Biomedical subjects

J W Mathewson

Publications and source records attributed to J W Mathewson.

29 records · Page 2Linked to original sources

PubMed1984

Repair of subdiaphragmatic total anomalous pulmonary venous connection without cardiopulmonary bypass.

Two neonates with asplenia syndrome, subdiaphragmatic total anomalous pulmonary venous connection, and pulmonary stenosis underwent a palliative operation without cardiopulmonary bypass. With the use of a side-biting clamp, and anastomosis was created between the pulmonary venous confluence and the right atrium. (Since children with asplenia syndrome have common mixing lesions, pulmonary venous drainage to the right atrium is not physiologically detrimental.) The descending vertical vein was ligated. A systemic-pulmonary shunt was performed. Both infants were discharged from the hospital less than 1 week after the operation. Both infants subsequently died, at 4 months and at 16 months of age. At autopsy, pulmonary venous drainage was unobstructed, with a surgical orifice 86% to 90% of the aortic anulus. We conclude that, in infants with asplenia syndrome and obstructed total anomalous pulmonary venous drainage, relief of pulmonary venous obstruction can be accomplished without cardiopulmonary bypass.

Cardiopulmonary Bypass↗

PubMed1983

Two-dimensional echocardiographic discrimination of normal from abnormal great artery relationships.

A prospective study was performed to determine the diagnostic accuracy of precordial two-dimensional echocardiographic techniques in discriminating normal from abnormal great artery relationships. We studied 503 children using standard parasternal short-axis view and a modified technique called rotating high long-axis view (RHLAV). In RHLAV, there is rapid superimposition of the proximal courses of the two great arteries seen by rotation of the ultrasonic beam. Discrimination was based on the crossing great artery relationship seen with normally related great arteries (NRGA) and the parallel courses found in both transposition and malposition of the great arteries (TGA/MGA). Using the RHLAV, the great artery interrelationship was accurately determined in all 503 patients. Precordial two-dimensional echocardiography can accurately discriminate great artery relationships and is a useful addition to other two-dimensional echocardiographic techniques.

Adolescent↗

PubMed1983

Congenital heart disease and pulmonary artery hypertension. I. Pulmonary vasoreactivity to 15% oxygen before and after surgery.

Pulmonary vasoreactivity at sea level was studied in 22 children before and in 15 children after corrective cardiac surgery for congenital heart disease and pulmonary artery hypertension; 8 children were studied both before and after cardiac surgery. During cardiac catheterization in 28 children, pulmonary and systemic hemodynamics were determined in room air and during breathing of 15% oxygen, which corresponds to a maximal hypoxic level commonly encountered during airplane travel. Before surgery, 19 of 22 children tolerated 15% oxygen (O2), which caused the following hemodynamic changes from room air status: the ratio of pulmonary to systemic arterial pressure increased from 0.70 to 0.78 (p less than 0.05), the ratio of pulmonary to systemic flow decreased from 2.2 to 2.0 (p greater than 0.05) and the ratio of pulmonary to systemic vascular resistance increased from 0.33 to 0.40 (p less than 0.02). In two children, severe pulmonary vasoconstriction developed within 5 minutes of 15% oxygen administration, requiring immediate discontinuation of hypoxia; neither patient had lasting deleterious effects. There was no evidence of increased pulmonary vasoreactivity in children with Down's syndrome compared with genetically normal children. After corrective surgery in 15 children (including both of the hyperreactors), no significant pulmonary vascular response to 15% oxygen was found. It is concluded that, in a small number of children with unrepaired congenital heart disease and pulmonary artery hypertension, pulmonary vascular hyperreactivity can be induced by breathing 15% oxygen; this reaction is life-threatening but reversible with the administration of 100% oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1983

Postoperative hemodynamic and electrophysiological evaluation of the Senning procedure.

To determine efficacy of the Senning procedure for correction of transposition of the great arteries we performed detailed hemodynamic and electrophysiological studies in 6 consecutive children operated upon at 5-18 months of age. Cardiac catheterizations were performed 10-19 months following surgery. All patients were asymptomatic on no medication. Hemodynamic studies demonstrated no evidence of pulmonary venous obstruction, pulmonary hypertension, or left ventricular outflow tract obstruction. 1 patient had mild upper baffle limb obstruction. Angiography demonstrated tricuspid insufficiency in 2 patients and a small atrial level shunt in 1. Ambulatory electrocardiographic monitoring in 5 of 6 patients revealed multiple premature ventricular contractions in 1. Invasive electrophysiological studies for sinus node function were normal. Corrected sinus node recovery time was 36-348 ms while total sinoatrial conduction time, determined in 4 patients, ranged between 83 and 128 ms. At our institution the Senning procedure has a low incidence of residual hemodynamic or electrophysiological abnormalities. Detailed postoperative evaluation is necessary to determine extent of residual problems.

Electrocardiography↗

PubMed1983

Vascular consequences of subclavian artery transection for the treatment of congenital heart disease.

The acute and chronic consequences of subclavian artery transection were analyzed in the noninvasive vascular laboratory. Twenty-eight patients (aged 1 day to 4 2/12 years, median 2 months) underwent subclavian artery transection (23 Blalock-Taussig, four subclavian aortoplasty for coarctation or interrupted arch, and one division of aberrant left subclavian). Bilateral systolic brachial artery pressure (BAP) was measured by Doppler instrumentation to obtain a "BAP index": BAP1 = (operated side BAP/control side BAP). Velocity waveform tracings and bilateral forearm skin temperatures were also obtained during studies before and sequentially after operation (4 hours to 12 years). Five patients underwent exercise testing of the upper extremity. Nine patients were studied for manual preference and limb development. Before operation, mean BAP1 was 0.99. Immediately (4 to 48 hours) after operation, mean BAP1 was 0.39. Three weeks postoperatively, BAP1 was 0.62, and thereafter it remained at 0.70. All differences between preoperative, immediate postoperative and late postoperative BAP1 are significant (p less than 0.001). Exercise resulted in a significant (p less than 0.01) increase in BAP bilaterally. Forearm skin temperature was initially lower (p less than 0.01) on the operated side but approximated the control side by 1 week. Limb girth was less on the operated side (p less than 0.01), without evidence of altered manual preference. In conclusion, subclavian artery transection causes permanent reduction in BAP1. The affected limb appears to respond to increased metabolic demand by increasing limb blood flow.

Arm↗

PubMed1983

Coarctation in the first year of life. Patterns of postoperative effect.

From 1975 to 1982, 31 infants were operated upon in the first year of life for aortic coarctation and congestive heart failure. Operations performed were resection and end-to-end anastomosis (RETE) in 14, subclavian flap aortoplasty (SFA) in six, patch aortoplasty (PA) in five, and other procedures in six. Thirty of the thirty-one (97%) survived the operation. To assess the effect of operation, 26 infants were studied noninvasively with Doppler arm-to-leg pressure measurements at rest and with stress. Preoperatively, the median arm-to-leg gradient at rest was 77 mm Hg. Serial postoperative Doppler studies demonstrated progressive changes in arm-to-leg pressure gradients: 69% had residual arm-to-leg gradients that spontaneously resolved, 13% had residual gradients that persisted, 13% had progressive increase in gradient, and one child had neither early nor late gradient. Stress testing often unmasked gradients not present in the resting state. No differences were noted among the three surgical groups: RETE, SFA, and PA. From our experience, we have made four conclusions with regard to repair of coarctation of the aorta in infants. First, surgical survival is expected. Second, the effect of the operation is dynamic, with four patterns defined: (1) complete relief of coarctation, (2) transient residual coarctation, (3) persistent residual coarctation, and (4) recurrent coarctation. Third, optimal surgical therapy seems to be an eclectic approach. Fourth, physiological evaluation of coarctation in infants can be obtained by Doppler techniques in conjunction with stress testing.

Aortic Coarctation↗

PubMed1980

Shock in infants and children.

Shock is a descriptive term indicating generalized inadequancy of organ perfusion. In the critically ill patient, the common denominator is insufficient microcirculatory flow. All patients have excessive sympathetic tone with arteriolar and venular vasoconstriction. Two phases may be clinically recognized. Phase 1 is usually reversible and is characterized by ischemic hypoxia. Phase 2 is often irreversible and is characterized by stagnant hypoxia, cell disruption, autolysis, and diffuse intravascular coagulation. Although the presentation of shock may vary with age, one usually detects evidence of inadequate tissue perfusion, hypotension, and poor urine output. Treatment consists of early recognition, establishment and maintenance of intravascular volume, and cardiorespiratory assistance with mechanical ventilation and various inotropic and vasoactive drugs. Pediatric mortality remains high despite new and sophisticated treatment methods.

Assisted Circulation↗

PubMed1977

Ventricular epicardial activation sequence in the lamb.

The ventricular epicardial activation sequence (VEAS) in 15 anesthetized lambs (near term fetus to 3.5 months of age) was determined using 40 simultaneously recorded bipolar electrograms for each animal. Isochrone maps were drawn by hand using relative activation times determined from the maximum first derivative of multiplexed signals recorded and analyzed by computer from single cardiac cycles. VEAS was similar for all ages studied. Earliest left ventricular (LV) activity appeared on the caudal dorsal and/or ventral free wall. Initial right ventricular (RV) activation appeared on the ventral anterior and/or lateral surface either simultaneously with or slightly later (2.5-3.5 msec) than initial LV activation. Excitation then proceeded circumferentially and in an apicobasilar direction and terminated on the right ventricular outflow tract.(RVO). All LV and RV epicardium except RVO activated within 7.5-12.5 msec. RVO required more than 1n.5 msec to activate in 12 of 15 animals. Total duration of RVO activation never exceeded 22.5 msec in any animal. Neither the duration nor the pattern of activation of LV or RV epicardium, including RVO, changed in a consistent fashion with age. These findings are similar to the known VEAS for adult ruminants. The data indicate that the VEAS assumes the adult pattern as of late gestation and suggest that changing right and left ventricular electromechanical events do not contribute to and probably are not affected by the process of ventricular epicardial activation. Speculation Although maturational changes in right and left ventricular electromechanical events do not appear to be related to the sequence of ventricular epicardial activation, such changes may be related to the distrubution of corresponding epicardial and intramural isopotentials.

Animals↗

PubMed1976

Left ventricular outflow tract obstruction produced by redundant mitral valve tissue in a neonate. Clinical, angiographic, and operative findings.

An unusual case of left ventricular outflow tract obstruction associated with severe left ventricular failure in a neonate is reported. The physical and laboratory data were consistent with the diagnosis of infantile valvular aortic stenosis. At operation, however, redundant gelatinous pedunculated tissue attached to the mitral valve annulus appeared to move through and obstruct the aortic valve during systole. The aortic valve showed only minimal thickening of the right and left coronary cusps. A distinct angiographic pattern was demonstrated during left ventricular cineangiography. In the frontal projection a large ovoid filling defect appeared to protrude through the aortic valve during systole and return to a subvalvular location during diastole. Recognition of this angiographic pattern should facilitate diagnosis and subsequent repair. Complete correction is possible by operative excision of the obstructing tissue without damaging the mitral valve. In contrast to isolated congenital infantile valvular aortic stenosis, a condition in which the valve leaflets are often primitive and deformed, aortic valvotomy and/or subsequent valve replacement are not necessary, resulting in a better long-term prognosis.

Angiocardiography↗

PubMedDate not supplied

Surgical closure of the tricuspid valve for pulmonary atresia, intact ventricular septum, and right ventricle to coronary artery communications.

A surgical approach is reported for a patient with pulmonary atresia, intact ventricular septum, and right ventricle to coronary artery communications through sinusoids. A shunt procedure was performed at two days of age; the right ventricular outflow tract was not opened. At subsequent catheterization, the tricuspid valve was temporarily closed with a balloon catheter and no change was seen in the ECG. At five months of age, the right ventricle was plicated and a patch was sewn over the tricuspid valve. One year after surgery, neither the right ventricular cavity nor the sinusoids could be demonstrated at angiocardiography; ECG changes of left ventricular ischemia have resolved, and the child is growing normally.

Cardiac Catheterization↗

PubMedDate not supplied

Building a pediatric cardiac catheterization laboratory and conference room: design considerations and filmless imaging.

Building or upgrading a dedicated pediatric cardiac catheterization laboratory is an expensive and elaborate undertaking complicated by long-standing biases based on adult laboratory requirements. Optimal design for the needs of pediatric cardiologists and their patients has never been published. This communication discusses these design issues in the context of pediatric needs and offers potential solutions. It also attempts to educate the reader on the basics of digital imaging and its advantages over cine film technology; and it explains how to achieve optimal filmless data acquisition and subsequent display for pediatric cardiac management.

Cardiac Catheterization↗