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).

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.

1:1 atrial-flutter. Prevalence and clinical characteristics.

UNLABELLED: Little is known about the epidemiology of 1:1 atrial flutter (AFL). Our objectives were to determine its prevalence and predisposing conditions. METHODS: 1037 patients aged 16 to 93 years (mean 64±12) were consecutively referred for AFL ablation. 791 had heart disease (HD). Patients admitted with 1/1 AFL were collected. Patients were followed 3±3 years. RESULTS: 1:1 AFL-related tachycardiomyopathy was found in 85 patients, 59 men (69%) with a mean age of 59±12 years. The prevalence was 8%. They were compared to 952 patients, 741 men (78%, 0.04), with a mean age of 65±12 years (0.002) without 1:1 AFL. Factors favoring 1:1 AFL was the absence of HD (35 vs 23%, 0.006), the history of AF (42 vs 30.5%)(0.025) and the use of class I antiarrhythmic drugs (34 vs 13%)(p<0.0001), while use of amiodarone or beta blockers was less frequent in patients with 1:1 AFL (5, 3.5%) than in patients without 1:1 AFL (25, 15%) (p<0.0001, 0.03). The failure of ablation (9.4 vs 11%), ablation-related complications (2.3 vs 1.4%), risk of subsequent atrial fibrillation (AF) (20 vs 24%), risk of AFL recurrences (19 vs 13%) and risk of cardiac death (5 vs 6%) were similar in patients with and without 1:1 AFL. CONCLUSIONS: The prevalence of 1:1 AFL in patients admitted for AFL ablation was 8%. These patients were younger, had less frequent HD, had more frequent history of AF and received more frequently class I antiarrhythmic drugs than patients without 1:1 AFL. Their prognosis was similar to patients without 1:1 AFL.

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.

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.

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).

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.

Influence of age on atrial fibrillation inducibility.

The prevalence of AF is known to increase in the elderly. Some electrophysiological changes were reported in these patients, but the effects of age on AF inducibility and other electrophysiological signs associated with atrial vulnerability are unknown. The purpose of the study was to evaluate the effects of age on atrial vulnerability and AF induction. The study consisted of 734 patients (age 16-85 years, mean 61 +/- 15 years) without spontaneous AF who were admitted for electrophysiological study. Study was indicated for dizziness or ventricular tachyarrhythmia. Programmed atrial stimulation was systematically performed. One and two extrastimuli were delivered in sinus rhythm and atrial driven rhythms (600, 400 ms). Univariate and multivariate analysis of several clinical and electrophysiological data were performed. AF inducibility, defined as the induction of an AF lasting > 1 minute, was paradoxically and significantly decreased in elderly (> 70 years) patients compared to younger patients (< 70 years) (P < 0.01). AF inducibility was present in 40% of 62 patients < 40 years, 39% of 99 patients age 40-50 years, 37% of 130 patients age 50-60 years, 38% of 222 patients age 60-70 years, and only 28% of 221 patients > 70 years. There was no significant correlation with the sex, the presence of dizziness, the presence or not of an underlying heart disease, the left ventricular ejection fraction, and the presence of salvos of atrial premature beats on 24-hour Holter monitoring. There was a significant correlation with a longer atrial effective refractory period in the elderly (226 +/- 41 ms) than in younger patients (208 +/- 31 ms) (P < 0.001). Other electrophysiological parameters of atrial vulnerability did not change significantly. Increased atrial refractory period and age >70 years were independent factors of decreased AF inducibility. Programmed atrial stimulation should be interpreted cautiously before the age of 70 years. AF induction is facilitated by the presence of a short atrial refractory period in these patients. Surprisingly, AF inducibility decreases in patients > 70 years because their atrial refractory period increases. Therefore, increased AF prevalence in these patients should be explained by nonelectrophysiological causes.

Significance of external cardioversion induced atrial tachyarrhythmias.

External cardioversion is used to stop VT or VF in emergency. Supraventricular tachyarrhythmias are sometimes noted after cardioversion in patients known to be previously in sinus rhythm. The purpose of the study was to evaluate the significance of supraventricular tachyarrhythmias induced by external cardioversion. The study population consisted of 22 patients who developed supraventricular tachyarrhythmias after transthoracic cardioversion (300 J) delivered to stop a VT or VF induced by electrophysiological study. Defibrillation used monophasic waveform. Supraventricular tachyarrhythmias complicated 6% of cardioversions for VT; before cardioversion, all patients were in sinus rhythm. After cardioversion, three patients developed a paroxysmal reentrant supraventricular tachycardia (PSVT), which was stopped by atrial pacing. The remaining patients developed AF that lasted from 3 minutes to 24 hours (n = 4). One patient remained in AF. AF developed after a sinus pause or bradycardia, which was due to the interruption of VT or VF in nine patients or was noted just when VT or VF stopped (n = 10). The analysis of clinical data indicated that all three patients who presented a PSVT had a history of PSVT. Among patients who developed a sinus pause dependent AF, two had a history of AF. Among ten patients who developed AF at the time of cardioversion, three had a history of AF. During follow-up (1-9 years), no patient without a history of AF developed spontaneous AF, but patients with history of tachycardias had arrhythmia recurrences. The mechanism of cardioversion related tachycardias can be a pause related dispersion of atrial refractoriness or an adrenergic reaction induced by VT or VF, factors that precipitate arrhythmias in patients with history of atrial arrhythmias (one third of patients). In conclusion, supraventricular tachyarrhythmia is relatively frequent after external cardioversion for ventricular tachyarrhythmia, has no prognostic significance in patients without previous history of atrial arrhythmias, but in those with history of tachycardias is associated with a high risk of recurrence.

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.