François Marçon

Value of Programmed Ventricular Stimulation After Tetralogy of Fallot Repair A Multicenter Study

Background—Studies have consistently shown that ventricular tachycardia (VT) and sudden cardiac death (SCD) complicate the long-term outcome after tetralogy of Fallot repair, yet the diagnostic and predictive value of electrophysiological testing in this population is uncertain. Methods and Results—A multicenter cohort of 252 patients with repaired tetralogy of Fallot undergoing programmed ventricular stimulation was followed up for 18.5±9.6 and 6.5±4.5 years after corrective surgery and electrophysiological testing, respectively. Clinical VT and/or SCD occurred in 24.6%. Sustained monomorphic VT and polymorphic VT were induced in 30.2% and 4.4%. Including polymorphic VT in the definition of inducibility improved sensitivity (66.1±6.0% versus 77.4±5.3%, P = 0.0082) with a marginal reduction in specificity (81.6±2.8% versus 79.5±2.9%, P = 0.0455). Positive and negative predictive values were 55.2±5.3% and 91.5±2.2%. Independent risk factors for inducibility were age at study ≥18 years (OR, 3.3), palpitations (OR, 2.8), prior palliative surgery (OR, 3.1), modified Lown criteria ≥2 (OR, 5.6), and cardiothoracic ratio ≥0.6 (OR, 3.3). Event-free survival rates in noninducible and inducible patients at 1, 5, 10, and 15 years were 97.9%, 92.8%, 89.3%, and 89.3% versus 79.4%, 62.6%, 58.7%, and 50.3%, respectively (P < 0.0001). Both inducible monomorphic VT [relative risk (RR), 5.0; P = 0.0002] and polymorphic VT (RR, 12.9; P < 0.0001) predicted future clinical VT and SCD. In a multivariate analysis, inducible sustained VT was an independent risk factor for subsequent events (RR, 4.7; 95% CI, 1.2 to 18.5; P = 0.0268). Conclusions—Programmed ventricular stimulation is of diagnostic and prognostic value in risk stratifying patients with repaired tetralogy of Fallot. In this patient population, inducible sustained polymorphic VT should not be disregarded as nonspecific.

Right ventricular overload and induced sustained ventricular tachycardia in operatively “repaired” tetralogy of Fallot

The aim of the study was to evaluate the main predictors of the inducibility of sustained ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot. Thirty-five patients (age 12 +/- 6 years) underwent right-sided cardiac catheterization, echocardiography, radionuclide angiography and ventricular stimulation; 10 had (group 1) and 25 had no (group 2) sustained VT. Group 1 patients were significantly older at the time of surgery and had longer follow-up periods (7 +/- 3 vs 4 +/- 4 years, p less than 0.02; and 12 +/- 4 vs 5 +/- 2 years, p less than 0.001, respectively). Right ventricular (RV) systolic pressure, end-systolic and end-diastolic normalized RV volumes were higher in group 1 (48 +/- 14 vs 38 +/- 11 mm Hg, p less than 0.05; 1.23 +/- 0.2 vs 0.86 +/- 0.17, p less than 0.001; and 2.35 +/- 0.37 vs 1.70 +/- 0.22, p less than 0.001, respectively). RV end-diastolic pressure, left ventricular and RV ejection fractions were similar in the 2 groups. A stepwise discriminant analysis was made to predict patients with inducible sustained VT (group 1): Time period from surgery to follow-up (p less than 0.001), normalized RV end-systolic volume (p less than 0.002) and RV systolic pressure (p = 0.01) were higher in group 1 and allowed classification of 90% of patients in group 1 and 96% in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of sustained ventricular tachycardia after surgical repair of tetralogy of Fallot

Between 1980 and 1996, 89 unselected consecutive patients with repaired tetralogy of Fallot (TOF) underwent examination, including a prospective right ventricular programmed stimulation with the same protocol (S1 S2, S3, S4). Age at surgery was 4.2 +/- 3.5 years and age at electrophysiologic study was 10.9 +/- 6.5 years. Follow-up since surgery was 14.4 +/- 4.8 years and patient follow-up after programmed stimulation was 7.8 +/- 4.2 years. The aim of this study was to evaluate the main predictors of the inducibility of a sustained monomorphic ventricular tachycardia (VT) and its significance to identify a group of patients at risk of sudden death: 21 (group A) had and 68 (group B) had no induced sustained VT. The induction of VT was related to older age at programmed stimulation, prolonged QRS duration, presence of complex ventricular arrhythmia, symptoms, right ventricular overload, and increased right ventricular systolic pressure. Predictors of induced VT selected by multivariate analysis were age at electrophysiologic study (p <0.0001), previous palliative shunts (p <0.001), right ventricular systolic pressure (p <0.007), and symptoms (p <0.005). Among group A patients, 4 had previous sustained VT before stimulation, and 1 had sustained VT only during follow-up after stimulation. No patients of group B had clinical sustained VT. Late mortality was low but similar between both groups. A negative electrophysiologic study may be helpful for the management of patients after surgical repair of TOF, but because the arrhythmic event rate is low, the findings of even a positive electrophysiologic study should be interpreted with caution.

Characteristics and long-term outcome of non-immune isolated atrioventricular block diagnosed in utero or early childhood: a multicentre study

AIMS The natural history of congenital or childhood non-immune, isolated atrioventricular (AV) block is poorly defined. METHODS AND RESULTS We retrospectively studied 141 children with isolated, non-immune AV block diagnosed in utero, or up to 15 years of age, at 13 French medical centres, between 1980 and 2009. Patients with structural heart disease or maternal antibodies were excluded. Atrioventricular block was asymptomatic in 119 (84.4%) and complete in 100 (70.9%) patients. There was progression to complete AV block in 29/41 (70.7%) patients with incomplete AV block over 2.8 ± 3.4 years (1-155 months), but all patients with incomplete AV block may not have been included in the study. Narrow QRS complex was present in 18 of 26 patients (69.2%) with congenital, and 106 of 115 (92.2%) with childhood AV block. Pacemakers were implanted in 112 children (79.4%), during the first year of life in 18 (16.1%) and before 10 years of age in 90 (80.4%). The mean interval between diagnosis of AV block and pacemaker implants was 2.6 ± 3.9 years (0-300 months). The pacing indication was prophylactic in 70 children (62.5%). During a mean follow-up of 11.6 ± 6.7 years (1-32 years), no patient died or developed dilated cardiomyopathy (DCM). The long-term follow-up was uncomplicated in 127 children (90.1%). CONCLUSION In this large multicentre study, the long-term outcome of congenital or childhood non-immune, isolated AV block was favourable, regardless of the patients age at the time of diagnosis. No patient died or developed DCM, and pacemaker-related complications were few.

Is the aorta truly dextroposed in tetralogy of Fallot? A two-dimensional echocardiographic answer.

The embryogenesis of tetralogy of Fallot is still much debated. In particular, the dextroposition of the aorta is not considered by all pathologists as a genuine abnormality in this congenital heart disease but rather as a false impression due to an exaggeration of the normal overriding caused by dilatation of the aorta secondary to abnormal hemodynamics. We used two-dimensional echocardiography to examine the spatial position of the aortic root in 22 patients with tetralogy of Fallot (aged 5 days to 24 years, mean 6.4 years) and in 23 normal subjects (aged 1 month to 27 years, mean 7.6 years). Using the parasternal short-axis view, we determined the percent rightward displacement of the aortic root in relation to the plane of the atrial septum, and the relationship between the aortic cusps and the atrial septum. We measured the value of the angle luminal diameter, which was defined as the angle between the plane of the atrial septum and the plane of the left coronary-noncoronary commissure and leaflet appositional plane. In the control group, the aortic root was displaced to the right by only 23.6 +/- 7.6%; the atrial septum crossed the posterior aspect of the aortic root at the middle (n = 19) or at the right half of the posterior cusp (n = 4), and the angle luminal diameter had a value of 43.3 +/- 8.8 degrees. In the 22 patients with tetralogy, the percent rightward shift of the aortic root was augmented to 55.5 +/- 9% (p less than .001) and the atrial septum was related to the posterior commissure in 14 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Paroxysmal Tachycardia in Children and Teenagers with Normal Sinus Rhythm and Without Heart Disease

BREMBILLA‐PERROT, B., et al.: Paroxysmal Tachycardia in Children and Teenagers with Normal Sinus Rhythm and Without Heart Disease. The purpose of this study was to evaluate the value of esophageal programmed stimulation in children and teenagers with normal sinus rhythm ECG and normal noninvasive studies, having palpitations and syncope, and no documented tachycardias. Paroxysmal tachycardias are frequent in children and are often related to accessory connection. These tachycardias are sometimes difficult to prove. Transesophageal atrial pacing was performed at rest and during infusion of isoproterenol in 31 children or adolescents aged 9–19 years (16 ± 3 years) with normal sinus rhythm ECG and suspected or documented episodes of paroxysmal tachycardia. Sustained tachycardia was induced in 27 patients, at rest in 13 patients, and after isoproterenol in 14 remaining patients. Atrioventricular nodal reentrant tachycardia was found as the main cause of paroxysmal tachycardia (22 cases). Six patients were followed by a vagal reaction and dizziness. These patients had spontaneous tachycardia with syncope. In three other patients, atrial fibrillation was also induced. Concealed accessory pathway reentrant tachycardia was identified in three patients. In two patients, a regular wide tachycardia with right bundle branch block morphology was induced; the diagnosis of verapamil‐sensitive ventricular tachycardia was made in a second study by intracardiac study. In conclusion, atrioventricular nodal reentrant tachycardia was found as the main cause of symptoms in children with normal sinus rhythm ECG. Syncope is frequently associated and provoked by a vagal reaction. This diagnosis could be underestimated in adolescents frequently considered as hysterical because noninvasive studies are negative.

Parental Electrocardiographic Screening Identifies a High Degree of Inheritance for Congenital and Childhood Nonimmune Isolated Atrioventricular Block

Background— The origin of congenital or childhood nonimmune isolated atrioventricular (AV) block remains unknown. We hypothesized that this conduction abnormality in the young may be a heritable disease. Methods and Results— A multicenter retrospective study (13 French referral centers, from 1980–2009) included 141 children with AV block diagnosed in utero, at birth, or before 15 years of age without structural heart abnormalities and without maternal antibodies. Parents and matched control subjects were investigated for family history and for ECG screening. In parents, a family history of sudden death or progressive cardiac conduction defect was found in 1.4% and 11.1%, respectively. Screening ECGs from 130 parents (mean age 42.0±6.8 years, 57 couples) were compared with those of 130 matched healthy control subjects. All parents were asymptomatic and in sinus rhythm, except for 1 with undetected complete AV block. Conduction abnormalities were more frequent in parents than in control subjects, found in 50.8% versus 4.6%, respectively (P<0.001). A long PR interval was found in 18.5% of the parents but never in control subjects (P<0.0001). Complete or incomplete right bundle-branch block was observed in 39.2% of the parents and 1.5% of the control subjects (P<0.0001). Complete or incomplete left bundle-branch block was found in 15.4% of the parents and 3.1% of the control subjects (P<0.0006). Estimated heritability for isolated conduction disturbances was 91% (95% confidence interval, 80%–100%). SCN5A mutation screening identified 2 mutations in 2 patients among 97 children. Conclusions— ECG screening in parents of children affected by idiopathic AV block revealed a high prevalence of conduction abnormalities. These results support the hypothesis of an inheritable trait in congenital and childhood nonimmune isolated AV block.

Relation between motion sickness susceptibility and vasovagal syncope susceptibility

Motion sickness is common in the population, especially in children, but its physiopathology is only partially understood and the true nature of the particular susceptibility of certain subjects remains completely unknown. Some symptoms of motion sickness, like pallor and cold sweating, are of an autonomic nature and the role of the autonomic nervous system in vasovagal syncope is well known. Our aim was therefore to study the relationship between motion sickness susceptibility and vasovagal syncope susceptibility. Questionnaires about susceptibility to motion sickness and to vasovagal syncope or presyncope in adulthood and childhood, filled in by 899 students (20.4 +/- 2.1 years, 405 men), were analysed. Motion sickness susceptibility in childhood was 31.1% and in adulthood 7.9% (p < 0.001). Vasovagal syncope susceptibility in childhood was 36.4% and in adulthood 33.9% (NS). A relationship between motion sickness susceptibility in adulthood and vasovagal syncope susceptibility in childhood and adulthood (p = 0.004 and 0.005, respectively) was found. Despite the limitations of a retrospective study this relationship between motion sickness susceptibility and vasovagal syncope susceptibility may indicate that a common mechanism exists, explaining the particular susceptibility of some subjects to both disorders. This paradigm may prove useful in better understanding the true nature of motion sickness and vasovagal syncope.

Inducible multiform ventricular tachycardia in Wolff-Parkinson-White syndrome.

The induction of ventricular tachycardia by ventricular stimulation was investigated in 46 patients with isolated Wolff-Parkinson-White syndrome (10 concealed) and 36 control patients with normal electrocardiograms and conduction systems. None of those studied had spontaneous ventricular arrhythmias or myocardial or valve disease. Single and double ventricular extrastimuli were delivered at 3 cycle lengths (sinus, 600 ms, 400 ms). In the controls ventricular simulation induced one episode (3%) of non-sustained ventricular tachycardia. Ventricular stimulation in patients with Wolff-Parkinson-White syndrome induced two episodes of ventricular fibrillation and 15 episodes of non-sustained multiform ventricular tachycardia (37%). Ventricular arrhythmias were induced only in patients with overt Wolff-Parkinson-White syndrome. In 14 patients the conformation of the electrocardiogram at the start of ventricular tachycardia resembled that of major pre-excitation. The absence of inducible ventricular tachycardia in patients with concealed Wolff-Parkinson-White syndrome suggests that anterograde conduction via an atrioventricular accessory pathway is required to initiate the ventricular arrhythmias: the ventricular tachycardia may be associated with reentry of impulses via atrioventricular connection during the phase of ventricular vulnerability. The similarity between the start of ventricular tachycardia and pre-excitatory complexes may also indicate local reentry into the ventricular area occupied by the bypass tracts. Patients with Wolff-Parkinson-White syndrome and anterograde pre-excitation are more likely to have inducible multiform ventricular tachycardia than individuals without Wolff-Parkinson-White syndrome.

Rapid and low-cost method to prove the nature of no documented tachycardia in children and teenagers without pre-excitation syndrome

Aims Symptoms in children are often difficult to interpret. The purpose of this study was to report the results of transoesophageal electrophysiological study (EPS) performed in children complaining of sudden onset tachycardia with normal non-invasive studies. Methods and results Eighty-two children and teenagers (mean age 15 +/- 3 years) presented with suspected but no documented paroxysmal supraventricular tachycardia (SVT). ECG was normal. Non-invasive studies were negative; 23 children had syncope with tachycardias. They underwent transoesophageal EPS in our out-patient clinic. The mean duration of transoesophageal EPS was 11 +/- 5 min. Electrophysiological study was negative in 25 children. AV nodal re-entrant tachycardia could be induced in 37 children, 11 of them associated with syncope. Wolff-Parkinson-White syndrome (WPW) was diagnosed in five children in which atrioventricular re-entrant tachycardia was inducible. Atrioventricular re-entrant tachycardia due to a concealed AP was induced in 14 children. Verapamil-sensitive ventricular tachycardia was induced in one patient. Factors associated with tachycardia inducibility were an older age (15.5 +/- 2 vs. 14 +/- 4 years) (P < 0.05) and the absence of syncope (81 vs. 52%) (P < 0.05). During a mean follow-up of 3 +/- 1 year, no patient with negative EPS developed documented tachycardia. In 17 children with inducible SVT, radiofrequency ablation of the re-entrant circuit was subsequently performed. Conclusion Transoesophageal EPS is a fast method for proving the nature of paroxysmal tachycardia in children and teenagers presenting with normal ECG and for demonstrating WPW syndrome not visible on standard ECG. The negative predictive value of transoesophageal EPS for the diagnosis of SVT was 100%.