Proposal for a new definition of congenital complete atrioventricular block.

The classic old definition of congenital heart block by Yater (1929) is still generally accepted: 'Heart block established in a young patient. There must be some evidence of the existence of the slow pulse at a fairly early age and absence of a history of any infection which might cause the condition after birth: notably diphtheria, rheumatic fever, chorea and congenital syphilis'. However, other definitions are used. We systematically reviewed 1825 cases from 38 separate studies. We conclude that complete AV blocks detected in utero in the absence of structural abnormalities differ from blocks detected later in life with respect to pathogenesis (they are generally associated with maternal anti-Ro/SSA antibodies), poorer childhood prognosis, increased risk of developing late-onset dilated cardiomyopathy, different maternal clinical features and increased risk of recurrence in future pregnancies. For these reasons we propose a new modern definition of congenital complete AV block which might be acceptable to cardiologists, rheumatologists, pediatricians and obstetricians: 'an AV block is defined as congenital if it is diagnosed in utero, at birth or within the neonatal period (0-27 days after birth)'.

Natural history of congenital complete atrioventricular block.

An update of studies on the natural history of congenital complete AV block is presented. A risk for heart failure, syncope, and sudden death is present at any age including fetal life. Unfavorable prognostic signs in utero are low and decreasing ventricular rate (VR), hydrops, AV valve regurgitation, and low aortic flow velocity. Indications for pacing in infancy are congestive heart failure, ventricular rate < 55 beats/min in isolated block and < 65 beats/min with associated disease, prolonged OTc, syncope attacks, frequent ventricular ectopic beats, and alternating ventricular pacemakers. Indications for immediate pacing in childhood and adult life are syncope, presyncope, VR rates lower than median for age, periods of junctional exit block, prolongation of QTc and mitral regurgitation, and change of ventricular pacemaker. Pacing is recommended to all patients older than 15 years.

Isolated congenital complete atrioventricular block in adult life. A prospective study.

BACKGROUND: The prognosis of congenital complete atrioventricular block (CCHB) is usually considered favorable in adults. This belief is based on studies comprising a limited number of patients and with rather short observation times. In the present study, the natural history of the disease was investigated by a prospective follow-up through decades of adult life of patients with a large group having well-defined CCHB without structural heart disease. METHODS AND RESULTS: The diagnostic criteria of CCHB proposed by Yater were applied. Patients registered as having CCHB in 1964, supplemented by younger patients all without symptoms during their first 15 years of life, were selected. The study was limited to patients with isolated, complete, permanent block. An interview was conducted with all patients and clinical follow-up data obtained. There were finally 102 patients, 61 women and 41 men. In November 1994, the time of observation, after the age of 15 years in survivors, was between 7 and 30 years. The mean age at follow-up or at death was 38 years, median age 37 years, and range 16 to 66 years. Stokes-Adams (SA) attacks occurred in 27 patients, in 8 with a fatal outcome. The first attack was fatal in 6 of these 8 patients. Nineteen survived and a pacemaker (PM) was implanted thereafter. Another 8 patients received a PM because of repeated fainting spells, and 27 others have had a PM implanted for other reasons such as fatigue, effort dyspnea, dizziness, ectopies during exercise tests, mitral regurgitation, and a low ventricular rate (VR). VR decreased with age, with a mean rate at 15 years of 46 beats per minute (bpm), at 16 to 20 years of 43 bpm, at 21 to 30 years of 41 bpm, at 31 to 40 years of 40 bpm, and after 40 years of age of 39 bpm. SA attacks occurred in all 7 patients with prolonged QTc time. Low VR at rest or at work, presence of bundle-branch block pattern, low working capacity, and ectopies at rest and/or during effort were not statistically significant risk factors. SA attacks occurred in 6 patients without any of these signs. Mitral regurgitation developed in 16 patients and 4 died. A PM reduced the risk of death. A change to a lower degree of block occurred in 6 patients. CONCLUSIONS: Prophylactic PM treatment is recommended even for symptom-free adults with CCHB because of the high incidence of unpredictable SA attacks with considerable mortality from first attacks, a gradually decreasing VR, significant morbidity, and a high incidence of "acquired" mitral insufficiency.

Extreme underdevelopment of the left heart. The ultimate hypoplastic left heart syndrome.

We report a case of extreme underdevelopment of the left heart with a 12-day survival. At postmortem, neither a left atrium nor connecting pulmonary veins were identified. The left ventricle was only identified on histology. This was, effectively, a case of absence of the left heart.

Left internal mammary artery flap aortoplasty.

In 14 consecutive 9- to 18-year-old patients with preductal aortic coarctation and isthmic hypoplasia, we resected the coarctation ridge through a longitudinal aortotomy and widened the aorta with an in situ left internal mammary artery flap. This technique resulted in no surgical complications. At 6-month follow-up examination, the average decrease in systolic pressure across the repair was 8.8 mmHg; all patients showed a clear reduction in arterial hypertension at rest and during exercise. Femoral pulses were easily palpable in all cases. Angiography and magnetic resonance imaging showed no aneurysm formation. The narrowest internal diameter of repair was 88% +/- 12% (mean +/- SD) of the diameter of the aortic arch. The internal mammary artery flap technique, which reflects the basic principle of autogenous arterial grafting in situ, allows appropriate circumferential widening of the aorta in many patients with coarctation and hypoplasia of the aortic isthmus involving delayed repair. This procedure should be considered when the internal mammary artery is of good caliber and quality and the anatomic conditions are not ideal for classic end-to-end anastomotic repair.

Friedreich's ataxia in 13 children: presentation and evolution with neurophysiologic, electrocardiographic, and echocardiographic features.

Thirteen children with Friedreich's ataxia were reviewed. The clinical presentation and evolution of the disease was compared to that observed in large series--based mainly on adult patients--and the few studies in children. The mean age of onset (5.3 +/- 2.7 years) was lower than that reported in the former studies. Progressive unremitting ataxia of all four limbs was the earliest and most consistent finding, whereas dysarthria and loss of joint or vibration sense occurred with less frequency than that reported in adult series. The tendon jerks were absent or reduced in the lower limbs in almost all children. The universal absence of lower limb reflexes was shown to be too rigid to be obligatory for the diagnosis of early cases of Friedreich's ataxia. Electrophysiologic investigations revealed typical findings, ie, normal or low-normal motor conduction velocities and absent sensory responses. Electromyography showed more features of denervation in the lower limbs than in the upper limbs. Cardiac symptoms and signs were minimal, whereas electrocardiographic abnormalities occurred in 92% of patients, presenting mostly as significant T-wave changes. Concentric symmetric thickening of both the interventricular and left ventricular posterior walls was the major echocardiographic finding.

The internal mammary artery as subclavian artery substitute in repair of coarctation of the aorta with subclavian flap technique.

In three children, aged 11, 11 and 13 years, long isthmic tubular hypoplasia of the aorta technically precluded resection and end-to-end anastomosis. The coarctation was instead corrected by means of a subclavian flap. Anastomosis between the distal end of the left internal mammary artery and the descending aorta permitted perfusion of the remaining portion of the subclavian artery. At invasive reexamination 6 months after surgery, there was adequate functional and anatomic relief of coarctation in all three children. The three mammary artery-aorta anastomoses were patent, which probably prevented the potential ischemia of the left arm after ligation of the subclavian artery.

Anatomy of congenital complete heart block and relation to maternal anti-Ro antibodies.

The anatomy of the conduction system was studied in 8 patients who had isolated congenital complete heart block. Atrial-axis discontinuity was seen in 7 hearts from children born to mothers with anti-Ro antibodies. The anticipated area of the atrioventricular node was occupied by fibrous and adipose tissue. The heart from the only child whose maternal serum was anti-Ro negative had nodoventricular discontinuity of the conduction system. This difference in anatomy may have etiologic significance.

Cuff pressures and Doppler gradients after coarctectomy. A long-term follow-up.

Fourty-six adult patients operated on as children with resection and end to end anastomosis because of coarctation of the aorta were studied. The age at operation was 7 to 13 years (mean age 10 years) and at follow-up 18 to 28 years (mean age 21 years). Arm and thigh cuff pressure was measured at rest, during and immediately after submaximal exercise. The systolic gradients were also estimated using continuous wave Doppler. Systolic blood pressure at rest was 150 mmHg or more in 12 patients (26%). The cuff pressure at rest correlated well with arm-leg gradients at rest and at work, and also with the Doppler gradients at rest. Doppler gradients slightly underestimated invasively measured gradients. The results imply that postoperative hypertension was explained by residual mechanical obstruction.

Q-T interval in congenital complete heart block.

The rate-corrected Q-T interval (Q-Tc) was measured in 273 children with congenital complete heart block. Fifty-nine had prolonged Q-Tc and 50 of these had symptoms. All 10 with isolated complete heart block, prolonged Q-Tc and bundle branch block had symptoms. The ventricular rate (VR) was significantly lower in patients with prolonged Q-Tc than in their age-matched controls. The outcome is worse for children with low VR and long Q-Tc than for those with low VR and normal Q-Tc. In 11 children a prolonged Q-Tc preceded symptoms by more than 1 month. This suggests that prolonged Q-Tc in children with congenital complete heart block can be of prognostic significance.

Long-term results following closure of isolated ostium secundum atrial septal defect in children and adults.

Information is presented on 166 patients operated for isolated atrial septal defect of secundum type with a mean follow-up time of 12 yr (range 8-21 yr). The mean age at operation was 23 yr (range 4-63 yr). The incidence of suspected mitral regurgitation is very low (4 cases). Postoperative flutter or fibrillation occurred in 24 cases, 20 out of these were operated after the age of 20 yr. In all 24 cases intermittent or permanent atrial dysrhythmia was present immediately postoperatively. The long-term results with regard to the occurrence of dysrhythmias and increased heart volumes is better in the younger age group.