Evolution of Clinical and Electrophysiological Data in Children with a Preexcitation Syndrome.

BACKGROUND: With ablation, the follow-up of preexcitation syndrome now is difficult to assess. The purpose was to collect data of children with a preexcitation syndrome studied on two separate occasions within a minimal interval of 1 year. METHODS: This is a retrospective chart review of 47 children initially aged 12 ± 4 years, who underwent two or more invasive electrophysiological studies (EPS) within 1-25 years of one another (6.3 ± 4.8) for occurrence of symptoms or new evaluation. RESULTS: Among initially symptomatic children (n = 25), four (19%) became asymptomatic and one presented life-threatening arrhythmia. Among asymptomatic children (n = 22), five became symptomatic (22.7%). Anterograde conduction disappeared in seven of 23 children with initially long accessory pathway-effective refractory period, but four of six had still induced atrioventricular reentrant tachycardia (AVRT). AVRT was induced at second EPS in three of 13 asymptomatic preexcitation syndrome with negative initial EPS. There were no spontaneous adverse events in the five children with criteria of malignancy at initial EPS; signs of malignancy disappeared in two. At multivariate analysis, AVRT at initial EPS was the only independent factor of symptomatic AVRT during follow-up. Absence of induced AVRT at initial EPS was the only factor of absence of symptoms and a negative study at the second EPS. CONCLUSIONS: There were no significant changes of data in children after 6.3 ± 4.8 years of follow-up. Most children with spontaneous/inducible AVRTs at initial EPS had still inducible AVRT at second EPS. Induced AF conducted with high rate has a relatively low prognostic value for the prediction of adverse events.

Age-related location of manifest accessory pathway and clinical consequences.

BACKGROUND: Accessory pathway (AP) ablation is not always easy. Our purpose was to assess the age-related prevalence of AP location, electrophysiological and prognostic data according to this location. METHODS: Electrophysiologic study (EPS) was performed in 994 patients for a pre-excitation syndrome. AP location was determined on a 12 lead ECG during atrial pacing at maximal preexcitation and confirmed at intracardiac EPS in 494 patients. RESULTS: AP location was classified as anteroseptal (AS)(96), right lateral (RL)(54), posteroseptal (PS)(459), left lateral (LL)(363), nodoventricular (NV)(22). Patients with ASAP or RLAP were younger than patients with another AP location. Poorly-tolerated arrhythmias were more frequent in patients with LLAP than in other patients (0.009 for ASAP, 0.0037 for RLAP, <0.0001 for PSAP). Maximal rate conducted over AP was significantly slower in patients with ASAP and RLAP than in other patients. Malignant forms at EPS were more frequent in patients with LLAP than in patients with ASAP (0.002) or PSAP (0.001). Similar data were noted when AP location was confirmed at intracardiac EPS. Among untreated patients, poorly-tolerated arrhythmia occurred in patients with LLAP (3) or PSAP (6). Failures of ablation were more frequent for AS or RL AP than for LL or PS AP. CONCLUSIONS: AS and RLAP location in pre-excitation syndrome was more frequent in young patients. Maximal rate conducted over AP was lower than in other locations. Absence of poorly-tolerated arrhythmias during follow-up and higher risk of ablation failure should be taken into account for indications of AP ablation in children with few symptoms.

Risk of atrial fibrillation after atrial flutter ablation: impact of AF history, gender, and antiarrhythmic drug medication.

INTRODUCTION: Atrial fibrillation (AF) and flutter (AFL) are frequently associated. We assessed the frequency and identified the predictors of AF occurrence after AFL ablation. METHODS AND RESULTS: A total of 1,121 patients referred for AFL ablation were followed for a mean duration of 2.1 ± 2.7 years. Antiarrhythmic drugs were stopped after ablation in patients with no AF prior to ablation, or continued otherwise. A total of 356 patients (31.7%) had a history of AF prior to AFL ablation. Patients with AF prior to ablation were more likely to be females (OR = 1.35, CI = 1.00-1.83, P = 0.05). After ablation, 260 (23.2%) patients experienced AF. In the multivariable model, AF prior to ablation (OR = 1.90, CI = 1.42-2.54, P < 0.001) and female gender (OR = 1.77, CI = 1.29-2.42, P < 0.001) were associated with a higher risk of AF after ablation. In patients without prior AF, class I antiarrhythmics and amiodarone prior to AFL ablation were independently associated with higher risk of AF after ablation (OR = 2.11, CI = 1.15-3.88, P = 0.02 and OR = 1.60, CI = 1.08-2.36, P = 0.02, respectively). In patients who experienced AF after ablation, 201/260 (77.3%) had a CHA2DS2-VASc ≥1. Two patients with AF prior to ablation had a stroke during the follow-up whereas none of the patients without AF prior to ablation had a stroke. CONCLUSIONS: AF occurrence after AFL ablation is frequent (>20%), especially in patients with a history of AF, in female patients, and in patients treated with class I antiarrythmics/amiodarone prior to AFL. Since most patients who experience AF after AFL ablation have a CHA2DS2-VASc ≥1, the decision to stop anticoagulants after ablation should be considered on an individual basis.

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.

Age-related prognosis of syncope associated with a preexcitation syndrome.

BACKGROUND: Syncope in Wolff-Parkinson-White syndrome (WPW) is without relationship with WPW or reveals a poorly tolerated arrhythmia. Electrophysiologic study (EPS) is recommended. The purpose of the study was to evaluate the influence of the patient's age on the causes and prognosis of syncope. METHODS: A total of 98 patients, mean age 35 ± 18 years, with WPW were admitted for syncope. Note that 29 were aged between 9 and 19 years (mean 15 ± 3) (children and teenagers/group I), 45 between 20 and 49 years (mean 34 ± 8) (adults/group II), and 24 between 50 and 70 years (mean 60 ± 8) (elderly/group III). EPS consisted of atrial pacing and programmed atrial stimulation in control state and after isoproterenol. RESULTS: Potentially malignant form (rapid conduction in accessory pathway >240 beats/min in control state or >300 beats/min after isoproterenol and atrial fibrillation [AF] induction) was more frequent in group I (34%) than in groups II (7%) (P < 0.002) and III (0%) (P < 0.001). Orthodromic atrioventricular reentrant tachycardia (AVRT) and AF were induced as frequently in groups I (59, 34%), II (47, 15.5%), and III (54, 17%). AVRT was induced in all but one patient with malignant form. EPS was as frequently negative in groups I (27.5%), II (44%), and III (37.5%). Natural follow-up (mean 8 ± 6 years) indicated a favorable prognosis, only related to AVRT induction. Induced AF was without significance. CONCLUSIONS: Data in syncope and WPW syndrome depended on age: electrophysiological malignant form was frequent in children/teenagers, rare in adults, and absent in elderly. AVRT, the main cause of syncope, was as frequent in all ranges of age. AF's induction alone had no significance. Final prognosis was favorable.

Complete atrioventricular block during ablation of atrial flutter.

We report the case of a 51-year-old patient who developed a complete atrioventricular (AV) block during the isthmic radiofrequency catheter ablation of a typical atrial flutter. The cause was an acute occlusion of the segment three of the right coronary artery. His recanalization was associated with the immediate restoration of a normal AV conduction. The complication is exceptional (one of 740 consecutive atrial flutter ablations). (PACE 2010; 516-519).

Factors likely to affect the long-term results of ventricular stimulation after myocardial infarction.

BACKGROUND: The results of programmed ventricular stimulation (PVS) may change after myocardial infarction (MI). The objective was to study the factors that could predict the results of a second PVS. METHODS: Left ventricular ejection fraction (LVEF) and QRS duration were determined and PVS performed within 3 to 14 years of one another (mean 7.5+/-5) in 50 patients studied systematically between 1 and 3 months after acute MI. RESULTS: QRS duration increased from 120+/-23 ms to 132+/-29 (p 0.04). LVEF did not decrease significantly (36+/-12 % vs 37+/-13 %). Ventricular tachycardia with cycle length (CL) > 220ms (VT) was induced in 11 patients at PVS 1, who had inducible VT with a CL > 220 ms (8) or < 220 ms (ventricular flutter, VFl) (3) at PVS 2. VFl or fibrillation (VF) was induced in 14 patients at PVS 1 and remained inducible in 5; 5 patients had inducible VT and 4 had a negative 2nd PVS. 2. 25 patients had initially negative PVS; 7 had secondarily inducible VT, 4 a VFl/VF, 14 a negative PVS. Changes of PVS were related to initially increasing QRS duration and secondarily changes in LVEF and revascularization but not to the number of extrastimuli required to induce VFl. CONCLUSIONS: In patients without induced VT at first study, changes of PVS are possible during the life. Patients with initially long QRS duration and those who developed decreased LVEF are more at risk to have inducible monomorphic VT at 2nd study, than other patients.

Are the results of electrophysiological study different in patients with a pre-excitation syndrome, with and without syncope?

AIMS: Syncope in Wolff-Parkinson-White (WPW) syndrome may reveal an arrhythmic event or is not WPW syndrome related. The aim of the study is to evaluate the results of electrophysiological study in WPW syndrome according to the presence or not of syncope and the possible causes of syncope. METHODS AND RESULTS: Among 518 consecutive patients with diagnosis of WPW syndrome, 71 patients, mean age 34.5 +/- 17, presented syncope. Transoesophageal electrophysiological study in control state and after isoproterenol infusion was performed in the out-patient clinic. Atrioventricular re-entrant tachycardia (AVRT) was more frequently induced than in asymptomatic patients (n = 38, 53.5%, P < 0.01), less frequently than in those with tachycardia; atrial fibrillation (AF) and/or antidromic tachycardia (ATD) was induced in 28 patients (39%) more frequently (P < 0.05) than in asymptomatic patients or those with tachycardia. The incidence of high-risk form [rapid conduction over accessory pathway (AP) and AF or ATD induction] was higher in syncope group (n = 18, 25%, P < 0.001) than in asymptomatic subjects (8%) or those with tachycardias (7.5%). Maximal rate conducted over AP was similar in patients with and without syncope, and higher in patients with spontaneous AF, but without syncope. Results were not age-related. CONCLUSION: Tachycardia inducibility was higher in patients with syncope than in the asymptomatic group. The incidence of malignant WPW syndrome was higher in patients with syncope than in asymptomatic or symptomatic population, but the maximal rate conducted over AP was not higher and another mechanism could be also implicated in the mechanism of syncope.

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.

Increased sensitivity of electrophysiological study by isoproterenol infusion in unexplained syncope.

UNLABELLED: The purpose of the study was to evaluate the interests of electrophysiologic study (EPS) after infusion of isoproterenol in patients with syncope and negative EPS in control state. METHODS: 1350 patients were consecutively admitted for syncope and EPS. Patients were included if they had no history of tachycardia, a normal Holter monitoring, a negative EPS in control state. EPS was repeated after infusion of 2-4 mug/kg of isoproterenol. RESULTS: 256 patients, 35 with exercise-related syncope and 105 with heart disease (HD), were recruited. After isoproterenol, an arrhythmia was identified as the sign associated with syncope in 102 patients (40%): SVT in 32 patients, VT in 36 patients, infrahisian 2nd or 3rd degree AV block in three patients and vasovagal reaction in 31 patients. Arrhythmias were more frequent in patients with HD (50/105) than in those without HD (52/151) (p<0.05); SVT tended to be more frequent in patients without HD (n=23) than in those with HD (n=9) (p<0.1); VT was more frequent in patients with HD (n=26) than in those without HD (n=10) (p<0.001). There was no relationship between a positive isoproterenol testing and occurrence of syncope at exercise (19/35 vs 81/221) (p<0.1). CONCLUSION: isoproterenol infusion increased the sensitivity of EPS in patients with syncope, related or not to exercise, and with negative study in control state, but principally in those with HD. However, SVT was diagnosed in patients without HD and EPS associated with isoproterenol infusion remained an important and rapid tool to establish this diagnosis.

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.

Predictors and prognostic significance of tachycardiomyopathy: insights from a cohort of 1269 patients undergoing atrial flutter ablation.

BACKGROUND: Atrial flutter-related tachycardiomyopathy (AFL-TCM) is a rare and treatable cause of heart failure. Little is known about its epidemiology and long-term prognosis. Our aims are to determine the prevalence, predictors and outcomes of AFL-TCM. METHODS AND RESULTS: A total of 1269 patients were referred for radiofrequency ablation of AFL between January 1996 and September 2014; 184 had reduced left ventricular ejection fraction (LVEF <40%). At 6 months after AFL ablation, 103 patients (8.1% of the population, 56% of patients with baseline LVEF <40%) had marked LVEF improvement: these were considered to have AFL-TCM. Patients with persisting reduced LVEF were considered to have systolic dysfunction unrelated to AFL. Patients were followed for a median (percentile25-75 ) of 1.15 (0.4-2.8) years. Patients with AFL-TCM were younger, had lower prevalence of ischaemic cardiomyopathy and used less antiarrhythmic drugs than patients with systolic dysfunction unrelated to AFL. In multivariable analysis, ischemic cardiomyopathy [odds ratio (OR) = 0.32, 95% confidence interval (CI) 0.15-0.68) P = 0.003] and prescription of antiarrhythmic drug before ablation [OR = 0.41, 95% CI 0.20-0.84, P = 0.02] were significantly associated with a lower probability of LVEF improvement during follow-up. Patients with AFL-TCM had similar survival to patients without systolic dysfunction at baseline [hazard ratio (HR) = 0.96 95% CI 0.34-2.65, P = 0.929], whereas patients with systolic dysfunction unrelated to AFL had higher mortality rates compared with patients without systolic dysfunction at baseline [HR = 2.88, 95% CI 1.45-5.72, P = 0.002]. CONCLUSIONS: Marked LVEF improvement was observed in 56% of patients with baseline LVEF <40% at 6 months after ablation. These patients had similar survival to patients without baseline systolic dysfunction, whereas patients who remained with LVEF <40% had a threefold increase in mortality rates.

Prediction of atrial fibrillation in patients with supraventricular tachyarrhythmias treated with catheter ablation or not. Classical scores are not useful.

BACKGROUND: Atrial fibrillation (AF) and other supraventricular tachyarrhythmias (SVTA) [atrial flutter (AFL), atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reentrant tachycardia (AVRT) and preexcitation syndrome (PS)] are frequently associated. We assessed the AF occurrence frequency and predictors according to the nature of SVTA and completion of SVTA ablation. METHODS AND RESULTS: 4169 patients were referred for SVTA (typical AVNRT: 1338, AVRT over a concealed accessory pathway: 329, atypical AVNRT: 205, AFL: 1321; PS: 976); mean age was 50±20years; electrophysiological study (EPS) was systematic; patients were followed for a mean duration of 3±4.5years. Ablation of SVTA was performed in 2949 patients (71%) and 1220 patients were not treated or treated with antiarrhythmic drugs. AF developed in 469 patients (11.2%). In the multivariable model, AF prior to ablation, history of AF, nature of SVTA (AFL), and presence of heart disease were associated with a high risk of AF during follow-up. Presence of heart failure, old age, diabetes and vascular disease were not predictive of AF. Ablation was a weak but significant factor of AF prevention. A score based on nature of SVTA, presence of heart disease and history of AF is proposed. CONCLUSIONS: AF occurrence in patients with SVTA cannot be predicted by the presence of heart failure, old age, diabetes and vascular disease, but only by the following criteria, presence of heart disease, history of AF and nature of the SVTA (SVTA).

Differences in mechanisms and outcomes of syncope in patients with coronary disease or idiopathic left ventricular dysfunction as assessed by electrophysiologic testing.

OBJECTIVES: This study evaluated the causes of syncope and the significance and differences in left ventricular (LV) dysfunction, coronary disease, and idiopathic dilated cardiomyopathy (DCM). BACKGROUND: Risk stratification of and indications for an automated defibrillator could differ according to the cause of LV dysfunction. METHODS: Electrophysiologic study, including atrial and ventricular programmed stimulation, was performed in 119 patients with coronary disease (group I) and 61 patients with DCM (group II) with an left ventricular ejection fraction (LVEF) <40% and syncope. Patients were followed from one to six years (mean 4 +/- 2 years). RESULTS: Sustained monomorphic ventricular tachycardia (VT) was induced in 44 group I patients (37%) and 13 group II patients (21%); ventricular flutter (>270 beats/min) or ventricular fibrillation (VF) was induced in 24 group I patients (19%) and 9 group II patients (15%); and various other arrhythmias were identified. Syncope remained unexplained in 34 group I patients (30%) and 16 group II patients (27%). Prognosis depended on the heart disease: VT or VF induction was a predictive factor of mortality in coronary disease and identified a group with high cardiac mortality (46%), compared with patients with a negative study, who had a lower mortality (6%; p < 0.001) than in other studies. Cardiac mortality was only correlated with LVEF in DCM. CONCLUSIONS: Various causes could explain syncope in 70% of patients with coronary disease and DCM, but differences were noted: VT was frequent in coronary disease with a bad prognosis, and ischemia could explain syncope; in DCM, different causes such as atrial tachycardia could be responsible for syncope, but the prognosis only depended on LVEF.

Risk and outcome after ablation of isthmus-dependent atrial flutter in elderly patients.

PURPOSE OF THE RESEARCH: To study the influence of age on the clinical presentation and long-term outcome of patients referred for atrial flutter (AFL) ablation. Age-related differences have been reported regarding the prognosis of arrhythmias. METHODS: A total of 1187 patients with a mean age 65±12 years consecutively referred for AFL ablation were retrospectively analyzed in the study. RESULTS: 445 (37.5%) patients were aged ≥70 (range 70 to 93) among which 345 were aged 70 to 79 years (29.1%) and 100 were aged ≥80 (8.4%). In multivariable analysis, AFL-related rhythmic cardiomyopathy and presentation with 1/1 AFL were less frequent (respectively adjusted OR = 0.44, 0.27-0.74, p = 0.002 and adjusted OR = 0.29, 0.16-0.52, p<0.0001). AFL ablation-related major complications were more frequent in patients ≥70 although remained lower than 10% (7.4% in ≥70 vs. 4.2% in <70, adjusted OR = 1.74, 1.04-2.89, p = 0.03). After 2.1±2.7 years, AFL recurrence was less frequent in patients ≥70 (adjusted OR = 0.54, 0.37-0.80, p = 0.002) whereas atrial fibrillation (AF) occurrence was as frequent in the 70-79 and ≥80 age subsets. As expected, cardiac mortality was higher in older patients. Patients aged ≥80 also had a low probability of AFL recurrence (5.0%) and AF onset (19.0%). CONCLUSIONS: Older patients represent 37.5% of patients referred for AFL ablation and displayed a <10% risk of ablation-related complications. Importantly, AFL recurrences were less frequent in patients ≥70 while AF occurrence was as frequent as in patients <70. Similar observations were made in patients ≥80 years. AFL ablation appears to be safe and efficient and should not be ruled out in elderly patients.

Recurrences of symptoms after AV node re-entrant tachycardia ablation: a clinical arrhythmia risk score to assess putative underlying cause.

PURPOSE OF THE RESEARCH: To identify clinical factors associated with the probability for each arrhythmic mechanism causing recurring symptoms after atrioventricular nodal re-entrant tachycardia (AVNRT) ablation. Slow pathway radiofrequency ablation is used to treat AVNRT. After ablation, recurrence of symptoms due to AVNRT or other arrhythmias can occur. RESULTS: We studied 835 patients successfully treated with AVNRT ablation. Variables associated with each specific arrhythmia underlying symptom recurrence were studied by logistic regression. During a mean follow-up of 2.2 ± 2 years, 136 (16%) patients had a recurrence of symptoms. Following invasive and non-invasive studies, symptoms were mostly attributed to sinus tachycardia, recurrence of AVNRT and atrial arrhythmias (respectively 4.7%, 5.2% and 6.1%). Older age and history of atrial fibrillation were associated with a markedly increased risk of symptom recurrence due to atrial arrhythmias (OR=15.58, 7.09-35.22, p<0.001) whereas younger age was associated with a higher risk of sinus tachycardia. A simple 3-item clinical score based on age categories and atrial fibrillation history efficiently predicted atrial arrhythmia (C-Index=0.82, 0.75-0.89) and sinus tachycardia (C-Index=0.83, 0.75-0.90). 8.3% of patients with scores=0 had atrial arrhythmias whereas 100% of patients with scores ≥4 had atrial arrhythmias. CONCLUSIONS: While recurrence of symptoms after successful AVNRT ablation is relatively frequent (16%), true AVNRT recurrence accounts for only 1/3 of these recurrences. A simple clinical score based on age and history of atrial fibrillation enables efficient risk stratification for symptom recurrence attributable to atrial arrhythmias and inappropriate sinus tachycardia.

AV nodal reentrant tachycardia or AV reentrant tachycardia using a concealed bypass tract-related adverse events.

OBJECTIVES: To jointly study paroxysmal supraventricular tachycardia (SVT)-related adverse events (AE) and ablation-related complications, with specific emphasis on the predictors of SVT-related AE as well as their significance by investigating their association with long-term mortality. METHODS: 1770 patients were included, aged 6 to 97, with either atrioventricular nodal reentrant tachycardia (AVNRT) or orthodromic atrioventricular reciprocal tachycardia (AVRT) mediated by concealed accessory pathway, consecutively referred for SVT work-up in a tertiary care center. RESULTS: SVT-related AE were identified in 339 patients (19%). Major AEs were identified in 23 patients (1%; 15 cardiac arrests or ventricular arrhythmias requiring cardioversion and 8 hemodynamic collapses). Other AE were related to syncope (n=236), acute coronary syndrome (n=57) and heart failure/rhythmic cardiomyopathy (n=21). In multivariable analysis, higher age, heart disease and requirement of isoproterenol to induce SVT were independently associated with a higher risk for SVT-related AE. During follow-up (2.8±3.0years), death occurred more frequently in patients with SVT-related AE, especially in patients with major adverse events (p<0.001). In multivariable analysis, major SVT-related AE remained significantly associated with occurrence of death (HR=6.72, IC=(2.58-17.52), p<0.001) independently of age and presence of underlying heart disease. Major SVT-related AE in the whole population referred for SVT were more frequent than immediate major ablation complications in patients undergoing SVT ablation (5/1186 vs. 23/1770, p=0.02). CONCLUSIONS: SVT-related AE are independent predictors of mortality and are more frequent than immediate major ablation complications in patients undergoing SVT ablation. The present findings support systematically performing SVT ablation in patients with SVT-related adverse events.

Causes and prognosis of cardiac arrest in a population admitted to a general hospital; a diagnostic and therapeutic problem.

BACKGROUND: The purpose of this study was to determine the causes and the prognosis of consecutive patients resuscitated from cardiac arrest occurring in a general hospital. We assessed 28 females and 94 males (aged 13-82 years) who were resuscitated from cardiac arrest not attributable to acute myocardial infarction. Ventricular fibrillation (VF) was documented in 97. Non-cardiac causes were excluded. Non-invasive studies (24 h Holter monitoring, 2D echocardiogram, signal-averaged ECG, exercise testing, magnetic resonance imaging) and invasive studies (right and left ventricular angiography, coronary angiography and complete electrophysiologic study (EPS) were performed. RESULTS: An underlying cardiac disease was found in 107 patients (88%). Patients were followed for a period ranging from 6 months to 10 years (mean 4+/-5 years). Several causes for cardiac arrest were identified and treated specifically. The prognosis was variable. Among surviving patients the following causes of cardiac arrest were found: Wolff-Parkinson-White syndrome (n=2), rapid supraventricular tachycardia (n=6), acquired or congenital long QT syndrome (n=7), complete atrioventricular block (n=3), proarrhythmic effect of an antiarrhythmic drug (n=5), vasospastic angina (normal coronary arteries) (n=5). Among ten patients with VF related to cardiac ischaemia two died suddenly. Ventricular tachycardia (VT) or VF was the main cause leading to resuscitation after cardiac arrest (n=64). The risk of recurrence of arrest is confirmed in the present study particularly in patients in whom VT/VF could not be suppressed by antiarrhythmic drug therapy (n=45) and in those where an ICD was not implanted (18 cardiac deaths (nine sudden cardiac deaths (SCD's)). The cause of cardiac arrest was not elucidated in 20 patients (16%). The prognosis of these patients differed according to the documentation of VF at the time of cardiac arrest: of those with documented VF (n=12), six patients died suddenly (one with an ICD); of those without documented VF (n=8), all are alive. CONCLUSION: To determine the precise cause of cardiac arrest was the first problem; the diagnosis of cardiac arrest clearly was erroneous in 8 of 122 patients (6.5%). In other patients, a ventricular tachyarrhythmia was identified as the cause for cardiac arrest in half of the population; the indication for an ICD is evident in this group. In 31% of patients with proven cardiac arrest, another arrhythmia requiring specific treatment was identified and ICD implantation was avoided; these patients had a survival of 92% at 3 years. In patients without an identified cause of cardiac arrest and negative EPS, the prognosis was unfavorable only in those with documented VF.

Absence of change of signal-averaged electrocardiogram identifies patients with ventricular arrhythmias who are non-responders to amiodarone.

OBJECTIVES: The aim of this study was to assess the ability of a non-invasive study, the signal-averaged ECG (SAECG), to predict the effect of amiodarone at ventricular level. BACKGROUND: Amiodarone is the main drug drug used in the treatment of ventricular arrhythmias. Standard ECG does not detect any change in QRS complex resulting from amiodarone therapy. SAECG is more sensitive than ECG for detecting changes in QRS complex. METHODS: The study examined the effects of amiodarone on SAECG in relation to the results of programmed ventricular stimulation in 68 patients with old myocardial infarction, spontaneous and inducible sustained ventricular tachycardia (VT). RESULTS: Amiodarone prolonged the total QRS duration (dur) (129+/-28 vs. 140+/-30 ms, P<0.05) and low amplitude signal (LAS) dur (45+/-20 vs. 51+/-20 ms, P<0.1), whereas the root-mean-square voltage of the last 40 ms of QRS complex (RMS 40) was significantly reduced (20+/-16 vs. 14+/-9 microV, P<0.05). Changes in SAECG parameters did not differ significantly in patients in whom amiodarone prevented the inducibility of VT (n=15) and those in whom VT remained inducible with amiodarone (n=53), but in baseline QRS duration was significantly shorter in patients in whom amiodarone prevented the VT induction (118+/-26 vs. 133+/-28 ms, P<0.05). In patients in whom amiodarone did not prolong the cycle length of VT (n=15), SAECG did not change significantly (QRS dur 131+/-29 vs. 132+/-27 ms, LAS 42+/-20 vs. 42+/-19 ms, RMS 40 22+/-14 vs. 19+/-11 microV). Comparison of the SAECG data in patients with no inducible VT and those with slowed VT differed significantly (P<0.05) between the control state and the recording with amiodarone. CONCLUSIONS: The effects of amiodarone on VT inducibility are predicted by a shorter baseline QRS duration and the degree of drug-induced prolongation of filtered QRS duration. Amiodarone prolonged the QRS duration, LAS duration and decreased RMS 40; this effect was more important in patients with no inducible VT and in those with only slowed VT, than in patients with unchanged or accelerated VT. The absence of changes of QRS duration predicted the induction of a more rapid or not slowed VT with amiodarone with a sensitivity of 87% and a specificity of 83%. Therefore, SAECG appears as an useful and simple means to predict the effects of amiodarone in patients with myocardial infarction and VT.

Utility of transesophageal atrial pacing in the diagnostic evaluation of patients with unexplained syncope associated or not with palpitations.

BACKGROUND: Noninvasive studies are often negative in patients with syncope, normal surface ECG and without heart disease. The purpose of the study was to determine the diagnostic impact of an esophageal electrophysiological study performed during a consultation. METHODS: A total of 154 patients aged from 16 to 87 years were consecutively recruited for unexplained syncope; they had a normal ECG in sinus rhythm, no documented arrhythmia and no patent heart disease. Half of them complained of palpitations. Electrophysiologic study was performed during a consultation by transesophageal route: rate of 2nd d AV block occurrence during atrial pacing and sinus node recovery time were determined; programmed atrial stimulation using one and two atrial extrastimuli were delivered in control state and then after infusion of 0.02-1 microg/min of isoproterenol; arterial blood pressure was monitored. RESULTS: (1) Electrophysiologic study was positive in 107 patients (69%); (2) sinus node dysfunction was noted in 9 patients (6%); (3) atrioventricular conduction disturbances were noted in 2 patients (1%); (4) vasovagal reaction which associated a junctional bradycardia and a fall of arterial blood pressure and which reproduced spontaneous symptoms was provoked by isoproterenol infusion in 21 patients (14%); (5) sustained atrial fibrillation was induced in 23 patients (15%); and (6) paroxysmal junctional tachycardia was induced in 52 patients (34%). Patients with negative study were younger (44+/-21.5 years) than those with sinus node dysfunction or atrial fibrillation (71+/-9 and 63+/-14 years, respectively). The treatment was guided by these data: patients with inducible atrial fibrillation were treated by antiarrhythmic drugs and those with inducible paroxysmal junctional tachycardia by the radiofrequency ablation of reentrant circuit. Syncope disappeared in all patients but 2. CONCLUSION: Esophageal electrophysiologic study performed during a consultation was a safe, rapid and economic means to detect an arrhythmia (sinus node dysfunction or supraventricular tachycardia) in patients with dizziness/syncope and palpitations in half cases. Supraventricular tachycardia was clearly an underestimated cause of syncope in this population.