PubMed Health⌕ Search

Biomedical subjects

A Buendia

Publications and source records attributed to A Buendia.

At least 19 recordsLinked to original sources
PubMed2000

Radiofrequency catheter ablation for the treatment of supraventricular tachycardias in children and adolescents.

We report our experience in radiofrequency catheter ablation between April, 1992 and December, 1998, in which we treated 287 patients less than 18 years of age (mean 14.3 +/- 3.1 years) with supraventricular tachycardia. Accessory, pathways were the arrhythmic substrate in 252 of the patients (87.8%), the patients having a total of 265 accessory pathways. Atrioventricular nodal re-entry was the cause of tachycardia in 26 patients (9.0%), while atrial flutter was detected in the remaining 9 patients (3.1%). We were able successfully to eliminate the accessory pathway in 236 patients (89%), but 25 patients had recurrent arrhythmias. Ablation proved successful in all cases of atrioventricular node re-entry tachycardia, the slow pathway being ablated in 25 patients, and the fast pathway in only one case. Recurrence of the arrhythmia occurred in three patients (11.5%). We performed a second ablation in these children, all then proving successful. The ablation was successful in all cases of atrial flutter, with one recurrence (11.1%). Overall, therefore, ablation was immediately successful in 271 patients (94.4%), with a recurrence of the arrhythmia in 29 cases (10.7%). The incidence of serious complications was 2.09%. There was one late death due to infective endocarditis, 3 patients suffered complete heart block, 1 had mild mitral regurgitation, and 1 patient developed an haematoma in the groin. We conclude that radiofrequency catheter ablation can now be considered a standard option for the management of paroxysmal supraventricular tachycardias in children and young adults.

Adolescent↗
PubMed2000

The adult patient with Ebstein anomaly. Outcome in 72 unoperated patients.

Knowledge of the long-term outcome in unoperated adult patients with Ebstein anomaly is limited, and the therapeutic approach is still controversial. We studied unoperated adult patients with Ebstein anomaly to define the patterns of presentation, anatomic characteristics, outcome, and predictive factors for survival. Seventy-two unoperated survivors of Ebstein anomaly aged over 25 years attended from 1972 to 1997 were reviewed and followed-up from 1.6 to 22.0 years. Patients were classified in 3 groups of severity according to the echocardiographic appearance of the septal leaflet attachment of tricuspid valve. The mean age at diagnosis was 23.9 +/- 10.4 years, and the most common clinical presentation was an arrhythmic event (51.4%). There were 30 (42%) deaths, including 6 from arrhythmia, 12 related to heart failure, 7 sudden, 2 unrelated, and 3 unascertained. According to Cox regression analysis, predictors of cardiac-related death included age at diagnosis (hazard ratio 0.89 for each year of age, 95% confidence intervals CI[ 0.84-0.94), male sex (3.93, 95% CI, 1.50-10.29), degree of echocardiographic severity (3.34, 95% CI, 1.78-6.24), and cardiothoracic ratio > or = 0.65 (3.57, 95% CI, 1.15-11.03). During follow-up, morbidity was mainly related to arrhythmia and refractory late hemodynamic deterioration. The magnitude of tricuspid regurgitation, cyanosis, and the New York Heart Association (NYHA) functional class at time zero were significant risk factors according to the univariate analysis, but not after multivariable confrontation. The results of this study suggest that pattern of presentation, clinical course, and prognosis of unoperated adult patients with Ebstein anomaly are influenced by several factors. Although the initial symptoms are usually mild and commonly related to supraventricular arrhythmias, these are not associated with the long-term outcome. The severity of the morbid anatomy was the main determinant of survival only in extreme cases, but not in those with mild or moderate deformations, which are more common in adults. Other independent risk factors such as cardiothoracic ratio, sex, age at diagnosis, and the echocardiographic evaluation may help to determine the therapeutic approach. Adult patients with Ebstein anomaly should not be considered as a simple low-risk group.

Adult↗
PubMed1998

Congenitally corrected transposition with atrioventricular septal defect.

We describe 4 cases of congenitally corrected transposition associated with atrioventricular septal defect, diagnosed by echocardiography and angiocardiography. Two had usual atrial arrangement and two had mirror imaged atrial arrangement . All cases were associated with subpulmonary valvar stenosis. All patients presented with cyanosis and were in sinus rhythm. Atrioventricular septal defect with common atrioventricular junction was easily diagnosed on the basis of a common atrioventricular valve permitting interatrial and interventricular communications. All patients had balanced right and left ventricles. The echocardiographic recognition of the ventricles was based on the presence of the moderator band within the morphologically right ventricle, the characteristics of the apical septal trabeculations, and the shape of the ventricles. Angiocardiographic recognition of the ventricles was achieved on the basis of right and left ventriculography. In one case with usual atrial arrangement, we recorded two His bundle potentials, one anteriorly and another posteriorly. Atrial stimulation revealed blocked atrioventricular conduction at the level of the posterior bundle, and normal atrioventricular conduction through the anterior bundle. In both cases with atrial mirror-imagery, only a posterior His bundle potential was found, with normal atrioventricular conduction revealed by atrial stimulation The clinical course with this combination depends on the other lesions present in addition to the common atrioventricular valve. Our electrophysiological studies show that the conduction system in presence of a common atrioventricular valve is as expected for congenitally corrected transposition with two atrioventricular valves.

Adolescent↗
PubMed1987

Congenitally corrected transposition with mirror-image atrial arrangement.

Congenitally corrected transposition (discordant atrioventricular and ventriculoarterial connexions) with mirror-image atrial arrangement is much less frequent than the same chamber combinations in the setting of usual atrial arrangement. This scarcity of cases has made their analysis difficult. In this study we have compared the anomalies found in 19 patients with congenitally corrected transposition in mirror-image arrangement with those in 39 patients having usual atrial arrangement. Absolute, relative and attributable risks were calculated for the presence of subvalvar pulmonary stenosis, ventricular septal defect, tricuspid regurgitation, atrioventricular block or the absence of these anomalies for each of the two groups. A greater absolute risk was found for both subvalvar pulmonary stenosis (68.4 vs. 43.6%, respectively) and ventricular septal defect (63.2 vs. 58.9%, respectively). The absolute risk for tricuspid regurgitation was 25.6% in those with usual arrangement as against 21.1% in those with mirror-image arrangement. Atrioventricular block was also more frequent in those with usual arrangement (25.6 vs. 10.5%) as was absence of associated cardiac defects (17.9 vs. 10.5%, respectively). The relative risks were greater for subvalvar pulmonary stenosis and ventricular septal defect in the patients with mirror-image as opposed to usual atrial arrangement (1.57: 1.00 and 1.07: 1.00, respectively), contrasting with greater relative risk for tricuspid regurgitation (1.26: 1.00), atrioventricular block (2.43: 1.00) and absence of associated anomalies (1.70: 1.00) in the patients with usual arrangement. The attributable risk for subvalvar pulmonary stenosis was estimated to be 24.8% and ventricular septal defect 4.3% for those having mirror-image atrial arrangement.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Hypertrophic↗
PubMed1986

Surgical results in subaortic stenosis.

Since 1965, 46 patients aged 4 to 42 years, underwent cardiac surgery for subaortic stenosis. Resection of the subvalvar obstruction without myomectomy was performed in all cases. Three patients died during the operation, another one after 6 months due to infective endocarditis and one more suddenly 11 years after treatment. One patient was lost to follow-up but 41 were available after at least 1 year of follow-up. Before surgery, 21 cases were in NYHA class I, 17 in class II and 8 in class III. One year after surgery 36 were in class I, 4 in class II and only one in class III. Actuarial survival rate was 91% from 1 to 12 years and 79% from 13 to 18 years. Event-free survival was 45% up to 18 years. The mean preoperative peak systolic gradient was 93.15 +/- 35.57 mm Hg. The first postoperative peak systolic gradient was 21.61 +/- 17.91 mm Hg (P = 0.001). Cases with adverse postoperative events such as aortic regurgitation (13 cases), restenosis (13 cases), death (2 cases) and infective endocarditis (2 cases) had a mean peak systolic gradient of 55.78 +/- 35.97 mm Hg, while in the event-free patients the gradient was 14.61 +/- 13.34 mm Hg (P = 0.001). Recurrent obstruction was observed in seven patients and an increase in the residual gradient in six. The initial mean postoperative peak systolic gradient in these patients had been 18.23 +/- 17.32 mm Hg and the second postoperative cardiac catheterisation showed a mean gradient of 59.23 +/- 37.78 mm Hg (P = 0.001). We conclude that long-term follow-up following removal of subaortic stenosis is mandatory in order to detect and treat adverse events.

Adolescent↗
PubMed1986

Late results of mitral valve replacement with the Björk-Shiley prosthesis in children under 16 years of age.

The late results of isolated mitral valve replacement were evaluated in 37 children under 16 years of age receiving a Björk-Shiley prosthesis for the treatment of rheumatic mitral lesions. Three patients died, one during the operation and the others 2 months postoperatively. Of the latter two, one had a cerebral hemorrhage and the second had septicemia. The survivors were followed up for a mean of 4.7 years (range 2.8 to 8.9 years). After the operation, all patients were placed on a strict anticoagulant regimen with acenocoumarol. The actuarial survival rate was 92% at the end of the follow-up period. Before valve replacement two patients were in New York Heart Association Class I, 15 in Class II, 18 in Class III, and two in Class IV. After treatment 33 were in Class I and one in Class II. No instances of thromboembolism or infective endocarditis were observed in the survivors. Twenty-one patients underwent cardiac catheterization 2 to 7 years after the operation for evaluation of surgical results. The mean pulmonary artery systolic pressure decreased significantly after operation (p = 0.001), and the mean pulmonary artery wedge pressure decreased to normal values (p = 0.001). A mild mean diastolic gradient across the mitral valve at rest was found after the operation (4.9 +/- 2.4 mm Hg). During isometric exercise this gradient increased to 6.5 +/- 4.6 mm Hg. In two patients a discrete paravalvular leak was demonstrated by cineangiography, but the pulmonary wedge pressure was normal in both. The overall results with the Björk-Shiley prosthesis are encouraging in patients in whom reconstructive operations cannot be performed.

Adolescent↗
PubMed1985

The clinical features and diagnosis of a discordant atrioventricular connexion.

Seventy-three patients were studied with a discordant atrioventricular connexion (ages 3 months to 46 years). In 58 the diagnosis was proved by angiography and in the other 15 at necropsy. Forty-eight had usual atrial arrangement and 25 mirror-image atria. Fifty-two patients had ventriculo-arterial discordance, 13 double outlet right ventricle, 4 ventriculoarterial concordance, 3 single outlet of the heart and 1 double outlet left ventricle. Nine with ventriculoarterial discordance had no other associated defects. The spatial relationship of the ventricles was variable, but in usual atrial arrangement the morphologically left ventricle tended to be on the right, and in mirror-image arrangement to the left of the morphologically right ventricle. The spatial relationship between the arterial valves was also variable, but in ventriculoarterial discordance and double outlet right ventricle the aortic valve was anterior and either to the right or left of the pulmonary valve in all but 3 cases. There is no typical clinical picture for these malformations. Symptoms depend upon the associated anomalies or the presence of atrioventricular dissociation. The diagnosis of a discordant atrioventricular connexion is best achieved by the echocardiographic and haemodynamic studies, but the electrocardiogram, chest radiograph and nuclear medicine studies may suggest its presence. Most patients are asymptomatic and progress normally to adult life. Only the symptomatic patients require surgical correction. Postoperative follow-up in the survivors is excellent, only 2 of 14 patients dying after surgery.

Adolescent↗
PubMed1983

Congenital absence of pulmonary valve leaflets.

Congenital absence of pulmonary valve leaflets is an uncommon condition usually associated with ventricular septal defect and an obstructive pulmonary valve ring. Twenty-one patients with these malformations are described. Twenty had an associated ventricular septal defect with ventriculoarterial concordance, and one also had transposition of the great arteries, ventricular septal defect, and obstructive pulmonary valve ring. The clinical features, cardiac catheterisation findings, and angiocardiographic results are presented. Twelve patients underwent cardiac surgery. Three patients died, one in the early, and the other two in the late postoperative period. The results, according to the surgical technique employed and postoperative cardiac catheterisation findings, showed that patients in whom the bioprostheses were implanted in the pulmonary position had a better late follow-up.

Adolescent↗
PubMed1982

Congenital absence of the pulmonary valve leaflets associated with complete transposition of the great arteries.

We describe the clinical and surgical findings of a patient with absence of the pulmonary valve leaflets and complete transposition of the great arteries. The main clinical features were a loud, single second heart sound, a loud pansystolic murmur over the entire precordial area, but no diastolic murmurs were heard. The electrocardiogram suggested right ventricular hypertrophy and right bundle branch block. The roentgenographic study showed cardiomegaly with dilatation of both branches of the pulmonary artery. Cardiac catheterization and angiocardiography showed systemic arterial desaturation, discordant ventriculo-arterial connections and absence of the pulmonary valve leaflets. The patient underwent surgical correction by the Rastelli technique with a favorable clinical course.

Blood Pressure↗
PubMed1980

Crossed atrioventricular connections.

Four cases of crossed atrioventricular connections are described. All of them were diagnosed at cardiac catheterization by angiocardiography and one was examined pathologically. Two possessed situs solitus, one with concordant connections and the other with discordant connections; the other had two situs inversus, both of them with concordant connections. Two had double-outlet right ventricle, one had transposition of the great arteries, and the other had normally related and connected great arteries. These cases have been interpreted as representing abnormal rotation of the ventricles following sepatation. A review of 36 cases previously reported on and our own cases, suggests that most patients have concordant atrioventricular connections. There are many types of ventriculo-arterial connections, the most frequent being transposition of the great arteries. There has not been any case reported with persistent truncus arteriosus. On the basis of atrioventriculo-arterial connections, we propose a classification for this malformation. We discuss the importance of the bulboventricular loop in the type of atrioventricular connections, some clinical implications for the diagnosis, and analyze the value of the rules to localize the ventricles by means of the position of the great arteries.

Adolescent↗
PubMed1980

Angiographic studies of atrioventricular discordance.

The results and value of conventional and axial angiocardiography were studied in 26 cases of atrioventricular discordance (AVD). The angiographic anatomy of this malformation was analyzed to determine the precise characteristics of atrioventricular and ventriculoarterial connections. The left and right ventricles in atrial situs solitus and levocardia show angiographic features that differ from those seen in atrial situs solitus and dextrocardia. The same differences are found in atrial situs inversus. Regardless of the type of ventriculoarterial connections, the ventricles maintain the same angiographic characteristics. The ventricular septum in AVD in situs solitus and levocardia and situs inversus and dextrocardia has a peculiar orientation. The use of axial angiocardiography facilitates detection and localization of the ventricular septal defect. In cases of malposition of the heart, the conventional frontal view allows visualization of the ventricular septum in all of its length. The axial projection is useful in diagnosing left ventricular outflow tract obstruction.

Adolescent↗