Lucile Houyel

Frequency and prognosis of arrhythmias after operative Correction of tetralogy of fallot

Two hundred twenty-four consecutive patients operated on for tetralogy of Fallot were followed from 1 to 28 years (mean 11). Mean age at surgery was 5.3 years (range 1 to 14). Postoperative right ventricular systolic pressure was 60 mm Hg in 19 of 213 patients (9%). Fourteen patients (6%) had ventricular premature complexes on surface electrocardiograms. Seventy-nine patients underwent treadmill exercise tests, and ventricular premature complexes were induced in 17 (22%). Twenty-four-hour ambulatory monitoring in 92 patients demonstrated significant ventricular arrhythmias (greater than or equal to grade 2 of the Lown classification) in 41 (45%). The frequency of ventricular arrhythmias correlated with length of follow-up and duration of cardiopulmonary bypass. No correlation was found with age at surgery, postoperative right ventricular systolic pressure and importance of conduction defects on electrocardiogram. There were no sudden or unexpected deaths during follow-up.

VENTRICULAR ARRHYTHMIAS AFTER CORRECTION OF VENTRICULAR SEPTAL DEFECTS : IMPORTANCE OF SURGICAL APPROACH

To compare the prevalence of conduction disturbances and ventricular arrhythmias in cases of postoperative ventricular septal defect, 100 patients (50 with repair by right atriotomy, group 1; and 50 with repair by right ventriculotomy, group 2) underwent complete evaluation including an electrocardiogram (ECG) and 24 h ambulatory ECG monitoring. The two groups were comparable except for a shorter follow-up duration (7 +/- 3 versus 12.4 +/- 7 years) and a younger age at evaluation (12.4 +/- 5 versus 16.9 +/- 7 years) in group 1. Complete right bundle branch block was less frequent in group 1 than in group 2 (20% versus 50%, p less than 0.05) but three of the four patients with complete atrioventricular (AV) block detected on ambulatory monitoring were in group 1. Six patients had significant supraventricular arrhythmias, all well tolerated. Ambulatory monitoring revealed significant ventricular arrhythmias (modified Lown grade 2 or higher) in 39 patients, with a lower prevalence in group 1 (30% versus 48%, p = 0.05). No correlation was found between prevalence of ventricular arrhythmias and right ventricular systolic pressure, cardiopulmonary bypass duration, presence of a synthetic patch, previous pulmonary artery banding, presence of complete right bundle branch block and cardiomegaly on chest X-ray film. Prevalence of ventricular arrhythmias increased with follow-up duration, age at evaluation and age at surgery. These were always well tolerated and did not warrant treatment. Thus, right atriotomy reduces the prevalence of right bundle branch block but does not prevent late AV block. Ventricular arrhythmias are frequent after surgical closure of ventricular septal defect whatever the surgical approach and their prevalence is not statistically different from that in postoperative tetralogy of Fallot.(ABSTRACT TRUNCATED AT 250 WORDS)

The risk for four specific congenital heart defects associated with assisted reproductive techniques: a population-based evaluation

STUDY QUESTION Are the risks of hypoplastic left heart syndrome, transposition of great arteries, tetralogy of Fallot (TOF) and coarctation of the aorta increased in infants conceived by different assisted reproductive techniques (ARTs)? STUDY ANSWER ARTs, and particularly intracytoplasmic sperm injection (ICSI), are specifically associated with a higher risk of TOF. WHAT IS ALREADY KNOWN ARTs are associated with an increase in the overall risk of birth defects. The risk for congenital heart defects (CHDs) associated with ARTs has been evaluated as a whole but there is limited information on the risks for specific CHDs. STUDY DESIGN, MATERIAL AND METHODS: We conducted a case-control study using population-based data from the Paris registry of congenital malformations for the period 1987-2009 and a cohort study of CHD (EPICARD) on 1583 cases of CHDs and 4104 malformed controls with no known associations with ARTs. ARTs included ovulation induction only, IVF and ICSI. RESULTS Exposure to ARTs was significantly higher for TOF than controls (6.6 versus 3.5%, P = 0.002); this was not the case for the other three CHDs. ARTs (all methods combined) were associated with a 2.4-fold higher odds of TOF after adjustment for maternal characteristics, paternal age and year of birth [adjusted odds ratios (OR): 2.4, 95% confidence interval (CI): 1.5-3.7] with the highest risk associated with ICSI (adjusted OR: 3.0, 95% CI: 1.0-8.9). No statistically significant associations were found for the other CHDs. LIMITATIONS Our study cannot disentangle to what extent the observed associations between the risk of TOF and ARTs are due to causal effects of ARTs and/or the underlying infertility problems of couples who conceive following ART. IMPLICATIONS The developmental basis of the specific association between the risk of TOF and ARTs need to be further investigated.

An overview of cardiac morphogenesis.

Accurate knowledge of normal cardiac development is essential for properly understanding the morphogenesis of congenital cardiac malformations that represent the most common congenital anomaly in newborns. The heart is the first organ to function during embryonic development and is fully formed at 8 weeks of gestation. Recent studies stemming from molecular genetics have allowed specification of the role of cellular precursors in the field of heart development. In this article we review the different steps of heart development, focusing on the processes of alignment and septation. We also show, as often as possible, the links between abnormalities of cardiac development and the main congenital heart defects. The development of animal models has permitted the unraveling of many mechanisms that potentially lead to cardiac malformations. A next step towards a better knowledge of cardiac development could be multiscale cardiac modelling.

Heart Transplant Patient Outcomes: 5-Year Mean Follow-Up by Coronary Computed Tomography Angiography

Backgrounds. We evaluate the feasibility and safety of coronary computed tomography angiography (CCTA) as the first-line investigation in heart transplant patients and the rate of coronary allograft vasculopathy detected using CCTA. Methods. From September 2003 to June 2009, we prospectively included 65 heart transplant recipients, retaining 62 who underwent yearly CCTA for coronary allograft vasculopathy detection (261 CCTAs). We used 16-slice, 64-slice, and 2×64-slice CT machines. Patients with coronary artery stenosis by CCTA had a confirmation and a further follow-up exclusively by conventional coronary angiography (CCA). Results. No major coronary events occurred during the study. Of the 62 baseline CCTAs, 37 (60%) were normal, 18 (29%) showed wall thickening, and 7 (11%) known significant stenosis, confirmed by CCA. The mean follow-up duration was 5 years. At the last follow-up, 26 (70%) patients with normal baseline findings remained normal, 9 (24%) had wall thickening, and 2 (6%) significant stenoses. Time to stenosis was consistently greater than 3 years. Of the 18 patients with initially wall thickening, 14 (78%) had wall thickening and 4 (22%) significant stenosis at last follow-up. The mean interval without any coronary lesion was 9.46±3.98 years. The mean interval without de novo significant stenosis was 10.31±4 years. Conclusions. CCTA seems to be a safe noninvasive tool for monitoring heart transplant patients, and thus obviating the need for CCA. In patients with normal baseline CCTA, a 2-year interval between CCTAs may be safe.

Electrophysiologic effects of sotalol on the immature mammalian heart.

Sotalol is a beta-blocker with class III antiarrhythmic properties that has recently been used in children for the treatment of supraventricular and ventricular arrhythmias. However, little is known about its electrophysiologic effects on the immature heart. Using intracardiac electrocardiographic recordings and stimulation techniques, 15 canine neonates (8-15 days) and 15 adult mongrel dogs were studied with cumulative doses of sotalol (0.5, 1, 2, and 4 mg/kg plus an additional dose of 8 mg/kg for neonates). Heart rate decreased significantly in the two groups, but more in adult dogs (-43% in adult dogs versus -25% in neonates, p less than 0.05). There was no significant change for QRS duration and His-Purkinje system conduction time interval. QT and atrioventricular nodal conduction time intervals increased in adult dogs and neonates. Sinus node recovery time increased significantly in the two groups, but more in adult dogs. Refractory periods of the atrioventricular (AV) node increased significantly in neonates. Atrial flutter was no longer inducible in 12 of 15 neonates after the 2 mg/kg dose. Atrial effective refractory period increased significantly more in neonates (96%, p less than 0.001) than in adult dogs (58%, p less than 0.001). Ventricular effective refractory periods increased significantly both in neonates (46%) and adult dogs (50%), in a similar way. In conclusion, sotalol has greater electrophysiologic effects on the immature heart at the atrial level when compared to the adult, and similar effects on the refractory period of AV node and ventricle.

Successful treatment of chaotic atrial tachycardia with oral flecainide

Two infants with chaotic atrial tachycardia diagnosed at birth and at 11 weeks of life, were treated successfully with oral flecainide. Both patients were in heart failure at initiation of therapy. Six months and 17 months later, respectively, they have had no recurrence of chaotic atrial tachycardia, left ventricular function returned to normal and therapy was stopped in both.

Transcatheter Closure of Large Atrial Septal Defects Feasibility and Safety in a Large Adult and Pediatric Population

Background—Data are needed on the safety and efficacy of device closure of large atrial septal defects. Methods and Results—Between 1998 and 2013, 336 patients (161 children <15 years) with large, isolated, secundum atrial septal defects (balloon-stretched diameter ≥34 mm in adults or echocardiographic diameter >15 mm/m2 in children) were managed using the Amplatzer device, at the Marie Lannelongue Hospital. Transthoracic echocardiographic guidance was used starting in 2005 (n=219; 65.2%). Balloon-stretched diameter was >40 mm in 36 adults; mean values were 37.6±3.3 mm in other adults and 26.3±6.3 mm/m2 in children. Amplatzer closure was successful in 311 (92.6%; 95% confidence interval, 89%–95%) patients. Superior and posterior rim deficiencies were more common in failed than in successful procedures (superior, 24.0% versus 4.8%; P=0.002; and posterior, 32.0% versus 4.2%; P<0.001). Device migration occurred in 4 adults (2 cases each of surgical and transcatheter retrieval); in the 21 remaining failures, the device was unreleased and withdrawn. After a median follow-up of 10.0 years (2.5–17 years), all patients were alive with no history of late complications. Conclusions—Closure of large atrial septal defects using the Amplatzer device is safe and effective in both adults and children. Superior and posterior rim deficiencies are associated with procedural failure. Closure can be performed under transthoracic echocardiographic guidance in experienced centers. Early device migration is rare and can be safely managed by device extraction. Long-term follow-up showed no deaths or major late complications in our population of 311 patients.

Assessing the role of multiple pregnancies in the association between tetralogy of Fallot and assisted reproductive techniques: a path-analysis approach.

BackgroundAssisted reproductive techniques (ART) are associated with a higher risk of tetralogy of Fallot (TOF) and multiple pregnancies may be associated with a higher risk of congenital anomalies. We assessed the extent to which the association between ART and risk of TOF may be mediated by the higher risk of multiple pregnancies associated with ART.MethodsWe conducted a case–control study using population-based data from the Paris Registry of Congenital Malformations for the period 1987–2009 and a cohort study of congenital heart defects (EPICARD). The study population included 395 cases of TOF and 4104 malformed controls with no known associations with ART. The analysis was based on a path-analysis model using a counterfactual approach, which allows decomposition of the total effect of ART into an indirect effect (that mediated by the association between ART and multiple pregnancies) and a direct effect.ResultsART (all methods combined) were associated with a 2.6-fold higher odds of TOF after adjustment for maternal and paternal characteristics and year of birth (adjusted OR 2.6, 95% CI, 1.5-4.5). Most (79%) of the effect associated with ART was a direct effect (i.e., not mediated by multiple pregnancies), whereas 21% of the effect of ART was due to its association with multiple pregnancies (i.e., the indirect effect). In vitro fertilization with intracytoplasmic sperm injection was associated with a 3.5-fold higher odds of TOF (adjusted OR 3.5, 95% CI, 1.1-11.2); 11% of this effect was mediated through the association of ICSI with multiple pregnancies.ConclusionsBy far, most of the higher risk of TOF associated with ART is a direct effect and only a small proportion of the effect may be mediated by multiple pregnancies.

Early neonatal death and congenital left coronary abnormalities: ostial atresia, stenosis and anomalous aortic origin.

BACKGROUND Congenital left coronary artery abnormalities such as ostial stenosis or atresia are extremely rare. Diagnosis in the neonate has not been reported. AIMS To describe five neonates with left coronary artery orifice abnormalities and discuss pathophysiology, diagnosis and treatment options, with a focus on the importance of autopsy in unexpected neonatal death. METHODS Retrospective assessment of medical files of neonates with left coronary abnormalities seen during a 12-year period (2000-2012). RESULTS Three neonates with anatomical (n=2) and functional (n=1) left coronary stenosis and two neonates with ostial atresia were identified. The three infants with coronary stenosis died within minutes to days after birth because of cardiac failure refractory to intensive care treatment; at autopsy, left coronary ostial stenosis (n=2) and high take-off with acute angle origin and tangential vertical course (n=1) were diagnosed. The fourth neonate was in cardiac failure due to critical aortic stenosis; left coronary ostial atresia was diagnosed during an emergency catheter procedure and the infant died after aortic valve dilatation. The fifth infant had a cardiac arrest on the third day of life; she was diagnosed with left coronary ostial atresia by coronary angiography and died during attempted revascularization surgery at 2 weeks of life. CONCLUSION Congenital coronary ostial abnormalities can lead to severe heart failure and unexpected neonatal death. Systematic examination of the coronary arteries should be part of any neonatal autopsy. Coronary angiography remains the diagnostic method of choice despite advances in non-invasive imaging. Revascularization surgery seems indicated in symptomatic children based on small patient series.