual clustering of arrhythmias. Six women (4 with normal menstrual cycles, 2 on estrogen replacement therapy), who qualified for paired electrophysiologic studies because of a negative initial electrophysiologic study that included provocation with isoproterenol, had inducibility into SVTs during the second study. All 6 had dual atrioventricular (AV) nodal pathway physiology, 4 had AV nodal reentrant tachycardia (AVNRT) induced, 1 had both AVNRT and reciprocating AV tachycardias, and 1 had nonsustained AVNRT and an atrial tachycardia induced. Successful ablation procedures were performed in 5 of the 6 patients. Thus, among women with a history of perimenstrual clustering of paroxysmal SVT and among those receiving estrogen replacement therapy, scheduling of elective electrophysiologic procedures at times of low estrogen levels (premenstrual or off estrogen replacement therapy) may facilitate the probability of a successful procedure.

Clinical and electrophysiologic characteristics and long-term efficacy of slow-pathway catheter ablation in patients with spontaneous supraventricular tachycardia and dual atrioventricular node pathways without inducible tachycardia

OBJECTIVES

We sought to investigate the long-term efficacy of slow-pathway catheter ablation in patients with spontaneous, documented paroxysmal supraventricular tachycardia (PSVT) and dual atrioventricular (AV) node pathways but without inducible tachycardia.

BACKGROUND

The lack of reproduction of clinical PSVT by programmed electrical stimulation, which is not uncommon in AV node reentrant tachycardia (AVNRT), is a dilemma in making the decision of the therapeutic end point of radiofrequency catheter ablation.

METHODS

Twenty-seven patients (group A) with documented but noninducible PSVT and with dual AV node pathways were prospectively studied. Programmed electrical stimulation could induce a single AV node echo beat in 12 patients, double echo beats in 4 patients and none in 11 patients at baseline or during isoproterenol infusion. Of the patients in group A, 16 underwent slow-pathway catheter ablation and 11 did not. The clinical and electrophysiologic characteristics of the 27 patients were compared with those of patients with dual AV node pathways and inducible AVNRT (group B, n = 55) and patients with dual AV node pathways alone without clinical PSVT (group C, n = 47).

RESULTS

During 23+/-13 months of follow-up, none of the 16 patients with slow-pathway catheter ablation had recurrence of PSVT. However, 7 of the 11 patients without ablation had PSVT recurrence at 13+/-14 months of follow-up (p < 0.03 by Kaplan-Meier analysis). Compared with groups B and C, group A consisted predominantly of men who had better retrograde AV node conduction and a narrower zone for anterograde slow-pathway conduction.

CONCLUSIONS

Slow-pathway catheter ablation is highly effective in eliminating spontaneous PSVT in which the tachycardia is not inducible despite the presence of dual AV node pathways.

AV nodal reentrant tachycardia with unusual characteristics: lessons from radiofrequency catheter ablation

There are still some AV nodal reentrant tachycardias with unusual AV nodal properties that need further study to understand these complexities. Accordingly, the two-dimensional model with alpha and beta pathways in the AV nodal reentrant tachycardia circuit certainly is an oversimplification and does not explain adequately the anatomic and physiologic complexity of the AV junctional area. The modern concept suggests that this arrhythmia takes place in a highly complex three-dimensional model with nonuniform anisotropy and discontinuous conduction property in the AV junctional area. Application of radiofrequency energy within the AV junctional area should always be performed carefully to achieve a successful ablation procedure and to minimize possible injury of AV nodal conduction.

Results of radiofrequency ablation in patients with clinically documented, but noninducible, atrioventricular node reentrant tachycardia and orthodromic atrioventricular reciprocating tachycardia

Among 1,281 patients with symptomatic supraventricular tachycardia, 34 patients (2.7%) with presumed diagnosis of atrioventricular node reentrant tachycardia and orthodromic atrioventricular reciprocating tachycardia did not have inducible tachycardia in the electrophysiologic laboratory. Application of radiofrequency energy to the presumed arrhythmogenic sites could achieve a high success rate, with a low recurrence rate in these patients.