Successful risk stratification of a patient with ventricular preexcitation by improved transesophageal electrophysiological study.

The patient is a 19 years-old man who often wakes up in dreams with palpitations and fatigue. The ECG shows: 1. Sinus rhythm; 2. Preexcitation syndrome. Transesophageal electrophysiological study (TEEPS) diagnosis:High-risk accessory pathway. During radiofrequency catheter ablation, the patient suddenly developed atrial fibrillation and quickly converted to ventricular fibrillation. After defibrillation, ventricular fibrillation is transformed into sinus rhythm. Subsequently, the patient's high-risk accessory pathway was successfully ablated. Studies have shown that about 25% of patients with WPW syndrome have a refractory period of less than 250 ms, which is one of the risk factors for the conversion of atrial fibrillation to ventricular fibrillation. Therefore, risk stratification is recommended for these symptomatic patients. From 1980 to 1990, there were literature reports on risk stratification of patients with preexcitation syndrome by TEEPS. But it has not become a routine examination of risk stratification in patients with preexcitation syndrome.The reason may be related to the hardware conditions and risk stratification methods used at that time. The TEEPS equipment currently used in our hospital can control the pacing voltage at about 12 mv on average. The voltage in this case report is 9 mv only. In addition, we successfully stratified the risk of patient with preexcitation syndrome without inducing atrial fibrillation. All the electrophysiological records of the patient during the examination were recorded simultaneously with the 12-lead ECG and the esophageal lead ECG. These improvements makes TEEPS a simple, safe and reliable non-invasive cardiac electrophysiological detection technology, which is worth popularizing in hospitals.

Non-invasive Risk Stratification in Pediatric Ventricular Pre-excitation.

Children with ventricular pre-excitation are at risk for sudden death. This retrospective pediatric study identified patients > 8 years of age who had undergone electrophysiology study (EPS). Our primary objective was to determine the performance characteristics of non-invasive risk stratification. Subjects were separated into two groups. Group 1 was asymptomatic or had non-specific symptoms (palpitations, chest pain, and light headedness) without documented supraventricular tachycardia (SVT). Group 2 had syncope, documented SVT, or a life-threatening event. As a secondary aim, we tested whether patients with severe symptoms had a shorter time from the date of diagnosis to the date of invasive risk stratification. Among 93 patients with an average age of 14.2 years, 25 patients had documented SVT, 6 had syncope, and 1 had a life-threatening event. The sensitivity of non-invasive risk stratification was 7%. The specificity was 91%. The positive predictive valve was 14% and the negative predictive value was 84%. Even patients with severe symptoms commonly underwent non-invasive risk stratification prior to EPS, albeit at a lower rate (Group 1, 98%; Group 2 84%, p = 0.02). The median time to EPS was 4.2 months (Group 1) and 4.5 months (Group 2, p = 0.63). Non-invasive risk stratification was a poor predictor of invasive risk stratification. Cardiologists should counsel families about the limitations of non-invasive risk stratification and consider starting with invasive risk stratification and possible ablation. Counterintuitively, severe symptoms were not associated with a shorter time to electrophysiology study.

Comparison of Electrophysiologic Profiles in Pediatric Patients with Incidentally Identified Pre-Excitation Compared with Wolff-Parkinson-White Syndrome.

The rising utilization of screening electrocardiograms has resulted in increased incidental identification of ventricular pre-excitation in pediatric patients. We compared accessory pathways of incidentally identified pre-excitation to Wolff-Parkinson-White Syndrome (WPW) with the aim to identify factors important in preprocedural counseling and planning. This single-center, retrospective study of patients ≤18 years without congenital heart disease identified 227 patients diagnosed with pre-excitation and referred for invasive electrophysiology study between 2008 and 2017. WPW Syndrome was diagnosed in 178 patients, while 49 patients had incidental identification of pre-excitation. Anterograde conduction of incidentally identified accessory pathways was not clinically different between the two cohorts at baseline or upon isoproterenol infusion. However, the proportion of accessory pathways meeting high-risk criteria was significantly lower than in patients diagnosed with WPW, 12% versus 28% (p < 0.05). Retrograde conduction at baseline of incidentally diagnosed accessory pathways was slower with a median block cycle length 365 milliseconds (IQR 260 to 450) versus 290 milliseconds (IQR 260 to 330, p < 0.01). In the incidentally identified cohort, right-sided, paraHisian, and fascicular pathways were more common with fewer attempted ablations (71% vs 94%, p < 0.001) and lower success rate (91% vs 97%, p < 0.001). A binomial logistic regression analysis further indicated patients incidentally identified with pre-excitation were associated with having lower rates of inducible supraventricular tachycardia, atrial fibrillation, and ablations performed, in addition, to having right-sided pathways. In conclusion, as patients with incidentally identified pre-excitation present more frequently for consideration of invasive electrophysiology study, these results impact procedural approaches, technical considerations, patient counseling, and outcome expectations.

Classical response of antidromic atriofascicular tachycardia to premature atrial extrastimulus delivered during septal refractoriness.

A 23-year-old gentleman presented with a history of palpitations. The 12-lead electrocardiogram showed no manifest ventricular pre-excitation. Echocardiogram was within normal limits. A retrograde study showed concentric activation of the atrium with decremental conduction. Atrial pacing from right atrial free wall showed progressive pre-excitation. No anterograde nodal duality was documented.

Pulseless Electric Activity with Pre-Excitation.

A 41-year-old man developed cardiac arrest. A resting 12-lead electrocardiogram showed a delta wave, suggestive of preexcitation syndrome. An electrophysiological test revealed the existence of inducible atrial fibrillation and a fasciculoventricular accessory pathway (FVAP). After these examinations, idiopathic ventricular arrhythmia was suspected. For evaluating concealed Brugada syndrome, pilsicainide was administered, which diminished the delta wave and no Brugada-like electrocardiogram was observed. Ventricular double extra-stimulation from the RV apex easily induced VF, which could not be defibrillated by an external defibrillator, and later stopped spontaneously. These results established the diagnosis of FVAP and idiopathic VF, and not pre-excited atrial fibrillation or Brugada syndrome.

Heart rate variability parameters in children with ventricular preexcitation.

INTRODUCTION: The autonomic nervous system has a regulatory effect on cardiac electrophysiology and arrhythmogenesis. We aimed to assess cardiac autonomic status using heart rate variability (HRV) parameters in children with ventricular preexcitation. METHODS: The electrocardiography, Holter monitoring, transesophageal electrophysiological study (TEEPS), and invasive electrophysiological study (EPS) results of ventricular preexcitation patients obtained over a 7-year period in our clinic were evaluated. According to the TEEPS results, patients' accessory pathway conduction was classified as adverse (n = 40) or nonadverse (n = 25). The HRV parameters of patients were compared according to tachycardia inducibility that assessed by TEEPS and EPS. Also, HRV parameters were compared in patients with adverse and nonadverse pathway conduction. Further, the HRV parameters of preexcitation patients were compared with those of healthy controls. RESULTS: LF/HF, the best measure of sympathovagal balance, was statistically higher in patients with adverse conduction than in patients without adverse conduction and controls (P  =  0.001). The LF/HF ratio was higher in ventricular preexcitation patients with inducible tachycardia than those without in EPS (P  =  0.001). In addition, the LF/HF ratio was higher in symptomatic ventricular preexcitation patients than asymptomatic ones (P  =  0.001). No difference in HRV parameters was found between preexcitation patients and controls. CONCLUSION: Autonomic tonus in patients with ventricular preexcitation may affect accessory pathway conduction properties, tachycardia inducibility, and symptomology. The indicator of sympathovagal balance, LF/HF ratio, increased in ventricular preexcitation patients with inducible tachycardia and those that were symptomatic.

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.

Intermittent preexcitation indicates "a low-risk" accessory pathway: Time for a paradigm shift?

We report three patients with intermittent loss of the preexcitation pattern in the ECG that had undergone an electrophysiological study. Despite apparently poorly conducting accessory pathway (AP), in each case a fast anterograde conduction, either during spontaneous atrial fibrillation or during incremental atrial pacing (on isoproterenol) was documented; shortest preexcited RR intervals of 200-240 ms were observed. We review the literature and conclude that intermittent preexcitation observed on resting 12-lead ECG lacks sufficient specificity for the diagnosis of an AP with long refractory period and cannot be considered a substitute for electrophysiological study in patients with this electrocardiographical phenomenon.

Respuesta al ECG de septiembre de 2016 / Response to ECG, September 2016

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Influence of advancing age on clinical presentation, treatment efficacy and safety, and long-term outcome of pre-excitation syndromes: a retrospective cohort study of 961 patients included over a 25-year period.

OBJECTIVES: There are very little data on pre-excitation syndrome (PS) in the elderly. We investigated the influence of advancing age on clinical presentation, treatment and long-term outcome of PS. SETTING: Single-centre retrospective study of patient files. PARTICIPANTS: In all, 961 patients (72 patients ≥60 years (mean 68.5±6), 889 patients <60 years (mean 30.5±14)) referred for overt pre-excitation and indication for electrophysiological study (EPS) were followed for 5.3±5 years. Usual care included 24 h Holter monitoring, echocardiography and EPS. Patients underwent accessory pathway (AP) ablation if necessary. PRIMARY AND SECONDARY OUTCOME MEASURES: Occurrence of atrial fibrillation (AF) or procedure-induced adverse event. RESULTS: Electrophysiological data and recourse to AP ablation (43% vs 48.5%, p=0.375) did not significantly differ between the groups. Older patients more often had symptomatic forms (81% vs 63%, p=0.003), history of spontaneous AF (8% vs 3%, p=0.01) or adverse presentation (poorly tolerated arrhythmias: 18% vs 7%, p=0.0009). In multivariable analysis, patients ≥60 years had a significantly higher risk of history of AF (OR=4.2, 2.1 to 8.3, p=0.001) and poorly tolerated arrhythmias (OR=3.8, 1.8 to 8.1, p=0.001). Age ≥60 years was associated with an increased major AP ablation complication risk (10% vs 1.9%, p=0.006). During follow-up, occurrence of AF (13.9% vs 3.6%, p<0.001) and incidence of poorly tolerated tachycardia (4.2% vs 0.6%, p=0.001) were more frequent in patients ≥60 years, although frequency of ablation failure or recurrence was similar (20% vs 15.5%, p=0.52). In multivariable analysis, patients ≥60 years had a significantly higher risk of AF (OR=2.9, 1.2 to 6.8, p≤0.01). CONCLUSIONS: In this retrospective monocentre study, patients ≥60 years referred for PS work up appeared at higher risk of AF and adverse presentation, both prior and after the work up. These results suggest that, in elderly patients, the decision for EPS and AP ablation should be discussed in light of their suspected higher risk of events and ablation complications. However, these findings should be further validated in future prospective multicentre studies.

Invasive electrophysiological evaluation and ablation in patients with asymptomatic ventricular pre-excitation persistent at exercise stress test.

AIMS: In patients with asymptomatic ventricular pre-excitation (VPE) persistent at exercise stress test, this study evaluates the proportion of cases with adverse conduction properties of the atrioventricular accessory pathway (AP) at invasive electrophysiological study and the long-term follow-up after they received treatment according to pre-determined criteria. METHODS AND RESULTS: Over 10 years, asymptomatic patients with VPE persistent at exercise stress test referred for invasive electrophysiological evaluation including isoproterenol (IPN) infusion were included. Ablation was planned if they had at least one of the following criteria: (i) shortest pre-excited R-R interval (SPERRI) ≤250 ms and/or (ii) inducible atrioventricular re-entrant tachycardia (AVRT). Cryoablation was electively used in para-hisian and mid-septal APs. Patients non-eligible for ablation received no therapy. Sixty-three patients (45 males; mean age 26 ± 14 years) underwent electrophysiological evaluation: 7 had fasciculo-ventricular fibres and were excluded, whereas 56 had 58 APs. Thirty-one patients (55%) were eligible and underwent successful ablation: 87% had at least the SPERRI ≤ 250 ms and 61% had at least inducible AVRT. In 15 cases (48%) the ablation criteria were met only during IPN infusion. During follow-up (73 ± 33 months), one patient was successfully retreated for resumption of VPE in the ablation group, whereas no event was observed in the group of patients who received no treatment. CONCLUSION: In this subset of patients with asymptomatic VPE, invasive electrophysiological evaluation shows fast antegrade conduction over the AP and/or inducible AVRT in about half of the cases. Patients who received no therapy because of a benign electrophysiological profile had an event-free follow-up.

Pre-excitation syndrome with a change in terminal QRS vector.

Most accessory pathways in pre-excitation syndrome are capable of antegrade conduction from atrium to ventricle, and identified by characteristic ECG abnormalities such as a delta wave (ventricular pre-excitation) and a shortened PR interval.Therefore, the traditional diagnosis method is to detect the initial changes of the QRS complex. Here we report a patient initially mistaken as having atrioventricular re-entrant tachycardia (AVRT) and concealed pre-excitation syndrome. A diagnosis of incomplete latent pre-excitation syndrome was established on the basis of differences between the ECGs during sinus rhythm and AVRT in terminal QRS vectors, demonstrated by intracardiac electrophysiological radiofrequency catheter ablation.