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Biomedical subjects

J F Keane

Publications and source records attributed to J F Keane.

At least 127 records · Page 7Linked to original sources

Aortic thrombosis in the neonate.

The case histories of two infants with aortic thrombosis are presented. Clinically, an obstructive aortic arch lesion was suspected because of a systolic pressure gradient between the upper and lower extremities in one infant and unequal peripheral pulses with lower limb cyanosis in the other. Noninvasive studies were inconclusive, the only abnormality noted echocardiographically being severe left ventricular dysfunction. Cardiac catheterization including angiography defined the severity of the obstruction and location of the thrombus in both babies. The thrombus originated within a ductus arteriosus aneurysm in one infant and was located in the ascending aorta and transverse arch in the other. Although successful surgical removal was accomplished, both babies died unexpectedly in the early postoperative period.

Aneurysm↗

Left ventricular function after repair of tetralogy of fallot and its relationship to age at surgery.

Left ventricular (LV) work-function curves were used to assess LV performance in eight postoperative tetralogy of Fallot (TOF) patients who underwent repair before 2 years of age (group 1) and 12 patients who underwent repair after 2 years of age (group 2). All patients were without significant residual shunts or pulmonary stenosis. Results were compared with those in seven control patients. Left- and right-heart hemodynamics were measured at various levels of afterload induced by methoxamine while heart rate was maintained constant. Cardiac output was serially measured. The slope (m) for each patient's LV end-diastolic pressure (EDP) vs LV minute-work index (MWI) relationship was determined. There were no significant differences in resting cardiac index, LV systolic pressure, LVEDP, aortic oxygen saturation or MWI among the groups. However, with afterload stress, group 2 patients had abnormal work-function curves with depressed slopes (m = 0.21 +/- 0.04) compared with the values for group 1 patients (m = 0.89 +/- 0.13, p less than 0.001) or the control group (m = 1.13 +/- 0.12, p less than 0.001). Thus, LV dysfunction unmasked by an afterload stress was present in the older TOF patients but not in the patients repaired during infancy. These findings raise the possibility that early, definitive repair of TOF may help preserve postoperative LV function.

Adolescent↗

Surgical management of multiple ventricular septal defects.

Between Jan. 1, 1973, and June 1, 1979, 29 patients underwent surgical closure of multiple ventricular septal defects (VSDs). Included are 19 patients with VSDs only (one death), five with tetralogy of Fallot (TF) (0 deaths), two with transposition of the great arteries and VSD (TGA/VSD) (one death), two with complete atrioventicular (AV) canal (one death), and one with common atrium (one death). The overall hospital mortality rate was 14% (4/29) and was significantly related to the complexity of the underlying malformation (p = 0.01) and the presence of major associated cardiac lesions (p = 0.005). The incidence of reoperation for overlooked VSDs was 28% (8/29) and was significantly related to the presence of muscular VSDs (all overlooked defects were muscular) and the failure preoperatively to diagnose multiple VSDs (p = 0.05). Of patients with shunt data available after the final operation, 85% (17/20) had a Qp/Qs less than or equal to 1.5, and no patient had a final Qp/Qs > 2.0. This experience indicates that satisfactory results usually can be achieved after operation for multiple VSDs and emphasizes the value of early assessment for residual shunting and reoperation when indicated.

Child↗

Intrauterine supraventricular tachycardia.

Six examples of intrauterine supraventricular tachycardia together with 31 previously reported cases are described and analyzed. Among the 37 infants, structural heart disease was present in only four (11%), three of whom died. Males comprised 68% of the group without identifiable heart disease or pre-excitation. Congestive heart failure was evident in 62% of the infants at birth or shortly thereafter; ascites was the predominant finding in three (8%). Neither the duration of SVT nor heart rate was predictive of the clinical status at birth. Infants without underlying heart disease or conduction abnormalities had a benign course after the neonatal period. Thirty-eight percent of the babies converted to sinus rhythm during or shortly after delivery without medication, and most of the others converted after digitalization. The failure of maternal digitalization to convert SVT to sinus rhythm in two of our infants was perhaps related to subtherapeutic maternal and fetal digoxin levels. Newborn infants presenting with unexplained ascites or congestive heart failure should have an ECG to determine whether pre-excitation is present, and their cardiac rhythm should be monitored for several days.

Ascites↗

His bundle electrogram after intracardiac repair of tetralogy of Fallot. Analysis of data in 59 patients.

His bundle electrograms were recorded in 59 patients after intracardiac repair of tetralogy of Fallot and were correlated with the postoperative electrocardiogram. Except for five patients with first degree atrioventricular block postoperatively all patients in Group A (those with either a normal electrocardiogram or solitary right bundle branch block) had a normal A-H interval (77.7 +/- 21.6 msec) (mean +/- standard deviation); all had a normal H-V interval (39.5 +/- 7.2 msec). Patients in Group B (bifascicular block) tended to have a normal A-H interval (97.2 +/- 26.2 msec) with a prolonged H-V interval (48.8 +/- 10.7 msec). Patients in Group C (trifascicular block) had prolongation of both the A-H (160.0 +/- 32.4 msec) and the H-V interval (58.8 +/- 10.6 msec) by comparison with control values. Patients in Group D (transient complete heart block) had a normal A-H interval (79.5 +/- 28.2 msec) but a prolonged H-V interval (57.8 +/- 16.4 msec), similar to that in Group C. A good hemodynamic result was associated with a normal H-V interval; a prolonged interval accompanied a poor result.

Adolescent↗

Cardiac output measured by thermodilution in infants and children.

To determine the accuracy and reproducibility of cardiac output determination by thermodilution (COT) in children, simultaneous outputs were measured by the Fick technique (COF) (using measured oxygen consumption) and thermodilution in 26 children, ranging in age from 8 to 86 months, who were undergoing cardiac catheterization. There was excellent correlation between mean output by thermodilution and by the Fick technique: COT = 1.10 COF -- 0.2 l/minute, R = 0.91. In three-quarters of the patients with COT differed by 15% or less and in none differed by more than 25%. Serial values of thermodilution outputs were reproducible in each patient with a SD of 5.5%. Our observations indicate that COT is accurate, reproducible, and valuable in the care of critically ill infants and children.

Cardiac Catheterization↗

Left ventricular function following attempted surgical repair of tetralogy of Fallot.

Left ventricular function was assessed by angiographic methods in 40 patients (ages 3-27), 1-12 years following repair of tetralogy of Fallot. Twenty of the 40 patients (group A) had a satisfactory repair with a pulmonary-systemic flow ratio (Qp/Qs) less then or equal to 1.5 and a right ventricular systolic pressure of less than or equal to 60% of the left ventricular value. The other 20 patients (group B) had a Qp/Qs greater than 1.5 and/or a right ventricular systolic pressure greater than 60% of the left ventricular value. Group A patients had a normal left ventricular end-diastolic volume (LVEDV), end-diastolic pressure (LVEDP), ejection fraction (LVEF), and mass (LVM), while the group B patients had significantly elevated LVEDV, LVEDP, LVM, and a significantly depressed LVEF. These findings indicate that patients with a satisfactory hemodynamic repair of tetralogy of Fallot have normal left ventricular function while patients with postoperative unsatisfactory hemodynamics have significantly impaired left ventricular function.

Adolescent↗

Idiopathic atrial flutter in infancy: a review of eight cases.

The experience of three institutions in the management of atrial flutter in infants under 2 years of age without associated heart disease is reviewed. Five babies with neonatal onset were treated with digoxin and had uncomplicated resolution of their arrhythmia, although one continued to have episodes of paroxysmal supraventricular tachycardia for six years. Two of the three older infants required DC cardioversion for complications after quinidine was substituted for digoxin therapy. Digoxin continues to be the preferred initial therapy for non-acutely ill patients; those showing signs of cardiac decompensation should be converted with DC countershock.

Atrial Flutter↗

Pediatric cardiac angiography using a 4 French catheter.

Thirty specially designed 4 French pigtail white Teflon catheters 50 cm in length were utilized for angiography using the retrograde arterial approach in 26 infants and children. Angiographic opacification was considered very satisfactory. Apart from one episode of temporary occlusion of the right coronary artery ostium, there were no other significant complications. The catheters were introduced percutaneously in 21 instances and distal pulses were palpable in 18 patients by the second day after catheterization. At postcatheterization testing with increasing volumes and flow rates, the first rupture occurred, delivering 13 ml at 13 ml/second. On testing an additional 15 catheters using fixed volumes of 5, 10, and 15 ml at increasing flow rates, rupture first occurred at 34, 22, and 18 ml/second, respectively. We conclude that this small catheter is relatively safe and satisfactory for the retrograde arterial approach in the study of infants and children.

Angiography↗

Multiple arrhythmias detected during nocturnal monitoring in patients with congenital complete heart block.

Twenty patients with congenital complete heart block (CHB) were monitored with ECG tape recordings while awake and asleep. Episodes of marked ventricular slowing during sleep (R-R greater than 3000 msec., i.e. less than 20 beats/min) were noted in 35% (7/20). Most of these sudden R-R prolongations were 2:1 or 3:1 exit block of the junctional focus. Atrial and ventricular rate changes were mostly concordant in 2/3 but the remainder demonstrated fixed ventricular rates while atrial rates varied normally, suggesting a "sick" or "lazy" junctional focus. Other arrhythmias were found in 60% (12/20), including several types of rhythms in three patients. One child with previously unsuspected superimposed multiple arrhythmias later had a syncopal episode despite proven supra-Hisian block. The multiple patterns of atrial and ventricular rate changes found indicate complex feedback mechanisms, suggesting that congenital CHB is not a single entity. Since a significant number of patients demonstrated one or another of these unexpected and potentially hazardous findings, we recommend that congenital block patients be carefully studied, including Holter monitoring done on a regular basis.

Adolescent↗

Angled views in cineangiocardiography of congenital heart disease.

Simple and compound sagittally angled views of the heart obtained cineangiocardiographically with a parallelographic U-arm device were evaluated clinically in 132 patients with congenital heart disease. The principle advantage of the apparatus was the case with which axial and oblique projections were obtained without repositioning of the patient, although rotation and angulation of the image intensifier-X-ray tube unit resulted in some increase in scattered radiation. Certain angled views, particularly the 40 degree cranial and the compound 25 degrees cranial/70 degrees left oblique projections, were better than standard frontal and lateral views for visualization of pulmonary arteries in the mediastinum, in ventricular septal defects and anomalies of the left ventricular outflow tract.

Angiocardiography↗

The surgical management of discrete and diffuse supravalvar aortic stenosis.

Between 1956 and 1976, 18 patients underwent surgery for supravar aortic stenosis at the The Children's Hospital Medical Center, Boston. Discrete obstruction, present in 11, was treated by insertion of a prosthetic gusset placed across the area of narrowing and extending into the noncoronary sinus of Valsalva. There was one operative death. Residual gradients (measured in five patients) ranged from 4-55 mm Hg, one of which was supravalvar in location. Significant aortic regurgitation was not common preoperatively. The diffuse form of supravalvar obstruction, a more difficult surgical problem, was present in seven patients. There were three operative deaths. Complete relief of the pressure gradient was achieved only in one instance by insertion of a left ventricular-aortic bypass shunt diverting the majority of the cardiac output into the descending thoracic aorta. This patient is now asymptomatic 20 months following operation. On the basis of this experience, it is suggested that patients with the diffuse form of supravalvar obstruction, and perhaps even those with a hypoplastic annulus alone, would benefit from a left ventricular-aortic bypass shunt.

Adolescent↗