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Biomedical subjects

A Garson

Publications and source records attributed to A Garson.

At least 181 records · Page 10Linked to original sources
PubMed1983

Pacemaker treatment of sick sinus syndrome in children.

The sick sinus syndrome is being recognized with increasing frequency in children. Although it is sometimes benign, it can be serious or have fatal consequences. Fifty-one patients (mean age 10.5 years) underwent permanent cardiac pacing for sick sinus syndrome. Twenty patients had epicardial ventricular pacing and 12 had an epicardial atrial implant. Seven had endocardial atrial pacing, six epicardial atrioventricular (AV) sequential pacing, four epicardial universal pacing and two endocardial universal pacing. Of the 49 symptomatic patients, 45 had relief of symptoms. Eleven of 18 patients with associated tachyarrhythmias had amelioration of their tachycardia. There were no early but two late deaths unrelated to the pacemakers. Seven patients during a mean follow-up period of 26 months required reoperation for pacing lead or sensing problems. Permanent pacing for sick sinus syndrome in children is a safe and symptomatically effective procedure.

Adolescent↗
PubMed1983

Effect of ouabain on the anterograde effective refractory period of accessory atrioventricular connections in children.

The anterograde effective refractory period of the accessory connection was determined before and after the administration of ouabain (0.015 mg/kg intravenously) during electrophysiologic studies in 21 patients with Wolff-Parkinson-White syndrome. The mean age (+/- standard deviation) was 10 +/- 2 years (range 1 month to 31 years). Each patient had stopped taking all cardiac drugs for more than 36 hours. Determination of the anterograde effective refractory period of the accessory connection was made using the atrial extrastimulus technique. A change in the anterograde refractory period of the accessory connection was defined as an increase or decrease of greater than 10 ms from the value before ouabain administration. The post-ouabain anterograde effective refractory period of the accessory connection increased in 2 (9%) of the 21 patients, decreased in 9 (43%) and was unchanged in 10 (48%). This study demonstrated a decrease in the anterograde effective refractory period of the accessory connection of 43% of patients with Wolff-Parkinson-White syndrome after the administration of ouabain.

Adolescent↗
PubMed1983

Verapamil: an effective calcium blocking agent for pediatric patients.

Verapamil is a slow-channel calcium-blocking agent that has been released recently by the Food and Drug Administration for treatment of cardiac dysrhythmias in all age groups. Its primary action is to slow conduction in the atrioventricular node, thereby abolishing those types of supraventricular tachycardia using the atrioventricular node as a part of the reentry circuit or slowing the ventricular rate in someone with atrial flutter. Other investigations have shown that it is likely to relieve left ventricular outflow obstruction in patients with hypertrophic obstructive cardiomyopathy. Because of its potential widespread usefulness in the pediatric population, all pediatricians should be more aware of how it is used and the potential hazards. The methods of administration and treatment of overdoses as well as indications for usage, contraindications, and adverse reactions will be explained.

Administration, Oral↗
PubMed1982

Anomalous origin of the left coronary artery from the right pulmonary artery associated with complex congenital heart disease.

The rare coexistence of anomalous origin of the left coronary artery from the main pulmonary artery with other cardiac malformations prompts us to report an unusual case of anomalous origin of the left coronary artery from the right pulmonary artery associated with complete atrioventricular canal, patent ductus arteriosus, and coarctation of the aorta. It is important to recognize the presence of an anomalous origin of the left coronary artery in complex congenital heart disease since the coronary artery anomaly will increase the morbidity of the associated congenital cardiac malformation. Conversely, correction of the associated congenital cardiac defect may decrease the pulmonary artery pressure resulting in reduced left coronary artery flow, myocardial ischemia, and death.

Abnormalities, Multiple↗
PubMed1982

Clinical confirmation of ECG criteria for left atrial rhythm.

Controversy exists as to which of several ECG criteria are necessary for the diagnosis of left atrial (LA) rhythm. We performed invasive electrophysiologic study in five patients (6 to 15 years-of-age) who had symptomatic supraventricular tachycardia (SVT) that could not be controlled by aggressive pharmacologic treatment. All patients were found to have automatic atrial tachycardia with the earliest site of activation during SVT in the LA. The ECG of each patient demonstrated negative P waves in lead I. The frontal plane P wave axis ranged between +90 to +270 degrees in each of our patients. Spontaneous "dome-and-dart" P waves occurred in lead V1 in two of our patients. We conclude that the necessary criterion for the diagnosis of LA rhythm should be negative P waves in lead I. The finding of "dome-and-dart" P waves in V1 is an additional useful and definitive criterion but is not present in each case.

Adolescent↗
PubMed1982

Prolonged and decremental antegrade conduction properties in right anterior accessory connections: Wide QRS antidromic tachycardia of left bundle branch block pattern without Wolff-Parkinson-White configuration in sinus rhythm.

Four patients are described who had long conduction times and decremental conduction through right anterior accessory connections. None had Wolff-Parkinson-White syndrome on their ECG. Each had recurrent sustained wide QRS tachycardia due to antegrade conduction through the accessory connection. Three patients underwent epicardial mapping and successful surgical division of their accessory connection. Two of the three had a second accessory connection that was also divided surgically. Each of the three are free of tachycardia without medication. It is postulated that these accessory connections represent the remnants of anterior atrioventricular ring tissue described by Anderson.

Adult↗
PubMed1982

Diagnosis, management, and long-term results of patients with congenital complete atrioventricular block.

Sixty-five patients with congenital complete atrioventricular block have been studied. The median age at time of diagnosis was 7 months with 26 infants being diagnosed prior to 1 month of age. Anatomic heart disease was present in 25/65 (39%) infants, with ventricular inversion/L-transposition of great arteries complex occurring in 20/25 infants (80%). The site of block was above the bundle of His in 11 of 18 (61%) patients studied, in the bundle of His in three of 18 (17%), and below the bundle of His in two of 18 (11%). Permanent pacemakers were implanted in 17 (26%). Ten patients (15%) have died. The highest risk was in patients with anatomic heart disease and patients diagnosed early in life.

Adolescent↗
PubMed1982

The electrophysiologic effects of procainamide in the immature heart.

The electrophysiologic effects of procainamide in young animals have not been established. To test the effects of this drug on the immature heart, we studied eight nonsedated, chronically instrumented puppies (age range 12-28 days, median 16 days; weight range 0.7-1.1 kg, median 0.8 kg). The electrophysiologic study was performed before and 30 minutes after procainamide was given intravenously (20 mg/kg infusion). At the time of the study, the serum concentrations of procainamide (8.2 +/- 1.7 micrograms/ml to 6.2 +/- 1.6 micrograms/ml; mean +/- SEM) were in the usual adult human therapeutic range (4-10 microgram/ml). Procainamide in puppies caused a significant lengthening of the atrial and ventricular refractory periods, a significant decrease of the sinus node recovery time and the sinus of atrial echo zone, a significant decrease in the heart rate, and a significant increase in the sinoatrial conduction time.

Electrocardiography↗
PubMed1981

Arrhythmogenic right ventricular dysplasia: a cause of ventricular tachycardia in children with apparently normal hearts.

Arrhythmogenic right ventricular dysplasia (ARVD), a cardiomyopathy with hypokinetic ares limited to the wall of the right ventricle (RV), has been recently described as a cause of recurrent ventricular tachycardia (VT) in young adults with an otherwise normal heart. We reviewed 26 cases of recurrent VT in children and found 10 patients with no clinically recognizable abnormality aside from the dysrhythmia. Three of these 10 patients had ARVD. These three patients were initially seen at 1, 12, and 14 years of age with premature ventricular contractions (PVCs) and/or VT. Sustained VT occurred spontaneously or during stress testing. The PVCs and the VT were of left bundle branch block contour, suggesting RV site of origin. The diagnosis of ARVD was based on wall motion abnormalities of the RV demonstrated angiographically. We suggest that ARVD could be a significantly common cause of VT in children with an apparently normal heart.

Adolescent↗
PubMed1981

Successful surgical treatment of atrial, junctional, and ventricular tachycardia unassociated with accessory connections in infants and children.

Five children with severe, life-threatening tachydysrhythmias were treated successfully with surgery. Three had atrial ectopic automatic tachycardia (AET), one had AV junctional (his bundle) automatic ectopic tachycardia (JET), and one had ventricular reentry tachycardia (VT). The mechanism and site of the tachycardia were diagnosed preoperatively using intracardiac electrophysiologic studies (EPS). Medical management with all available drugs failed to control the tachycardia in each patient. The two patients with left atrial AET underwent cryoablation of the focus using cardiopulmonary bypass. The patient with right atrial AET had removal of the anterior one third of the right atrial appendage and cryoablation of the edges. The patient with AV JET first had incision and suture ligation of the bundle of His and implantation of a ventricular pacemaker, but the tachycardia recurred 2 weeks later. Cryoablation of the bundle of His prevented further recurrences. Tachycardia stopped in the patient with VT during incision of a tumor in the apex of the left ventricle. No patient had tachycardia after surgery and none has required medical treatment.

Adolescent↗
PubMed1981

Congenital complete atrioventricular block: clinical and electrophysiologic predictors of need for pacemaker insertion.

Because of initial Adams-Stokes attack in the patient with congenital complete atrioventricular (A-V) block may sometimes prove fatal, there is a need to be able to identify the patient at great risk of having such attacks. Twenty-four children with congenital complete A-V block were followed up for 1 to 19 years to determine the efficacy of current methods of predicting risk for Adams-Stokes syncope and the usefulness of pacemaker therapy in relieving symptoms. The heart rate at rest, configuration of surface electrocardiographic complexes, data obtained during intracardiac electrophysiologic study and response to graded treadmill exercise testing were compared in children with and without syncope. One or more Adams-Stokes episodes were experienced by eight children, one of whom died. Only a persistent heart rate at rest of 50 beats/min or less demonstrated any significant (probability [p] less than 0.01) correlation with the incidence of syncope. Intracardiac electrophysiologic study was of little benefit because of site of block did not correlate with syncope. Although the increase in heart rate during treadmill exercise testing showed no correlation with prevalence of syncope or location of block, exercise-induced ventricular ectopic beats may have predictive value in older children and young adults. Ventricular pacemakers were implanted in 10 children. Each child was asymptomatic over a 1 to 10 year follow-up period. Because extreme bradycardia may contribute to the prevalence of Adams- Stokes attacks in children with congenital complete A-V block, careful evaluation of heart rate at rest may be an effective means of differentiating patients at risk of syncope. Pacemaker therapy is a feasible and effective method of treatment in young children and relieves symptoms

Adolescent↗
PubMed1981

Electrophysiologic studies of supraventricular tachycardia in children. I. Clinical-electrophysiologic correlations.

We investigated the clinical features, surface ECG findings, associated with congenital heart disease (CHD), and status at follow-up in 103 children who underwent intracardiac electrophysiologic evaluation of supraventricular tachycardia (SVT). Age at catheterization ranged from 2 days to 17 years (mean 4.2 years). Diagnosis of the mechanism was based upon standard electrophysiologic techniques. Of the 103 patients, 37 had reentry without a bypass tract (10 sinoatrial node, two atrial muscle, and 25 atrioventricular node); 51 had reentry with a bypass tract (28 manifest Wolff-Parkinson-White [WPW], 18 unidirectional retrograde accessory pathway [URAP], an five Lown-Ganong-Levine); and 15 had an ectopic focus (11 atrial, four junctional). Distinguishing features among the common types are depicted in Table III. We conclude that in children the various mechanisms of SVT (1) are likely to be found in different clinical situations, (2) have a different potential for surgical cure, and (3) have a different prognosis for long-term treatment. Since curative surgery was theoretically possible in 57% of our patients (WPW, concealed WPW, atrial, and junctional ectopic), we recommend electrophysiologic study in any patient who has had frequent recurrences of SVT for longer than 1 year and who requires drugs in addition to digoxin for treatment.

Adolescent↗
PubMed1981

Supraventricular tachycardia in children: clinical features, response to treatment, and long-term follow-up in 217 patients.

We reviewed the records of 217 children whose first episode of supraventricular tachycardia occurred before 18 years (median age 24 months). There were 112 males and 105 females. Of the 49 with congenital heart disease, SVT began before any operation in 26 and greater than 2 weeks postoperatively in 23. Wolf-Parkinson-White syndrome was present on surface ECG in 47/217 (22%). Congestive heart failure accompanied the first episode of SVT in 38% of the patients who were 4 months of age or younger, and in only 19% of those over 4 months (P less than 0.001). Treatment was successful in stopping SVT within 48 hours in 90/142 (63%). Successful short-term treatment included digoxin 57/184 (68%), cardioversion 12/20 (60%), vagal maneuvers 12/19 (63%), phenylephrine 3/9, and overdrive pacing 4/5. SVT recurred at least once in 83% of all patients. On follow-up (mean 4.6 years), episodes of SVT were still present in 56%. Three patients died--two from incessant SVT and one from a CVA after VSD repair. We conclude that long-term status was difficult to predict, but SVT was present in fewer patients whose age at onset was less than 4 months and in those with unoperated CHD. Early recurrence was not a poor prognostic sign. We recommended treatment for at least one year in all patients with SVT, whether or not the first episode terminates spontaneously.

Adolescent↗