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PubMed2003

Electrocardiographic differentiation of typical atrioventricular node reentrant tachycardia from atrioventricular reciprocating tachycardia mediated by concealed accessory pathway in children.

The value of the electrocardiogram (ECG) in children with supraventricular tachycardia (SVT) is unclear. The noninvasive differentiation of typical atrioventricular node reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT) mediated by concealed accessory pathway conduction is clinically important, as it helps in counseling and potentially facilitates ablation procedures. One hundred forty-eight ECGs showing narrow QRS complex SVT were obtained from children before successful radiofrequency catheter ablation. An initial 102 ECGs were analyzed by 3 blinded observers to assess the utility of various electrocardiographic findings. No electrocardiographic criteria were found to discriminate between SVT mechanisms on 1- to 3-channel Holter/event recorder tracings (n = 32); their interpretation mainly (55%) resulted in an incorrect SVT diagnosis. On 12-lead ECGs (n = 70), the 2 arrhythmias were accurately diagnosed in 76% of patients; 5 findings were found to be discriminators of tachycardia mechanism. Predictors of AVRT were visible P waves in 74% of cases (sensitivity 92%; specificity 64%), RP intervals of > or =100 ms in 91% (sensitivity 84%; specificity 91%), and ST-segment depression of > or =2 mm in 73% of cases (sensitivity 52%; specificity 82%). Pseudo r' waves in lead V(1) and pseudo S waves in the inferior leads during tachycardia predicted AVNRT in 100% of cases (sensitivity 55% and 20%, respectively; specificity 100% for both). Based on these results, we developed a new diagnostic 12-lead electrocardiographic algorithm for pseudo r'/S waves, RP duration, and ST-segment depression during tachycardia. Two observers tested the algorithm in 46 (21 AVNRT; 25 AVRT) additional cases; they correctly diagnosed the SVT mechanism in 91% and 87%, respectively. Thus, the stepwise use of diagnostically relevant 12-lead electrocardiographic parameters helps to more accurately differentiate mechanisms of reentrant SVT.

Algorithms↗
PubMed2005

Radiofrequency catheter ablation of coexistent idiopathic left ventricular tachycardia and atrioventricular nodal reentrant tachycardia.

A healthy 15-year-old male patient presented with a 6-month history of recurrent attacks of palpitations. On multiple emergency room visits, a sustained wide QRS complex tachycardia with a right bundle branch block and northwest axis deviation was documented. The tachycardia was not terminated by intravenous adenosine, but was suppressed with intravenous verapamil. There was no evidence of structural heart disease, myocarditis, long QT syndrome, or electrolyte imbalance after a series of standard examinations. Idiopathic left ventricular tachycardia (ILVT) was suspected. Electrophysiologic studies revealed 2 inducible tachycardias, which were shown to represent atrioventricular nodal reentrant tachycardia (AVNRT) and ILVT. Transformation from AVNRT to ILVT occurred spontaneously following atrial pacing. Successful ablation of ILVT and the slow atrioventricular nodal pathway resulted in cure of the double tachycardia.

Adolescent↗
PubMed1995

ECG criteria to distinguish between aberrantly conducted supraventricular tachycardia and ventricular tachycardia: practical aspects for the immediate care setting.

UNLABELLED: To reevaluate ECG criteria for distinguishing supraventricular tachycardia (SVT) with aberrant conduction from ventricular tachycardia (VT), 133 wide QRS tachycardias were recorded in patients undergoing invasive electrophysiological (EP) study. Surface ECG leads (standard 12-lead and MCL leads) were compared to EP recordings to provide a standard for correct diagnosis. Criteria from six studies were pooled to select QRS morphology agreed to be highly specific for SVT or VT (specificity > 90%). Some morphological criteria were modified to simplify analysis for the immediate care setting. RESULTS: Although the 12-lead ECG was useful in distinguishing aberrancy from VT, 13 tachycardias (10%) were misdiagnosed or could not be diagnosed. The MCL1 lead recorded clearly different QRS morphology than lead V1 in 40% of VT cases and was diagnostically inferior to V1. Most established criteria were highly specific for a diagnosis, but not very sensitive as individual criteria. Neither a QRS width of > 0.14 seconds nor a monophasic R wave pattern in lead V1 were valuable in diagnosing VT. CONCLUSIONS: In distinguishing SVT with aberrant conduction from VT: (1) Although the 12-lead ECG is valuable, about 1 in 10 wide QRS tachycardias defy differentiation; (2) tachycardias > 190 beats/min often do not exhibit unequivocal criteria with which to make a certain diagnosis; (3) multiple leads are required for accurate assessment of QRS width, presence of AV dissociation or VA block, QRS axis, and morphological criteria; and (4) the MCL1 lead cannot be substituted for V1 in the use of morphological criteria for VT.

Adolescent↗
PubMed1977

Atrial tachycardia without P waves masquerading as an A-V junctional tachycardia.

Two patients who presented by scalar ECG with an A-V junctional tachycardia were demonstrated during an electrophysiologic evaluation to have an atrial tachycardia without P waves in the surface ECG. Case 1 had an atrial tachycardia that conducted through the A-V node with a Wenckebach block. Atrial activity was recorded only from the proximal portion of the coronary sinus and from right atrial areas near the tricuspid valve. Case 2 had an atrial tachycardia that abruptly began and terminated following carotid sinus massage. Atrial activity was recorded only in the coronary sinusos, and pacing at that site resulted in atrial capture, with Wenckebach conduction to the ventricles. These observations demonstrate that an atrial tachycardia without P waves can simulate A-V junctional tachycardia with or without Weckebach block. Such findings may have a bearing on some important electrophysiologic concepts such as the origin of A-V junctional rhythms and the need for atrial participation in A-V nodal re-entry.

Atrioventricular Node↗
PubMed1990

Reversibility of tachycardia-induced cardiomyopathy after cure of incessant supraventricular tachycardia.

Seven of 17 patients with incessant supraventricular tachycardia caused by an accessory pathway with a long retrograde conduction time were seen with symptoms or echocardiographic signs of a tachycardia-induced cardiomyopathy. Three patients were in New York Heart Association functional class II with dyspnea and four were in class III. Eight patients (six with tachycardia-induced cardiomyopathy) underwent surgery because of failure of medical treatment (including one patient in functional class I) and one underwent direct current catheter ablation of the atrioventricular (AV) node. In six patients echocardiograms recorded before and after the procedure were available. Before surgery or direct current ablation the mean left ventricular ejection fraction was 36.3 +/- 8.7%, the left ventricular end-diastolic diameter 55.7 +/- 7.6 mm and the left ventricular end-systolic diameter 44.3 +/- 7.8 mm. A mean of 21.6 +/- 6.8 months after the procedure the mean left ventricular ejection fraction increased to 58.6 +/- 8.0%, the left ventricular end-diastolic diameter decreased to 49.0 +/- 3.6 mm and the left ventricular end-systolic diameter decreased to 32.2 +/- 2.7 mm; all six patients were in functional class I. These results confirm that control of incessant tachycardia leads to a regression of symptoms and signs of cardiomyopathy and progressive normalization of the dimensions of the heart. Because of these findings, surgery should be considered early in patients with an accessory AV pathway and incessant tachycardia. The presence of a tachycardia-induced cardiomyopathy should therefore be an indication for surgery rather than a contraindication.

Adult↗
PubMed1994

Abnormal coronary flow dynamics at rest and during tachycardia associated with impaired left ventricular relaxation in humans: implication for tachycardia-induced myocardial ischemia.

OBJECTIVES: This study attempted to clarify the effect of ventricular relaxation abnormalities on coronary flow dynamics at rest and during tachycardia in humans. BACKGROUND: Ventricular relaxation abnormality has been demonstrated in animals to have an adverse impact on early diastolic coronary flow dynamics. However, this relation has not been established in humans. Even if the adverse effect were latent at rest, it might become evident during tachycardia because tachycardia reduces coronary flow reserve and facilitates the production of myocardial ischemia. METHODS: Doppler phasic left coronary flow velocity pattern was obtained at rest and during tachycardia in 23 patients without coronary stenosis. The time constant of left ventricular isovolumic pressure (tau) was used to assess ventricular relaxation. RESULTS: The time to peak flow velocity of the diastolic coronary flow wave was longer, and the fraction of the first third of diastolic coronary flow was smaller, in patients with a longer tau (r = 0.58, p < 0.01; r = -0.44, p < 0.05), indicating a close relation between early diastolic coronary flow dynamics and ventricular relaxation. Although rapid atrial pacing yielded an increase in the coronary flow velocity integral per minute in all patients, diastolic coronary flow velocity integral per minute increased in 9 patients with a normal (< or = 40 ms) tau at rest but decreased in 14 patients with a longer (> 40 ms) tau at rest. CONCLUSIONS: Impaired left ventricular relaxation was associated with decreased coronary flow in early diastole at rest and decreased coronary flow throughout diastole during tachycardia in patients without coronary stenosis. These findings may provide more insight into the mechanism of tachycardia-induced subendocardial ischemia in patients with impaired ventricular relaxation but without concomitant coronary stenosis.

Adult↗
PubMed2000

Lidocaine-sensitive atrial tachycardia: lidocaine-sensitive, rate-related, repetitive atrial tachycardia: a new arrhythmogenic syndrome.

OBJECTIVES: The goal of this study was to report a variety of atrial tachycardia that might be caused by an unusual electrophysiologic substrate. BACKGROUND: The mechanism of atrial tachycardias is attributed to re-entry, abnormal automaticity or triggered activity, based on their electropharmacological responses. A rate-related and lidocaine-sensitive atrial tachycardia has not been reported. METHODS: Eight patients (3 women and 5 men, aged 14 to 60 years) with repetitive, uniform atrial tachycardias were studied. In six patients the arrhythmia had been refractory to at least three antiarrhythmic agents (class 1A and C sodium channel blockers, amiodarone, beta-adrenergic blocking agents, verapamil, digoxin). Conventional electrocardiograms, Holter recordings and B mode echocardiograms were performed in each patient. Intravenous lidocaine and verapamil were tested in the eight patients. Six patients underwent an electrophysiologic study. RESULTS: The baseline electrocardiogram showed nearly incessant runs of atrial tachycardia in all patients. The mean atrial ectopic cycle length ranged from 376 to 502 ms. In seven patients a progressive prolongation of the cycle length from the beginning to the end of the salvos was documented. The arrhythmia was suppressed by increments of sinus node rate and by atrial pacing at cycle lengths longer than that of the atrial tachycardia. In all patients the arrhythmia was abolished by intravenous lidocaine, whereas intravenous verapamil was ineffective. Four symptomatic patients were successfully treated with radiofrequency ablation of the ectopic focus, and two patients were treated with oral mexiletine. CONCLUSIONS: The peculiar electropharmacological responses of this arrhythmia suggest an uncommon underlying mechanism that remains to be elucidated.

Adolescent↗
PubMed2003

Para-Hisian entrainment: a novel pacing maneuver to differentiate orthodromic atrioventricular reentrant tachycardia from atrioventricular nodal reentrant tachycardia.

INTRODUCTION: Para-Hisian pacing during sinus rhythm can help to identify the presence of an accessory pathway (AP). In this maneuver, the retrograde activation time and pattern are compared during capture and loss-of-capture of the His bundle while pacing from a para-Hisian position. However, identification of a retrograde AP does not necessitate that it is operative during the tachycardia of interest; conversely, slowly conducting or "distant" bypass tracts may not be identified. We evaluated the utility of entrainment or resetting of tachycardias from the para-Hisian position to help distinguish atrioventricular nodal reentrant tachycardia (AVNRT) from orthodromic atrioventricular tachycardia (AVRT). METHODS AND RESULTS: Para-Hisian entrainment/resetting was evaluated in 50 patients: 33 with AVNRT and 17 with AVRT. The maneuvers were performed using a standard quadripolar catheter placed at the His position: low output for right ventricular (RV) capture and high output for both RV and His capture. The retrograde atrial activation sequence, SA interval (interval from stimulus to earliest retrograde atrial activation), and "local" VA interval (interval between the ventricular and atrial electrograms at the site of earliest retrograde atrial activation) were compared between His and His/RV capture. The DeltaSA was > 40 ms in patients with AVNRT and was < 40 ms in all but one patient with AVRT. In concert with the DeltaSA interval, the DeltaVA interval was able to fully define the mechanism of the tachycardia in all patients studied. CONCLUSION: Para-Hisian entrainment/resetting can determine the course of retrograde conduction operative during narrow complex tachycardias. It is a useful diagnostic maneuver in differentiating AVNRT and orthodromic AVRT.

Adolescent↗
PubMed1991

Repetitive nonsustained monomorphic ventricular tachycardia aborted by methoxamine and sleep "heart rate dependent ventricular tachycardia".

Methoxamine, an alpha adrenoreceptor agonist, and sleep abolished repetitive nonsustained monomorphic ventricular tachycardia in a 41-year-old man without detectable underlying heart disease. Detailed pacing studies revealed that the occurrence of ventricular tachycardia was totally dependent on the basic heart rate. Sleep and the alpha adrenoreceptor agonist abolished the ventricular tachycardia by slowing the basic heart rate. Verapamil, propranolol, and disopyramide were able to decrease the upper limit of the tachycardia-initiating heart rate, but none of them were able to increase the lower limit (75/min). Failure to increase the lower limit of the tachycardia-initiating heart rate was a major reason why these conventional antiarrhythmic drugs were unable to suppress his daytime episodes of repetitive ventricular tachycardia.

Adult↗
PubMed1993

Effects of overdrive stimulation on functional reentrant circuits causing ventricular tachycardia in the canine heart: mechanisms for resumption or alteration of tachycardia.

INTRODUCTION: The purpose of the experiments described in this article was to investigate the effects of overdrive stimulation on functional anisotropic reentrant circuits causing ventricular tachycardia in infarcted canine ventricles. We determined how overdrive stimuli affect reentrant circuits to alter characteristics of the tachycardia. METHODS AND RESULTS: Activation patterns were determined by mapping excitation with a 192 bipolar electrode array. We found that overdrive stimuli could activate the circuits with the same pattern as the reentrant wavefront and that after overdrive stopped either the last or the next to last stimulated wavefront continued propagating through the circuit as a new reentrant impulse and tachycardia continued. When the circuit was not altered after overdrive, the exit route that the stimulated wavefront took from the circuit to activate the rest of the ventricles was also not altered and the tachycardia after overdrive had the same cycle length and QRS morphology as prior to overdrive. In some experiments, however, the overdrive stimuli did not follow the original reentrant pathway but led to the formation of a different circuit with a different exit route to the ventricles. As a result, after overdrive stimulation tachycardia had a different QRS morphology and cycle length than prior to stimulation. When the new circuit after overdrive was small and the revolution time of the reentrant impulse around the circuit was short, fibrillation occurred. CONCLUSION: Functional reentrant circuits can either be maintained or altered after a period of overdrive stimulation. The results explain many of the effects that have been seen during overdrive stimulation of clinical ventricular tachycardia.

Animals↗
PubMed1997

Tachycardia-induced cardiomyopathy secondary to right ventricular outflow tract ventricular tachycardia: improvement of left ventricular systolic function after radiofrequency catheter ablation of the arrhythmia.

INTRODUCTION: Several reports describe development of cardiomyopathies secondary to supraventricular tachycardia. Few reports have described cardiomyopathies secondary to ventricular tachycardia. METHODS AND RESULTS: We describe a patient who presented with dilated cardiomyopathy and repetitive nonsustained monomorphic ventricular tachycardia. Cardiac catheterization showed hemodynamically insignificant coronary artery disease. Radiofrequency ablation of a right ventricular outflow tract ventricular tachycardia resulted in improvement of the left ventricular systolic function and resolution of heart failure symptoms. CONCLUSIONS: This report suggests that right ventricular outflow tract ventricular tachycardia may cause reversible tachycardia-induced cardiomyopathy.

Aged↗
PubMed1984

Assessment of a prototype implantable cardioverter for ventricular tachycardia. Relation between synchronisation of sensing and origin of the tachycardia.

The feasibility of internal cardioversion for ventricular tachycardia using a prototype of an implantable cardioverter which delivers a low energy discharge via an intracardiac lead and its acceptability to the patient were studied. The cardioverting discharge was synchronised to the apical right ventricular electrogram. In 29 episodes of ventricular tachycardia (RR interval 250-700 ms) the apical electrogram was reliably sensed. The interval from the onset of the QRS complex to the marker of sensing of the electrogram was significantly greater in the 15 episodes arising from the left ventricle than in the 14 episodes arising from the right ventricle; in three cases of ventricular tachycardia arising from the left ventricle the interval exceeded 100 ms. In all cases except one, however, sensing occurred within the first 80% of the QRS complex. In two episodes (RR interval 150 and 190 ms--that is, less than the refractory period of the unit) sensing of the electrogram was unreliable. The unit successfully terminated 10 of 15 episodes of ventricular tachycardia using energies ranging between 0.01 and 1.0 J, but 19 of the 23 discharges delivered to conscious patients caused varying degrees of discomfort. Sensing within 100 ms of the onset of the QRS complex (-20% to 83% of QRS) permitted effective and safe termination of ventricular tachycardia. Although there was neither acceleration of tachycardia nor ventricular fibrillation, subthreshold discharges advanced the next local ventricular electrogram in seven instances. An external low energy cardioverter connected to an intracardiac lead is a useful alternative to repeated external direct current shocks.

Adolescent↗
PubMed2003

Permanent junctional reciprocating tachycardia: an incessant tachycardia in children.

UNLABELLED: Permanent junctional reciprocating tachycardia is an infrequent form of reentrant supraventricular tachycardia but is the commonest incessant tachycardia in childhood. The persistent nature of the tachycardia can lead to heart failure secondary to left ventricular dysfunction and the arrhythmia is often refractory to drug control. STUDY OBJECTIVE: To review the main clinical features and therapeutic options currently available for this arrhythmia. DESIGN: Retrospective study. PATIENTS: A group of 5 children with a diagnosis of permanent junctional reciprocating tachycardia. RESULTS: Age at presentation ranged between 14 days and 12 years. Three were asymptomatic. The first echocardiogram displayed left ventricular dilation and decreased shortening fraction in one child. Pharmacological therapy was initially successful in all. During follow-up (0.2-4.5 years) the arrhythmia became resistant to medication in one case and radiofrequency ablation was carried out. CONCLUSIONS: Permanent junctional reciprocating tachycardia has a wide range of clinical presentations. Pharmacological therapy is recommended, but radiofrequency ablation is the definitive treatment and only depends on patient age.

Anti-Arrhythmia Agents↗
PubMed1984

[Effect of tachycardia on hemodynamics and coronary circulation. Different relevance of ventricular tachycardias for healthy persons, coronary patients and patients with left heart hypertrophy].

Investigations on the haemodynamics, coronary flow and metabolism of tachycardias were carried out in 195 patients during routine diagnostic examinations (left ventricular catheterization; intracardiac electro-physiological studies) from 1974 to 1980. The following measurement methods were used: 1. controlled cardiac electrostimulation to simulate paroxysmal tachycardias (atrial, atrioventricular-sequential and ventricular stimulation); 2. intracardiac pressure; 3. cincecardiographic parameters; 4. coronary flow; 5. coronary reserve (dipyridamol vasodilation); 6. cardiac output; 7. myocardial ischaemia; 8. myocardial oxygen consumption. The results are presented as follows: I. Adaptive alterations of arterial pressure and coronary flow with an abrupt start and stop of a tachycardia paroxysm; II. Arterial pressure in the steady state of a tachycardia, metabolic effects, evidence of ischaemia and coronary reserve; III. Effects of a tachycardia on the determinant parameters of the aortic valve function in aortic stenosis before and after aortic valve replacement; IV. Definition of the atrial pump support of the left ventricle during tachycardia.

Aortic Valve↗
PubMed1995

Ventricular tachycardia may masquerade as supraventricular tachycardia in patients with preexisting bundle-branch block.

We present the cases of three patients with preexisting bundle-branch block in whom wide-complex tachycardias were considered to be of supraventricular origin because QRS morphologies were essentially unchanged from those during normal sinus rhythm. The patients experienced adverse effects from medications for supraventricular tachycardia. Ventricular tachycardia eventually was diagnosed in all three by means of invasive electrophysiologic studies. Ventricular tachycardia may masquerade as supraventricular tachycardia in patients with fixed intraventricular conduction disturbance. Emergency therapy based solely on the QRS identity criteria may result in poor clinical outcome.

Aged↗
PubMed1990

Cycle length alternation during supraventricular tachycardia: occurrence and mechanism in a canine model of AV reentrant tachycardia.

Cycle length alternation (CLA) is commonly observed during supraventricular tachycardia (SVT) onset and termination. The present study was designed to gain insights into the mechanism and potential clinical relevance of CLA by comparing computer simulations of tachycardia to directly observed behavior in a canine model of AV reentrant tachycardia (AVRT). The computer model was based on the hypothesis that CLA is secondary to feedback between AV nodal output during SVT and subsequent AV nodal input, and used the measured anterograde AV nodal recovery curve (AV vs A1A2) to predict sequential AV and RR intervals during SVT. Orthodromic AVRT was created experimentally in 11 open-chested, autonomically-blocked (atropine plus nadolol) dogs using a sensing and pacing circuit that mimicked a retrograde-conducting accessory pathway. Steady-state cycle length and AV interval during experimental AVRT closely paralleled predictions made by the computer model. CLA appeared consistently at the onset of experimental AVRT at programmed VA intervals less than or equal to 100 msec (corresponding to VA less than or equal to 150 msec as measured clinically) in all dogs. The amplitude and duration of CLA increased as the VA interval decreased, and closely paralleled predictions based on the computer model. Abrupt accelerations in atrial pacing to the same rate as AVRT did not result in alternation of cycle length. In conclusion, alternation of cycle length results from feedback between AV nodal output and subsequent AV nodal input at the onset of reentrant supraventricular tachycardia, and does not require changes in autonomic tone or dual AV nodal pathways. CLA occurrence, amplitude, and duration are predictable based on AV node recovery properties, and depend on retrograde conduction properties of the reentrant circuit. The presence of CLA suggests that the AV node is an integral component of the SVT reentry circuit, and may be useful clinically to identify the mechanism of supraventricular tachycardias.

Animals↗
PubMed1990

Reentrant fascicular tachycardia with cycle length alternans: insights into the tachycardia mechanism and origin.

This report details the electrophysiology of a unique case of reentrant fascicular tachycardia in a patient without structural heart disease. Persistent cycle length alternans, with constant fluctuation in alternate RR intervals, occurred during tachycardia. A distinct mode of spontaneous termination of tachycardia was observed. The findings were consistent with the presence of decremental conduction properties in the tachycardia circuit or decremental dual functional pathways within one limb of the circuit. These observations provide further evidence in support of a fascicular origin of the tachycardia.

Bundle of His↗
PubMed2006

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.

Arrhythmias, Cardiac↗