Congenital paroxysmal atrial tachycardia

Ten infants who had paroxysmal atrial tachycardia in utero or at birth are reported. Because of apparent fetal distress, caesarean section was performed in 4 cases and labour was induced in 1. Birthweight was generally large for gestational age. Severe ascites and hydrops at birth were manifestations of cardiac failure. Atrial flutter was recorded in 4 infants and supraventricular tachycardia in 5. The WoLff-Parkinson-White syndrome became evident later in 2. Digoxin was given to all 10 infants, and cardioversion was required and was effective in 4. Known recurrences in childhood have occurred in only 1 patient. Congenital atrial tachyarrhythmias may be commoner than generally believed, and fetal electrocardiography may help to avoid unnecessary termination of pregnancy. Blood sugar determinations are important, since neonatal hypoglycaemia was found. Cardioversion should be performed promptly in severely ill infants or if there is no response to digoxin. Care is required to avoid digoxin toxicity.     

Congenital paroxysmal atrial tachycardia.

Ten infants who had paroxysmal atrial tachycardia in utero or at birth are reported. Because of apparent fetal distress, caesarean section was performed in 4 cases and labour was induced in 1. Birthweight was generally large for gestational age. Severe ascites and hydrops at birth were manifestations of cardiac failure. Atrial flutter was recorded in 4 infants and supraventricular tachycardia in 5. The WoLff-Parkinson-White syndrome became evident later in 2. Digoxin was given to all 10 infants, and cardioversion was required and was effective in 4. Known recurrences in childhood have occurred in only 1 patient. Congenital atrial tachyarrhythmias may be commoner than generally believed, and fetal electrocardiography may help to avoid unnecessary termination of pregnancy. Blood sugar determinations are important, since neonatal hypoglycaemia was found. Cardioversion should be performed promptly in severely ill infants or if there is no response to digoxin. Care is required to avoid digoxin toxicity.     

Characteristics of paroxysmal atrial tachycardia in infants according to the age of onset

Seventy consecutive patients hospitalized before 1 year of age for reentrant paroxysmal atrial tachycardia (PAT) were studied according to the age of onset of arrhythmia making 3 distinctive groups: group I: 10 patients in whom onset of the arrhythmia occurred during foetal life; group II: 39 infants whose arrhythmia appeared during the first month of life and group III consisting of 21 patients in whom tachycardia began between 1 and 12 months of age. The characteristics and the consequences of the arrhythmia as well as the patients' course and the different treatments used were analysed. Foetal tachycardias were characterized by a slower heart rate. Episodes were most often short and repetitive as opposed to post-natal tachycardias which were often prolonged but somewhat unfrequent. Before the age of 3 months the occurrence of heart failure was more frequent. Independently of the age of onset, 43% of patients presented Wolff-Parkinson-White syndrome (WPW), which disappeared spontaneously in 1 out of 3 cases. The existence of WPW syndrome was correlated with late relapses.     

Cardiovascular collapse after verapamil in supraventricular tachycardia.

Five babies who presented with supraventricular tachycardia were treated with verapamil intravenously. All developed severe hypotension and two died. Verapamil should not be used in the initial management of supraventricular tachycardia in neonates.     

Predictors of refractory tachycardia in infants with supraventricular tachycardia

Reentrant supraventricular tachycardia (SVT) is the most common arrhythmia in infants. There are few predictors as to which patients will have recurrent or refractory SVT. We retrospectively reviewed records of all infants with SVT evaluated at The Hospital for Sick Children, Toronto, between January 1, 1995, and December 31, 1999. Patients with reentrant SVT documented in infancy and structurally normal hearts were included. Patients were placed in two groups: the "simple" group consisted of patients with SVT completely controlled by not more than one medication, and the "complex" group consisted of patients with recurrent episodes requiring at least one medication change for control. Forty-two cases were analyzed—23 in the simple group and 19 in the complex group. One patient in each group died. Age at presentation was 50.4 ± 13.2 days for the simple group versus 10.2 ± 2.5 days for the complex group (p <0.01). Complex patients were treated with a median of three medications and were more likely to have echocardiographically reduced ventricular function. The surface electrocardiogram RP interval during SVT was significantly longer in complex patients (p <0.001). There were no differences between the groups in gender, cycle length in SVT or sinus rhythm, the presence of pre-excitation, initial medication choice, or duration of therapy. Recurrent SVT in infancy is associated with younger age and/or ventricular dysfunction at presentation and also with slower ventriculoatrial conduction. The similar duration of therapy for simple and complex patients suggests that the early clinical course of SVT in infancy is not predictive of long-term outcome.     

经食管心房调搏在儿童阵发性室上性心动过速机制研究中的价值

目的探讨经食管心房调搏(TEAP)在儿童阵发性室上性心动过速(PSVT)机制研究中的价值。方法回顾性分析2008年1月至2013年12月行TEAP检查且后期行射频消融术(RFCA)的50例PSVT患者的电生理资料。结果以经心内电生理检查(IEPS)为诊断金标准,TEAP对房室结折返性心动过速(AVNRT)、左侧房室旁道(LAP)、右侧房室旁道(RAP)的灵敏度分别为92.9%、83.1%、90%,特异度为86.4%、100%、95%,准确性为90%、96%和94%。TEAP对AVNRT诊断符合率为92.9%(26/28),其中对慢快型AVNRT的诊断符合率为100%,而2例快慢型的AVNRT均被误诊为房室折返性心动过速(AVRT)。TEAP对AVRT诊断的符合率为86.4%(19/22),3例被诊断为慢快型的AVNRT。结论 TEAP对儿童PSVT发生机制的判定及初步定位具有很好的临床实用价值,但对少数PSVT发生机制的判定具有一定的局限性。