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The reentrant circuit of common atrial flutter is known to be located in the right atrium between two anatomical barriers. Recent electrophysiologic studies have defined the tricuspid annulus as the anterior barrier, and the terminal crest and its continuation as the eustachian ridge as the posterior barrier. Construction of a bidirectional block to conduction between these two barriers by means of lesions created with radiofrequency current have been shown to be effective in ablating the flutter. We now find that surgical creation of such a block to conduction between the barriers by a simple modification of the atrial incision line is equally effective. In a 6-year-old boy, who was admitted to our hospital for closure of an atrial septal defect and treatment of sustained atrial flutter, the atriotomy was performed perpendicular to the terminal groove and extended towards the tricuspid annulus, placing some cryothermal lesions between the end of the incision and the annulus. The septal defect was closed using a Dacron patch. The child was free of arrhythmia both during the postoperative stay and over the initial three months of follow-up. We conclude that this simple modification of the atrial incision line provides cure of atrial flutter in children who require atriotomy for repair of congenital cardiac anomalies. It may also be beneficial in preventing 'incisional' reentrant tachycardia.

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Cardiac rhabdomyoma is a rare tumor. Because of its rate of regression, mainly in the first year of life, conservative therapy is generally suggested when diagnosis occurs in infancy. We report surgical ablation of a rhabdomyoma in a 2-month-old boy in whom the tumor extended into the subaortic outflow tract. The tumor, which had a dual attachment to the aortic and mitral valves, was safely removed without any valvar damage. We suggest immediate surgical intervention for those rhabdomyomas which are life-threatening because of their size, location, or arrhythmogenicity.

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BACKGROUND: Immediate results after surgical repair of the anomalous origin of the coronary artery are well known, but few studies reported midterm results in a relatively large population. METHODS AND RESULTS: Between 1980 and 1995, 39 consecutive patients with anomalous origin of the coronaries artery from the pulmonary artery had restoration of a two-coronary-artery system. Median age at surgery was 18.5 months (range, 2.7 months to 38 years). Left ventricular (LV) function was normal in 13 patients. Direct aortic implantation was performed in 34 patients (87%), associated with mitral valvuloplasty in 3 patients. Hospital death occurred in 5 patients (13%; 70% confidence limits [CL], 8 to 20). Two patients were lost to follow-up. Mean follow-up was 40 +/- 42 months. There was no late death after 1 month, and the survival rate was 84% (70% CL, 67 to 93). One patient had a mitral valvuloplasty 18 months after reimplantation. At the last follow-up, LV shortening fraction (SF) was normal in 86% (70% CL, 61 to 96), but LV dilation persisted in 73% of patients, and 12 of the survivors (39%) had abnormal regional wall motion of the left ventricle. A perfusion defect with incomplete redistribution was observed in 8 patients on thallium-201 imaging performed in 45% of survivors. Total mortality was related only to the preoperative SF: 12% versus 24.8% (P < .05). No factor was related to SF recovery. CONCLUSIONS: Despite no late deaths and SF recovery, LV dilation and ischemic segments of the left ventricle persisted at the long-term follow-up.

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A child with anomalous origin of the left coronary artery from the right pulmonary artery, ventricular septal defect, fetal growth retardation, and facial abnormalities was born to a woman in whom plasma phenylalanine concentrations had been raised throughout pregnancy. The cardiac abnormalities were diagnosed by angiography when the child was eight months old. The anomalous coronary artery was imaged in a subsequent echocardiogram. Development retardation was caused by maternal phenylketonuria, which may also have been responsible for the development of the ventricular septal defect and the coronary anomaly. If dietary treatment of the mother had been started before pregnancy damage to the child might have been prevented.

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The "absent" pulmonary valve syndrome is associated with aneurysmal dilatation of the pulmonary trunk, stenosis of the ventriculo-arterial junction with or without malalignment of the outlet septum, and ventricular septal defect. When the outlet septum is malaligned, the morphology resembles that of tetralogy of Fallot. We report our experience with 4 infants with this syndrome. All were in severe respiratory distress and cardiac failure when first seen. Cardiac catheterization was performed at 0.5-4.5 months of age in 3 of them. In the other, the clinical and echocardiographic features were considered sufficient to establish the diagnosis. Banding of the pulmonary trunk was carried out at the age of 2.5-5 months. The distal pulmonary arterial pressure in 3 cases dropped to 12-19 mm Hg. These patients could be extubated within one week postoperatively. Their course 1-3 years later is excellent, with rare episodes of mild respiratory problems only and markedly diminished pulmonary insufficiency. One child, weighing 3250 g at surgery, whose pulmonary arterial pressure did not drop below 29 mm Hg, could not be weaned off the respirator. Corrective surgery was undertaken 17 days later, but the patient died of respiratory complications. Based on clinical and Doppler sonographic findings, on control catheterization data and on haemodynamic findings in 3 surviving infants and two further patients with an uneventful course who, as yet, have not undergone surgery, we conclude that the beneficial effect of banding is the combined result of reduced pulmonary arterial pressure and decreased pulmonic regurgitation.

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We report our results with 14 cases of tetralogy of Fallot, which were treated with a modified Blalock-Taussig shunt first, total correction having been performed in 9 of them after a mean interval of 15 months. The age of the patients ranged from 12 days to 3.3 years, with a mean of 4.7 months in 12 patients below the age of one year. In 11 cases we used a 5 mm Gore-Tex prosthesis, in 2 a 6 mm prosthesis and in one a 4 mm prosthesis. All children survived the operation. In one case shunt thrombosis occurred after a bout of pneumonia and a second shunt had to be constructed on the other side. Control angiography, performed after a mean period of 15 months in 13 patients revealed a patent shunt, though angulation of the ipsilateral pulmonary artery was noted in one case. The ratio of the diameter of the pulmonary artery to the aorta increased by 20%. The significance of these findings with regard to the question of primary or two-stage repair in infants less than one year old is discussed in view of different risk factors.

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A case of a now 10-month-old female infant is reported, who presented at birth with microcephalus, growth retardation, dystrophia, facial dysplasia and cardiac defect. Etiologically a classical phenylketonuria of the mother with very high levels of serum phenylalanine (51 and 41 mg/dl, respectively), which was not known until then, was diagnosed already after her confinement. The mother, aged 26, originates from Roumania. She had never been treated by any phenylalanine-limited diet. Psychological testing revealed a severely reduced intelligence (IQ = 63). The child, having normal levels of serum phenylalanine, presented with mild statomotor retardation at the age of ten months. Even in countries with a general neonatal screening program, a hitherto undiagnosed maternal phenylketonuria has to be considered within the differential diagnosis of a dystrophic microcephalic newborn, beside more common causes like the fetal alcohol syndrome.

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In 26 patients with unidirectional retrograde accessory pathways (URAP), antegrade conduction properties were evaluated. During electrophysiologic study the interval from the low septal right atrial potential to the His bundle potential (LSRA-H) in sinus rhythm (SR) was found to be less than 60 msec in 7 out of the 18 patients with left-sided URAP and in one out of two patients with septal URAP. Each of the six patients with right-sided URAP had an LSRA-H equal to or greater than 70 msec. During atrial extrastimulus testing, LSRA-H failed to prolong more than 100 msec (LSRA-H increment equal to or less than 100 msec) in four of six patients with left-sided URAP and LSRA-H of less than 60 msec in SR as well as in the one of two patients with septal URAP in whom the LSRA-H in SR was less than 60 msec. During rapid atrial pacing, we found 1:1 AV node conduction at a pacing rate of more than 200 bpm in the one patient with septal URAP and in 7 out of 14 patients with left-sided URAP who could be assessed. Three of these patients had progression from 1:1 AV conduction to 2:1 AV block without intervening Wenckebach. In conclusion, accelerated AV node conduction in SR and reduced AV node function during rapid atrial pacing or extrastimulus testing was found in 44% of our patients with left-sided or septal URAP. Since these patients are at higher risk for faster ventricular response to atrial flutter and fibrillation and for high frequency during supraventricular tachycardia, these findings were of clinical relevance.(ABSTRACT TRUNCATED AT 250 WORDS)

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Postoperative pulse width thresholds were measured at a constant of 5 volts in 140 patients. In 41 patients, transvenous atrial and/or ventricular leads were implanted at a median age of 13 years (3-78 yrs). Myo-epicardial leads were implanted in 99 patients at a median age of 8 3/4 years (1 wk to 76 yrs). The initial rapid rise of threshold was found to persist not longer than to the third follow-up period of 11 days to 5 weeks in all atrial and transvenous ventricular leads; in myo-epicardial ventricular leads it persisted until the period of more than 5 weeks to 6 months. During initial rise, pulse width threshold m + sem did not exceed 0.45 ms. We therefore suggest that a pulse width setting of 0.5 ms at 5 V is a safe setting for this period. In only one patient did a late rise of threshold occur. The comparison of pulse width thresholds of transvenous versus myo-epicardial leads showed lower mean values for transvenous atrial leads in each follow-up period, but the difference was not statistically significant. The pulse width thresholds of transvenous ventricular leads were significantly lower than those of myo-epicardial leads in some follow-up periods. We therefore conclude that transvenous leads have a slight advantage with regard to postoperative pulse width threshold.

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Many electrophysiological and histological investigations have demonstrated that post-operative dysrhythmias which occur in children with heart disorders requiring extensive surgical treatment in the area of the right atrium, are often caused by intraoperative lesions of the sinoatrial node. Accordingly, accurate determination of that epicardial area which is closest to the primary pacemaking area of the sinoatrial node could prevent injuries and, thus, reduce the risk of postoperative arrhythmias. To localize the relevant area we developed a method which is based on the mapping technique in a series of experiments in dogs. The electrophysiological results were confirmed by histological or gross anatomical methods. After right lateral thoracotomy in the fifth intercostal space, the epicardial surface of the right atrium is subdivided into numbered fields by means of an imaginary grid. The local electrical activities are recorded as bipolar electrograms with the aid of two tripolar electrode probes, one fixed on the epicardium of the right atrial appendage and one placed onto the individual grid fields by the investigator. Intervals thus occur between those potentials derived from the mobile electrode probe and those derived from the fixed probe. Electrical activity originating from the sinoatrial node arrives earlier at the individual fields lying closer to the node than at the field of the fixed probe at the atrial appendage. Thus, the individual field associated with the longest interval between probe potentials must lie closest to the sinoatrial node. An electronic device with digital display of the interval length has been developed which enables, within three minutes, determination of the individual field with the longest interval. Comparison of the digital values with those measured from the electrograms shows good agreement. The experiments were carried out on eleven sheep dogs and large mongrels. In seven cases the location of the sinoatrial node was determined by subsequent histological examination. The assumption that the area associated with the longest interval between the probe potentials lies closest to the primary pacemaking region of the sinus node could be confirmed, since in all these cases the cranial portion of the sinoatrial node was located in the field with the greatest interval measured. In the other four cases the sinoatrial node was localized by dissection with the aid of a stereomicroscope. In three of the four cases, the cranial part of the sinoatrial node was also situated in the field associated with the longest interval.(ABSTRACT TRUNCATED AT 400 WORDS)

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