Search PubMed⌕ Search

Biomedical subjects

T P Graham

Publications and source records attributed to T P Graham.

At least 37 records · Page 2Linked to original sources
PubMed1991

Unique variant of partial anomalous pulmonary venous connection with intact atrial septum.

Partial anomalous pulmonary venous connections (PAPVCs) are rare in association with an intact atrial septum. However, the diagnosis should be considered in patients with otherwise unexplained findings of left-to-right shunt and right heart enlargement. An unusual variant is presented, which we considered unsuitable for operative repair, based on findings at catheterization. Developmental, hemodynamic, and surgical considerations are discussed.

Angiography↗
PubMed1991

Complete repair of atrioventricular septal defect.

We report our experience with 103 consecutive children who underwent repair of complete atrioventricular septal defect between 1971 and 1990. Ninety-one patients were less than 18 months old (mean age, 6.2 months; mean weight, 5.8 kg) and were repaired using deep hypothermia and circulatory arrest. There were 15 perioperative deaths. Twelve patients were older (mean age, 40.2 months; mean weight, 18.9 kg) and were repaired using moderate hypothermia and cardiopulmonary bypass. There were two perioperative deaths. Repairs were performed with the single-patch technique. Four younger patients required repeat repair to control residual mitral regurgitation. Two of the older children required late reoperation to replace one or both atrioventricular valves. Three younger children underwent pulmonary artery banding initially; 1 died after complete repair. Three older children underwent initial pulmonary artery banding; 2 died at definitive repair, and the survivor required pulmonary artery reconstruction, which was repeated subsequently. Since 1977 our policy has been to perform primary definitive repair whenever possible. Two patients died late from unrelated causes. At the most recent follow-up the majority of patients had no or minimal symptoms. We continue to advocate primary definitive repair whenever possible using the single-patch technique in symptomatic patients with complete atrioventricular septal defect.

Cardiac Catheterization↗
PubMed1991

Echocardiographic estimation of critical left ventricular size in infants with isolated aortic valve stenosis.

With the current trend to performing surgical valvotomy for infantile aortic stenosis without cardiac catheterization, there is a need to develop echocardiographic criteria for adequacy of left ventricular size. The echocardiograms and catheterization data of all 25 infants less than 3 months of age undergoing aortic valvotomy for isolated aortic valve stenosis from September 1980 through July 1990 were reviewed. Significant differences (p less than 0.05) between the survivors and nonsurvivors were noted for age at operation (30 +/- 28 vs. 3 +/- 1.5 days), mitral valve diameter (10.1 +/- 1.7 vs. 7.7 +/- 1.5 mm), left ventricular end-diastolic dimension (18.4 +/- 6.4 vs. 11.4 +/- 3 mm), left atrial dimensions (15.3 +/- 3.8 vs. 10 +/- 2.4 mm), left ventricular cross-sectional area on the parasternal long-axis echocardiogram (4 +/- 1.9 vs. 2 +/- 1.9 cm2) and angiographically determined left ventricular end-diastolic volume (43 +/- 23 vs. 11 +/- 5 ml/m2). There was no difference with respect to patient weight, body surface area, aortic root dimension or left ventricular ejection fraction. Left ventricular cross-sectional area less than 2 cm2 as measured on the parasternal long-axis echocardiogram was found in 5 of 7 nonsurvivors and 0 of 12 survivors, making this a risk factor for perioperative death (p less than 0.05). Left ventricular end-diastolic dimension less than 13 mm was found in 5 of 6 nonsurvivors and 2 of 17 survivors, making this another risk factor for early mortality (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1990

Normal values for noninvasive estimation of left ventricular contractile state and afterload in children.

The outcome and suitability for therapeutic interventions in children with congenital heart disease depend frequently on left ventricular function. Congenital heart disease is characterized by changes in loading conditions, making it difficult to assess ventricular contractility using conventional load-dependent indexes. Two-dimensional and M-mode echocardiography and arterial blood pressure were used to study left ventricular morphometrics and contractility in 44 normal children, aged 2 to 12 years. Left ventricular end-systolic and end-diastolic length, diameter, wall thickness, volume and mass all showed linear increases with body surface area (p less than 0.001 in all). Shortening and ejection fractions, velocity of circumferential fiber shortening, morphometric ratios and endocardial meridional and circumferential stress (mean 46 and 115 g/cm2, respectively) all remained constant. A load-independent measure of the normal resting left ventricular contractile state was determined by relating the rate-corrected velocity of circumferential fiber shortening to end-systolic endocardial meridional and circumferential stress; there was an inverse linear correlation (r = -0.641 and -0.557 respectively, p less than 0.001). These data provide a quantitative basis for assessment of myocardial hypertrophy, afterload and contractile state in childhood.

Blood Pressure↗
PubMed1990

Reappraisal of localized resection for subvalvar aortic stenosis.

Between June 1972 and August 1989, we operated on 45 patients with fixed subaortic stenosis. Discrete membranous stenosis was present in 28 patients and tunnel stenosis, in 13. Four patients had subvalvar stenosis complicating double-outlet right ventricle. There were 33 male and 12 female patients. Mean age at operation was 7.1 +/- 4.3 years (range, 6 months to 21 years). Local resection of the fibrous membrane was performed in 26 patients. Local resection was combined with myectomy in 18 patients. Aortoventriculoplasty (modified Konno procedure) was required at operation in 3 patients. There were three perioperative deaths at initial operation and two deaths at the time of reoperation. Follow-up ranges from 1 month to 17 years (average follow-up, 47.0 months). Reoperation for recurrent obstruction has been required in 12 patients (27%), and 3 patients have required a second reoperation. Mild to moderate aortic regurgitation was present in 17 patients. Subaortic stenosis is a spectrum of anatomical derangements ranging from a discrete fibrous membrane to a long, tortuous fibrous tunnel with aortic annulus hypoplasia. Successful removal of a discrete fibrous membrane can be followed later by recurrent stenosis necessitating myectomy or aortoventriculoplasty. Correction of subvalvar aortic stenosis can be followed by recurrent stenosis necessitating reoperation as long as 17 years after the initial procedure.

Cardiomyopathy, Hypertrophic↗
PubMed1990

An outbreak of acute rheumatic fever in Tennessee.

From January, 1987, until July, 1988, a significant increase in newly diagnosed cases of acute rheumatic fever was noted at our hospital. In sharp contrast to the 3 cases seen in 1986, 14 cases were diagnosed in 1987 (a significant increase from 1985 to 1986, P = 0.001). In the first 6 months of 1988 an additional 12 new cases were diagnosed (a further significant increase from 1987, P = 0.02). No further cases were diagnosed between July, 1988, and September, 1989. The major clinical manifestations were carditis in 73%, polyarthritis in 58% and chorea in 31%. In 15 of 26 patients an antecedent illness which included pharyngitis was noted; the remainder of patients were asymptomatic. Group A beta-hemolytic streptococci were isolated from 13 of 19 children cultured. Isolates from two patients with acute rheumatic fever were submitted for M typing: one isolate was mucoid M18/T18; the other isolate was a mucoid nontypable strain. The demographic characteristics of the 26 patients agree with classic descriptions in that patients were more likely to be urban, to come from large families and to have low incomes; racial breakdown of the group mirrored the Tennessee pediatric population. These characteristics stand in contrast to reports of recent outbreaks which describe suburban high income patients. These data suggest that practitioners should be again aware of acute rheumatic fever and that aggressive identification and treatment of streptococcal pharyngitis should continue to be a relevant public health concern.

Acute Disease↗
PubMed1990

Impact of Fontan operation on left ventricular size and contractility in tricuspid atresia.

Left ventricular dimensions and contractility were determined by echocardiography in 33 patients with tricuspid atresia in 1985 and again in 1988. Eight patients remained palliated throughout the 3-year period; neither the left ventricular end-diastolic diameter (153 +/- 15% of normal vs. 157 +/- 19%, p = NS) nor a load-independent index of contractility (rate-corrected velocity of shortening [VCFc]/end-systolic meridional stress [ESSM]) changed. Eleven patients underwent a Fontan operation during the study and were reevaluated at least 6 months after surgery; left ventricular dimension decreased (130 +/- 15% vs. 114 +/- 19%, p less than 0.001), and the contractility index VCFc/ESSM improved (p less than 0.05). Fourteen patients had undergone a Fontan operation 0.9-9.5 years (mean, 4.2 years) before initial examination in 1985. Over the 3-year period, left ventricular dimensions did not change (121 +/- 17% vs. 118 +/- 11%, p = NS), but the contractility index showed significant improvement (p less than 0.01). Eight additional patients were studied just before and after a Fontan operation to examine the early effects of surgery. Left ventricular dimensions decreased from 130 +/- 14% to 100 +/- 13% by 10 days p less than 0.001) with no further change at 2 months. An inappropriate degree of ventricular hypertrophy was observed in only the early postoperative period. Successful Fontan repair results in rapid reduction of left ventricular size, followed by regression of hypertrophy to a normal mass-to-volume ratio. Operating at more favorable dimensions and loading conditions results in an early increase in left ventricular contractility, which further improves in the medium term follow-up.

Echocardiography↗
PubMed1989

Absence of left ventricular volume loading in infants with coarctation of the aorta and a large ventricular septal defect.

Clinical characteristics and angiographic ventricular volume data were obtained in 25 infants aged 1 to 66 days who presented with coarctation of the aorta, ventricular septal defect and congestive heart failure to determine if left ventricular volume loading was present and if there were hemodynamic or volumetric variables that were predictive of operative mortality in this group. Pulmonary to systemic flow ratio averaged 2.8 +/- 0.8 and right ventricular/left ventricular peak pressure ratio was 0.96 +/- 0.12. Left ventricular end-diastolic volume averaged 116 +/- 49% of normal and was less than the investigators' lower limit of normal in 5 (20%) of 25 patients. In contrast, right ventricular end-diastolic volume, measured in eight patients, averaged 173 +/- 47% of normal and was greater than the investigators' upper limit of normal in seven (88%) of eight. Left ventricular ejection fraction averaged 0.47 +/- 0.17 and was below normal (less than 0.55) in 14 (58%) of 24 patients. Preoperative volume and ejection fraction data did not differ in infants with coarctation plus ventricular septal defect and a similar group of 19 infants with isolated coarctation. Abnormal left ventricular operative volume distensibility was inferred by normal or decreased left ventricular end-diastolic volume and increased left ventricular end-diastolic pressure (greater than 12 mm Hg) in 12 (55%) of 24 patients. Early plus late mortality was related to left ventricular size: 3 of 5 patients with a small left ventricular end-diastolic volume died, compared with only 4 of 20 with a normal or increased volume (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗
PubMed1989

Ten years' experience with the Senning operation for transposition of the great arteries: physiological results and late follow-up.

We report our results in 93 consecutive infants and children who underwent atrial repair of simple transposition of the great arteries using the Senning operation between February 1978 and February 1988. Mean age at operation was 5.6 +/- 6.3 months (range, 1 week to 4 years); 60 were less than 6 months old. There were 65 boys and 28 girls. Operative mortality was 5.4%, and there has been 1 late death. Average follow-up is 45.1 months with 39 followed more than 3 years and 25 followed more than 5 years. Postoperative cardiac catheterization was performed in 43 patients. Right ventricular ejection fraction at rest averaged 0.50 +/- 0.09 and was normal in 26 patients. Response of right ventricular ejection fraction to afterload stress was abnormal in 12 of 14 patients tested. Right ventricular ejection fraction increased normally during exercise in 6 patients, but was abnormal in 15. Mild tricuspid regurgitation was noted in 10 patients. Mild obstruction of the superior vena cava was noted in 4 patients. Baffle leak requiring reoperation occurred in 1 patient. Seventy-two of 80 patients are in sinus rhythm by latest electrocardiogram. Postoperative electrophysiological studies were performed in 34 patients and Holter monitoring was performed in 22. A major arrhythmia occurred in 8 patients: 3 required a pacemaker for junctional rhythm or sinus node dysfunction, 2 have symptomatic or inducible supraventricular tachycardia, 2 have junctional rhythm, and 1 has sick sinus syndrome. Eight additional patients have delayed sinus node recovery time. At last follow-up, 78 children (97.5%) are in New York Heart Association functional class I, and 2 (2.5%) are in class II.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1989

Clinical assessment of ventricular function after surgical treatment of congenital heart defects.

The assessment of ventricular function has contributed to the current surgical evaluation and surgical treatment of congenital heart defects, but many issues remain unresolved. The challenge of assessing ventricular function after surgical repair of congenital heart defects includes not only the general problem of distinguishing adverse loading conditions from myocardial failure but also more unique problems of right heart function and developmental differences in ventricular function. The possibility and significance of diastolic dysfunction are essentially unexplored and contingent upon our better understanding of the determinants of diastolic indices. Many of the technologies and methods are currently available and there is the beginning of a move toward better designed clinical trials and analysis of results. The assessment of ventricular function will become increasingly important as surgical techniques are improved and we are left with the more difficult choices between competing approaches.

Cardiac Output↗
PubMed1988

Left-ventricular cavity dimensions in children with normal and dilated hearts.

Studies were carried out to find how left-ventricular length and length/diameter ratio relate to body size and degree of dilation. By use of M-mode and two-dimensional echocardiography, diastolic cavity long axis (Led), diastolic cavity diameter (Ded), systolic cavity long axis (Les), systolic cavity diameter (Des), fractional L shortening (SFL), and fractional D shortening (SFD) were measured in children, adolescents, and young adults between two and 23 years of age, with body-surface area (BSA) between 0.5 and 2.1 m2 and with a variety of volume loads and SFD values. In normal subjects, Led/Ded was about 1.9. Regardless of age and pathology (in this age range), Led correlated consistently with BSA (Led = 3.9 + 3.2 BSA), indicating that the long axis changes rather little with pathological dilation. A plot of Led/Ded vs BSA/D2ed (in m2/cm2) formed a straight-line relation: Led/Ded = 0.77 + 16.4 BSA/D2ed. Similar relations were found for end-systolic dimensions. End-systolic L/D ratio exceeded end-diastolic L/D ratio to a degree that depended on both end-diastolic L/D ratio and SFD:Les/Des = Led/Ded + (0.22 + 2.67 Led/Ded)(SFD)2. Relations like these may be useful in the interpretation of echocardiographic images. The results suggest that left-ventricular L/D ratio may be influenced by myocardial anisotropy (dominance of hoop over meridional fiber orientation tending to promote prolate shape especially during systole) and external factors that antagonize extension of the long axis.

Adolescent↗
PubMed1988

Predictors of operative mortality in critical valvular aortic stenosis presenting in infancy.

Congenital aortic stenosis presenting within the first 6 months of life is a highly lethal anomaly. Although aortic valvotomy has offered excellent palliation in many instances, the operative risk remains substantial. To better understand the factors associated with a poor operative result, the records of all patients less than 6 months of age undergoing aortic valvotomy at our institution from 1972 through 1986 were analyzed. Nineteen patients (58%) (Group I) survived operation; 14 (42%) (Group II) died. The following variables were analyzed in an attempt to define those with prognostic significance: mean pulmonary artery pressure (PAP), left ventricular (LV) peak systolic pressure, LV end-diastolic pressure, peak systolic aortic valve gradient, LV end-diastolic volume (LVEDV), LV ejection fraction, and age at operation. The only variables that were significantly different in the two groups were mean PA (Group I, 29 +/- 3 mm Hg, and Group II, 54 +/- 3 mm Hg; p less than 0.001) and LVEDV (Group I, 50 +/- 8 ml/m2, and Group II, 20 +/- 4 ml/m2; p less than 0.05). No patient with an LVEDV of 20 ml/m2 or less survived operation. We conclude that small LV dimension and elevation of PAP may be predictive of a poor surgical result in patients with severe aortic stenosis presenting in infancy.

Actuarial Analysis↗
PubMed1988

Decreased early diastolic function after indomethacin administration in premature infants.

The effect of indomethacin on systolic and diastolic cardiac function was assessed in 15 premature infants. Seven infants (group 1) received indomethacin to treat a clinically significant patent ductus arteriosus (PDA), and eight infants (group 2) received indomethacin prophylactically at 24 hours of age because of their high risk for PDA. Diastolic cardiac function was assessed using instantaneous rates of change of left ventricular (LV) cavity dimension, derived from M-mode echocardiography. The maximum velocity of lengthening of the LV cavity dimension, an index of early diastolic function, fell from 63 +/- 19 mm/sec before indomethacin to 48 +/- 16 mm/sec 1 hour after indomethacin in group 1 (P less than 0.01), with the ductus still patent and the LV chamber still dilated, and also decreased in group 2, from 52 +/- 7 mm/sec to 38 +/- 6 mm/sec (P less than 0.01). This index, when normalized for loading conditions, was decreased 1 hour after indomethacin at 12 +/- 2 sec-1 and 12 +/- 1 sec-1 for groups 1 and 2, respectively, compared with values before indomethacin of 15 +/- 3 sec-1 and 15 +/- 2 sec-1. There was no effect of indomethacin on the indices of systolic function. We conclude that indomethacin decreases early diastolic function in premature infants.

Diastole↗
PubMed1987

Detection of caval obstruction by magnetic resonance imaging after intraatrial repair of transposition of the great arteries.

Vena caval obstruction may cause significant morbidity after intraatrial repair of transposition of the great arteries (TGA). Two noninvasive methods of diagnosing vena caval obstruction were compared with cardiac catheterization. Echocardiographically gated magnetic resonance imaging (MRI) and echocardiographic evaluation (2-dimensional saline contrast echocardiography and pulsed Doppler flow measurement) were performed on 15 patients 0.7 to 13.5 years after intraatrial repair of TGA (8 Mustard, 7 Senning). At catheterization, complete superior vena cava or partial caval obstruction (gradient greater than 5 mm Hg from cava to systemic venous atrium) was present in 7 of 15 patients. Superior vena cava obstruction was directly visualized by MRI in both patients with catheterization-proved complete superior vena cava occlusion. A dilated azygous/hemiazygous venous complex (greater than or equal to 5 mm cross-sectional diameter) was seen by MRI in 5 of 7 patients with complex or partial vena caval obstruction and in no patient without vena caval obstruction. MRI showed superior vena caval dilatation (ratio of superior vena caval diameter to aortic diameter greater than 1.45) in 3 of 5 patients with partial vena caval obstruction and in 0 of 8 without vena caval obstruction. Direct visualization of narrowing within the atrium was unreliable for any MRI plane because of the 3-dimensional nature of the intraatrial baffle. Two-dimensional saline contrast echocardiography, successfully performed in 12 of 15 patients, detected complete superior vena caval obstruction only in the 2 patients with catheterization-proved complete superior vena cava occlusion. Contrast echocardiography failed to identify any of the 5 patients with partial vena caval obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Altered early left ventricular diastolic cardiac function in the premature infant.

Developmental changes in diastolic ventricular function were assessed in 31 premature infants and in 10 normal-term infants. They were studied during the first 72 hours of life using instantaneous rates of change of left ventricular (LV) cavity dimension, derived from M-mode echocardiography. Maximal velocity of lengthening of the LV cavity was significantly lower in premature infants (38 +/- 7 mm/s) than in term infants (88 +/- 15 mm/s). This variable increased with increasing maturity over the 4 gestational age groups evaluated (r = 0.87). This index normalized for instantaneous LV dimension was lower in the most immature infants (4.5 +/- 1 s-1) than in term infants (6.8 +/- 2 s-1). Eight of the premature infants were studied serially at 1, 3 and 7 days of age. Maximal velocity of lengthening divided by stroke dimension improved from 12.9 +/- 2 s-1 at 1 day of age to 16.5 +/- 3 s-1 at 7 days. These results suggest depressed early diastolic function in premature infants.

Diastole↗