Paul Stanger

Radiofrequency catheter ablation of supraventricular arrhythmias in patients with congenital heart disease: results and technical considerations.

OBJECTIVES The aim of this study was to report the results and techniques of radiofrequency ablation for treatment of supraventricular arrhythmias in patients with congenital structural heart disease. BACKGROUND The management of patients with congenital and other structural heart disease may be complicated by serious arrhythmias due to Wolff-Parkinson-White syndrome or by atrial arrhythmias after cardiac surgery. Ablation techniques using radiofrequency current are revolutionizing the management of arrhythmias, but reports have included few with structural heart disease. METHODS Fifteen patients with significant heart disease underwent radiofrequency ablation: 11 with Wolff-Parkinson-White syndrome and 4 with intraatrial reentrant tachycardia after atrial surgery. Seven had Ebsteins anomaly, complex in two, and the rest had other defects. Coexistence of structural defects introduced significant technical difficulties to radiofrequency ablation in patients with the Wolff-Parkinson-White syndrome and was accomplished by adaptation of current techniques. Ablation of intraatrial reentrant tachycardia was performed by finding early atrial activation sites with electrogram fractionation for radio-frequency application. RESULTS Radiofrequency ablation was initially successful in 14 of 15 patients, with cure in 10 and clinical improvement in 14. Two patients subsequently underwent cardiac surgery without perioperative arrhythmias. CONCLUSIONS Radiofrequency ablation in patients with congenital heart disease and arrhythmias in both safe and effective and may be the preferred approach to treatment in some patients. In patients who are to undergo surgical correction or palliation, preoperative radiofrequency ablation of the tachycardia substrate is effective and may be preferred to operative accessory pathway division. The ablation of intraatrial reentrant tachycardia shows promise in the management of patients who have undergone extensive atrial surgery, and it may eventually become the preferred approach, particularly when there are contraindications to the use of antiarrhythmic agents.

Complications of Cardiac Catheterization of Neonates, Infants, and Children A Three-Year Study

In order to assess the influence of recent modifications in cardiac catheterization technique and patient management, a prospective study of all complications in a series of 1160 cardiac catheterizations of neonates, infants, and children was performed. Thirty-four major and 136 minor complications were recorded. Fatal complications were rare in all age groups (0.26%); however, postcatheterization deaths not attributable to the procedure were common in critically ill neonates with nonremediable lesions.Arrhythmias and arterial complications accounted for 78% of all complications. Although the incidence of arrhythmias was high (8.3% of all cases), particularly in infants, almost all responded to simple therapeutic measures. Five arrhythmias resulted in clinical deterioration and two contributed to death.The incidence of arterial complications varied considerably with the method of arterial entry. Percutaneous catheterization by the sheath method was associated with fewer complications than with the Seldinger technique, arteriotomy, or insertion of a teflon cannula into an exposed artery. Complications were particularly common after brachial arteriotomy in patients with coarctation of the aorta (16.1%).Complications of contrast media and perforation of the heart were infrequent, each occurring once.Although the total number of major complications was only moderately less frequent than in patients of comparable age in the Cooperative Study on Cardiac Catheterization,1 there was a considerable reduction in the most severe complications and deaths. The changes in catheterization technique and patient management that contributed to decreased mortality and morbidity are discussed.

Tetralogy of Fallot with Absent Pulmonary Valve

Absent or hypoplastic pulmonary valve is an uncommon condition usually associated with a ventricular septal defect and an obstructive pulmonary valve ring. Secondary abnormalities involving the pulmonary arteries and major bronchi are common, and many result in severe pulmonary complications. Eight patients with absent pulmonary valve, ventricular septal defect and obstructed pulmonary valve ring are herein described. The clinical features, cardiac catheterization, cineangiographic and postmortem findings are presented. Possible fetal hemodynamics and their influences are discussed, as are postnatal hemodynamics and their clinical consequences. Patients with this combination of lesions have been regarded as having a very poor prognosis, and recent publications have advocated early surgical intervention; however, most published series are small, and only 106 cases have been documented. These cases have been reviewed for clinical and anatomic features as well as an overview of prognosis and results of surgical intervention.

Tetralogy of Fallot with Absent Pulmonary Valve: Natural History and Hemodynamic Considerations

Absent or hypoplastic pulmonary valve is an uncommon condition usually associated with a ventricular septal defect and an obstructive pulmonary valve ring. Secondary abnormalities involving the pulmonary arteries and major bronchi are common, and many result in severe pulmonary complications. Eight patients with absent pulmonary valve, ventricular septal defect and obstructed pulmonary valve ring are herein described. The clinical features, cardiac catheterization, cineangiographic and postmortem findings are presented. Possible fetal hemodynamics and their influences are discussed, as are postnatal hemodynamics and their clinical consequences. Patients with this combination of lesions have been regarded as having a very poor prognosis, and recent publications have advocated early surgical intervention; however, most published series are small, and only 106 cases have been documented. These cases have been reviewed for clinical and anatomic features as well as an overview of prognosis and results of surgical intervention.

Complications of pediatric cardiac catheterization: A 3-year study

To determine the current risk of pediatric cardiac catheterization, the complications and incidents of all catheterizations performed in a pediatric laboratory between January 1986 and October 1988 were prospectively recorded and compared with results from a 1974 study from the same institution. In the current study 1,037 catheterizations, 885 diagnostic and 152 diagnostic/interventional procedures, were performed in 888 patients (aged 1 day to 27 years, median 15.6 months). There were 15 major complications (1.4%), 70 minor complications (6.8%) and 30 incidents (2.9%). Two patients died as a result of the procedure and two as a result of pericatheterization clinical deterioration caused by the cardiac abnormality. The great majority of complications were successfully treated or were self-limited and the patients had no residua. Of patients with 13 nonfatal major complications and 70 minor complications, residua were evident in 7 patients and 3 without evident residua had the potential for sequelae (0.7% and 0.3% of catheterizations). A comparison of the diagnostic and balloon atrial septostomy cases in the present study with similar cases in the 1974 study shows that the incidence of major complications has decreased from 2.9% to 0.9% (p less than 0.0001); minor complications and incidents have decreased from 11.7% to 7.9% (p less than 0.006) and pericatheterization deaths not attributable to catheterization have decreased from 2.8% to 0.2% (p less than 0.0001). Changes in pericatheterization medical management, patient selection for catheterization and catheterization techniques probably account for these improvements.

Surgical treatment of truncus arteriosus in the first 6 months of life.

One hundred six infants were seen at the University of California Medical Center between 1974 and 1981 with the diagnosis of truncus arteriosus. One hundred of these underwent physiologic correction prior to 6 months of age. Six infants died prior to operation while undergoing intense medical therapy to improve their basic condition. There were 11 operative deaths with a mortality rate of 11%. Of the 86 long-term survivors, 55 have returned for conduit change because of either body growth or pseudointima proliferation of the conduit. There had been no mortalities at the time of conduit change, and 29 of these were repaired using a straight tube between the ventricle and pulmonary trunk, while 26 had valve conduits placed. Physiologic correction in the first 6 months of life has been accomplished with a low mortality rate and apparent good long-term results with none of the survivors having evidence of elevated pulmonary vascular resistance.

Evaluation of complex congenital ventricular anomalies with magnetic resonance imaging

Complex ventricular anomalies are frequently associated with abnormalities of thoracic and abdominal situs, arterioventricular connection, and venous connection. The definition of all components of these anomalies is difficult to accomplish with imaging techniques. This study compared the effectiveness of electrocardiographic (ECG) gated spin-echo magnetic resonance imaging (MRI) with cardiac angiography for the evaluation of all components of central cardiovascular anatomy in patients with the clinical diagnosis of single or common ventricle or complete atrioventricular (AV) septal (canal) defect. MRI studies and angiograms of 29 patients were evaluated independently. A sequential approach was used to define cardiac anatomy assessing nine anatomic features in each patient. MRI provided 261 observations and angiography provided 209 observations. In the mutual 209 observations, only 17 discrepancies were found. Comparison of MRI and angiography in individual cases showed that MRI was as effective as angiography in the depiction of ventricular anomalies, including determination of morphology and evaluation of the size of the ventricles, the orientation of the ventricular septum relative to the AV valves, as well as the origins and spatial relationships of the great arteries. MRI was more informative for the determination of thoracic and abdominal situs and systemic and pulmonary venoatrial connections, but was not as effective for the evaluation of semilunar valves. Thus MRI provides complete evaluation of central cardiovascular anatomy and is effective in the anatomic assessment of most components of complex ventricular anomalies.

Isolated Aortic Stenosis in the Neonate Natural History and Hemodynamic Considerations

We have reviewed the clinical and catheterization data and pathologic findings in ten infants under one month of age with isolated severe aortic valve stenosis. All presented with evidence of progressive cardiac failure and diminished cardiac output. A hyperdynamic right ventricular impulse was present in nine infants who were subsequently shown to have a left-to-right atrial shunt, through a stretched patent foramen ovale. Calculated aortic valve area ranged from 0.12 cm2/m2 to 0.29 cm2/m2. Three patients died prior to surgical intervention because of low cardiac output and refractory metabolic acidosis. Aortic valvotomy was attempted in the remaining seven. Five died intraoperatively or in the immediate postoperative period and one other died six months after surgery. Necropsy was obtained in all nine patients who died.We believe that, in this group, the clinical course reflects fetal and postnatal hemodynamics. We have discussed the probable hemodynamic factors which occur and have related them to the morphological development of aortic stenosis in these infants. The poor prognosis of these patients probably results from a combination of factors which include left ventricular outflow obstruction, often associated with a small aortic annulus, a markedly thickened left ventricle, and left ventricular malfunction secondary to subendocardial ischemia and/or endocardial fibroelastosis.

The levoatriocardinal vein: Morphology and echocardiographic identification of the pulmonary—systemic connection

OBJECTIVES This study considers the array of pulmonary-systemic connections made by the levoatriocardinal vein. The primary and associated lesions that play a role in forming this vein are examined, and echocardiography is discussed as a method for its rapid identification. BACKGROUND The levoatriocardinal vein is a pulmonary-systemic connection that provides an alternative egress for pulmonary venous blood in left-sided obstructive lesions. It is thought to result from the persistence of anastomotic channels that connect the capillary plexus of the embryonic foregut to the cardinal veins. Only 12 cases of levoatriocardinal vein have been reported since its first description in 1926. A comprehensive description of the morphology and echocardiographic identification of this lesion has been unavailable because of its rarity. METHODS A retrospective study was performed in 13 patients with a levoatriocardinal vein from the University of California, San Francisco. Echocardiographic findings were compared with those obtained by angiography or at necropsy. In addition, the details of 12 previously published case reports were reviewed. Age at presentation, primary obstruction to pulmonary venous return, integrity of the atrial septum and origin and drainage of the levoatriocardinal vein were compared. RESULTS Patient age at presentation was < 2 years, with most patients presenting before age 6 months. Variations of the hypoplastic left heart syndrome accounted for the majority of primary defects encountered, although multiple but less severe left-sided lesions were seen. The atrial septum was functionally intact in most patients. The levoatriocardinal vein, defined echocardiographically, originated predominantly from the smooth-walled left atrium and drained to the superior vena cava or innominate vein; however, variations of this pattern existed. CONCLUSIONS As a physiologic entity, the levoatriocardinal vein provides a mechanism for decompression of pulmonary venous return primarily in patients with left ventricular inflow obstruction. A levoatriocardinal vein is thought to form when the atrial septum fails to provide an alternate egress for left atrial blood. However, when a septal defect or alternative shunt occurs in conjunction with a levoatriocardinal vein, the clinical presentation may be postponed. Echocardiography provides a rapid, noninvasive modality for identifying the pulmonary-systemic connection, which may masquerade as the vertical vein in anomalous pulmonary venous connection or act as an occult source of left to right shunting in patients undergoing surgery for hypoplastic left heart syndrome.

Doubly committed subarterial ventricular septal defects: Echocardiographic features and surgical implications

Doubly committed subarterial (supracristal, subpulmonary) ventricular septal defects are often complicated by aortic regurgitation resulting from aortic valve herniation into the defect. The clinical, echocardiographic and catheterization findings in 48 patients aged 0.3 to 46.4 years (median 9.5) with a doubly committed subarterial ventricular septal defect were reviewed. Aortic valve herniation was present in 38 (79%) and 55% of these had aortic regurgitation. The prevalence of both findings increased gradually with advancing age. The defect was closed surgically in 41 patients. Surgery during the first 2 years of life (median 0.4 year) was performed in 13 patients (group I), mainly because of a large shunt with a pulmonary to systemic flow ratio (Qp/Qs) 3.8 +/- 1.4 (mean +/- SD). Aortic regurgitation was present preoperatively in two patients (15%), persisted postoperatively in one patient and did not develop in any after repair (median duration of follow-up 2.3 years, range 0.1 to 7.4). In the other 28 patients (group II) surgery was performed between 4.8 and 46.4 years of age (median 11.5). These patients were generally less symptomatic and had a smaller shunt (Qp/Qs 1.5 +/- 0.5, p less than 0.001). Preoperative aortic regurgitation was present in 18 (64%). It persisted in 15 postoperatively, but in 13 of these it had diminished. Two-dimensional echocardiography in multiple views identified the site of the ventricular septal defect in all patients. Serial echocardiographic examinations demonstrated the progressive nature of aortic valve herniation, the partial occlusion of the defect by the herniated sinus and the development of aortic regurgitation. These findings suggest that timely surgical closure of these defects may prevent aortic regurgitation.