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The value of the electrocardiogram (ECG) in children with supraventricular tachycardia (SVT) is unclear. The noninvasive differentiation of typical atrioventricular node reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT) mediated by concealed accessory pathway conduction is clinically important, as it helps in counseling and potentially facilitates ablation procedures. One hundred forty-eight ECGs showing narrow QRS complex SVT were obtained from children before successful radiofrequency catheter ablation. An initial 102 ECGs were analyzed by 3 blinded observers to assess the utility of various electrocardiographic findings. No electrocardiographic criteria were found to discriminate between SVT mechanisms on 1- to 3-channel Holter/event recorder tracings (n = 32); their interpretation mainly (55%) resulted in an incorrect SVT diagnosis. On 12-lead ECGs (n = 70), the 2 arrhythmias were accurately diagnosed in 76% of patients; 5 findings were found to be discriminators of tachycardia mechanism. Predictors of AVRT were visible P waves in 74% of cases (sensitivity 92%; specificity 64%), RP intervals of ≥100 ms in 91% (sensitivity 84%; specificity 91%), and ST-segment depression of ≥2 mm in 73% of cases (sensitivity 52%; specificity 82%). Pseudo r′ waves in lead V1 and pseudo S waves in the inferior leads during tachycardia predicted AVNRT in 100% of cases (sensitivity 55% and 20%, respectively; specificity 100% for both). Based on these results, we developed a new diagnostic 12-lead electrocardiographic algorithm for pseudo r′/S waves, RP duration, and ST-segment depression during tachycardia. Two observers tested the algorithm in 46 (21 AVNRT; 25 AVRT) additional cases; they correctly diagnosed the SVT mechanism in 91% and 87%, respectively. Thus, the stepwise use of diagnostically relevant 12-lead electrocardiographic parameters helps to more accurately differentiate mechanisms of reentrant SVT. [Copyright &y& Elsevier]

Congenitally corrected transposition of the great arteries (CCTGA) in the absence of major cardiac anomalies is thought to have a good outcome, although this has not been well documented. The objective of the present study was to compare the characteristics and outcomes of patients with a prenatal diagnosis of CCTGA to the characteristics and outcomes of those diagnosed postnatally. The optimal outcome was defined as intervention-free survival. All patients with CCTGA diagnosed prenatally and postnatally from 1999 to 2006 at 2 tertiary care institutions were reviewed. Patients with a single ventricle, heterotaxy, or valvar atresia were excluded. The differences between groups were assessed using the t test and chi-square test. A total of 54 patients (16 prenatal with 14 live born and 39 postnatal) were included. The patients diagnosed prenatally were diagnosed at a median gestational age of 20 weeks (range 16 to 37). Two deaths in each group were due to heart failure. The intervention-free survival rate for the prenatal and postnatal groups at 1, 6, and 36 months was 79%, 45%, and 30% and 85%, 61%, and 23%, respectively (p = NS). Of 37 patients, 14 (38%) underwent an arterial switch plus atrial baffling so that the morphologic left ventricle supported the systemic circulation, and 6 (16%) underwent repair of associated lesions so the morphologic right ventricle supported the systemic circulation; 4 (11%) of the 37 patients had pacemaker only. Prenatal patients with >1 fetal echocardiogram (12 of 14) did not have progression before birth. In conclusion, CCTGA has a >70% risk of intervention in the first 3 years after birth. The outlook is guarded and has an important effect on prenatal counseling. [Copyright &y& Elsevier]

Pulmonary valve stenosis or atresia with intact ventricular septum represents a spectrum of severity. This study aimed to identify ultrasound markers of biventricular versus non-biventricular outcome. The fetal echocardiograms of 41 fetuses diagnosed with pulmonary stenosis or atresia and right ventricular (RV)/left ventricular (LV) length ratios >0.4 from 17 to 31 weeks of gestation were reviewed. Of 27 live-born patients with intention to treat, 8 had non-biventricular outcomes and 19 had biventricular circulation. At the time of diagnosis, poor RV function, flow reversal in the arterial duct, the degree of tricuspid valve (TV) regurgitation, and inferior vena cava Doppler flow pattern did not differ between the 2 outcome groups. However, RV sinusoids, the RV/LV length ratio, the TV/mitral valve ratio, and TV inflow duration were significantly different. Cut-off values derived from receiver-operating characteristic curves yielding the best sensitivity and specificity for a non-biventricular outcome were TV/mitral valve ratio <0.7, RV/LV length ratio <0.6, TV inflow duration <31.5% of cardiac cycle length, and the presence of RV sinusoids. If 3 of these 4 criteria were fulfilled, this predicted a non-biventricular outcome with sensitivity of 100% and specificity of 75%. In conclusion, in fetuses ≤31 weeks of gestation with pulmonary stenosis or atresia and intact ventricular septum, progression to a non-biventricular outcome can be predicted by a 4-criterion scoring system. The criteria may be useful in selecting fetuses for prenatal catheter intervention to prevent progressive RV hypoplasia. [Copyright &y& Elsevier]