Left heart volume characteristics following ventricular septal defect closure in infancy

Echocardiographic Comparison of Left Ventricular Systolic Function and Aortic Blood Flow Velocimetry in Children with Ventricular Septal Defect

BACKGROUND

The assessments of left ventricular (LV) longitudinal systolic dynamics in children with ventricular septal defect (VSD) have achieved a major milestone in the evaluation of LV systolic function.

OBJECTIVES

This study aims to evaluate the LV function, LV mass (LVM), and the descending aorta blood flow in children with VSD compared to that obtained in age and sex-matched controls.

RESULTS

The mean LVM of the control, 113.5 ± 123.9 was higher than that of those who had VSD, 75.8 ± 83.9, and the difference in mean was found to be statistically significant (Mann-Whitney U = 2.322, P = 0.022). The mean EF of the control, 67.9 ± 10.3 was comparable to that of those with VSD, 65.6 ± 13.9, (Student's t = 1.223, P = 0.223). Similarly, the mean descending aorta blood flow of control, 1.6 ± 2.2 was comparable to that of those with VSD, 3.9 ± 16.1, (Mann-Whitney U = 1.002, P = 0.321). There was a very weak positive correlation between LVM and descending aorta blood flow among the subjects (n = 85, r = 0.117, P = 0.425). There was a very weak negative correlation between LVM and descending aorta blood flow among control. (n = 85, r = -0.065, P = 0.609).

CONCLUSION

The LVM among children with VSD is lower than controls but there is no difference between LV function in subjects and controls. There is a linear increase of LVM with descending aorta blood flow.

Left Ventricular Dysfunction Following Repair of Ventricular Septal Defects in Infants

Left ventricular systolic dysfunction (LVSD) is frequently observed following repair of ventricular septal defects (VSD), although little is known about its incidence, time course, or risk factors. Among infants undergoing VSD repair, for postoperative LVSD, we sought to determine (1) incidence, (2) predictors, and (3) time to resolution. We queried our institution's surgical database for infants who underwent repair of isolated VSDs from November 2001 through January 2019. The primary outcome was postoperative LVSD, which was defined as a shortening fraction (SF) of <26% by M-mode. Postoperative echocardiograms were reviewed, and measurements were made using standard methods. Receiver operating characteristic analysis was generated to determine the preoperative left ventricular internal dimension (LVIDd) z-score most predictive of LVSD. Multivariable analysis was conducted to determine associations with LVSD; covariates in the model were weight percentile, genetic syndrome, preoperative diuretic, VSD type, and preoperative LVIDd z-score. Of the 164 patients who met inclusion criteria, 62 (38%) had postoperative LVSD. Fifty-eight (94%) of patients had resolution of LVSD within 9 months of surgery. Preoperative LVIDd z-score of >3.1 was associated with both an increased incidence of postoperative LVSD and prolonged time to resolution. Multivariable logistic regression analysis showed only preoperative LVIDd z-score was independently associated with postoperative LVSD. LVSD following VSD closure is common, but nearly all cases resolve by 9 months postoperatively. Elevated LVIDd prior to surgery is associated with postoperative LVSD. These data suggest VSD closure should be considered prior to the development of significant left ventricular dilation.

Echocardiographic Left Ventricular Z-Score Utility in Predicting Pulmonary-Systemic Flow Ratio in Children With Ventricular Septal Defect or Patent Ductus Arteriosus

BACKGROUND

The correlation between the Z-score of the left ventricular (LV) diameter and the LV volume-overload due to pulmonary over-circulation in children with ventricular septal defect (VSD) or patent ductus arteriosus (PDA) remains unclear.

METHODS AND RESULTS

The present, retrospective study enrolled 70 children (aged 0.3-16.8 years; 33 males, 37 females) with a diagnosis of isolated VSD and/or PDA who underwent cardiac catheterization (CC) between 2015 and 2019. Patients with chromosomal/genetic anomalies, growth disorder, right-ventricular enlargement or other conditions causing LV enlargement were excluded. Echocardiographic parameters were retrospectively evaluated from the medical records, converted to a Z-score, then compared with CC data. The pulmonary-systemic flow ratio on CC (cQp/Qs) correlated significantly with the Z-score of both the LV end-diastolic diameter (Zd) (r=0.698, P<0.0001) and LV end-systolic diameter (r=0.593, P<0.0001). Regression analysis and curve-fitting were used to predict the cQp/Qs based on the Zd, and a significant regression equation was found on cubic regression (R2of 0.524, P<0.0001) showing a strong correlation with the cQp/Qs (r=0.724, P<0.0001).

CONCLUSIONS

The Z-score of the LV diameter can be a useful, non-invasive marker for evaluating LV volume overload and determining the surgical indications in children with VSD or PDA because of its strong correlation with the cQp/Qs.

Impact of percutaneous ventricular septal defect closure on left ventricular remodeling and function

Background

Ventricular septal defect (VSD) is the most common congenital heart disease. In patients with large VSD, left side chambers are subjected to volume overload with subsequent chambers dilatation and eccentric left ventricular hypertrophy. Percutaneous closure of VSD has been shown to be an effective method with equal safety and efficacy when compared to surgery. The effect of VSD closure on LV remodeling has been mainly assessed in patients treated with surgery and to date published data remain scarce. Therefore, we aim to evaluate the effect of percutaneous VSD closure on different LV parameters.

Results

Seventeen patients (median age 6 years (IQR 4.75–8 years), 70.6% females) who underwent percutaneous VSD closure were enrolled in the study. Sixteen patients (94%) had perimembranous VSD, and one patient had muscular VSD. The procedure was successful in all patients with no major complications. Nit Occlud® Lê coil device was implanted in 16 patients (94%), and one patient received Amplatzer PDA duct occlude device. At 6-months follow-up, there was a significant reduction in indexed LV dimensions [LVEDD/BSA (median 46.5 mm/m² vs. 42.9 mm/m², p = 0.03), LVESD/BSA (median 31.7 mm/m² vs. 26.7 mm/m², p = 0.02)], indexed LV volumes [LVEDV/BSA (median 52.6 ml/m² vs. 37.3 ml/m², p = 0.02), LVESV/BSA (median 31.7 ml/m² vs. 23.3 ml/m², p = 0.02)] and indexed LV mass (median 62.4 gm/m² vs. 57.9 ml/m², p = 0.01). There was a significant reduction in LVEDD Z-score (p = 0.01) and LVESD Z-score (p = 0.04). There was no significant change in LV EF.

Conclusions

Percutaneous VSD closure is associated with improvement of various LV parameters with consequential favorable LV remodeling and function.

Recent advances in managing septal defects: ventricular septal defects and atrioventricular septal defects

This review discusses the management of ventricular septal defects (VSDs) and atrioventricular septal defects (AVSDs). There are several types of VSDs: perimembranous, supracristal, atrioventricular septal, and muscular. The indications for closure are moderate to large VSDs with enlarged left atrium and left ventricle or elevated pulmonary artery pressure (or both) and a pulmonary-to-systemic flow ratio greater than 2:1. Surgical closure is recommended for large perimembranous VSDs, supracristal VSDs, and VSDs with aortic valve prolapse. Large muscular VSDs may be closed by percutaneous techniques. A large number of devices have been used in the past for VSD occlusion, but currently Amplatzer Muscular VSD Occluder is the only device approved by the US Food and Drug Administration for clinical use. A hybrid approach may be used for large muscular VSDs in small babies. Timely intervention to prevent pulmonary vascular obstructive disease (PVOD) is germane in the management of these babies. There are several types of AVSDs: partial, transitional, intermediate, and complete. Complete AVSDs are also classified as balanced and unbalanced. All intermediate and complete balanced AVSDs require surgical correction, and early repair is needed to prevent the onset of PVOD. Surgical correction with closure of atrial septal defect and VSD, along with repair and reconstruction of atrioventricular valves, is recommended. Palliative pulmonary artery banding may be considered in babies weighing less than 5 kg and those with significant co-morbidities. The management of unbalanced AVSDs is more complex, and staged single-ventricle palliation is the common management strategy. However, recent data suggest that achieving two-ventricle repair may be a better option in patients with suitable anatomy, particularly in patients in whom outcomes of single-ventricle palliation are less than optimal. The majority of treatment modes in the management of VSDs and AVSDs are safe and effective and prevent the development of PVOD and cardiac dysfunction.

Timing in resolution of left heart dilation according to the degree of mitral regurgitation in children with ventricular septal defect after surgical closure

OBJECTIVE

Children with ventricular septal defects (VSD) can have chronic volume overload, which can result in changes of left heart echocardiographic parameters. To evaluate the changes before and after surgical closure, the children were divided into three groups according to the degree of mitral regurgitation (MR), and their echocardiographic characteristics were reviewed at serial follow-up after surgical closure.

METHODS

The preoperative, and one-, three-, and 12-month postoperative echocardiographic data of 40 children who underwent surgical closure of VSD were retrospectively reviewed. Left ventricular end-diastolic volume (LVEDV), left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD), mitral valvular characteristics, including degree of MR and mitral valve annulus, and left atrial (LA) characteristics, including volume and dimensions, were observed.

RESULTS

Preoperative LVEDV, LVEDD, LVESD, mitral valvular annulus, LA volume, and LA dimensions were significantly larger in children with MR. Additionally, there were significant decreases in LVEDV, LVEDD, LA volume, and LA dimensions at one, three, and 12 months postoperatively. The degree of MR also improved to a lower grade after surgical closure of the VSD without additional mitral valve repair.

CONCLUSION

The echocardiographic parameters of left heart dilation and MR in children with VSD improved within the first year after surgical closure without additional mitral valve repair. Furthermore, in all of the patients with VSD, regardless of MR, LA dilation was reduced within three months after surgical closure of the VSD; however, LV and mitral valve annular dilatation decreased within 12 months.

Left ventricular mechanics after closure of ventricular septal defect: influence of size of the defect and age at surgical repair

To evaluate the influence of the size of the defect and the age of surgical repair on left ventricular mechanics, including geometry, shape, diastolic and systolic function as well as myocardial contractility, we used cross-sectional echo-Doppler to study 20 patients (12 males, 8 females) who had undergone successful surgical closure of a ventricular septal defect. The patients were divided in two groups, corrected early and late, on the basis of the degree of left-to-right shunting (ratio of pulmonary to systemic output of greater or less than 2.5/1) and the age at the surgical repair (older or younger than 2 years of age). The group undergoing early correction included 11 patients, mean age 7.1+/-1.8 years (range 4.2-11.8 years), having surgery at mean age of 1.3+/-0.6 years for a large ventricular septal defect (mean ratio of pulmonary to systemic output of 3.1/1; range 3.4-2.7/1) with a mean postoperative follow-up 4.6+/-1.9 years. The group of nine patients undergoing late correction had a mean age of 11.3+/-4.9 years (range 6.7-17.2 years), with a later surgical repair (mean age 4.7+/-2.7 years) for a moderate-sized ventricular septal defect (mean pulmonary/systemic output ratio 2.1/1; range 2.3-1.7) and a mean postoperative follow-up of 7+/-4.2 years. Each group of surgically repaired patients was compared with a control group matched for age, body surface area and gender. No significant differences were found between the normal controls and those undergoing early correction for any assessed functional index regarding left ventricular geometry (normalized volumes and mass for body surface area, mass/volume and thickness/radius ratios), shape (long axis-short axis ratio), diastolic (mitral and pulmonary venous flow patterns) and systolic (fractional shortening and rate-corrected mean velocity of circumferential fibre shortening) function. In addition, the data points for each patient for the rate-corrected mean velocity of circumferential fibre shortening to end-systolic stress relationship were within the 95% confidence limits of normal, suggesting normal left ventricular contractility. On the other hand, the patients undergoing surgery at a later age showed a persistent increase of the normalized left ventricular end-diastolic volume and mass, with an higher mass/volume ratio and reduced end-systolic stress compared with normal controls. Furthermore, left ventricular shape (long axis-short axis ratio) was abnormal at end-diastole but with its normal values at end-systole. Our data suggest that, in the presence of a large ventricular septal defect, early successful surgical repair <2 years of age results in complete recovery of left ventricular mechanics in the postoperative follow-up. In contrast, surgical closure at > 2 years of age, even for a moderately sized ventricular septal defect, deleteriously affects postoperative left ventricular geometry and shape. Since prolonged volume overload may be detrimental to myocardial function, earlier surgical repair should be recommended.

The adult patient with congenital heart disease

In adults with congenital heart disease who are confronted with noncardiac surgery, perioperative risks can be reduced, often appreciably, when problems inherent to this patient population are anticipated. The first necessity is to clarify the diagnosis and to be certain that appropriate information is obtained from a cardiologist with adequate knowledge of congenital heart disease in adults. Physiology and anatomy can vary significantly among patients who superficially carry identical diagnoses. Elective noncardiac surgery should be preceded by clinical assessment including review of clinical and laboratory data and securing the results of necessary diagnostic studies. Preoperative assessment should be performed far enough in advance of the anticipated date of surgery to allow critical assessment of the data and potential discussions with colleagues. Appropriate cardiovascular laboratory studies to be obtained or reviewed include electrocardiograms, chest radiographs, echocardiograms, and cardiac catheterization data, which may include specialized intracardiac electrophysiologic testing. Congenital heart disease in adults is a new and evolving area of special interest and expertise in cardiovascular medicine. Multidisciplinary centers for the care of these patients are being developed. The 22nd Bethesda Conference recommended that these centers include among their consultants anesthesiologists with special expertise in managing patients with congenital heart disease. These anesthesiologists can have the option of serving either as the attending anesthesiologists when patients require noncardiac surgery or as consultants and resource individuals to other anesthesiologists.

Acute changes in left ventricular geometry after volume reduction operation

BACKGROUND

After surgical removal of a volume load, regression of myocardial mass proceeds slowly relative to diminution in ventricular cavity size, resulting in increased wall thickness and decreased cavity dimensions, which may affect the filling properties and performance of the heart. We investigated the acute changes in ventricular geometry that occur after the Fontan operation and hemi-Fontan operation for tricuspid atresia, and compared them with closure of a ventricular septal defect in a two-ventricle heart.

METHODS

We reviewed the results of echocardiography performed before and 8 +/- 7 days after (1) Fontan operation for tricuspid atresia (n = 9), (2) hemi-Fontan operation for tricuspid atresia (n = 10), and (3) closure of a ventricular septal defect (n = 13). Measurements were made from images of the left ventricle at end-diastole: (1) apical, septal, and posterior wall thickness; and (2) long- and short-axis cavity diameters, cross-sectional areas, and ventricular volume. Posterior wall thickness to cavity dimension ratio was calculated.

RESULTS

Wall thickness increased in all groups, with the greatest degree of increase after the Fontan operation. Cavity measures decreased most dramatically after the Fontan operation, with less dramatic and equivalent changes noted after the hemi-Fontan operation and ventricular septal defect closure. Posterior wall thickness to cavity diameter ratios were equivalent in all before operation, increased after operation, and were greatest after the Fontan operation.

CONCLUSIONS

Changes in ventricular geometry identified as an increase in wall thickness and a decrease in cavity dimension are most dramatic after the Fontan operation. Changes seen after the hemi-Fontan operation are of a milder degree, which may in part explain the excellent clinical course after this operation.

Adult congenital heart disease: principles and management guidelines: Part II

The treatment of congenital heart disease may be palliative because many residua and sequelae persist into adulthood. Except for trivial lesions and anomalies such as PDA or secundum ASD where surgical cure is possible, continued supervision is mandatory. These patients deserve expert medical assessment from adult cardiologists and from other specialists when appropriate. The prevalence of postoperative adult congenital heart disease is increasing: by the year 2000 it is estimated that over 2000 in each million of the adult population will have congenital heart disease, one third of these having undergone cardiac surgery. It is important that some adult cardiologists in each major centre develop skills in adult congenital heart disease for this new patient population.

Predictors of postoperative ventricular dysfunction in infants who have undergone primary repair of a ventricular septal defect

By means of postoperative radionuclide angiography we identified a subset of infants undergoing primary repair of their ventricular septal defects (VSD) who had postoperative morbidity and ventricular dysfunction. Twenty-three consecutive infants undergoing repair of an uncomplicated VSD were studied. Radionuclide-determined postoperative ventricular dysfunction (VD), as defined by a left ventricular ejection fraction less than 0.30 2 to 4 hours after surgery, was correlated with clinical signs of postoperative morbidity. Six patients developed postoperative VD. Clinical correlates of VD included the use of postoperative inotropic support, increased number of postoperative intensive care days, and a low growth rate 3 months postoperatively. Potential predictors of VD were evaluated. A preoperative pulmonary-to-systemic blood flow ratio (Qp/Qs) greater than 3.0 and a pulmonary-to-systemic vascular resistance ratio (Rp/Rs) less than 0.20, taken in combination, gave a positive predictive value for VD of 100%. It is concluded that the preoperative Qp/Qs and Rp/Rs can be used to predict those infants at risk for postoperative morbidity following repair of their VSD.

Left ventricular end-systolic wall stress to volume relationship before and after surgical closure of ventricular septal defect

Left ventricular function was examined angiographically in 64 patients with ventricular septal defect and 13 postoperative patients with a preoperatively large shunt (postoperative group). The unoperated 64 patients were divided into three groups; small (left-to-right shunt ratio less than 35%), moderate (35%-50%), and large (greater than 50%). The control group consisted of 27 patients with Kawasaki disease. For assessing left ventricular function, left ventricular shape and the end-systolic wall stress to end-systolic volume index ratio, as well as left ventricular ejection fraction were examined. Left ventricular ejection fraction was higher in the small-shunt group (p less than 0.05) than in the control group, but normal in the other groups. Left ventricular end-diastolic shape was normal only in the small-shunt group and more spherical in the other groups. The large-shunt group alone manifested more spherical left ventricular end-systolic shape and lower end-systolic wall stress to end-systolic volume index (p less than 0.001). These findings suggest that the left ventricular dysfunction is present in patients with a left-to-right shunt larger than 50%, but this change was reversible in patients who underwent early repair of ventricular septal defect.

Computer assisted echocardiographic assessment of left ventricular function before and after anatomical correction of transposition of the great arteries

Left ventricular function before and after anatomical correction of transposition of the great arteries was assessed by computer assisted analysis of 78 echocardiographs from 27 patients obtained one year before to five years after operation. Sixteen patients had simple transposition, and 11 had complex transposition with additional large ventricular septal defect. Immediately after correction mean shortening fraction fell from 46(9)% to 33(8)%. There was a corresponding drop in normalised peak shortening rate from 5.4(3.7) to 3.3(1.1) s-1 and normal septal motion was usually absent. Systolic shortening fraction increased with time after correction and left ventricular end diastolic diameter increased appropriately for age. The preoperative rate of free wall thickening was significantly higher in simple (5.6(2.8) s-1) and complex transposition (4.5(1.8) s-1) than in controls (2.9(0.8) s-1). After operation these values remained high in both the short and long term. Thus, computer assisted analysis of left ventricular dimensions and their rates of change before and after anatomical correction showed only slight postoperative changes which tended to become normal with time. Septal motion was commonly absent after operation. This was associated with an increase in the rate of posterior wall thickening that suggested normal ventricular function associated with an altered contraction pattern. Computer assisted echocardiographic analysis may be helpful in the long term assessment of ventricular function after operation for various heart abnormalities.

Comparison of ventricular function after Senning and Jatene procedures for complete transposition of the great arteries

Postoperative right (RV) and left ventricular (LV) volume characteristics in patients with complete transposition of the great arteries were studied to compare ventricular function after Senning and Jatene procedures and to analyze RV dimensional change during systole in patients after the Senning procedures. RV end-diastolic volume (EDV) was 181 +/- 74% of normal (mean +/- standard deviation) and RV ejection fraction (EF) was 0.48 +/- 0.09 in 15 patients who underwent the Senning procedure. In 9 patients who underwent the Jatene procedure, LVEDV was 152 +/- 27% of normal and LVEF was 0.61 +/- 0.09. One patient with aortic regurgitation, 1 with aortic regurgitation and residual ventricular septal defect, and 1 with aortic regurgitation and generalized LV wall hypokinesia of unknown cause had large LVEDVs. Pulmonary ventricular EDV and EF were within normal ranges except in the patients with persistent pulmonary hypertension, who had large EDVs and low EFs regardless of the anatomic type of ventricle, either the left or right. The study of RV dimensional change in the Senning group showed a reduced systolic shortening of the anteroposterior diameter compared with the preoperative transposition of the great arteries and normal. This reduced shortening may be related to postoperative adhesion of the RV free wall to the anterior chest wall and fixation of the atrium secondary to the intraatrial repair. In conclusion, systemic ventricular function after intraatrial repair for complete transposition of the great arteries is depressed by unavoidable residua and sequelae: persistent RV hypertension, anatomy of the right ventricle and, possibly, postoperative adhesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of hemodynamic status in the intensive care unit immediately after closure of ventricular septal defect

Hemodynamic values measured 12 to 24 hours postoperatively in the intensive care unit (ICU) were compared with those measured at a later cardiac catheterization in 68 patients after closure of ventricular septal defect (VSD). A pulmonary arterial (PA) saturation of more than 80% or a pulmonary to systemic blood flow ratio (Qp:Qs) greater than 1.5 in the ICU were sensitive indicators for identifying patients at risk of having a hemodynamically significant residual left-to-right shunt (Qp:Qs greater than 1.5) at catheterization. Measurement of PA pressure in the ICU was a useful predictor of PA pressure at catheterization. In the absence of factors known to alter PA pressure, measurement of PA pressure in the ICU overestimates what it will be at a subsequent cardiac catheterization. Early assessment of hemodynamics after closure of VSD is useful in identifying patients at risk of having hemodynamically significant residual VSD and those who may have persistent PA hypertension.

Ventricular performance in adults after operation for congenital heart disease

Symptomatic ventricular dysfunction in adults who have had reparative operations for the more common congenital heart defects is uncommon. However, both invasive and noninvasive laboratory assessments of ventricular function have revealed abnormalities in some subsets of patients after repair of atrial septal defect, ventricular septal defect, aortic or pulmonary stenosis, tetralogy of Fallot, transposition of the great arteries and tricuspid atresia. Possible causative factors of late ventricular dysfunction after repair include the duration and severity of volume or pressure overload; the duration and severity of cyanosis; intermittent episodes of imbalance between myocardial oxygen supply and demand; residuae, sequelae and complications of treatment; and acquired disease. Further long-term follow-up studies are needed to assess the effect of current methods of therapy as well as timing of operative intervention on ventricular function in adults.

Determination of left ventricular diastolic chamber stiffness and myocardial stiffness in patients with congenital heart disease

Left ventricular diastolic indexes were derived in 13 patients aged 5 to 21 years. Three had a normal heart, three had lesions causing volume overload and seven had coarctation of the aorta, including one whose main lesion was severe endocardial fibroelastosis. At cardiac catheterization simultaneous high fidelity pressure (P) and left ventricular volume (V) measurements were obtained and several points in one diastolic cycle taken. With use of a monoexponential formula (P = aebv) for P versus V, dP/dv and the operant chamber stiffness b were obtained. Similarly, with use of sigma = alpha e beta epsilon, d sigma/d epsilon, elastic stiffness (E) and the muscle stiffness constant KE were obtained. Values for b were 0.0273 +/- 0.0065 in normal subjects, 0.017 +/- 0.0043 in those with volume overload, 0.0369 +/- 0.0173 in those with coarctation (without endocardial fibroelastosis) and 0.0192 in the child with endocardial fibroelastosis. The plot of P versus V for coarctation was to the left and steeper than normal and the patients with volume overload had a flattened rightward curve, whereas the curve for those with endocardial fibroelastosis was extremely rightward. The stress-radii curves of the normal subjects and those with coarctation were similar whereas the curves for patients with volume overload and endocardial fibroelastosis were rightward of normal. The value for KE was 8.92 +/- 0.87 for the normal subjects, 8.26 +/- 0.75 for those with volume overload, 9.2 +/- 2.5 for those with coarctation and 22.75 for those with endocardial fibroelastosis. Thus, the pressure-loaded ventricle is stiffer than the normal, which in turn, is stiffer than the volume-loaded ventricle. This response, due to hypertrophy, appears to be appropriate in that diastolic stress was normalized and muscle stiffness was not increased except in the patient with endocardial fibroelastosis.

Early intracardiac repair of large ventricular septal defects with conventional cardiopulmonary bypass and moderate hypothermia

With the use of conventional cardiopulmonary bypass and moderate hypothermia, primary intracardiac repair of large ventricular septal defects was performed in 30 children below the age of two years. All babies were falling to thrive and suffered from cardiac failure resistant to medical therapy, or had evidence of early pulmonary vascular disease. Two patients died after the operation, giving an operative mortality of 6.7%. Twenty-eight survivors have been followed for periods of one month to two and a half years. All are thriving and have normal or mildly enlarged hearts on their chest skiagrams. Primary intracardiac repair of large ventricular septal defects can be performed in infants and small children with a low operative risk when the standard cardiopulmonary bypass technique is being used.

Preoperative diagnosis and management of infants with critical congenital heart disease

Operative repair with an associated low morbidity and mortality is available now for most infants with congenital cardiac defects. Precise preoperative diagnosis is an essential part of continuing attempts to lower the operative risk for these patients. In this review we cover major areas of concern in regard to preoperative diagnosis and management. Long-term follow-up studies with clinical, hemodynamic, electrophysiological, and exercise data are required to assess current diagnostic and therapeutic practices.

Assessment of left-to-right shunt and left ventricular function in isolated ventricular septal defect. Echocardiographic study

This echocardiographic study was designed to assess left ventricular function and pulmonary blood flow in ventricular septal defect. Fifty-one patients aged 2 weeks to 21 years were investigated (group 2). Five of 10 operated patients were studied one week after surgical closure of the defect (group 3) and seven 3 to 6 weeks postoperatively (group 4). The control group consisted of 45 normal subjects aged 2 weeks to 21 (group 1). Left atrium/aortic root dimension ratio (LA/Ao) was used to express the pulmonary systemic flow ratio. Left ventricular chamber size was assessed by measurement of left ventricular end-diastolic dimension and volume. The left ventricular mass and the ratio of end-diastolic volume to left ventricular mass were determined to relate the degree of left ventricular hypertrophy to volume overload. Myocardial function was evaluated using ejection phase indices. Ventricular septal thickness, posterior wall thickness, and echocardiographic patterns of septal motion were also studied. The left atrium/aortic root dimension, end-diastolic volume, and left ventricular mass were significantly greater in group 2 patients (P less than 0.05) than in the normal controls. There was a very good correlation between LA/Ao and pulmonary/systemic flow ratio (r = 0.83). Eleven of the group 2 patients showed asymmetric septal hypertrophy (unrelated to shunt size) but left ventricular function as assessed by ejection phase indices appeared unimpaired. Immediately after operation (group 3) there was a deterioration in left ventricular function in 5 patients as shown by reduced ejection fraction, mean velocity of circumferential shortening, and relative changes in minor axis with systole. Septal motion was impaired but returned to normal in 3 to 6 weeks in 7 patients (group 4). Left atrial/aortic root dimension, end-diastolic volume, and left ventricular mass decreased significantly immediately after operation (group 3) but were still raised at 3 to 6 weeks (group 4).

Operative closure of isolated defects of the ventricular septum: planned delay

Selection of patients and the timing of operation for closure of ventricular septal defect (VSD) can be difficult because the risk of operation must be balanced against the hemodynamic abnormality and the age and size of the infant. In the past 6 years we have individualized our approach to the timing and necessity of operation in the patient with an isolated VSD. During this period, 133 patients with VSD were evaluated, and 71 underwent operative closure of the VSD. Of the 133 patients, 90 were 2 years old or younger, and 40 of them required operation because of congestive failure and growth retardation. Of the 45 infants who did not undergo operation, 17 have small intracardiac shunts with normal pulmonary vascular resistance while the other 28 infants remain compensated and are growing despite moderate left-to-right shunts. A persistent, large intracardiac shunt was the indication for operation in 31 of the 48 older patients; the other 17 older patients remain well. Although 3 severely growth-retarded infants (2 to 4 kg) died soon after operation, all infants weighing 4 kg or more survive. No child has died during preoperative observation, and irreversible pulmonary vascular changes have not occurred. Most infants with VSD and large intracardiac shunts do require early VSD closure, but the risk of operation remains high in the tiny neonate with profound failure. With appropriate hemodynamic and clinical criteria, operation for selected infants can be delayed so that the risk of operation can be minimized.