Fasciculoventricular and atrioventricular accessory pathways in patients with Danon disease and preexcitation: A multicenter experience.

BACKGROUND: Studies have suggested that a fasciculoventricular pathway (FVP) may be the cause of preexcitation in patients with Danon disease, a rare X-linked dominant genetic disorder of hypertrophic cardiomyopathy. OBJECTIVE: The purpose of this study was to describe the prevalence of ventricular preexcitation on resting 12-lead electrocardiogram (ECG) in patients with Danon disease and the electrophysiological study (EPS) results of those with preexcitation. METHODS: Patients with confirmed Danon disease diagnosed with preexcitation (PR ≤120 ms, delta wave, QRS >110 ms) on ECG were included from a multicenter registry. The incidence of arrhythmias, implantable cardioverter-defibrillator (ICD) procedures, ICD shocks, and EPS results were collected. RESULTS: Thirteen of 40 patients (32.5%) with Danon disease were found to have preexcitation (mean age 17.3 years; 38% women). EPS performed in 9 of 13 patients (69%) demonstrated FVP only in 2 (22.2%), extranodal pathway without exclusion of FVP in 2 (22.2%), and both FVP and extranodal pathway in 5 (55.6%). Two patients had malignant accessory pathway (AP) properties. Over median follow-up of 842 days (interquartile range 138-1678), 11 patients (85%) had ICD placement, and 6 (46.1%) underwent heart transplantation. No patients required therapy for ventricular tachycardia, and 2 patients (15%) had paroxysmal atrial fibrillation. CONCLUSION: In a large multicenter cohort of patients with Danon disease, there was a high prevalence of FVP and extranodal pathways diagnosed on EPS in those with preexcitation. These findings suggest patients with preexcitation and Danon disease should undergo EPS to assess for FVP and potentially malignant extranodal AP.

Hallazgos electrocardiográficos anormales en la población mayor de 40 años. Prevalencia y significación clínica. Resultados del estudio OFRECE / Abnormal electrocardiographic findings in the population older than 40 years. Prevalence and clinical significance. Results of the OFRECE study

Introducción y objetivos: Las anomalías electrocardiográficas son muy comunes. El propósito de este estudio es analizar la prevalencia de hallazgos electrocardiográficos anormales y su significado clínico en la población general española de 40 o más años. Métodos: Subanálisis del estudio OFRECE; se seleccionó una muestra representativa de la población española de 40 o más años. Se dispuso de datos clínicos y electrocardiograma de todos los participantes. La lectura de los electrocardiogramas fue centralizada, los evaluaron de manera independiente 2 cardiólogos expertos y se consultó con un tercero en caso de desacuerdo, para llegar al diagnóstico final por consenso. Antes de iniciarse la lectura de los electrocardiogramas, se establecieron estrictamente los criterios diagnósticos de cada una de las anomalías analizadas. Se estudiaron la prevalencia y los factores clínicos asociados con: crecimiento de cavidades, trastornos de conducción, anomalías de la repolarización, ondas Q patológicas, extrasistolia auricular y ventricular y preexcitación. Resultados: Se evaluó a 8.343 individuos (media de edad, 59,2 años; el 52,4% mujeres). Solo 4.074 (51,2%) presentaron un electrocardiograma rigurosamente normal. Las anomalías más frecuentes fueron las alteraciones inespecíficas de la repolarización (16%) asociadas con enfermedad coronaria y fibrilación auricular; el bloqueo de rama derecha (8,1%) asociado con enfermedad pulmonar obstructiva crónica; el hemibloqueo anterosuperior izquierdo (6,5%) relacionado con la hipertensión y la insuficiencia cardiaca y el intervalo PR largo (3,7%) se asociaron con enfermedad coronaria. Conclusiones: Las anomalías electrocardiográficas son muy comunes en la población general de 40 o más años. Tan solo la mitad de la población tenía un electrocardiograma rigurosamente normal

Introduction and objectives: Abnormal electrocardiographic findings are highly common. The aim of this study was to analyze the prevalence of abnormal electrocardiographic patterns in the general Spanish population aged 40 years or older. Methods: This subanalysis of the OFRECE study selected a representative sample of the Spanish population aged 40 years or older. Clinical data and electrocardiograms were available in all participants. The electrocardiograms were read centrally. Each electrocardiogram was independently assessed by 2 trained cardiologists and, if there was disagreement, a third was consulted to reach a consensus-based diagnosis. Prior to reading the electrocardiograms, diagnostic criteria were strictly defined for each of the abnormalities analyzed. We analyzed the prevalence and clinical factors associated with cavity enlargement, conduction disorders, repolarization abnormalities, pathological Q waves, atrial and ventricular premature beats, and pre-excitation. Results: A total of 8343 individuals were evaluated, (mean age, 59.2 years; 52.4% women). Only 4074 (51.2%) participants had a completely normal electrocardiogram. The most frequent abnormalities were nonspecific repolarization abnormalities (16%) associated with coronary heart disease and atrial fibrillation; right bundle-branch block (8.1%) associated with chronic pulmonary obstructive disease; left anterior hemiblock (6.5%) related to hypertension and congestive heart failure; and long PR interval (3.7%), which was associated with coronary heart disease. Conclusions: Electrocardiographic abnormalities are very common in the general population aged 40 years or older. Only about half of the population had a completely normal electrocardiogram

[Preexcitation Syndromes in Children and Adolescents].

Preexcitation syndromes are becoming a more often detected disease in the pediatric population. Their essential feature is the presence of additional paths / pathways in the heart, through which the impulse is conducted faster than physiologically. This leads to faster ventricular excitation and may lead to creating dangerous arrhythmias. The most common preexcitation syndrome is Wolff - Parkinson-White syndrome, which affects 2/ 1000 people. The presence of an accessory pathway could result in serious consequences, ranging from supraventricular tachycardia to sudden cardiac death. There are both invasive and non-invasive methods of diagnosing preexcitation syndromes. Therapeutic treatment includes pharmacotherapy and ablation, which makes it possible to permanently remove the cause of the arrhythmia.

Application of the 2015 ACC/AHA/HRS guidelines for risk stratification for sudden death in adult patients with asymptomatic pre-excitation.

The management of the asymptomatic pre-excited patient largely hinges on risk stratification and individual patient considerations and choice. A high threshold to treat patients may lead to a small overall risk of death while a low threshold clearly leads to increased invasive testing and ablation with associated cost and procedural risk. A firm recommendation to uniformly assess all by electrophysiology study or, alternatively, reassure all is inappropriate and unjustified by data as reflected in the recent guideline recommendations. The use of noninvasive and invasive parameters to identify the potentially at-risk individual with surveillance for symptoms in those comfortable with this approach or ablation for those choosing this alternative for individual reasons remains the cornerstone of best practice.

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.

Pseudo-preexcitation is prevalent among patients with repaired complex congenital heart disease.

This study aimed to evaluate the prevalence of preexcitation and possible pseudo-preexcitation among patients undergoing complex congenital heart surgery at a single center. During a 6-year period (2007-2013), the study retrospectively reviewed the electronic medical records and electrocardiograms (ECGs) of 98 patients who had undergone complex cardiac surgery at the University of Iowa Children's Hospital. The presence and timing of delta waves or short PR interval were evaluated as well as the results of testing for the presence of an accessory pathway. The ECG of 17 patients (17.3%) showed delta waves. Eight of these patients also had a short PR interval. A significant majority of the 17 patients (n = 13) with delta waves showed hypoplastic left heart syndrome (HLHS), with atrioventricular canal defect and Ebstein's anomaly also represented. Two patients with delta waves had adenosine testing that showed antegrade conduction block, greatly reducing the likelihood of an accessory pathway. One patient with delta waves had an electrophysiology study demonstrating an accessory pathway, and the remaining patients had no additional testing for an accessory pathway. For 12 patients, the findings showed a short PR interval on at least one ECG with no evidence of delta waves. Delta waves were commonly seen in patients with HLHS and less commonly in patients with other diagnoses. The high prevalence of preexcitation in combination with our testing confirmed the lack of an accessory pathway in the presence of a delta wave, suggesting that pseudo-preexcitation may be a frequent finding. A short PR interval also was seen frequently in patients exhibiting HLHS, with and without the presence of a delta wave.

Prevalence, causes of reappearance of symptoms or preexcitation syndrome after ablation of accessory pathway and management.

AIM: The purpose of the study was to look for the prevalence, significance and management of preexcitation syndrome (PS) or symptoms reappearance after accessory pathway (AP) ablation. AP ablation actually is the first treatment of PS. METHODS: Successful AP ablation was performed in 261 patients; reappearance of symptoms or PS on ECG occurred in 47 patients (18%) from 20minutes to several years. Their data were compared with remaining patients. RESULTS: Recurrences were more frequent in patients with spontaneous malignant form (34 vs. 21%), in congenital heart disease (4.2 vs. 0%) (P<0.002), in case of complication (11 vs. 2%) (P<0.007) and of a longer duration of applications (304±209 vs. 188±182sec) (P<0.019). Forty percent of patients had the same symptoms and electrophysiological data as before ablation. Twenty-four percent had an improvement of symptoms and/or electrophysiological data. However, 3 initially asymptomatic patients became symptomatic after ablation. Twenty-six percent had another AP or another rhythm disorder. We recommend transesophageal electrophysiological study for the control because only 40% of patients required second ablation. CONCLUSIONS: Reappearance of symptoms or a PS on ECG after AP ablation was not rare (18%) and was inconsistently associated with the reappearance of all initial AP electrophysiological properties. Only 40% of patients required a second AP ablation. Another arrhythmia was possible. Non-invasive second evaluation should be preferred. However, asymptomatic patients before ablation could become symptomatic.

Spontaneous atrioventricular nodal reentrant tachycardia in patients with idiopathic ventricular arrhythmias: the incidence, clinical, and electrophysiologic characteristics.

INTRODUCTION: Spontaneous or inducible atrioventricular nodal reentrant tachycardia (AVNRT) may coexist with idiopathic ventricular arrhythmias (IVAs). The aim of this study was to determine the incidence and the clinical and electrophysiologic characteristics of patients with spontaneous AVNRT among patients with IVAs. METHODS: Nine hundred eighty-seven consecutive patients with IVA (n = 398), patients with clinical and spontaneous AVNRT (n = 327), and patients with preexcitation syndrome (n = 262) were prospectively included in the study. RESULTS: Spontaneous AVNRT was present in 36 (9.0%) of 398 patients with IVA. The most common (97%) mode of presentation was palpitation due to spontaneous AVNRT. Absence of symptoms was frequent among patients with IVA and without spontaneous AVNRT compared to patients with IVA and spontaneous AVNRT (28.9% vs 0%, P = 0.0001). Patients with IVA and spontaneous AVNRT had lower median premature ventricular contraction (PVC) burden (1.9% vs 9.45%, P = 0.0001) and higher left ventricular ejection fraction (LVEF; 64.2 ± 4.9% vs 59.2 ± 9.9%, P = 0.0001) compared to patients with IVA and without spontaneous AVNRT. Relatively high PVC burden (≥10%) was present in 19.4% of patients with spontaneous AVNRT and IVA. The prevalence of IVA was significantly higher in patients with AVNRT compared to patients with preexcitation syndrome (11% vs 0.76%, P < 0.0001). CONCLUSIONS: Spontaneous AVNRT among patients with IVAs was relatively common in our study population. Spontaneous AVNRT in patients with IVAs can be a protective factor for left ventricular function. Greater LVEF in patients with spontaneous AVNRT and IVA compared to patients with IVA alone can be explained by earlier recognition of IVAs due to presence of symptomatic AVNRT and/or lower PVC burden.

Incidence and prognostic significance of spontaneous and inducible antidromic tachycardia.

AIMS: Orthodromic atrioventricular reentrant tachycardia (ORT) is the most common arrhythmia at electrophysiological study (EPS) in patients with pre-excitation. The purpose of the study was to determine the clinical significance and the electrophysiological characteristics of patients with inducible antidromic tachycardia (ADT). METHODS AND RESULTS: Electrophysiological study was performed in 807 patients with a pre-excitation syndrome in control state and after isoproterenol. Antidromic tachycardia was induced in 63 patients (8%). Clinical and electrophysiological data were compared with those of 744 patients without ADT. Patients with and without ADT were similar in term of age (33 ± 18 vs. 34 ± 17), male gender (68 vs. 61%), clinical presentation with spontaneous atrioventricular reentrant tachycardia (AVRT) (35 vs. 42%), atrial fibrillation (AF) (3 vs. 3%), syncope (16 vs. 12%). In patients with induced ADT, asymptomatic patients were less frequent (24 vs. 37%; <0.04), spontaneous ADT and spontaneous malignant form more frequent (8 vs. 0.5%; <0.001) (16 vs. 6%; <0.002). Left lateral accessory pathway (AP) location was more frequent (51 vs. 36%; P < 0.022), septal location less frequent (40 vs. 56%; P < 0.01). And 1/1 conduction through AP was more rapid. Orthodromic AVRT induction was as frequent (55.5 vs. 55%), but AF induction (41 vs. 24%; P < 0.002) and electrophysiological malignant form were more frequent (22 vs. 12%; P < 0.02). The follow-up was similar; four deaths and three spontaneous malignant forms occurred in patients without ADT. When population was divided based on age (<20/≥20 years), the older group was less likely to have criteria for malignant form. CONCLUSION: Antidromic tachycardia induction is rare in pre-excitation syndrome and generally is associated with spontaneous or electrophysiological malignant form, but clinical outcome does not differ.

Missing diagnosis of preexcitation syndrome on ECG: clinical and electrophysiological significance.

UNLABELLED: Electrocardiographic criteria of preexcitation syndrome are sometimes not visible on ECG in sinus rhythm (SR). The purpose of the study was to evaluate the significance of unapparent preexcitation syndrome in SR, when overt conduction through accessory pathway (AP) was noted at atrial pacing. METHODS: Anterograde conduction through atrioventricular AP was identified at electrophysiological study (EPS) in 712 patients, studied for tachycardia (n=316), syncope (n=89) or life-threatening arrhythmia (n=55) or asymptomatic preexcitation syndrome (n=252). ECG in SR at the time of EPS was analysed. RESULTS: 78 patients (11%) (group I) had a normal ECG in SR and anterograde conduction over AP at atrial pacing; 634 (group II) had overt preexcitation in SR. Group I was as frequently asymptomatic (35%) as group II (35%), had as frequently tachycardias, syncope or life-threatening arrhythmia as group II (43, 5, 2% vs 43, 13, 8%). AP was more frequently left lateral in group I (57%) than in group II (36%)(p<0.001). AV re-entrant tachycardia, atrial fibrillation (AF), antidromic tachycardia were induced as frequently in group I (54, 18, 10%) as in group II (54, 27, 7%). Malignant forms (induced AF with RR intervals between preexcited beats <250ms in control state or <200ms after isoproterenol) were as frequent in group I (11.5%) as II (14%). CONCLUSIONS: The frequency of unapparent preexcitation syndrome represents 11% of our population with anterograde conduction through an AP and could be underestimated. The risk to have a malignant form is as high as in patients with overt preexcitation syndrome in SR.

Risk of atrial fibrillation according to the initial presentation of a preexcitation syndrome.

BACKGROUND: Atrioventricular reentrant tachycardia (AVRT) is frequent in Wolff-Parkinson-White syndrome (WPW). Atrial fibrillation (AF) is rare. The purpose of the study was to determine the factors of spontaneous AF in WPW according to the initial presentation. METHODS AND RESULTS: Electrophysiological study (EPS) was performed among 709 patients with a preexcitation syndrome. First event was AF in 44 patients. Remaining patients were studied for AVRT (314), syncope (94), adverse presentation without AF (9) or systematically (248 asymptomatic patients). Patients with AF were older than other patients (44 ± 16 years vs 34.5 ± 17) (0.0003); maximal rate conducted over accessory pathway (AP) was higher in patients with AF than in other patients except in adverse presentation (0.0002); AVRT was induced more frequently in patients with AF than in asymptomatic patients (57% vs 14.5%) but less than in patients with AVRT (89%). AF was induced more frequently in patients with AF than in other patients except in adverse presentation (<0.0001). During follow-up AF occurred more frequently in patients with AF (5; 11%) than in patients with AVRT (7; 2%), with syncope (1%) and asymptomatic patients (4; 1.6%). Older age predicted recurrence (54 ± 16 vs 40 ± 17). CONCLUSIONS: AF was the first event in only 6% of patients with WPW and was a rare event in other patients. They are older but 10% are less than 18 years and have a more rapid conduction over AP than other patients.

Prevalence of preexcitation in a young population of male Swiss conscripts.

BACKGROUND: Sudden cardiac death can be the first clinical presentation of asymptomatic ventricular preexcitation. Recent data about prevalence of preexcitation in the electrocardiograms (ECG) of the general population are scarce. OBJECTIVE: The aim of the present study was to analyze the prevalence of preexcitation in a contemporary population of young conscripts. METHODS: We reanalyzed all consecutive ECGs of Swiss citizens who underwent conscription for the army between March 1, 2004, and July 31,2006. All ECGs with the diagnosis preexcitation were included in the present study. RESULTS: We analyzed ECGs of 41,699 male conscripts. Mean age was 19.2 ± 1.1 years. Preexcitation was found in 53 individuals. The length of the delta wave was 46 ± 10 ms. The most frequent localization of the accessory pathway was the left free wall. CONCLUSION: The prevalence of preexcitation in young, predominantly male conscripts is 0.13%. This is comparable with previous findings in children.

A multicenter, long-term study on arrhythmias in children with Ebstein anomaly.

To assess the prevalence, history, and treatment of arrhythmias, in particular preexcitation and Wolff-Parkinson-White (WPW) syndrome, in patients with Ebstein anomaly (EA) during childhood and adolescence, we performed a multicenter retrospective study of all consecutive live-born patients with EA, diagnosed, and followed by pediatric cardiologists between 1980 and 2005 in The Netherlands. During a follow-up after EA diagnosis of 13 years 3 months (range: 6 days to 28 years 2 months), 16 (17%) of the 93 pediatric EA patients exhibited rhythm disturbances. Nine patients showed arrhythmic events starting as of the neonatal period. Supraventricular tachycardia was noted in 11 patients. One patient died in the neonatal period due to intractable supraventricular tachycardia resulting in heart failure and one patient died at 5 weeks of age most probably due to an arrhythmic event. The 14 surviving patients all show preexcitation, albeit 4 of them intermittently, and all have a right-sided accessory pathway location. Nine patients underwent catheter ablation of an accessory pathway. Only four patients are currently on antiarrhythmic drugs. The 17% prevalence of rhythm disturbances in pediatric EA patients, most commonly supraventricular arrhythmias, is significantly lower than in adult EA patients. Life-threatening rhythm disturbances are not frequent early in life. Symptomatic patients are well treated with radiofrequency catheter ablation.

Sudden cardiac death stratification in asymptomatic ventricular preexcitation.

The second survey deals with risk stratification in subjects, either adults or children, with ventricular preexcitation and no symptoms in their history. Current European electrophysiological practice is still variable among different centres. Although invasive stratification is still part of the practical management of asymptomatic subjects, a not negligible proportion of physicians do not completely rely on cut off values provided in the literature, proceeding to ablation irrespective of the stratification process. These concerns are mainly due to the perception of lack of strong evidence that, according to the majority of centres, is still needed.

[The familial incidence of accessory atrioventricular pathways (the pre-excitation syndrome)]. / Frecuencia familiar de vías accesorias atrioventriculares (síndrome de preexcitación).

Cases of familial preexcitation syndrome represent a specific subgroup of patients that may result from diverse mechanisms: failure in development and genetic predisposition are the main mechanism involved. We determined the prevalence of this syndrome in first degree relatives of patients with proved accessory pathways by electrophysiologic study and compared such prevalence with the general population (0.15%). In five out of 469 patients (1.06%) we found an accessory pathway in one or more member of their family. Only 6 out of 3752 had preexcitation (0.15%); this prevalence was similar to the general population (P = NS). The identification of family members with this syndrome may be incomplete because we only chose for the study symptomatic patients. We did not observed multiple pathways and in one case we found atrial septal defect. Our data demonstrated familial preexcitation in five families suggesting hereditary predisposition.