Efficacy and Safety of Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia in the Elderly

Atrioventricular nodal reentrant tachycardia

Atrioventricular nodal reentrant tachycardia represents the most frequent, regular tachyarrhythmia in humans, but its exact circuit has so far remained elusive. This review presents new evidence that allows the proposal of a model for the arrhythmia circuit as well as a reclassification of the types of atrioventricular nodal reentrant tachycardia and discusses the implications for effective and safe catheter ablation of the arrhythmia.

A rare complication after radiofrequency catheter ablation in an adolescent case: skin burn

Radiofrequency catheter ablation is a preferred treatment method for cardiac arrhythmias in children due to its high success rate and low complication risk. We present an adolescent patient who underwent radiofrequency catheter ablation for Wolff-Parkinson-White syndrome and developed a skin burn at the site of the electrode patch. Skin burns can catastrophic consequences, especially in patients with life-threatening arrhythmias; therefore, clinicians should be aware of this complication.

Reduction of Radiation Exposure in Atrioventricular Nodal Reentrant Tachycardia Ablations Using an Electroanatomical Mapping System With Fluoroscopy Integration Module

Introduction: Atrioventricular nodal reentrant tachycardia (AVNRT) is a common supraventricular tachycardia. Current guidelines recommend electrophysiology study (EPS) and ablation, which have been proven to show high success rates with very low complication rates. Usually, ablation of AVNRT is performed conventionally using only fluoroscopy. Electroanatomical mapping systems (EMS) are widely used in complex arrhythmias. One of their advantages is their potential in decreasing the need of fluoroscopy time (FT). In this study we analyzed patients undergoing either conventional AVNRT ablation or by using an EMS with a fluoroscopy integrating system (FIS).

Materials and Methods: We included 119 patients who underwent AVNRT ablation in our study. Eighty-nine patients were ablated conventionally using only fluoroscopy, 30 patients were ablated using EMS + FIS.

Results: We found that the use of EMS + FIS led to a significant reduction of FT (449.90 ± 217.21 vs. 136.93 ± 109.28 sec., p < 0.001) and dose-area-product (DAP, 268.27 ± 265.20 vs. 41.07 ± 27.89 μGym², p < 0.001) without affecting the procedure time (PT, 66.55 ± 13.3 vs. 67.33 ± 13.81 min, p = 0.783). Furthermore, we found no significance with regard to complications.

Conclusion: The use of EMS+FIS is safe and feasible. It leads to a significant reduction of both FT and DAP without affecting PT and safety. Hence, EMS + FIS is beneficial for both the operator and the patients by reducing the radiation exposure.

Wenckebach cycle length: A novel predictor for AV block in AVNRT patients treated with ablation

BACKGROUND

Radiofrequency catheter ablation remains the most effective management option for atrioventricular nodal reentry tachycardia (AVNRT). The risk of atrioventricular (AV) block requiring permanent pacemaker is substantial, but, currently, a reliable method to predict this complication is lacking.

METHODS

The electrophysiologic studies (EPS) and baseline characteristics of patients who underwent catheter ablation for the treatment of AVNRT were retrospectively analyzed to investigate predisposing factors for AV block after treatment. Patients were followed for AV block at one month and one year after hospital discharge.

RESULTS

Among 784 patients treated with catheter ablation for AVNRT between 1999 to 2019, 15 developed AV block. Patients with AV block were older (p = .001). Among the recorded EPS parameters, patients with AV block had significantly higher Atrial His interval (120 vs. 110 ms, p = .049), Wenckebach cycle length (WCL) (400 vs. 353 ms, p < .001) and tachycardia CL (400 vs. 387 ms, P = .01) during the ablation compared to their peers without AV block. Additionally, only WCL (OR = 1.1, 95% CI 1.02-1.19, p = .017) remained significant after adjustment for age, gender, ERP, AH interval, and HR. This association was confirmed by comparing patients with (n = 15) and without (n = 15) AV block using propensity score-matching. A WCL≥400ms was associated with a 4-fold higher incidence of AV block (4.79% vs. 1.25%).

CONCLUSION

Increased pre-procedural WCL was associated with a high risk for AV block after catheter ablation treatment for AVNRT. These findings suggest that this readily available EPS-derived parameter may be a novel marker of risk for severe complications in these patients.

Periprocedural, early, and long-term risks of pacemaker implantation after atrioventricular nodal re-entry tachycardia ablation: a French nationwide cohort

AIMS

Pacemaker implantation (PI) after atrioventricular nodal re-entry tachycardia (AVNRT) ablation is a dreadful complication. We aimed to assess periprocedural, early, and late risks for PI.

METHODS AND RESULTS

All 27 022 patients who underwent latest AVNRT ablation in France from 2009 to 2017, were identified in the nationwide medicalization database. A control group of 305 152 patients hospitalized for arm, leg, or skin injuries with no history of AVNRT or supraventricular tachycardia were selected. After propensity score matching, both groups had mean age of 53 ± 18 years and were predominantly female (64%). During this 9-year period, 822 of 27 022 (3.0%) AVNRT patients underwent PI, with significant higher risk in propensity-matched AVNRT patients compared to propensity-matched controls [2.9% vs. 0.9%; hazard ratio 3.4 (2.9-3.9), P < 0.0001]. This excess risk was significant during all follow-up, including periprocedural (1st month), early (1-6 months), and late (>6 months) risk periods. Annualized late risk per 100 AVNRT patients was 0.2%. In comparison to controls, excess risk was 0.2% in <30-year-old AVNRT patients; 0.7% in 30-50-year-old; 1.1% in 50-70-year-old and 6.5% over 70-year-olds. Risk for PI was also significantly different according to three procedural factors: centres, experience, and ablation date, with a 30% decrease since 2015.

CONCLUSION

Periprocedural, early, and late risks for PI were higher after AVNRT ablation compared to propensity-matched controls. Longer follow-up is needed as the excess risk seems to persist late after AVNRT ablation.

Clinical predictors of heart block during atrioventricular nodal reentrant tachycardia ablation: A multicenter 18-year experience

BACKGROUND

Catheter ablation is considered the first-line treatment of symptomatic atrioventricular nodal reentrant tachycardia (AVNRT). It has been associated with a risk of heart block (HB) requiring a pacemaker. This study aims to determine potential clinical predictors of complete heart block as a result AVNRT ablation.

METHODS

Consecutive patients undergoing catheter ablation for AVNRT from January 2001 to June 2019 at two tertiary hospitals were included. We defined ablation-related HB as the unscheduled implantation of pacemaker within a month of the index procedure. Use of electroanatomic mapping (EAM), operator experience, inpatient status, age, sex, fluoroscopy time, baseline PR interval, and baseline HV interval was included in univariate and multivariate models to predict HB post ablation.

RESULTS

In 1708 patients (56.4 ± 17.0 years, 61% females), acute procedural success was 97.1%. The overall incidence of HB was 1.3%. Multivariate analysis showed that age more than 70 (odds ratio [OR] 7.907, p ≤ .001, confidence interval [CI] 2.759-22.666), baseline PR ≥ 190 ms (OR 2.867, p = .026, CI 1.135-7.239) and no use of EAM (OR 0.306, p = .037, CI 0.101-0.032) were independent predictors of HB.

CONCLUSION

Although the incidence of HB post AVNRT ablation is generally low, patients can be further stratified using three simple predictors.

Impact of age on catheter ablation of premature ventricular contractions

INTRODUCTION

Catheter ablation (CA) of frequent premature ventricular contractions (PVC) is increasingly performed in older patients as the population ages. The aim of this study was to assess the impact of age on procedural characteristics, safety and efficacy on PVC ablations.

METHODS

Consecutive patients with symptomatic PVCs undergoing CA between 2015 and 2020 were evaluated. Acute ablation success was defined as the elimination of PVCs at the end of the procedure. Sustained success was defined as an elimination of symptoms, and ≥80% reduction of PVC burden determined by Holter-electrocardiogram during long-term follow. Patients were sub-grouped based on age (<65 vs. ≥65 years).

RESULTS

A total of 114 patients were enrolled (median age 64 years, 71% males) and followed up for a median duration of 228 days. Baseline and procedural data were similar in both age groups. A left-sided origin of PVCs was more frequently observed in the elderly patient group compared to younger patients (83% vs. 67%; p = .04). The median procedure time was significantly shorter in elderly patients (160 vs. 193 min; p = .02). The rates of both acute (86% vs. 92%; p = .32) and sustained success (70% vs. 71%; p = .90) were similar between groups. Complications rates (3.7%) did not differ between the two groups.

CONCLUSION

In a large series of patients with a variety of underlying arrhythmia substrates, similar rates of acute procedural success, complications, and ventricular arrhythmia-free-survival were observed after CA of PVCs. Older age alone should not be a reason to withhold CA of PVCs.

Arrhythmias in Patients ≥80 Years of Age: Pathophysiology, Management, and Outcomes

Advances in medical care have led to an increase in the number of octogenarians and even older patients, forming an important and unique patient subgroup. It is clear that advancing age is an independent risk factor for the development of most arrhythmias, causing substantial morbidity and mortality. Patients ≥80 years of age have significant structural and electrical remodeling of cardiac tissue; accrue competing comorbidities; react differently to drug therapy; and may experience falls, frailty, and cognitive impairment, presenting significant therapeutic challenges. Unfortunately, very old patients are under-represented in clinical trials, leading to critical gaps in evidence to guide effective and safe treatment of arrhythmias. In this state-of-the-art review, we examine the pathophysiology of aging and arrhythmias and then present the available evidence on age-specific management of the most common arrhythmias, including drugs, catheter ablation, and cardiac implantable electronic devices.

Catheter Ablation of Atrioventricular Nodal Re-entrant Tachycardia: Facts and Fiction

Collapse

Influence of advancing age on clinical presentation, treatment efficacy and safety, and long-term outcome of inducible paroxysmal supraventricular tachycardia without pre-excitation syndromes: A cohort study of 1960 patients included over 25 years

AIM

To investigate the influence of increasing age on clinical presentation, treatment and long-term outcome in patients with inducible paroxysmal supraventricular tachycardia (SVT) without pre-excitation syndromes.

METHODS

Clinical and electrophysiological study (EPS) data, as well as long-term clinical outcome (mean follow-up 2.4±4.0 years) were collected in patients referred for regular tachycardia with inducible SVT during EPS without pre-excitation.

RESULTS

Among 1960 referred patients, 301 patients (15.4%) were aged ≥70 (70-97). In this subset, anticoagulants were prescribed in 49 patients following an erroneous diagnosis of atrial tachycardia and 14 were previously erroneously diagnosed with ventricular tachycardia because of wide QRS. Ablation was performed more frequently in patients ≥70 despite more frequent failure and complications. During follow-up, higher risks of AF, stroke, pacemaker implantation and death were observed in patients ≥70 whereas SVT recurrences were similar in both age groups. In multivariable analysis, age ≥70 was independently associated with higher risks of SVT-related adverse events prior to ablation (OR = 1.93, 1.41-2.62, p<0.001), conduction disturbances (OR = 11.27, 5.89-21.50, p<0.001), history of AF (OR = 2.18, 1.22-3.90, p = 0.009) and erroneous diagnosis at baseline (OR = 9.14, 5.93-14.09, p<0.001) as well as high rates of procedural complications (OR = 2.13, 1.19-3.81, p = 0.01) and ablation failure (OR = 1.68, 1.08-2.62, p = 0.02). In contrast, age ≥70 was not significantly associated with a higher risk of AF in multivariable analysis.

CONCLUSIONS

A sizeable proportion of patients with inducible SVT without pre-excitation syndromes are elderly. These patients exhibit higher risks of erroneous tachycardia diagnosis prior to EPS as well as failure and/or complication of ablation, but similar risk of SVT recurrence. These results support performing transesophageal EPS in most patients and intracardiac EPS in selected patients. EPS may furthermore prove useful in elderly patients with regular tachycardia, mainly by avoiding treatment based on an erroneous diagnosis.

Classification, Electrophysiological Features and Therapy of Atrioventricular Nodal Reentrant Tachycardia

Atrioventricular nodal reentrant tachycardia (AVNRT) should be classified as typical or atypical. The term 'fast-slow AVNRT' is rather misleading. Retrograde atrial activation during tachycardia should not be relied upon as a diagnostic criterion. Both typical and atypical atrioventricular nodal reentrant tachycardia are compatible with varying retrograde atrial activation patterns. Attempts at establishing the presence of a 'lower common pathway' are probably of no practical significance. When the diagnosis of AVNRT is established, ablation should be only directed towards the anatomic position of the slow pathway. If right septal attempts are unsuccessful, the left septal side should be tried. Ablation targeting earliest atrial activation sites during typical atrioventricular nodal reentrant tachycardia or the fast pathway in general for any kind of typical or atypical atrioventricular nodal reentrant tachycardia, are not justified. In this review we discuss current concepts about the tachycardia circuit, electrophysiologic diagnosis, and ablation of this arrhythmia.

Incidence and Factors Predicting Skin Burns at the Site of Indifferent Electrode during Radiofrequency Catheter Ablation of Cardiac Arrhythmias

Radiofrequency catheter ablation (RFA) has become a mainstay for treatment of cardiac arrhythmias. Skin burns at the site of an indifferent electrode patch have been a rare, serious, and likely an underreported complication of RFA. The purpose of this study was to determine the incidence of skin burns in cardiac RFA procedures performed at one institution. Also, we wanted to determine the factors predicting skin burns after cardiac RFA procedures at the indifferent electrode skin pad site. Methods. A retrospective case control study was performed to compare the characteristics in patients who developed skin burns in a 2-year period. Results. Incidence of significant skin burns after RFA was 0.28% (6/2167). Four of the six patients were female and all were Caucasians. Four controls for every case were age and sex matched. Burn patients had significantly higher BMI, procedure time, and postprocedure pain, relative to control subjects (p < 0.05, one-tailed testing). No one in either group had evidence of dispersive pad malattachment. Conclusions. Our results indicate that burn patients had higher BMI and longer procedure times compared to control subjects. These findings warrant further larger studies on this topic.

Case series: Radiofrequency cathether ablation of atrioventricular nodal reentrant tachycardia in octogenerians

Ablation in octogenerians is effective and allows rationalisation of pharmacotherapy. Advancing age should not be a barrier to its use.

Clinical and electrophysiological characteristics of typical atrioventricular nodal reentrant tachycardia in the elderly - changing of slow pathway location with aging

BACKGROUND

The aim of this study was to retrospectively evaluate the clinical and electrophysiological characteristics of elderly patients with typical atrioventricular nodal reentrant tachycardia (AVNRT), and to assess the acute safety and efficacy of slow-pathway radiofrequency (RF) ablation in this specific group of patients.

METHODS AND RESULTS

The present study retrospectively included a total of 1,290 patients receiving successful slow-pathway RF ablation for typical slow-fast AVNRT. Patients were divided into 2 groups: group I included 1,148 patients aged <65 years and group II included 142 patients aged >65 years. The required total procedure duration and total fluoroscopy exposure time were significantly higher in group II vs. group I (P=0.005 and P=0.0001, respectively). The number of RF pulses needed for a successful procedural end-point was significantly higher in group II than in group I (4.4 vs. 7.2, P=0.005). While the ratio of the anterior location near to the His-bundle region was significantly higher in group II, the ratio of posterior and midseptal locations were significantly higher in group I (P=0.0001). The overall procedure success rates were similar. There was no significant difference between the 2 groups in respect of the complications rates.

CONCLUSIONS

This experience demonstrates that RF catheter ablation, targeting the slow pathway, could be considered as first-line therapy for typical AVNRT patients older than 65 years as well as younger patients, as it is very safe and effective in the acute period of treatment.

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.

Role of isoproterenol in predicting the success of catheter ablation in patients with reproducibly inducible atrioventricular nodal reentrant tachycardia

Noninducibility of the arrhythmia is the widely accepted endpoint of successful ablation of atrioventricular nodal reentrant tachycardia (AVNRT). However, to rely upon that as the only endpoint, the arrhythmia must also be inducible before ablation. Despite the fact that AVNRT is not reproducibly inducible in a significant number of cases, the role of reproducible arrhythmia induction and its relationship with the infusion of isoproterenol after successful ablation of AVNRT has not been well defined. We studied 175 consecutive patients who all underwent successful radiofrequency ablation after showing that they had reproducibly inducible AVNRT without use of isoproterenol. In Group 1 (n=90), isoproterenol was used for arrhythmia reinduction after ablation, whereas in Group 2 (n=85) it was not. The procedural and follow-up data of both groups were recorded, and the results of appropriate statistical tests were analyzed. During a mean follow-up time of 18.7 ± 4.5 months, 4 patients in Group 1 and 3 patients in Group 2 experienced recurrences. Regardless of elimination or modification of slow-pathway conduction, no significant difference was seen in the recurrence rates of AVNRT between the 2 groups (P=0.72). We conclude that, when the original arrhythmia in patients with AVNRT is reproducibly inducible in the basal state, the use of isoproterenol after ablation in order to confirm the noninducibility of AVNRT does not appear to alter the recurrence rates and can be omitted.

Permanent pacemaker implantation for late atrioventricular block in patients receiving catheter ablation for atrioventricular nodal reentrant tachycardia

The present study investigated the incidence and predictors of permanent pacemaker (PPM) implantation for late atrioventricular block (AVB) in patients with atrioventricular nodal reentrant tachycardia (AVNRT) who received ablation. The data from 3,442 patients with AVNRT who received ablation were analyzed. Those who developed late AVB (>1 month after ablation) and received a PPM were identified. The incidence of PPM implantation in 1,148 matched patients with Wolff-Parkinson-White syndrome and in the whole population of Taiwan were compared. Of the patients with AVNRT receiving ablation (mean follow-up duration 128.3 ± 62.5 months), 15 (0.4%) received PPM implantation for late AVB (mean interval after catheter ablation 95.4 ± 55.0 months). Only age (odds ratio 1.05, p = 0.02) and transient AVB (odds ratio 8.55, p = 0.01) during the procedure were independently associated with PPM implantation for late AVB. The patients with AVNRT had a greater incidence of PPM implantation due to late AVB compared to the matched patients with Wolff-Parkinson-White syndrome. The annual incidence of PPM implantation for AVB was also greater in the patients with AVNRT than in the general population. In conclusion, the incidence of PPM implantation for late AVB in patients with AVNRT who received catheter ablation was low but still greater than that in patients with Wolff-Parkinson-White syndrome and the general population in Taiwan.

Difference of clinical course after catheter ablation of atrioventricular nodal reentrant tachycardia between younger and older patients: atrial vulnerability predicts new onset of atrial fibrillation

BACKGROUND

The aim of this study was to compare the long-term procedural outcomes, the stability of atrioventricular conduction, and the new onset of atrial fibrillation (AF), after ablation of atrioventricular nodal reentrant tachycardia (AVNRT).

METHODS AND RESULTS

Consecutive patients with AVNRT (n=109), who underwent slow-pathway ablation, were divided into two groups based on the median age of the studied patients: the younger group aged <55 years and the older group aged ≥55 years. During a mean follow-up period of 60.6 months, the rate of change in the PR interval from before ablation to follow-up was significantly greater in older patients compared with younger patients. However, there was no delayed-onset high-degree AV block during follow-up in either group. No patients in the younger group suffered from persistent AF, whereas persistent AF occurred in 5/54 (9.3%) older patients. Multivariate Cox analysis revealed that atrial vulnerability, with induction of AF during the electrophysiological study, was the only predictor of the development of AF (Hazard ratio: 13.9, 95% confidence interval: 1.62-119.2, p<0.01).

CONCLUSION

Slow-pathway ablation of AVNRT is a reliable strategy even in older patients. However, physicians should consider regular long-term follow-up of older patients with atrial vulnerability, in order to assess the subsequent development of AF.

Supraventricular tachycardia: diagnosis and management

Supraventricular tachycardia (SVT) includes all forms of tachycardia that either arise above the bifurcation of the bundle of His or that have mechanisms dependent on the bundle of His. We conducted a review of the techniques used to differentiate the mechanisms of SVT. We searched the PubMed and MEDLINE databases for English-language literature published from 1970 to 2008. Articles were selected for either their historical importance or up-to-date clinical data. This review focuses on techniques for scrutinizing electrocardiograms of patients, analyzing in particular the onset of tachycardia, the mode of tachycardia termination, and the effects of premature ventricular contractions, premature atrial contractions, and aberrancy during tachycardia. Both short-term and long-term management of SVT are examined, including the urgent treatment of patients in the emergency department. This review also describes management of patients who have ongoing symptomatic SVT, outlining such available treatment options as atrioventricular node-blocking drugs, antiarrhythmic drugs, and catheter ablation.

Efficacy and safety of radiofrequency catheter ablation in the elderly

INTRODUCTION

Radiofrequency (RF) catheter ablation has not been widely undertaken in elderly patients. The aim of our study was to compare the success rate of radiofrequency ablation and the incidence of severe procedural complications in young-adult and elderly patients.

METHODS

We enrolled all patients undergoing radiofrequency catheter ablation procedures for supraventricular and ventricular arrhythmias at our Cardiology Department from January 2000 to December 2005. The patients were divided into two groups according to age: patients aged <70 years (group A) and those aged >or=70 years (group B). Group B was then divided into two subgroups: B1 (age 70-79 years) and B2 (age >or=80 years). We recorded the incidence of procedural complications and the long-term efficacy (mean follow-up 46 +/- 20 months).

RESULTS

We studied 605 patients, 69% in group A and 31% in group B (24% in subgroup B1 and 7% in B2). The prevalence of structural heart disease was higher in elderly patients than in young adults (83 vs 37%, p < 0.01). The rate of procedural complications was 1.3%; no differences emerged between groups A and B (1.2 vs 1.5%, p = NS) or among groups A, B1 and B2 (1.2 vs 1.4 vs 2%, p = NS). The success rate of catheter ablation was 91%, with no differences between the age-groups (92 vs 88%, p = NS) or among groups A, B1 and B2 (92 vs 88 vs 88%, p = NS).

CONCLUSION

Catheter ablation in elderly and very elderly patients is as effective and safe as in young-adult subjects, at least in cases which do not require left heart catheterization.

Slow Atrioventricular Nodal Reentrant Arrhythmias: Clinical Recognition, Electrophysiological Characteristics, and Response to Radiofrequency Ablation

BACKGROUND

Atrioventricular nodal reentrant tachycardia (AVNRT) is a common form of supraventricular tachycardia (SVT). Rarely, patients may present with an unusual form of atrioventricular nodal reentrant arrhythmia (AVNRA) with a cycle length greater than 600 ms. We describe the clinical presentation, electrophysiology characteristics, and response to radiofrequency ablation in a group of patients with AVNRA.

METHODS AND RESULTS

Six patients with slow documented sustained supraventricular arrhythmias at rates <100 bpm underwent electrophysiology study. Baseline clinical and electrophysiologic characteristics were: mean age 77 +/- 5 years; left ventricular ejection fraction 51 +/- 10%; hypertension 66%; diabetes mellitus 33%; coronary artery disease 33%; sinus cycle length 874 +/- 110 ms; PR 261 +/- 54 ms; atrial to His (AH) 181 +/- 49 ms. AVNRA was diagnosed based on previously described criteria for AVNRT. Mean tachycardia cycle length (TCL) during AVNRA was 668 +/- 74 ms. The AH and His to atrial (HA) intervals during the AVNRA was 434 +/- 50 and 234 +/- 81 ms, respectively. Two patients had slow-fast AVNRA while the others had slow-slow AVNRA. Most common symptoms reported during AVNRA were shortness of breath, fullness in the throat, chest tightness, dizziness, near-syncope, and syncope. Radiofrequency catheter ablation (RFCA) of the slow pathway was performed successfully in five of six patients. Post-ablation AV nodal Wenckebach occurred at 666 +/- 49 ms compared with 521 +/- 91 ms at baseline.

CONCLUSION

AVNRA may occur at rates less than 100 bpm in the elderly and may be misdiagnosed as junctional rhythm. Slow AVNRA can cause significant symptoms. Slow pathway ablation can be successfully performed in AVNRA.

Ablation of supraventricular tachycardia in a 96 year old

Atrioventricular nodal re-entrant tachycardia (AVNRT) is a common arrhythmia that is frequently encountered in clinical practice. Though more common in the younger population, it affects individuals of all ages. The elderly in particular are usually more symptomatic and more frequently require emergency treatment including urgent hospital admissions. We report on a 96-year-old lady who presented with troublesome supraventricular tachycardia that was difficult to control with drug treatment. Electrophysiologic testing revealed AVNRT that was ablated successfully using the standard technique with no complications. She continued to do well at follow-up 1 month after the ablation. This case highlights the need to routinely offer this highly effective technique as the first-line treatment to the elderly along the same indications as those commonly observed among younger patients.

Contemporary catheter ablation of arrhythmias in geriatric patients: patient characteristics, distribution of arrhythmias, and outcome

AIMS

Catheter ablation is a treatment of first choice for many arrhythmias. Data in geriatric patients are still limited, mostly focusing on single arrhythmia types. The aim of the study was to investigate characteristics of contemporary ablation therapy in the very elderly, focusing on patient characteristics, arrhythmia spectrum, and outcome in a large cohort.

METHODS AND RESULTS

We studied 131 consecutive patients aged 80 and older (mean age 83 +/- 3) undergoing ablation for any indication from 1998 until 2004. Sixty-eight patients (52%) had structural heart disease. Most common indications were typical atrial flutter (54%), atrioventricular nodal re-entrant tachycardia (AVNRT) (22%), and atrial fibrillation (AF) (18%). Patients with structural heart disease had more often atrial flutter (72 vs. 35%, P < 0.001) and less AVNRT (7 vs. 38%, P < 0.001) than those without structural heart disease. In almost all patients with AF, ventricular rate control was achieved by elimination of atrioventricular conduction and pacemaker implantation. Success rate exceeded 97% for all ablation types. There was one major complication (0.8%), a stroke after isthmus ablation.

CONCLUSION

Almost half of the very elderly patients undergoing ablation have structural heart disease. Indications have changed significantly in recent years, typical atrial flutter is nowadays the predominant indication. The arrhythmia spectrum differs significantly between patients with and without structural heart disease. Regardless of the presence or absence of structural heart disease, success is excellent. Catheter ablation is an excellent therapy option for geriatric patients with arrhythmias.

Electrophysiologic characteristics and results of radiofrequency catheter ablation in elderly patients with atrioventricular nodal reentrant tachycardia

BACKGROUND

As in the general population, atrioventricular nodal reentrant tachycardia (AVNRT) is the most common regular supraventricular tachycardia in the elderly patients. We tried to compare electrophysiologic characteristics, efficacy, and risks of the radiofrequency (RF) catheter ablation of the slow pathway in elderly and young patients with AVNRT.

METHODS

Between April 2001 and March 2005, 268 consecutive patients (190 females; mean age, 49 +/- 14 years) with AVNRT underwent RF catheter ablation at our institution. The patients were categorized into 2 groups: group 1 consists of patients younger than 65 years (n = 156), and group 2 consists of patients 65 years or older (n = 112).

RESULTS

Compared with the younger subgroup, elderly patients more often had structural heart disease (11.6% vs 2.5%, P = .004), but there were no statistically significant differences in sex and symptoms during tachycardia (all P > .05). AVNRT cycle length was significantly longer in group 2 than in group 1 patients (P = .005). Among the conduction intervals of tachycardia, only atrio-his interval was significantly longer in group 2 patients (P = .007). The ablation fluoroscopy time, RF pulse duration, target temperature, applied energy, and number of RF applications were comparable in the 2 groups (All P > .05). Risk of atrioventricular block, pericardial effusion, and vascular thrombosis were similar in both groups (All P > .05). During follow-up with duration of 14 months, similar rate of recurrence was observed in the 2 groups (P = .94).

CONCLUSIONS

In elderly patients, slow pathway ablation is as effective and safe as in younger patients. Therefore, when considering different treatment options in elderly patients, an increased risk of complications or lower efficacy should not be a factor in determining the best therapeutic approach.

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.

Long-term efficacy and safety of radiofrequency ablation in elderly patients with atrioventricular nodal re-entrant tachycardia

AIMS

The purpose of this study was to evaluate the efficacy, risks, safety, and follow-up of radiofrequency (RF) catheter ablation of atrioventricular nodal re-entrant tachycardia (AVRNT) in patients (pts) > or = 75 years old (n=42) (GpI) compared with pts younger than 75 years (n=234) (GpII).

METHODS AND RESULTS

The study population consisted of 276 consecutive pts (39.5% men/60.5% women), from 15 to 98-year-old (average 56+/-17 years) with AVRNT referred for RF ablation (RFA) from October 1997 to January 2004. Combined anatomical and electrogram approaches were used to guide RFA. The cumulative risk of AVRNT recurrence was analysed by the Kaplan-Meier method and log-rank test. The average follow-up was 34+/-18 months. GpI (80+/-4 years) differed significantly from GpII (51+/-14 years) regarding: heart rate tachycardia (160+/-20 vs. 180+/-30 bpm; P=0.0001), the slow pathway antegrade refractory period (370+/-70 vs. 340+/-60 ms; P=0.01), the fast pathway antegrade refractory period (360+/-60 vs. 330+/-60 ms; P=0.003), retrograde refractory period (360+/-60 vs. 330+/-60 ms; P=0.0007), left ventricular ejection fraction (60+/-12 vs. 65+/-7%; P=0.0009), and ischaemic ECG signs during tachycardia (76.2% vs. 61%; P=0.09). RFA was successfully obtained in 275/276 (99.6%), 42/42 in GpI (100%), and 233/234 (99.6%) in GpII. Five complications occurred (1.8%): major complications in two pts (0.7%) and minor complications in three pts (1.1%). Major complications were deep venous thrombosis with pulmonary embolus (n=1) and pericardial effusion (n=1), minor complications were groin haematoma (n=3). One complication was observed in GpI (groin haematoma) (2.4%) and four in GpII (deep venous thrombosis with pulmonary embolus in one, groin haematoma in two, and pericardial effusion in one) (1.7%). The number of recurrences was not statistically different between the two groups (0 vs. 3.4%; P=0.5) with a respective average follow-up of 28+/-18 and 35+/-18 months, respectively.

CONCLUSION

Catheter ablation of AVRNT in elderly and very elderly pts appears to be a reasonable approach regarding feasibility and effectiveness without increasing the risk of AV block.

Temas de actualidad 2005: electrofisiología y arritmias

Cardiac electrophysiology laboratories deal with a wide range of pathological conditions, diagnostic techniques, and treatments. Since a huge quantity of material has been published in recent months, this article will be limited to discussion of the most significant developments in the prognostic evaluation of arrhythmias, hereditary disease, syncope, atrial fibrillation, implantable cardioverter-defibrillators, cardiac resynchronization therapy, and catheter ablation. Even within these areas, discussion will be restricted to specific concrete topics and to a limited number of publications that were judged to have important implications for clinical practice. Our principal aim was to provide clinical cardiologists with an overview of the latest developments in cardiac electrophysiology.