ABSTRACT
The normal fetal heart rate ranges between 110 und 180 beats per minute (bpm). Intrauterine arrhythmias are not an uncommon finding. Fetal echocardiography (ECG) allows for correct diagnosis of the arrhythmia, which is prerequisite for decision making and treatment. Most fetal rhythm disturbances are the result of premature atrial contractions and are of little clinical significance. Intrauterine bradycardias (heart rate <â¯110â¯bpm) result from sinus node dysfunction, complete AV block and nonconducted atrial bigeminy. Isolated complete heart block related to maternal anti-SSA/Ro or SSB/La auto-antibodies is irreversible in almost all fetuses. Anti-inflammatory therapy and chronotropic medication may improve outcome. Newborn babies often require pacemaker implantation to augment cardiac output. Intrauterine tachycardias (heart rate >â¯180â¯bpm) are most commonly related to supraventricular tachycardia and atrial flutter. Specific antiarrhythmic medication is available to stop the arrhythmia and to prevent hemodynamic deterioration.
Subject(s)
Fetal Diseases , Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/therapy , Bradycardia , Echocardiography , Electrocardiography , Female , Fetal Diseases/diagnosis , Humans , Infant, Newborn , PregnancyABSTRACT
BACKGROUND: Idiopathic ventricular tachycardia (VT) in children with a structurally normal heart can cause significant morbidity, and although rare, mortality. Conventional activation and pace mapping may be limited by nonsustained tachycardia or unstable hemodynamics. OBJECTIVE: The aim of this study was to assess feasibility of catheter ablation of idiopathic VT in the pediatric population guided by noncontact mapping. METHODS: Twenty consecutive pediatric patients with idiopathic VT underwent electrophysiologic study with the intention to use the noncontact mapping system EnSite 3000 (EnSite Array, St. Jude Medical Inc., Minneapolis, Minnesota). The multielectrode balloon array was introduced into the left or right ventricle, respectively, and tachycardia was analyzed using color-coded isopotential maps as well as reconstructed unipolar electrograms on the virtual geometry. The region of origin was identified in all of them, and the site of earliest activation with a QS pattern of the unipolar electrograms was guided for sites of ablation. RESULTS: Idiopathic VT originated from the right ventricular outflow tract in 6 patients, from the left ventricle in 8, and from the aortic sinus cusp in 6 in this cohort with a median age of 14.4 (range: 4.8 to 20.9) years. Ablation was attempted in 18 of 20 children, and was acutely successful in 17 of these 18 (94%). During a mean follow-up of 2.3 +/- 1.7 years, VT recurred in 3, 2 of them have been treated with a second procedure, resulting in an overall intermediate-term success in 16 of 18 (89%) children with idiopathic VT. CONCLUSION: Noncontact mapping can safely and effectively be used to map and guide catheter ablation of the tachycardia substrate of idiopathic VT in pediatric patients.
Subject(s)
Body Surface Potential Mapping/methods , Catheter Ablation , Heart Ventricles/pathology , Tachycardia, Ventricular/surgery , Adolescent , Adult , Age Factors , Body Surface Potential Mapping/instrumentation , Bundle-Branch Block , Child , Child Welfare , Child, Preschool , Electrophysiology , Feasibility Studies , Female , Heart Ventricles/surgery , Hemostasis , Humans , Kaplan-Meier Estimate , Male , Retrospective Studies , Statistics, Nonparametric , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/pathology , Young AdultABSTRACT
BACKGROUND: Several case reports have documented coronary artery stenosis or even occlusion after radiofrequency energy ablation (RFA) in children and adults. Coronary involvement early and late after RFA has also been described in animal models. OBJECTIVE: The purpose of this study was to assess prospectively the incidence of coronary artery injury early after catheter ablation for supraventricular tachycardias (SVT) in children. METHODS: From October 2002 to January 2008, 212 consecutive patients younger than 21 years with SVT underwent selective coronary angiography before and 30 minutes after RFA or cryoablation. RESULTS: Median patient age was 12 years (range 0.3-20.4 years), and median body weight was 47 kg (range 5.5-130 kg). An accessory pathway was diagnosed in 112 patients, AV nodal reentrant tachycardia (AVNRT) in 84 patients, and both an accessory pathway and AVNRT in 16 patients. Congenital heart disease was present in 31 patients. In 2 of 117 patients who had RFA for an accessory pathway, an acute reduction in luminal diameter of the coronary artery adjacent to the ablation site was observed. These two patients with a structurally normal heart showed ST-segment changes with normalization of the ECG within 1 week. Both were clinically asymptomatic, and two-dimensional echocardiography documented normal ventricular function. Noninvasive testing did not reveal any evidence of persistent myocardial ischemia. No coronary artery damage was noted after ablation for AVNRT or after ablation with cryoenergy. CONCLUSION: Coronary artery narrowing adjacent to the RFA site was noted in 2 of 117 patients with an accessory pathway and occurred only in patients with a posteroseptal pathway. Coronary angiography could be helpful in avoiding coronary lesions in these settings.
