Elucidation of the natural history of ventricular septal defects by serial Doppler color flow mapping studies

The Prevalence and Spontaneous Closure of Ventricular Septal Defects the First Year of Life

INTRODUCTION

Ventricular septal defect (VSD) is one of the most common congenital heart defects. We aimed to determine the prevalence of VSD in a population-based cohort of newborns and assess the rate of spontaneous closure during the first 12 months of life.

METHODS

The Copenhagen Baby Heart Study (CBHS) is a population-based cohort study, including more than 25,000 newborns born in the greater Copenhagen area. Newborns underwent echocardiography within 60 days of birth. Newborns with VSDs had echocardiographic follow-up after 3, 6, and 12 months.

RESULTS

A total of 850 newborns (3.3% of 25.556) with a VSD were identified in the CBHS. Of these, 787 (92.6% [95% CI 90.1-94.2]) were muscular VSDs, 60 (7.0% [95% CI, 5.5-9.0]) were perimembranous, and 3 (0.4% [95% CI, 0.0-1.1]) were subarterial. After 1 year, 83.5% (607 of 727) of all VSDs had closed spontaneously, resulting in a decrease of prevalence from 3.3% at birth to 0.5% in 1-year old children. Muscular VSDs showed significantly higher rate of spontaneous closure compared with perimembranous VSDs (86.9% (582/670) vs. 46.9% (25/54), p < 0.001). Determinants associated with spontaneous closure were smaller size of the VSD (p < 0.001) and the absence of multiple VSDs (p < 0.0025).

CONCLUSION

The prevalence of VSDs in unselected newborns was 3.3%. Almost 9/10 of all VSDs identified in newborns, close spontaneously during the first year of life, ultimately resulting in a prevalence of VSD in 1-year-old children of 0.5%. The identified factors associated with spontaneous closure were muscular type, small size, and absence of multiple VSDs.

Electrocardiographic characteristics of newborns with ventricular septal defects: a Copenhagen Baby Heart Study

Ventricular septal defects (VSD) represent the most common congenital heart defect in newborns. We assessed the electrocardiographic characteristics of newborns with VSDs in a general population sample. The Copenhagen Baby Heart Study is a prospective population-based cohort study offering cardiac evaluation of newborns. Echocardiograms and electrocardiograms were obtained within 30 days after birth and systematically analysed. A VSD was identified in 530 newborns (mean age 11 ± 7 days, 42% boys). Newborns with VSDs had a more left-shifted QRS axis (116 ± 34 vs. 120 ± 3°, p = 0.02), and a higher S-wave amplitude in V1 (721 ± 584 vs. 636 ± 549 µV, p = 0.001) than controls. The largest differences were found in newborns with large or perimembraneous VSDs with a higher frequency of left axis deviation, higher S-wave amplitudes in V1, and higher R- and S-wave amplitudes in V6 compared with controls. R-waves in V1 and V6 were significantly associated to left ventricular mass, whereas S-waves in V1 and V6 were dependent on left ventricular end-diastolic diameter on echocardiography.  Conclusion: Newborns with VSDs showed significant differences in QRS axis, and R- and S-wave precordial amplitudes compared to matched controls. Perimembranous and large VSDs had the greatest effect on the neonatal ECG. What is Known: • Ventricular septal defects in newborns are prevalent and may affect cardiac function and structure. What is New: • The Copenhagen Baby Heart Study is the largest study including a cohort of unselected newborns undergoing postnatal cardiac examination. • We found that newborns with VSD showed significant electrocardiographic differences depending on size and type of VSD compared with healthy newborns.

Performance Assessment of Row-Column Transverse Oscillation Tensor Velocity Imaging Using Computational Fluid Dynamics Simulation of Carotid Bifurcation Flow

In this work, the accuracy of row-column tensor velocity imaging (TVI), i.e., 3-D vector flow imaging (VFI) in 3-D space over time, is quantified on a complex, clinically relevant flow. The quantification is achieved by transferring the flow simulated using computational fluid dynamics (CFD) to a Field II simulation environment, and this allows for a direct comparison between the actual and estimated velocities. The carotid bifurcation flow simulations were performed with a peak inlet velocity of 80 cm/s, nonrigid vessel walls, and a flow cycle duration of 1.2 s. The flow was simulated from two observation angles, and it was acquired using a 3-MHz 62+62 row-column addressed array (RCA) at a pulse repetition frequency ( f_prf ) of 10 and 20 kHz. The tensor velocities were obtained at a frame rate of 208.3 Hz, at f_prf = 10 kHz , and the results from two velocity estimators were compared. The two estimators were the directional transverse oscillation (TO) cross correlation estimator and the proposed autocorrelation estimator. Linear regression between the actual and estimated velocity components yielded, for the cross correlation estimator, an R ² value in the range of 0.89-0.91, 0.46-0.77, and 0.91-0.97 for the x -, y -, and z -components, and 0.87-0.89, 0.40-0.83, and 0.91-0.96 when using the autocorrelation estimator. The results demonstrate that an RCA can, with just 62 receive channels, measure complex 3-D flow fields at a high volume rate.

Risk Factors for Delayed Extubation after Ventricular Septal Defect Closure: a Prospective Observational Study

Objective

The objective of our study was to determine the feasibility of early extubation and to identify the risk factors for delayed extubation in pediatric patients operated for ventricular septal defect closure.

Methods

A prospective, observational study was carried out at our Institute. This study involved consecutive 135 patients undergoing ventricular septal defect closure. Patients were extubated if feasible within six hours after surgery. Based on duration of extubation, patients were divided two groups: Group 1= extubation time ≤ 6 hours, Group 2= extubation time >6 hours.

Results

A total of 99 patients were in Group 1 and 36 patients in Group 2. Duration of ventilation was 4.4±0.9 hours in Group 1 and 25.9±24.9 hours in Group 2 (P<0.001). Univariate analysis showed that young age, low weight, low partial pressure of oxygen, trisomy 21, multiple ventricular septal defect, high vasoactive inotropic score, transient heart block and low cardiac output syndrome were associated with delayed extubation. However, regression analysis revealed that only trisomy 21 (OR: 0.248; 95%CI: 0.176-0.701; P=0.001), low cardiac output syndrome (OR: 0.291; 95%CI: 0.267-0.979; P=0.001), multiple ventricular septal defect (OR: 0.243; 95%CI: 0.147-0.606; P=0.002) and vasoactive inotropic score (OR: 0.174 95%CI: 0.002-0.062; P=0.039) are strongest predictors for delayed extubation.

Conclusion

Trisomy 21, low cardiac output syndrome, multiple ventricular septal defect and high vasoactive inotropic score are significant risk factors for delay in extubation. Age, weight, pulmonary artery hypertension, size of ventricular septal defect, aortic cross-clamp and cardiopulmonary bypass time did not affect early extubation.

Isolated Aneurysms of the Membranous Ventricular Septum Without Residual Shunts: Systematic Review and Description of 3 Cases in Adults

A ventricular septal defect is the most common congenital cardiac abnormality encountered in infants and children. Many of them survive through adulthood before diagnosis. Two-thirds of the cases involve the membranous part of the septum. In the absence of an interventricular shunt or concomitant cardiac surgery, guidelines for surgical intervention or resection of isolated aneurysms of the membranous septum are not well established. In this report, we discuss a multi-imaging modality approach for the diagnosis and assessment of membranous ventricular septal aneurysms and review the experts' consensuses for follow-up and treatment strategies.

Prediction of spontaneous closure of isolated ventricular septal defects in utero and postnatal life

BACKGROUND

Ventricular septal defect (VSD) is a highly prevalent fetal congenital heart defect, which can become spontaneously closed during infancy. The current study aims to characterize fetal VSDs that were subsequently spontaneously closed in the first 2 years of life in eastern China.

METHODS

Between January 2011 and December 2013, 257 fetal patients diagnosed with isolated VSD by fetal echocardiography at Nanjing Maternity and Child Health Care Hospital, China, were enrolled in the study. Subjects were divided into three groups: group 1 = persistent VSD; group 2 = closed after birth; group 3 = closed during gestation. Fetal echocardiography data, physical features at birth and follow-up outcomes for 2 years were compared to identify factors contributing to spontaneous closure (SC) of VSD. A predictive formula was applied to patients admitted to hospital in the first quarter of 2014 (n = 23) for validation.

RESULTS

SC occurred in 42.8% patients. Birth weight (3.095 ± 0.774, 3.174 ± 0.535, 3.499 ± 0.532 kg in groups 1, 2 and 3, respectively) and defect diameter (3.422 ± 0.972, 2.426 ± 0.599, 2.292 ± 0.479 mm, in groups 1, 2 and 3, respectively) showed statistically significant differences between the three groups (P = 0.004 and P = 0.000, respectively). Receiver operating characteristic (ROC) curves identified cut-off value for the defect diameter as 2.55 mm, and logistic regression analysis identified the SC probability = (1 + exp -[-2.151 - 0.716*birth weight + 1.393*diameter])^-1. Results indicated that male fetuses, full-term birth, muscular VSD, and defects without blood flow crossing the septum, have higher incidence of SC.

CONCLUSIONS

The major determinants of SC of isolated VSD are birth weight and diameter of the defect. In addition, VSD location may also affect the SC incidence.

Circulating matrix metalloproteinase-2 and -9 enzyme activities in the children with ventricular septal defect

Ventricular septal defect (VSD) is the most common form of congenital heart diseases. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases involved in causal cardiac tissue remodeling. We studied the changes of circulating MMP-2 and MMP-9 activities in the patients with VSD severity and closure. There were 96 children with perimembranous VSD enrolled in this study. We assigned the patients into three groups according to the ratio of VSD diameter/diameter of aortic root (Ao). They were classified as below: Trivial (VSD/Ao ratio ≤ 0.2), Small (0.2 < VSD/Ao ≤ 0.3) and Median (0.3 < VSD/Ao) group. Plasma MMP-2 and MMP-9 activities were assayed by gelatin zymography. There was a significant higher MMP-2 activity in the VSD (Trivial, Small and Median) groups compared with that in Control group. The plasma MMP-9 activity showed a similar trend as the findings in MMP-2 activity. After one year follow-up, a significant difference in the MMP-9 activity was found between VSD spontaneous closure and non-closure groups. In conclusion, a positive trend between the severity of VSD and activities of MMP-2 and MMP-9 was found. Our data imply that MMP-2 and MMP-9 activities may play a role in the pathogenesis of VSD.

Investigation of membranous ventricular septal defect complicated with tricuspid regurgitation in ventricular septal defect occlusion

This study aimed to explore the mechanism of membranous ventricular septal defect complicated with tricuspid regurgitation and the significance of ventricular septal defect occlusion by echocardiography. A total of 43 patients with membranous ventricular septal defect complicated with tricuspid regurgitation were observed by echocardiography and the changes in length, area and volume of tricuspid regurgitation prior to and following ventricular septal defect occlusion were measured. There were four different mechanisms of membranous ventricular septal defect complicated with tricuspid regurgitation. The various indices of tricuspid regurgitation volume were significantly reduced following occlusion. Ventricular septal defect occlusion significantly reduces tricuspid regurgitation volume complicated with membranous ventricular septal defect and echocardiography is an ideal method to detect these changes.

Spontaneous closure of muscular trabecular ventricular septal defect: comparison of defect positions

AIM

To evaluate the timing and frequency of spontaneous closure of the muscular trabecular ventricular septal defect (VSD).

METHODS

We performed a historical cohort study for which 150 patients <3 months of age (median age, 9 days) diagnosed as having a muscular trabecular VSD were selected. Median age at latest follow-up was 2.8 years. Another 32 patients diagnosed after 3 months of age were also reviewed. Using colour Doppler, defects were classified into three groups: anterior, apical and midventricular.

RESULTS

  Spontaneous closure occurred in 126 patients (84%): anterior, 36 of 47 (83%); apical, 26 of 31 (84%); and midventricular, 64 of 72 (89%). Multivariate analyses showed a lower frequency of spontaneous closure for patients of age of ≥ 20 days at initial echocardiography [hazard ratio 0.60, 95% confidence interval (CI) 0.39-0.89] and for anterior and apical muscular trabecular VSD (hazard ratio 0.66, 95% CI 0.47-0.95). The prevalence of the midventricular muscular trabecular VSD was significantly lower in patients ≥ 3 months of age at initial echocardiography than in those < 3 months (p = 0.010).

CONCLUSION

We infer that midventricular muscular trabecular VSD tends to close spontaneously earlier and more frequently than either anterior or apical muscular trabecular VSD.

Color Doppler echocardiographic study on the incidence and natural history of early-infancy muscular ventricular septal defect

BACKGROUND

Most small muscular ventricular septal defect (M-VSD) types have been diagnosed using color Doppler echocardiography. The purpose of this study was to understand the incidence of small M-VSD in the neonatal period and analyze the natural history of these M-VSDs.

MATERIALS AND METHODS

All individuals in our study were neonates delivered at term who had a normal healthy appearance. Each accepted neonate had an examination with complete color Doppler echocardiography once before discharge. If the examination was confirmed for M-VSD, the study participants were then classified according to defect type. Further examination was arranged with color Doppler echocardiography at 1 month, 2 months, 4 months, 6 months, 9 months, and 12 months of age or until there was complete spontaneous closure.

RESULTS

Among 2891 neonates, we found that 72 (24.9/1000) were diagnosed with M-VSD. Among this group, 38 were male and 34 were female. Only six infants were lost to follow-up. Fifty-four of the 66 infants (81.8%) had M-VSD closed spontaneously at 12 months' follow-up. Significantly, 33 of 37 infants (89.2%) with mid-muscular type, the most common type of M-VSD, closed within the 1(st) year of life compared with apical type (17/24:70.8%). Four of the five infants (80%) had anterior type M-VSD closed. Infants with posterior type M-VSD were not seen during this study period.

CONCLUSION

Although the incidence of M-VSD was common in the neonatal period, there was also a high rate of spontaneous closure. Therefore, comparison of M-VSD appearance with the incidence of congenital heart disease in neonates had a decisive influence on analysis.

No inflammatory response related to pulmonary hemodynamics in children with systemic to pulmonary shunts

OBJECTIVE

The hypothesis was that the levels of circulating inflammatory mediators are related to the degree of volume and pressure stress on the pulmonary vasculature in children with congenital systemic to pulmonary shunts.

DESIGN

Prospective, cross-sectional study.

SETTING

Tertiary center covering all pediatric heart surgery and interventions in Norway.

PATIENTS

Seventy-four children, aged 0-12 years, admitted for surgical or interventional treatment of congenital systemic to pulmonary shunts.

OUTCOME MEASURES

Plasma levels of eight mediators of vascular inflammation and endothelial activation, sampled from different vascular compartments.

RESULTS

Patients with the most pronounced pulmonary flow and pressure stress demonstrated no elevation of inflammatory mediator levels when compared with healthy controls. No pulmonary production or uptake of the measured markers was found. Hemodynamic explanatory factors showed weak correlations to the inflammatory marker levels by univariate analysis. Age was the only factor that significantly explained inflammatory response in the multivariate model. The presence of Down syndrome, irrespective of hemodynamic category, was associated with elevated plasma levels of soluble tumor necrosis factor receptor I, when controlling for age.

CONCLUSIONS

Inflammatory mediators show no significant relationship to pulmonary hemodynamics in children with systemic to pulmonary shunts. Children with Down syndrome may have an increased inflammatory response.

Usefulness of live/real time three-dimensional transthoracic echocardiography in diagnosing acquired left ventricular-right atrial communication misdiagnosed as severe pulmonary hypertension by two-dimensional transthoracic echocardiography

We describe an adult patient with an acquired left ventricular-right atrial communication that was misdiagnosed as severe pulmonary hypertension (PH) by two-dimensional (2D) transthoracic echocardiography, but accurately detected on three-dimensional (3D) transthoracic echocardiography. Open heart surgery confirmed the defect.

Spontaneous closure of perimembranous ventricular septal defect after school age

BACKGROUND

The number of studies of long-term follow up to adolescence is very low on spontaneous closure (SC) of perimembranous ventricular septal defects (P-VSD) in children not undergoing surgical closure because of small left-to-right shunting.

METHODS

Seventy patients with a P-VSD with pulmonary-to-systemic flow ratio (Qp/Qs) < 1.7 underwent cardiac catheterization at the age of 2-10 years (mean, 5.1 years). Excluding 22 patients who dropped out by 15 years, 48 were selected. Qp/Qs ranged from 1.00 to 1.68 (mean, 1.17). The average follow-up period of 37 patients excluding the SC patients was 17.8 years. They were classified according to Qp/Qs into three groups: group I, 1.4 <or= Qp/Qs < 1.7; group II, 1.2 <or= Qp/Qs < 1.4; and group III, 1.0 <or= Qp/Qs < 1.2.

RESULTS

SC occurred in 11 patients (23%). SC rates in group I and II were lower than those in group III (I, 0/8 0%; II, 1/10 10%; III, 10/30 33%). In 23 patients (48%), an aneurysm of the ventricular membranous septum (AVMS) was detected, but no significant relationship was found between the presence of AVMS and SC rate.

CONCLUSIONS

SC occurred in 23% of patients with a P-VSD of Qp/Qs < 1.7 up to adolescence. But a P-VSD of Qp/Qs >or= 1.2 showed no tendency to close spontaneously. The factor most influencing SC of P-VSD after school age seemed to be the shunt ratio.

Pulmonary arterial hypertension in congenital cardiac disease--the need for refinement of the Evian-Venice classification

Pulmonary hypertension associated with congenital systemic-to-pulmonary shunts has been classified, in the Evian-Venice classification, as Pulmonary Arterial Hypertension, which includes a heterogeneous group of conditions. Emerging options for treatment of patients with pulmonary arterial hypertension are related to those with the idiopathic form of the disease, but may also improve quality of life and survival in patients with pulmonary arterial hypertension associated with congenital cardiac disease. Despite the evident similarities in pulmonary vascular disease, it is important also to recognise the differences between patients in whom pulmonary arterial hypertension is the consequence of systemic-to-pulmonary shunts as opposed to those with other conditions. Patients with pulmonary hypertension associated with congenital cardiac disease themselves constitute a heterogeneous population, in which generalisation may be hazardous. Specific considerations need to be given to the type of cardiac diagnosis, the prognosis and evolution of pulmonary vascular disease, and the circulatory physiology before embarking on new strategies for medical treatment in the individual patient. In this review, we highlight the features that require specific attention in these patients. In addition, we discuss briefly the data currently available on the effectiveness of the new anti-proliferative drugs in patients with the Eisenmenger syndrome.

Real‐time three‐dimensional echocardiography provides novel and useful anatomic insights of perimembranous ventricular septal aneurysm

BACKGROUND

Real-time three-dimensional echocardiography (RT3DE) is a new image modality, and it can display a unique image reconstruction in a variety of heart diseases. However, clinical assessment of ventricular septal aneurysm (VSA) by RT3DE has not been reported. This pilot prospective study is to survey what kinds of new insights of VSA can be provided by RT3DE as compared with conventional 2-dimensional echocardiography (2DE).

METHODS

We investigated the diagnostic value of RT3DE and 2DE in 60 consecutive patients with VSA. From different transthoracic windows, structures of interest can be displayed from any orientation through adjusting cropping and slicing the RT3DE datasets. The results were compared with those in 2DE.

RESULTS

RT3DE reconstruction of VSA was feasible in 56 of 60 patients (93%). When compared with 2DE, additional information provided by RT3DE included blood flow through left ventricle to right ventricle, visualization of VSD enface border in 56 patients (93%), morphology of the VSA from apical short axis view in 48 patients (86%), hypertrophied margin of the interventricular septum in 26 patients (43%), dynamic changes of VSA and tricuspid valve in 18 patients (30%), adhesion of chordae tendineae in VSA in 16 patients (26%).

CONCLUSIONS

Structures of interest can be evaluated from unique RT3DE in any orientation during scanning. RT3DE offers additional novel views and has the advantages of not only displaying better visualization of VSA, but also adequately showing the spatial relationship with its adjacent structures. It can provide novel and useful anatomic insights than 2DE while assessing patients with VSA.

Maternal use of acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), and muscular ventricular septal defects

BACKGROUND

Muscular ventricular septal defects (mVSDs) are the most common congenital heart defects. Previous studies have suggested maternal use of acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), and/or fever as risk factors. We evaluated the association between mVSDs and maternal use of acetaminophen or NSAIDs adjusting for fever.

METHODS

Infants with nonsyndromic mVSDs (cases) and without birth defects (controls), with gestational age > or =37 weeks and their mothers were enrolled in the National Birth Defects Prevention Study. Two exposure periods were defined: the first trimester of pregnancy, and one month before pregnancy through delivery. Mothers reporting fever or medication use at least once during either period were considered exposed. Adjusted odds ratios and 95% confidence intervals were estimated independently for each exposure period.

RESULTS

The analysis included 168 cases and 692 controls. Two case groups were evaluated: all mVSD infants (n = 168) (including those with associated minor cardiac defects or noncardiac defects), and infants with isolated mVSDs (n = 133). Mothers of cases were less likely to be African-American than Caucasian (OR, 0.36; 95% CI, 0.18, 0.73). Approximately equal numbers of case mothers and control mothers (10.4 versus 9.7%, respectively) reported at least one febrile episode during the first trimester. Neither acetaminophen nor NSAID exposure was significantly associated with mVSDs. This was true for both case groups and both exposure periods.

CONCLUSIONS

Significant associations were not detected between the occurrence of mVSDs and maternal use of NSAIDs or acetaminophen adjusting for maternal fever, nor were they detected between maternal fever and mVSDs.

Spontaneous closure of ventricular septal defects followed up from <3 months of age

BACKGROUND

This study evaluates the incidence and timing of spontaneous closure (SC) of ventricular septal defect (VSD) using Doppler color flow mapping.

METHODS

A total of 225 infants (mean age 30 days) were diagnosed with uncomplicated VSD: 31 (14%) subpulmonary VSD, 159 (70%) perimembranous, and 35 (16%) muscular. The patients were divided into two groups according to the presence or absence of congestive heart failure (CHF). SC was confirmed with color Doppler.

RESULTS

Surgical closure was performed in 59 patients (26%). SC occurred in 107 patients (48%); three (10%) of 31 with subpulmonary VSD, 75 (47%) of 159 with perimembranous VSD, and 29 (83%) of 35 with a muscular VSD. Average age at SC was 19 months. In three SC patients with a subpulmonary VSD, there was no aortic valve prolapse and no aortic regurgitation. SC occurred in 96% of SC patients with a perimembranous VSD by the age of 6 years, and in 93% of those with a muscular VSD by the age of 3 years. In patients without CHF, the rate of SC was 72%; 23% in subpulmonary VSD, 74% in perimembranous, and 85% in muscular. SC occurred in only 23% of patients with a perimembranous VSD with CHF. Mean age at the final examination was 6.9 years in 59 patients with a VSD remaining open, and 63% of patients with a perimembranous VSD remaining open had an aneurysm of the ventricular membranous septum.

CONCLUSIONS

The SC rate of VSD by mean age of 6.9 years was 48%, but it was 72% in patients without CHF. In patients with CHF, SC was seen only in patients with a perimembranous VSD. The rate of SC was 10% in subpulmonary VSD. The authors contend that SC probably occurred by growth of muscular septum surrounding VSD. Muscular VSD spontaneously closed earlier than perimembranous VSD.

Mechanism of tricuspid regurgitation in paramembranous ventricular septal defect

Literature has been limited in regard to the mechanisms of tricuspid regurgitation (TR) in patients with paramembranous (perimembranous) ventricular septal defect (VSD). Most observations have noted tricuspid valve clefts or dysplasia. We describe another mechanism for production of TR in association with paramembranous VSD. In 8 patients, we found significant TR produced by the VSD jet pushing the tricuspid anterior leaflet forward to open the tricuspid valve orifice. In these patients, a moderate paramembranous VSD extended slightly below the septal tricuspid leaflet with only partial obstruction of the VSD jet. All patients had restrictive VSD with low right ventricular pressure. This mechanism to produce TR was best defined by intraoperative transesophageal echocardiography, but current higher resolution imaging should allow correct diagnosis. We believe that when this mechanism for TR is found in association with a moderate VSD, surgical VSD closure is warranted.

Quantitative assessment of severity of ventricular septal defect by three-dimensional reconstruction of color Doppler-imaged vena contracta and flow convergence region

BACKGROUND

The aim of the present study was to investigate the feasibility and potential value of the computer-controlled, 3D, echocardiographic reconstruction of the color Doppler-imaged vena contracta (CDVC) and the flow convergence (FC) region as a means of accurately and quantitatively estimating the severity of a ventricular septal defect (VSD).

METHODS AND RESULTS

We performed a 3D reconstruction of the CDVC and the FC region in 19 patients with an isolated VSD using an ultrasound system interfaced with a Tomtec computer. The variable asymmetric geometry of the CDVC and the FC region could be 3D-visualized in all patients. The 3D-measured areas of CDVC correlated well with volumetric measurements of the severity of VSD (r=0.97, P:<0.001). Regression analysis between the shunt flow rate (calculated from the product of the area of CDVC and the continuous Doppler-derived velocity time integral) and the corresponding reference results (calculated by cardiac catheterization) demonstrated a close correlation (r=0.95, P:<0.001). There was also a good correlation between shunt flow rates calculated using the conventional 2D, 1-axis measurement of the FC isovelocity surface area with the hemispheric assumption (r=0.95, P:<0.001); shunt flow rates calculated using 3D, 3-axis measurements of the FC region (r=0.97, P:<0.01); and reference results by cardiac catheterization. However, the 2D method substantially underestimated the actual shunt flow rate.

CONCLUSIONS

The 3D reconstruction of the CDVC and the FC region may aid in quantifying the severity of VSD.

The natural history of ventricular septal defects

AIMS

To correlate the size and position of isolated ventricular septal defects with closure rate in a cohort of children with mean follow up of more than six years.

DESIGN

A birth cohort was identified using the northern region cardiac database. The following were noted from case notes: defect size, position, means of closure, and age at closure.

RESULTS

68 children were identified. 49 defects were small, 14 were moderate, and 5 were large. 13 cases required surgical closure, including 12 perimembranous defects. 35 defects closed spontaneously. Nine of the small muscular defects remained open and five of the small perimembranous defects remained open. The spontaneous closure rate for muscular defects was significantly greater than for perimembranous defects. Mean age of follow up for patients who still have defects is 76 months.

CONCLUSIONS

The position of a ventricular septal defect is extremely relevant to its natural history. Perimembranous defects accounted for most of the moderate and large defects that required surgical intervention. After more than six years almost a third of all perimembranous and just over two thirds of all muscular defects closed spontaneously.

Spontaneous closure of muscular ventricular septal defect identified by echocardiography in neonates

Muscular ventricular septal defects were diagnosed by echocardiography in 97 neonates within 7 days of birth. In 82 of the neonates (84.5%), the defect was solitary, while 15 had multiple defects. The solitary defects was located at mid-septal, apical, anterior and inlet locations in 42 (51.2%), 21 (25.6%), 14 (17.1%) and 5 (6.1%) neonates, respectively. Multiple defects occurred in the apical, anterior and mid-septal areas. The diameter of the solitary defects ranged from 1 to 6 mm (2.3 +/- 0.8 mm), while the multiple lesions were 1 to 4 mm in diameter (2.1 +/- 0.8 mm) in 28 instances in which they could measured. It proved possible to follow 79 of the patients for period of 10 to 13 months. The defects closed spontaneously in 56 (84.8%) of 66 patients with a single defect, and in 7 (53.8%) of 13 of those with multiple defects (P<0.05). For the solitary defects, the position and size were factors determining the likelihood and speed of closure. Defects located at the apical septum, or defects larger than 4 mm in diameter, closed slowly and at a later stage. Echocardiography is an useful technique in establishing of natural history of muscular ventricular septal defects encountered in neonates.

Congenital isolated apical ventricular septal defects

The diagnosis of apical ventricular septal defects (VSDs) is difficult and the ratio of spontaneous closure is not well known. At the Ankara University Pediatric Cardiology Department, between the years 1992 and 1997, 33 patients were identified by color-flow Doppler (CFD) imaging as having a small defect at the apical portion of the ventricular septum. The age range was 1 day to 13 years. All patients were asymptomatic with normal telecardiograms and electrocardiograms. There were grade 2-3/6, pansystolic murmurs at the apex or closer to the apex in 19 patients. In 30 patients, narrow and short colored jets were seen at the apex of the heart, distal to the moderator band. The jets were wide in three patients. These defects were difficult to image and required specific angulation of the transducer. Of the 23 patients who had follow-up examinations, at 3 months to 3.5 years, there was spontaneous closure in ten (43.5%). To the authors' knowledge, this report is the largest series of isolated apical trabecular ventricular septal defects (t-VSDs). In their experience, color-flow imaging is more sensitive in detecting a small apical VSD. They conclude that although the closure of apical VSD is not the rule, the prognosis is excellent.

Clinical and echocardiographic evaluation of neonates with heart murmurs

In this study, 116 neonates (58M, 58F), aged 12h to 14d, with heart murmurs were examined by echocardiography: 26 were preterm and 90 full-term neonates. The clinical diagnosis was classified into definite heart disease, possible heart disease and innocent murmur. The final diagnosis was based on echocardiography and, in some cases, cardiac catheterization or surgery. The results showed that 97 (84%) neonates had heart diseases; 19 (16%) had a normal heart, including 7 with tricuspid regurgitation and 9 with physiological peripheral pulmonic stenosis. Out of 88 neonates with clinically definite heart disease, the final diagnosis was changed to normal heart in 9 (10%) cases and the lesion-specific diagnosis was changed in 9 (10%) neonates. In four cases, the clinical diagnosis of ventricular septal defect or pulmonary stenosis was changed to double-outlet right ventricle, single ventricle, hypoplastic left heart syndrome or tetralogy of Fallot. The clinical diagnosis was correct in 77-85% for varying simple lesions. In 5 of 21 neonates with clinically possible heart disease, the diagnosis was changed to normal heart. In one of six neonates with clinically innocent murmurs, the diagnosis was changed to small muscular ventricular septal defect. We concluded that 84% of heart murmurs in neonates were due to heart diseases and only 16% were innocent murmurs. Although clinical evaluation could determine the presence or absence of heart disease in most neonates, the lesion-specific diagnosis was not quite satisfactory. Echocardiography is necessary for neonates with a clinically diagnosed heart disease or possible heart diseases, and may be unnecessary for those with innocent murmurs diagnosed by paediatricians.

High prevalence of muscular ventricular septal defect in preterm neonates

Isolated muscular ventricular septal defect was identified in 9 of 159 consecutive preterm neonates by color Doppler echocardiography, a prevalence of 56.6/1,000 live births. The neonates with ventricular septal defects appear clinically healthy, and in 87.5% of them the defect spontaneously closed within 6 to 11 months. The prevalence and rate of spontaneous closure are similar to those in full-term neonates.

Transaortic approach has a role in the surgical treatment of ventricular septal defects

A transaortic approach was used for surgical closure of ventricular septal defects (VSDs), sometimes as first choice and otherwise as an alternative approach. This paper presents the experience in a group of 124 patients who underwent VSD closure by a transaortic approach in an 18-year-period, between 1974 and 1992. Patients were divided in three groups: (I) Isolated VSD, 89 patients (mean age 7.6 years); (II) VSD associated with other malformations, 27 patients (mean age 10.8 years); and (III) recurrent VSD, eight patients (mean age 15.6 years). Two deaths occurred in the postoperative period (2/124), one after closure of VSD in a patient with severe pulmonary hypertension; another death was observed after transaortic closure of the VSD as part of the repair of a complex heart malformation. There were no instances of new right bundle branch block (RBBB) in the group operated on for isolated VSDs. Three cases of left bundle branch block (LBBB) (3.4%) occurred in the isolated VSD group. There were no cases of complete aortic valve (AV) block in the whole series and no instances of AV dysfunction. The transaortic approach is an alternative for the surgical treatment of ventricular septal defects. The ease of exposure and closure of defects suggest this technique to be a particularly attractive approach in the treatment of small to moderate-sized VSDs and also in recurrent VSDs.

Quantitation of echocardiographic predictors of outcome in infants with isolated ventricular septal defect

Clinical and morphometric features such as ventricular septal defect (VSD) size and location may determine outcome in infants with an isolated VSD. However, no currently available data allow quantitative estimation of the probability of spontaneous closure or surgery in individual patients. To identify independent predictors of outcome and to quantitate the probability of spontaneous closure and surgery in patients with isolated VSD, we studied 156 consecutive infants who had a diagnosis of an isolated VSD between January 1, 1988, and December 31, 1990, and who were subsequently monitored for 28.5 +/- 15 months. Of the 149 patients with membranous (n = 100) and muscular (n = 49) defects who were studied, 46 (31%) patients had spontaneous closure, and an additional 37 (25%) patients underwent surgical repair. Univariate analysis identified defect cross-sectional area indexed to body surface area, location in the muscular septum, presence of Down syndrome, and in membranous defects the presence of aneurysmal tissue as potential predictors of spontaneous closure or surgery. Multiple logistic regression analysis with these candidate variables identified indexed defect cross-sectional area as an independent predictor of spontaneous closure and surgery (p < 0.001). An inverse nonlinear relationship was seen between indexed VSD area and the probability of spontaneous closure (probability = (1 + e[-1.74 + 4.57CSA])-1 and a positive nonlinear relationship between indexed VSD area and the probability of surgery (probability = (1 + e[3.39 - 2.31CSA])-1). Muscular defects were more likely to close spontaneously than membranous defects (odds ratio 2.6, 95% CL = 1.01 - 6.8, p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

High prevalence of muscular ventricular septal defect in neonates

OBJECTIVES

This study sought to use echocardiography to evaluate the prevalence of muscular ventricular septal defect in neonates.

BACKGROUND

Ventricular septal defect is usually asymptomatic and closes spontaneously. An increase in its prevalence has been noted recently. One reason is the improved detection of small defects, especially with the increased used of echocardiography. Therefore, one would expect a higher prevalence in neonates on the basis of echocardiographic screening.

METHODS

Color Doppler echocardiography was performed in 1,053 consecutive neonates 6 to 170 h old at Western Galilee Hospital, Israel. Data on the neonates, parents and family were obtained to analyze the influencing factors. The identified patients were followed up for 1 to 10 months or until ventricular septal defect closure.

RESULTS

Muscular ventricular septal defect was found in 56 (25 male, 31 female) of the 1,053 neonates, a prevalence of 53.2/1,000 live births. All neonates were asymptomatic. Six had a systolic murmur. Electrocardiographic findings were normal in 44 (97.8%) of 45 neonates followed up, and left ventricular hypertrophy occurred in 1 (2.2%). By echocardiography, 50 ventricular septal defects (89.3%) were single and 6 (10.7%) were multiple. The defects (range 1 to 5 mm in diameter, mean [+/- SD] 2.3 +/- 0.8) occurred anywhere along the muscular septum; 43 (76.8%) were detectable only on color Doppler imaging. The left atrium and left ventricle were mildly dilated. Of 45 neonates who were followed up for 6 to 10 months or until closure of the defects, 40 (88.9%) had defects that closed spontaneously. The risk of ventricular septal defect was not significantly associated with gestational age, birth weight, birth order, maternal age, diabetes, smoking, exposure to drugs or infection, paternal age, familial congenital heart disease, religion or consanguinity.

CONCLUSIONS

There is a prevalence of muscular ventricular septal defect in neonates of 53.2/1,000 live births. The patients were asymptomatic, and 88.9% had defects that closed spontaneously within 1 to 10 months. These defects may be caused by environmental factors. In many cases, muscular ventricular septal defect may also result from delayed physiologic development.

Early echocardiographic prediction of symptomatic patent ductus arteriosus in preterm infants undergoing mechanical ventilation

OBJECTIVE

To identify early echocardiographic markers allowing prediction of subsequent symptomatic patent ductus arteriosus (PDA).

METHODS

One hundred sixteen preterm infants ( < 1500 gm) requiring mechanical ventilation underwent echocardiography at a mean postnatal age of 19 hours (range, 7 to 31 hours). Four potential markers were studied: the left atrial to aortic root ratio, pulsed Doppler signal within the course of the duct (ductal diameter), and the direction of postductal aortic diastolic flow. Subsequent ductal closure or significant patency (if suspected clinically) was confirmed echocardiographically.

RESULTS

A significant PDA developed in 42 infants (36%). Ductal diameter was the most accurate echocardiographic marker in predicting subsequent significant most accurate echocardiographic marker in predicting subsequent significant PDA. With a ductal diameter of 1.5 mm or greater there were 34 true-positive, 11 false-positive, 63 true-negative, and 8 false-negative results, giving a positive likelihood ratio of 5.5 and a negative likelihood ratio of 0.22 for prediction of development of a PDA requiring treatment. The sensitivity was 81% and the specificity was 85%. Only one infant older than 28 weeks of gestational age had a significant PDA, and limiting the analysis to infants younger than 29 weeks of gestation further improved the predictive accuracy of ductal diameter. The positive likelihood ratio was 8.1 and the negative likelihood ratio was 0.19, with a sensitivity of 83% and a specificity of 90%.

CONCLUSION

Color Doppler measurement of the internal ductal diameter allows early prediction of significant PDA in preterm infants.

Longitudinal changes in the diameter of the ductus arteriosus in ventilated preterm infants: correlation with respiratory outcomes

This study aimed to examine the early natural history of ductal shunting in ventilated preterm infants (< 1500 g) and to document the association between this shunting and respiratory outcomes. The size of the ductal shunt was assessed in 48 infants using serial echocardiographic measurement of colour Doppler internal ductal diameter and pulsed Doppler postductal aortic diastolic flow (PADF). At all postnatal ages, normal antegrade PADF was invariably seen when the ductal diameter was 1.5 mm or less, and was usually abnormal (absent or retrograde) when more than 1.5 mm. Longitudinal progress of ductal diameter fell into three groups: (i) asymptomatic spontaneous closure (n = 31)--in 20 of these infants closure occurred within 48 hours; (ii) symptomatic PDA which enlarged after a postnatal constriction (n = 9); and (iii) symptomatic PDA that showed minimal postnatal constriction (n = 8). Infants in group 2 were significantly less mature and had PDAs which became symptomatic significantly later than those in group 3. Logistic regression showed that ductal shunting had a significant correlation with mean oxygenation index over the first five days but not with ventilator or oxygen days. Gestation had the most significant association with the latter two variables, with atrial shunting also being related to days in oxygen. The preterm duct displays a wide spectrum of postnatal constrictive activity. Symptomatic PDAs usually showed slower early postnatal constriction. Ductal shunting independently related to short term but not long term respiratory outcomes.

Prevalence, relation to spontaneous closure, and association of muscular ventricular septal defects with other cardiac defects

Previous studies on muscular ventricular septal defect (VSD) have not taken into account the specific defect location in the septum. We retrospectively reviewed all patients with a muscular VSD, with and without associated malformations, diagnosed over 32 months to determine the prevalence and rate of spontaneous closure of single defects in relation to location in the muscular septum. Defects were classified into 4 groups: midmuscular, apical, anterior, and posterior. Two hundred seven patients were identified, of whom 125 had a single defect. The relative prevalence of single muscular VSD was: midmuscular 55 (44%), apical 31 (25%), anterior 33 (26%), and posterior 6 (5%). Thirty patients had signs of spontaneous closure and only 1 underwent surgery. There was no difference in rate of closure with respect to anatomic locations. Patients with multiple muscular VSD were either referred for surgery in the first year of life or had a course similar to patients with a single VSD. Muscular VSD associated with other cardiac malformations was more often encountered in patients with conoventricular VSD and coarctation of the aorta. The distribution of anatomic groups of muscular VSD in association with malformations was similar to the single VSD.

Morphological, haemodynamic, and clinical variables as predictors for management of isolated ventricular septal defect

OBJECTIVE

To assess the predictive impact of morphological, haemodynamic, and clinical variables in the management of patients with isolated ventricular septal defect.

DESIGN

Retrospective analysis of variables by a sophisticated database management system.

PATIENTS AND METHODS

263 consecutive patients with isolated ventricular septal defect diagnosed by echocardiography. The morphological type and haemodynamic character of the ventricular septal defect was characterised in each patient. In addition, variables were introduced to represent the need for diuretics, growth, and potential delay in growth. In 43 patients (16.3%) the ventricular septal defect was closed surgically; 220 patients (83.7%) were managed conservatively and spontaneous closure of the ventricular septal defect occurred in 65 (29.5%). There were no deaths.

RESULTS

All patients managed surgically had non-restrictive defects and were operated on during the first year of life. A few patients with non-restrictive defects were managed conservatively. The two groups differed significantly only with respect to mean growth delay (0.65 (0.27) v 0.9 (0.21), P < 0.001). Only the morphology of the ventricular septal defect significantly (P < 0.001) influenced the probability of closure.

CONCLUSIONS

Findings imply that early surgical closure of ventricular septal defect is indicated in patients with non-restrictive ventricular septal defect and severe growth delay. Other patients should be managed conservatively. In these patients the morphological type of the defect determines the probability of spontaneous closure and provides an estimate of the period over which decreased in size or closure can be expected.

Characterization of aneurysmal transformation in perimembranous ventricular septal defects: an adhered anterior leaflet of tricuspid valve predisposes to the development of left ventricular-to-right atrial shunt

BACKGROUND

The most common type of left ventricular-to-right atrial shunts are those associated with perimembranous ventricular septal defect when the defects diminish in size via aneurysmal transformation. This study is to characterize the echocardiographic features and to determine the possible mechanisms.

METHODS AND RESULTS

From January 1986 to December 1992, of 930 consecutive patients with isolated perimembranous ventricular septal defect, 692 showed evidence of aneurysmal transformation. Excluding those with subaortic ridge, echocardiographic analysis was based on 664 of them. Of these, 94 patients had left ventricular-to-right atrial shunts, 115 had their defects spontaneously closed and in 455 only interventricular shunt persisted. Four types of echocardiographic findings featured in the aneurysmal transformation process: type A, both the anterior and septal leaflets of tricuspid valve contributed to the process; type B was similar to type A, but the arc-like structure from the anterior leaflet is much less evident; in type C, only the septal leaflet, and in type D, other adjacent tissues, contribute to the aneurysmal transformation. Type A morphology was closely associated with the development of left ventricular-to-right atrial shunt while types C and D were most commonly seen in those spontaneously closed defects and those with only interventricular shunt. The vegetations of infective endocarditis were located at the atrial side of the tricuspid valve in patients with left ventricular-to-right atrial shunts, while they were in the right ventricle in those with only interventricular shunt.

CONCLUSION

The morphology of the aneurysmal transformation in perimembranous ventricular septal defect can be characterized by echocardiograms. Although the septal leaflet of the tricuspid valve is usually involved in this process, it is the incorporation of the anterior leaflet that predisposes to the development of left ventricular-to-right atrial shunts.

Increasing incidence of ventricular septal defects caused by improved detection rate

In a population-based study in children born alive during the 10-year period from 1982 to 1991 (n = 22,810), ventricular septal defects (VSDs) were diagnosed in 127 cases, an incidence of 5.6 per 1000. The incidence was significantly higher in the cohort of children born during the 6-year period from 1986 to 1991 than among those born in the preceding 4-year period, 1982-1985 (6.5 and 4.0 per 1000 respectively; p < 0.05). The increase was caused entirely by an increased detection rate of small defects in the muscular part of the interventricular septum after introducing echocardiography as a standard method for investigating suspect congenital heart defects in the neonatal period. This also explained entirely an increase in the total incidence of congenital heart defects to 10.6 per 1000 in the last period from 8.4 per 1000 in the first, although this increase was not significant (p > 0.05). More children born in 1986-1991 had spontaneous closure of their VSDs (75.5%) than those born in 1982-1985 (51.5%) (p < 0.05). In 69.3% of patients the VSDs closed during the first year of life. For the cohort born in 1986-1991, 84.6% of the defects located in the muscular part of the septum closed spontaneously. Small defects in the muscular part of the interventricular septum with spontaneous closure in early life may represent the tail of a normal developmental process, and not defects in the sense of malformations.

Evaluation of ventricular septal defect by transesophageal echocardiography: intraoperative assessment

The miniaturization of transesophageal echocardiography (TEE) probes, together with the development of the capability for biplane imaging from the esophagus, have increased the use of TEE in pediatric cardiology. The aim of this study was to evaluate the TEE findings in patients with ventricular septal defect (VSD) before and after closure primarily by means of pediatric biplane probes. This study group included 69 patients who underwent VSD closure as an isolated repair or as a part of a definitive repair of a more complicated lesion. Ages ranged from 6 days to 15.6 years (median 1 year, 4 months), with operative weights ranging from 2.9 kg to 68 kg (median 10 kg). Preoperative and follow-up transthoracic echocardiograms (TTE) were also performed. Intraoperative TEE was performed without complication in all 69 patients. Preoperative results: (1) anatomic findings: Two muscular VSDs were detected by matrix TEE but could not be observed by TTE. A patient with preoperative TTE diagnosis of an ostium primum ASD was found to have atrioventricular (AV) canal by TEE. In three of six AV canal type VSDs, both TTE and TEE demonstrated left ventricular-right atrial shunting (2) aortic regurgitation associated with VSD: Aortic regurgitation as a result of right coronary cusp prolapse was detected in one of five supracristal VSDs in which the biplane or matrix TEE was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-dimensional reconstruction of ventricular septal defects: validation studies and in vivo feasibility

OBJECTIVES

The purpose of this study was to demonstrate the feasibility of in vivo three-dimensional reconstruction of ventricular septal defects and to validate its quantitative accuracy for defect localization in excised hearts (used to permit comparison of three-dimensional and direct measurements without cardiac contraction).

BACKGROUND

Appreciating the three-dimensional spatial relations of ventricular septal defects could be useful in planning surgical and catheter approaches. Currently, however, echocardiography provides only two-dimensional views, requiring mental integration. A recently developed system automatically combines two-dimensional echocardiographic images with their spatial locations to produce a three-dimensional construct.

METHODS

Surgically created ventricular septal defects of varying size and location were imaged and reconstructed, along with the left and right ventricles, in the beating heart of six dogs to demonstrate the in vivo feasibility of producing a coherent image of the defect that portrays its relation to surrounding structures. Two additional gel-filled excised hearts with defects were completely reconstructed. Quantitative localization of the defects relative to other structures (ventricular apexes and valve insertions) was then validated for seven defects in excised hearts. The right septal margins of the exposed defects were also traced and compared with their reconstructed areas and circumferences.

RESULTS

The three-dimensional images provided coherent images and correct spatial appreciation of the defects (two inlet, two trabecular, one outlet and one membranous Gerbode in vivo; one inlet and one apical in excised hearts). The distances between defects and other structures in the excised hearts agreed well with direct measures (y = 1.05x-0.18, r = 0.98, SEE = 0.30 cm), as did reconstructed areas (y = 1.0x-0.23, r = 0.98, SEE = 0.21 cm2) and circumferences (y = 0.97x + 0.13, r = 0.97, SEE = 0.3 cm).

CONCLUSIONS

Three-dimensional reconstruction of ventricular septal defects can be achieved in the beating heart and provides an accurate appreciation of defect size and location that could be of value in planning interventions.

Implication of aneurysmal transformation in isolated perimembranous ventricular septal defect

Defects on the membranous ventricular septum (perimembranous ventricular septal defect [VSD]) may spontaneously close or diminish in size by "aneurysmal transformation" (i.e., adherence of the tricuspid valve or adjacent tissue onto the VSD). It was recently shown that the appearance of aneurysmal transformation may be associated with subaortic ridges, as well as left ventricular (LV)-to-right atrial (RA) shunts. In all, 877 consecutive patients with isolated perimembranous VSD were retrospectively studied. Results of actuarial analysis showed that patients with a perimembranous VSD had a 98% probability of aneurysmal transformation by the age of 240 months. Of these patients, the expected probabilities of developing LV-RA shunt, spontaneous closure and subaortic ridge were 45, 35 and 6%, respectively. Patients with LV-RA shunts had higher probabilities of developing infective endocarditis (p = 0.002) and persistent left-to-right shunts (p < 0.001). The presence of a subaortic ridge may be accompanied by LV outflow tract obstruction (10 of 25 patients), infundibular pulmonary stenosis (n = 3), or aortic valve deformity or aortic regurgitation (n = 5), and none of those with a subaortic ridge closed spontaneously. It was confirmed that a substantial proportion of aneurysmal transformation of isolated perimembranous VSD is associated with LV-RA shunts and subaortic ridges.

Doppler echocardiographic evaluation of ventricular septal defects in adults

Ventricular septal defects account for 10% to 15% of all congenital heart defects observed in adults. The type of defects observed tend to fall at the extreme ends of the spectrum: small restrictive defects with minimal shunts, and large nonrestrictive defects associated with severe occlusive pulmonary vascular disease. Doppler echocardiography has evolved into a powerful diagnostic modality that comprehensively evaluates the anatomical and pathophysiological consequences of a ventricular septal defect. The spectrum of findings caused by ventricular septal defects is the subject of this review.

Echocardiographic and anatomic correlation of ventricular septal defect morphology in newborn Yucatan pigs

With the use of a Yucatan micropig strain with a high incidence of ventricular septal defects (VSDs), results of two-dimensional and color-flow Doppler echocardiography of VSD morphology in newborn piglets were correlated with autopsy findings. A spectrum of perimembranous, muscular outlet, and doubly committed subarterial VSDs was found. Echocardiography was performed in 29 piglets weighing 1.2 to 4.4 (mean 2.8) kg, studied at age 4 to 18 (mean 8) days. VSD was diagnosed by means of echocardiography in 16 of 29 subjects; morphologic findings included perimembranous defects in 12, muscular outlet in two, and doubly committed subarterial defect in two. At autopsy the presence and location of defects were confirmed in all pigs. No additional defects were found. VSD diameters were 1.0 to 5.0 (mean 3.94) mm on echocardiography and 1.0 to 6.0 (mean 2.84) mm at autopsy. After aortic valve diameter was used as an internal control for tissue shrinkage during fixation, echocardiography/color Doppler imaging tended to overestimate VSD diameter by 21% (0.6 mm). In conclusion, echocardiography/Doppler imaging accurately identified the presence, morphology, and size of even the smallest VSDs in newborn Yucatan micropigs. Echocardiographic classification of VSD morphology in vivo will facilitate future research on specific types of VSDs in this animal model.

Incidence and natural course of trabecular ventricular septal defect: two-dimensional echocardiography and color Doppler flow imaging study

This study was designed to determine the prevalence of trabecular ventricular septal defect (t-VSD) in neonates and to evaluate the effects of its location, morphologic features, and size on its natural course during infancy. One thousand twenty-eight term newborn infants were examined by color Doppler flow imaging with orthogonal ultrasonographic views. Ten girls and 11 boys (2.0%) were found to have t-VSD. The natural course of the defect was examined in 42 consecutive cases, consisting of this group of 21 neonates and another group of 21 neonates with t-VSD. The morphologic features of the defect within the trabecular septum were classified as one or two defects (36 cases) and as a mesh-like defect (six cases). Reduction in size began from the right ventricular side or from within the trabecular septum. Spontaneous closure occurred most commonly during the first 6 months of life and was observed in 32 cases (76%) by 12 months of age: the frequency of closure was not related to the morphologic features and the initial size of the defect, but apical defects tended to have higher persistent patency than did defects in other locations (p less than 0.05). We conclude that the frequency of t-VSD in neonates and the frequency of spontaneous closure during early infancy are higher than previously believed. This information is important for predicting the natural course of t-VSD and deciding on its proper management.

Quantitative assessment of aortic regurgitation by combined two-dimensional, continuous-wave and colour flow Doppler measurements

The width of the regurgitant jet at the aortic valve plane, i.e. the core flow diameter, the ratio of the jet width to the left ventricular outflow diameter, the regurgitant volume and regurgitant fraction were determined using two-dimensional, continuous wave and colour flow Doppler echocardiography. The relationship between the non-invasive measurements and semiquantitative angiographic grading of the regurgitant flow (1 + to 4+) was examined in a primary group of 20 patients with chronic aortic regurgitation. Cut-off points for the non-invasive measurements were selected so as to separate patients with mild or moderate regurgitation (1+ or 2+) from patients with moderately severe or severe regurgitation (3+ or 4+). These cut-off points were prospectively applied in a new group of 35 patients with aortic regurgitation to predict the angiographic grading. Jet width correctly predicted the angiographic grading in 86% of cases, the ratio of the jet width to the outflow diameter in 83% of cases, the regurgitant volume in 86% of cases and the regurgitant fraction in 91% of cases. We conclude that the severity of aortic regurgitation as determined by angiographic grading can be estimated with reasonable accuracy by non-invasive techniques based on colour flow imaging.

Intraoperative transesophageal echocardiography of ventricular septal defect

The accuracy and limitations of intraoperative two-dimensional (2-D) and color Doppler flow mapping transesophageal echocardiography (TEE) of ventricular septal defect (VSD), before and after cardiopulmonary bypass, were analyzed in 62 children. Twenty-one patients had an isolated VSD, and 41 had a VSD plus additional cardiac anomalies. Two-dimensional and color Doppler flow mapping TEE were performed with a miniaturized 5-MHz single (transverse) plane transducer in the 51 of 62 patients weighing less than 20 kg. The remaining 11 were monitored using a single plane adult probe (n = 4) and a biplane (transverse plus longitudinal) probe (N = 7). Prebypass TEE provided a correct diagnosis in 57 of 62 cases (92%) and corrected an erroneous preoperative transthoracic echocardiographic diagnosis in three of 62 cases (5%). Single plane TEE diagnosis was erroneous in five patients: four with doubly-committed subarterial VSD and one with multiple small apical muscular defects and pulmonary hypertension. Biplane TEE (transverse longitudinal) provided clear and complete imaging of the right ventricular outflow tract in all seven cases in whom it was used. Postbypass TEE showed absence of a hemodynamically significant residual VSD in 30 of 40 patients (95%) who underwent VSD patch closure, prospectively identified two of 40 with significant residual VSD, and accurately measured the color Doppler jet width of all residual VSDs. We conclude that hemodynamically significant VSDs can be identified immediately after cardiopulmonary bypass based on the width of the residual VSD color Doppler flow map jet. Therefore, 2-D and color Doppler flow mapping TEE provide an accurate diagnosis in most cases of VSD but may miss doubly-committed subarterial and apical muscular VSD unless biplane TEE is used.

The role of Doppler echocardiography in the diagnosis, follow-up, and management of ventricular septal defects

The defects of the ventricular septum have received special attention from investigators working in echocardiography. The method showed an incomparable capability to identify all the morphological features of the defects. The increasing improvement in definition of transducers associated with conventional and color Doppler contributed significantly to the reliability to detect most of the defects. The great majority of associated lesions can be easily identified and serial examinations allow prediction of which defect may become smaller or even close spontaneously as well as which have acquired deleterious changes in the heart. Several authors have shown very good statistical correlations between echocardiographic indices and hemodynamic parameters in patients with this type of defect. Doppler echocardiography has become an invaluable tool in the diagnosis and follow-up of ventricular septal defect reducing the need for cardiac catheterization and helping management of these patients.

Quantification of left to right shunts by echo Doppler cardiography in patients with ventricular septal defects

Thirty-one patients with ventricular septal defect were evaluated with Echo Doppler cardiography and colour flow mapping. The ventricular septal defect area was estimated by measurement of the jet diameter by colour flow mapping. The ventricular septal defect flow was calculated as the product of the cross-sectional area of the ventricular septal defect and the velocity time integral of flow through the defect. In ten patients the diameter obtained by colour flow mapping was compared with the diameter obtained at angiography, r = 0.88 (SD = 0.14 cm). The aortic flow was calculated as the product of left ventricular outflow tract cross-sectional area and the corresponding velocity time integral. QP/QS ratio was estimated as (ventricular defect flow + aortic flow)/aortic flow and compared to estimates by a radionuclide or oximetric method. A correlation of r = 0.95 (SD = 0.23) was found.