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PubMed1994

[Incessant ectopic atrial tachycardia in pregnancy: radiofrequency catheter ablation in immediate postpartum with disappearance of tachycardia-related dilated cardiomyopathy].

A 29-year-old woman presented with incessant atrial tachycardia and tachycardia-related cardiomyopathy during the last weeks of pregnancy. At 40 weeks of gestation a healthy infant was delivered by Cesarean section. Various medical treatments and two attempts of electrical cardioversion were ineffective in restoring sinus rhythm. Electrophysiologic study with endocardial activation mapping confirmed the diagnosis and thereafter radiofrequency transcatheter ablation of the ectopic focus was successfully carried out and sinus rhythm was restored. Serial 24-h Holter monitoring at 1, 3, and 6 months showed the persistence of sinus rhythm. Echocardiographic examinations demonstrated a very rapid recovery of both left ventricular diameters and ejection fraction to normal limits within two weeks after ablation. In this case-report the potential role of pregnancy and recent advances in the understanding and treatment of ectopic atrial tachycardia are summarized. Although endocardial mapping is difficult, radiofrequency catheter ablation appears to be the elective technique for the treatment of this particular arrhythmia, often refractory to antiarrhythmic drugs. Moreover, this case highlights that tachycardia-related cardiomyopathy should be seriously considered in any patient with apparently end-stage dilated cardiomyopathy and persistent tachycardia.

Adult↗
PubMed1993

[Long-term follow-up of anti-tachycardia surgery in patients with ventricular tachycardia].

From March 1980 to May 1992 mapping guided surgery was performed in 132 patients with drug-refractory recurrent ventricular tachycardia. There were 121 patients (group I) with coronary disease and 11 patients (group II) had noncoronary ventricular tachycardia. Patients in group I underwent subendocardial resection and cryoablation was performed in group II patients. Perioperative mortality (< 30 days after surgery) was 8% (10/132 patients). During the mean follow-up of 41 +/- 24 months, 37/122 patients (30%) died, 35/111 patients in group I (32%) and 2/11 patients in group II (18%) (p = 0.29). In group I, sudden death occurred in 8/111 patients (7%) and cardiac death in 23/111 patients (21%); in group II, 1/11 patients (9%) died from sudden and 1/11 patients (9%) from cardiac death. Nonfatal recurrences occurred significantly more frequently in group II (6/11 patients, 55%) than in group I (16/111 patients, 14%) (p < 0.01). During the follow-up functional class of heart failure improved in 69 patients (57%), remained constant in 27 patients (22%) and decreased in the remaining 26 patients (21%). The surgical approach to control ventricular tachycardia has low rates of sudden death and nonfatal recurrences in patients with drug-refractory ischemic ventricular tachycardia. Patients with noncoronary disease had a high incidence of nonfatal ventricular tachycardia after surgery and should be considered for other therapeutic approaches in the future.

Adolescent↗
PubMed1998

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.

Adolescent↗
PubMed1986

High-frequency analysis of the surface electrocardiograms of patients with supraventricular tachycardia: accurate identification of atrial activation and determination of the mechanism of tachycardia.

Signal processing of the electrocardiogram (ECG) was performed during supraventricular tachycardia (SVT) in 24 patients in an attempt to locate the P wave and to characterize its morphology in three orthogonal planes. In patients with atrioventricular reciprocating tachycardia, a discrete atrial signal could be identified within the ST segment and/or T wave with inferior-to-superior orientation. Atrial activation was identified in patients with primary atrial tachycardia as long as there was a constant relationship between each QRS complex and the preceding atrial signal. Patients with atrioventricular nodal reentrant tachycardia were deduced to have simultaneous atrial and ventricular activation when no atrial signal could be seen elsewhere in the cycle. Mean maximum P wave amplitude was 25.4 +/- 6.3 microV during SVT, with a mean noise level below 1.0 microV. Signal processing of the ECG during SVT enhances the detection of the P wave and the appreciation of P wave morphology, both of which are important factors in the noninvasive determination of the electrophysiologic mechanisms of SVT.

Atrial Flutter↗
PubMed1997

Pharmacologic management of supraventricular tachycardias in children. Part 2: Atrial flutter, atrial fibrillation, and junctional and atrial ectopic tachycardia.

OBJECTIVE: To review the literature regarding the use of antiarrhythmic agents in the management of atrial flutter (AF), atrial fibrillation (Afib), junctional ectopic tachycardia (JET), and atrial ectopic tachycardia (AET) in infants and children. To discuss the advantages and disadvantages of specific agents in each type of arrhythmia in an effort to develop treatment guidelines. DATA SOURCE: A MEDLINE search encompassing the years 1966-1996 was used to identify pertinent literature for discussion. Additional references were found in the articles, which were retrieved via MEDLINE. STUDY SELECTION: Clinical trials that address the use of antiarrhythmic agents for the treatment of supraventricular tachycardia, AF, Afib, JET, and AET in children were selected. Literature pertaining to dosage, pharmacokinetics, efficacy, and toxicity of antiarrhythmic agents in children were considered for possible inclusion in the review; information judged to be pertinent by the authors was included in the discussion. DATA EXTRACTION: Although there are numerous reports of antiarrhythmic use in children, there are very few large studies designed that evaluate the use of specific antiarrhythmic agents in the treatment of AF, Afib, JET, or AET. Ideally, controlled clinical trials are used to develop clinical guidelines; however, in this situation, most data and information must be obtained from case series of children treated. Although the results from these types of studies may be useful in developing guidelines for the optimal use of these agents for the treatment of AF, Afib, JET, and AET, controlled trials are required for establishing standard treatment guidelines for all patients. DATA SYNTHESIS: Despite limited scientific evaluation of conventional agents in the treatment of AF, Afib, JET, or AET in children, they continue to be the standards of care. Most information regarding the use of conventional agents in children has been extrapolated from the adult literature. Little justification for the use of the agents or dosing in children is available. Controlled trials regarding the use of newer antiarrhythmic agents (propafenone, amiodarone, flecainide) are available; however, the variance in dosing schemes, presence of structural heart disease, and patient age may confound the results. CONCLUSIONS: Because of greater clinical experience, conventional antiarrhythmic agents generally remain as first-line therapy in the management of most supraventricular tachycardias in children. Atrial pacing or cardioversion to reestablish sinus rhythm is indicated for initial episodes of AF in infants, followed by chronic prophylactic therapy in those with significant structural heart disease or in infants in whom AF recurs. Attempts to eliminate AF in children outside the neonatal or infancy period should begin with trials of traditional agents such as digoxin or procainamide, and if unsuccessful, subsequent trials of amiodarone. Digoxin and beta-blockers remain the mainstay of therapy for children with Afib, followed by procainamide for treatment failures. Intravenous amiodarone, the newest addition to our antiarrhythmic armamentarium, is the most promising agent in the treatment of postoperative JET. This arrhythmia has been traditionally managed with corporal cooling and/or digoxin therapy; however, intravenous amiodarone may now be a valuable option. Although relatively unsuccessful in the management of congenital JET and AET, conventional agents are typically used prior to the initiation of long-term therapy with potentially more toxic agents such as amiodarone or propafenone. Additional well-designed, controlled trials are needed to further evaluate the comparative efficacy of agents such as flecainide, sotalol, moricizine, propafenone, and amiodarone in the management of AF, Afib, JET, and AET in children, as well as to evaluate the dosing and toxicity in various age groups.

Anti-Arrhythmia Agents↗
PubMed1994

[Incessant fetal tachycardia coinciding with supraventricular tachycardia of the mother].

The case of a gestant diagnosed fetal arrhythmia in the 35th week of gestation is presented. A fetal echocardiography indicates an aneurysm of the interauricular septum and a fetal supraventricular tachycardia. Also is obtained an ambulatory 24-hour Holter electrocardiograph of the gestant and fetus rhythm. The register makes evident a gestant supraventricular tachycardia and as well a fetal supraventricular tachycardia, occurring in both without clinical company. Following the birth, the tachycardia in the newborn is identified to be automatic and incessant, requiring digital for its control. In postpartum registers of the mother no significant arrhythmia of any type is observed. We conclude that the ambulatory monitoring with a Holter electrocardiograph could be a good method of diagnosis and follow-up of fetal and gestant arrhythmias.

Adult↗
PubMed1988

Electrocardiographic criteria for ventricular tachycardia in wide complex left bundle branch block morphology tachycardias.

Four electrocardiographic criteria for ventricular tachycardia (VT) were proposed and evaluated. These included (1) an R wave in V1 or V2 of greater than 30-ms duration; (2) any Q wave in V6; (3) a duration of greater than 60 ms from the onset of the QRS to the nadir of the S wave in V1 or V2 and (4) notching on the downstroke of the S wave in V1 or V2. The data showed that all 4 criteria had high predictive accuracy (96 to 100%) and specificity (94 to 100%). The relatively low sensitivities of the 4 criteria alone (30 to 64%) might limit their efficacy. Grouped criteria, however, could differentiate VT from supraventricular tachycardias with high sensitivity, specificity and predictive accuracy. The amount of tracings having either electrocardiographic criteria (1) or (2) or (3) or (4) was determined. The proposed combined criteria had a sensitivity of 100%, specificity of 89% and a predictive accuracy of 96%. Left axis deviation alone was of no value in distinguishing VT from supraventricular tachycardia. Characteristic patterns were present for left bundle branch block pattern VT associated with anterior and inferior myocardial infarction. In conclusion, the 12-lead electrocardiogram alone, when systematically analyzed, can be used to accurately diagnose the origin of wide complex tachycardias with left bundle branch block pattern. Attention to these criteria may lead to more rapid and effective therapy.

Bundle-Branch Block↗
PubMed2006

Atrioventricular nodal reentrant tachycardia associated with idiopathic ventricular tachycardia: clinical and electrophysiologic characteristics.

BACKGROUND: Case reports have described the coexistence of ventricular tachycardia (VT) and supraventricular tachycardia in the same patient. This study examines the frequency of dual atrioventricular nodal (AVN) physiology, AVN echo beats, and atrioventricular nodal reentrant tachycardia (AVNRT) in patients with VT. METHODS: Programmed atrial and ventricular stimulation was performed in 132 consecutive patients referred for electrophysiologic study of symptomatic VT. Of the 132, 99 patients had structural heart disease, and 33 patients had idiopathic ventricular tachycardia (IVT). RESULTS: Among the 33 patients with IVT, 23 had dual AVN physiology. Compared with patients with structural heart disease undergoing VT ablation, dual AVN pathways (70% vs 27%, P < .0001), dual AVN pathways with echo beats (24% vs 8%, P = 0.03), and AVNRT (21% vs 1%, P = .0002) were more common in patients with IVT. CONCLUSION: Dual AVN physiology and AVNRT appear to be associated with IVT. This finding suggests that patients with IVT should undergo a complete electrophysiologic evaluation, and the diagnosis of coexistent AVNRT should be considered in this population.

Adolescent↗
PubMed2001

Electrophysiologic and clinical effects of angiotensin-converting enzyme inhibitors in patients with prior myocardial infarction, nonsustained ventricular tachycardia, and depressed left ventricular function. MUSTT Investigators. Multicenter UnSustained Tachycardia Trial.

Angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce sudden cardiac death and all-cause mortality. They also may have direct antiarrhythmic properties. We retrospectively analyzed the data from the Multicenter UnSustained Tachycardia Trial (MUSTT), to determine the effects of ACE inhibitors on inducibility of sustained ventricular tachycardia and on sudden cardiac death and overall mortality in 2,087 patients with prior myocardial infarction, nonsustained ventricular tachycardia, and depressed left ventricular function. Results of electrophysiologic testing were compared by use of ACE inhibitors at baseline, and outcomes were compared between the 564 patients prescribed ACE inhibitors at discharge and the 1,523 patients who did not receive treatment. The inducibility of sustained ventricular tachycardia during electrophysiologic testing did not differ by baseline ACE inhibitor use (unadjusted p = 0.75). Patients discharged from hospital on ACE inhibitors had a lower ejection fraction, more extensive coronary artery disease, and fewer previous revascularizations at baseline. After adjustments for differences in baseline factors and initial hospitalization variables, there were no significant differences in total mortality (p = 0.47) or arrhythmic death or cardiac arrest (p = 0.51) with ACE inhibitor use at discharge over a median 43 months of follow-up.

Aged↗
PubMed1996

Electrophysiologic comparison between incessant and paroxysmal tachycardia in patients with permanent form of junctional reciprocating tachycardia.

To clarify the differences between the incessant and paroxysmal types of the permanent form of junctional reciprocating tachycardia, we performed electrophysiologic studies in 11 patients with long RP' tachycardia using a slowly conducting accessory pathway as the retrograde conduction, and concluded that the short AH intervals during sinus rhythm and tachycardia are very important factors in the development of incessant tachycardia.

Adolescent↗
PubMed1997

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.

Adult↗
PubMed2001

Differentiation of atypical atrioventricular node re-entrant tachycardia from orthodromic reciprocating tachycardia using a septal accessory pathway by the response to ventricular pacing.

OBJECTIVES: The purpose of this study was to determine whether the response to ventricular pacing during tachycardia is useful for differentiating atypical atrioventricular node re-entrant tachycardia (AVNRT) from orthodromic reciprocating tachycardia (ORT) using a septal accessory pathway. BACKGROUND: Although it is usually possible to differentiate atypical AVNRT from ORT using a septal accessory pathway, a definitive diagnosis is occasionally elusive. METHODS: In 30 patients with atypical AVNRT and 44 patients with ORT using a septal accessory pathway, the right ventricle was paced at a cycle length 10 to 40 ms shorter than the tachycardia cycle length (TCL). The ventriculo-atrial (VA) interval and TCL were measured just before pacing. The interval between the last pacing stimulus and the last entrained atrial depolarization (stimulus-atrial [S-A] interval) and the post-pacing interval (PPI) at the right ventricular apex were measured on cessation of ventricular pacing. RESULTS: All 30 patients with atypical AVNRT and none of the 44 patients with ORT using a septal accessory pathway had an S-A-VA interval >85 ms and PPI-TCL >115 ms. CONCLUSIONS: The S-A-VA interval and PPI-TCL are useful in distinguishing atypical AVNRT from ORT using a septal accessory pathway.

Adult↗
PubMed1997

A new electrocardiographic algorithm using retrograde P waves for differentiating atrioventricular node reentrant tachycardia from atrioventricular reciprocating tachycardia mediated by concealed accessory pathway.

OBJECTIVES: The purpose of this study was to use an electrocardiographic (ECG) algorithm, derived from the results of radiofrequency ablation, to discriminate atrioventricular node reentrant tachycardia (AVNRT) from atrioventricular reciprocating tachycardia (AVRT) and to localize a concealed accessory pathway, prospectively. BACKGROUND: Information about ECG criteria for differentiating AVNRT from AVRT is limited and has not been confirmed by surgical or catheter ablation. METHODS: Four hundred six ECGs (obtained from 406 different patients) that demonstrated narrow QRS complex (< 0.12 s) supraventricular tachycardia with an RP' interval less than the P'R interval or pseudo r' wave in lead V1 or pseudo S wave in inferior leads, or both, were examined, and the results were confirmed by radiofrequency catheter ablation. The initial 226 ECGs were analyzed to develop a stepwise algorithm, and the subsequent 180 ECGs were prospectively evaluated by the new algorithm. RESULTS: The presence of a pseudo r' wave in lead V1 or a pseudo S wave in leads II, III, aVF indicated anterior-type AVNRT with an accuracy of 100%. With the difference of RP' intervals in leads V1 and III > 20 ms, posterior-type AVNRT could be differentiated from AVRT utilizing a posteroseptal pathway with a sensitivity of 71% (95% confidence interval [CI] 55% to 89%), a specificity of 87% (95% CI 67% to 97%) and a positive predictive value of 75% (95% CI 56% to 91%). According to the polarity of retrograde P waves in leads V1, II, III, aVF and I during AVRT, the concealed accessory pathway could be localized to one of the nine regions on the atrioventricular annuli with an accuracy of 75% (for a right midseptal pathway) to 93.8% (for a left posterior pathway). Overall, the new algorithm had an accuracy of 97.8% in discriminating AVNRT from AVRT and 88.1% in localizing a concealed accessory pathway, prospectively. Prediction was incorrect in only 15 patients (9.1%). CONCLUSIONS: The new ECG algorithm derived from the analysis of retrograde P waves during tachycardia could provide a criterion for differential diagnosis between AVNRT and AVRT and for predicting the location of concealed accessory pathways.

Adolescent↗
PubMed2003

Coincidence of idiopathic ventricular outflow tract tachycardia and atrioventricular nodal reentrant tachycardia.

BACKGROUND: Tachycardia-induced tachycardia appears to be a relatively rare condition. In such cases an important question arises whether catheter ablation of one arrhythmia may prevent the occurrence of another. This paper reviews single-centre experience with coincident idiopathic outflow tract ventricular tachycardia (VT) and atrioventricular (AV) nodal reentry tachycardia (AVNRT), and strategy of treatment. METHODS AND RESULTS: Seven of 46 patients (15%) with clinically documented idiopathic outflow tract VT were found to have reproducibly inducible AVNRT at the time of an electrophysiological study. There were two men and five women (mean age 35+/-9 years, range 20-44) without structural heart disease. During the study, AVNRT spontaneously triggered VT in three cases. Radiofrequency catheter ablation of the slow pathway did not suppress subsequent inducibility of VT in any of them. Successful catheter ablation of VT did not prevent clinical recurrence of AVNRT in one patient, and led to transition of VT into typical AVNRT in another. CONCLUSION: Coincidence of idiopathic outflow tract VT and AVNRT was found in 15% of cases of clinically documented idiopathic VT. Catheter ablation of one arrhythmia substrate did not prevent inducibility or clinical recurrence of the other. These data support the strategy of performing catheter ablation of both arrhythmia substrates during one session.

Adult↗
PubMed1984

Discrimination of supraventricular tachycardia from sinus tachycardia of overlapping cycle length.

For more than 15 years, pulse generators (PG) have been implanted for the control of tachyarrhythmias. Manually activated systems have not achieved wide acceptance, mainly because of the need for direct patient participation. Automatic antitachycardia PGs have been limited by lack of flexibility of programmable parameters and the inability to discriminate pace-terminable tachycardias from sinus tachycardia. New algorithms for differentiating these tachycardias are becoming available. In addition to high rate detection criteria, there are three additional criteria that might characterize the tachycardias: (1) sudden onset, (2) rate stability, (3) sustained high rate. Future antitachycardia pacing systems will be able to employ even more elaborate algorithms when more sophisticated microprocessor capabilities and new sensors become available.

Atrioventricular Node↗
PubMed1989

"Clockwise" and "counterclockwise" bundle branch reentry as a mechanism for sustained ventricular tachycardia masquerading as supraventricular tachycardia.

A 35-year-old man presented with a regular tachycardia having a typical right bundle branch block morphology. Electrophysiological testing revealed inducible tachycardia exhibiting counterclockwise as well as clockwise bundle branch reentry, leading to left and right bundle branch block morphologies. The disappearance of spontaneous episodes of these tachycardias following resolution of right bundle branch block in the resting electrocardiogram suggested that slow conduction in the right bundle branch played an essential role in the tachycardia circuit.

Adult↗
PubMed1990

A prospective study of right ventricular pulse pressure and dP/dt to discriminant-induced ventricular tachycardia from supraventricular and sinus tachycardia in man.

In the future, automatic implantable cardioverter defibrillators (AICD) may incorporate sensors to differentiate hemodynamically stable from unstable ventricular tachycardias (VT). These sensors should also discriminate between ventricular and supraventricular tachycardias to avoid inappropriate responses from the device. Right ventricular pulse pressure (RVPP) and maximal systolic right ventricular dP/dt (dP/dt) were measured before, during and after 91 episodes of hemodynamically stable VT (VTs), hemodynamically unstable VT (VTus), supraventricular tachycardia (SVT) and sinus tachycardia (ST) induced in 49 male patients. The mean percent changes (mean +/- S.E.M.) in RVPP from baseline (% delta RVPP) during VTs and VTus were -35 +/- 3% and -72 +/- 3%, respectively (both P less than 0.001). The % delta RVPP during ST was +56 +/- 11% (P less than 0.01) and % delta RVPP was unchanged from baseline during SVT (+2 +/- 9%; P greater than 0.01). Mean % change in RV dP/dt from baseline was -20 +/- 3% during VTs (P less than 0.001), -36 +/- 5% during VTus (P less than 0.001), +15 +/- 13% during SVT (P less than 0.01), and +85 +/- 23% during ST (P greater than 0.01). The mean percent changes in RVPP were significantly different between each arrhythmia group (P less than 0.01). The mean % changes in RV dP/dt were significantly different only between ST and VTs or VTus and between SVT and VTus. The range of values for % delta RVPP during VTs overlapped considerably with the ranges of % delta RVPP during VTus and SVT. The ranges of % delta RVPP overlapped minimally between VTus and SVT. Percent change RVPP separated each episode of VTs and VTus from those of ST. The range of common values for % delta dP/dt between all four groups was extensive. It is concluded that % delta RVPP from baseline is significantly different between groups of patients during VTs, VTus, SVT, and ST, but that a large degree of overlap in the range of values for % delta RVPP and RV dP/dt between different arrhythmias groups may limit the specificity of these hemodynamic variables in separating different arrhythmias.

Cardiac Pacing, Artificial↗
PubMed2005

"V-H-A Pattern" as a criterion for the differential diagnosis of atypical AV nodal reentrant tachycardia from AV reciprocating tachycardia.

BACKGROUND: During ventricular extrastimulation, His bundle potential (H) following ventricular (V) and followed by atrial potentials (A), i.e., V-H-A, is observed in the His bundle electrogram when ventriculo-atrial (VA) conduction occurs via the normal conduction system. We examined the diagnostic value of V-H-A for atypical form of atrioventricular nodal reentrant tachycardia (AVNRT), which showed the earliest atrial activation site at the posterior paraseptal region during the tachycardia. METHODS: We prospectively examined the response of VA conduction to ventricular extrastimulation during basic drive pacing performed during sinus rhythm in 16 patients with atypical AVNRT masquerading atrioventricular reciprocating tachycardia (AVRT) utilizing a posterior paraseptal accessory pathway and 21 with AVRT utilizing a posterior paraseptal accessory pathway. Long RP' tachycardia with RP'/RR > 0.5 was excluded. The incidences of V-H-A and dual AV nodal physiology (DP) were compared between atypical AVNRT and AVRT. RESULTS: V-H-A was demonstrated in all the 16 patients (100%) in atypical AVNRT and in only 1 of the 21 (5%) in AVRT (P < 0.001). DP was demonstrated in 10 patients (63%) in atypical AVNRT and in 4 (19%) in AVRT (P < 0.05). The sensitivity of V-H-A for atypical AVNRT was higher than that of DP (P < 0.05). Positive and negative predictive values were 94% and 100%, respectively, for V-H-A and 71% and 74%, respectively, for DP. CONCLUSIONS: The appearance of V-H-A during ventricular extrastimulation is a simple criterion for differentiating atypical AVNRT masquerading AVRT from AVRT utilizing a posterior paraseptal accessory pathway.

Adolescent↗