Size Of Ventricular Septal Defect Research Articles

Membranous Septal Aneurysm: An Unusual Cause for Right Ventricular Outflow Tract Obstruction in a Malaligned Ventricular Septal Defect with Aortomitral Discontinuity (Double-Outlet Right Ventricle) Associated with Visceral Heterotaxy

The development of a septal aneurysm in the natural history of membranous ventricular septal defects usually makes the defect hemodynamically less significant. This report describes a case of severe right ventricular outflow obstruction produced by a membranous septal aneurysm in a patient who had an anterior malaligned ventricular septal defect with aortomitral discontinuity (double-outlet right ventricle). This patient did not have pulmonary stenosis other than the dynamic obstruction produced by the septal aneurysm. In this patient, the septal aneurysm produced both favorable and unfavorable hemodynamic effects. A reduction in the size of the ventricular septal defect produced a favorable effect, whereas a right ventricular outflow obstruction led to the unfavorable situation of right ventricular hypertension and hypertrophy. The large septal aneurysm in the presence of an already compromised right ventricular outflow tract related to an anteriorly malaligned septum resulted in severe obstruction.

Invited Commentary

Invited Commentary

Complete heart block associated with device closure of perimembranous ventricular septal defects

The development of the Amplatzer Membranous VSD Occluder (AGA Medical Corp, Plymouth, Minn) for closure of the perimembranous ventricular septal defect has ameliorated many of the technical difficulties of previous devices. Application of this new technology requires comparative evaluation with the current standard of surgical repair. We report our experience of complete heart block associated with device closure of a large perimembranous ventricular septal defect with unequivocal indications for intervention. We performed a retrospective review of 20 patients between January 2003 and August 2005 who underwent perimembranous ventricular septal defect device closure, 18 with hemodynamically large shunts meeting the surgical criteria for intervention. The median age was 1.6 years (range, 0.5-16.2 years), and the median weight was 9.7 kg (range, 6.2-43 kg). Acute complete shunt occlusion was achieved in all patients. There were no acute procedural complications. The median follow-up time was 23.1 months (range, 1-37.8 months). Four (22%) had complete heart block at 17 days, 4.2 months, 8.8 months, and 37.5 months after implantation, respectively. No risk factors were identified for development of complete heart block, including age, weight, trisomy 21, preceding conduction abnormalities, perimembranous ventricular septal defect size related to body surface area or device size, and progressive device flattening. Device closure of large perimembranous ventricular septal defects in infants and children with the Amplatzer Membranous VSD Occluder resulted in excellent closure rates but an unacceptably high rate of complete heart block.

Midterm Assessment of the Reconstructed Arteries After the Arterial Switch Operation

The arterial switch operation is the preferred treatment for transposition of the great arteries (TGA), but there are concerns on the fate of the neoarterial trunks. Ninety-three children were reviewed for functional and morphologic assessment of both reconstructed arteries after the arterial switch operation. Longitudinal analysis focused on neoaortic valve function, neoaortic obstruction, and neopulmonary stenosis as well as on the time-related size changes of both roots, with its clinical implications. Within a mean follow-up of 4.8 +/- 3.9 years, aortic regurgitation of 2 or greater developed in 10% in TGA with intact ventricular septum (IVS) versus 23% in TGA with ventricular septal defect (VSD). A VSD and major pulmonary to aortic annulus size discrepancy were main precursors of early neoaortic valve dysfunction, whereas development of aortic regurgitation of 2 or greater was additionally promoted by the duration of follow-up. Presence of a VSD enhanced neoaortic root enlargement, resulting in a mean root z-score of 3.25 in TGA/VSD versus 1.96 in TGA/IVS. Root dilation was more severe in case of aortic regurgitation of 2 or greater (z = 3.38). Neoaortic obstruction occurred in 8%, mostly at the neosinotubular anastomosis, and correlated with prior pulmonary to aortic ratio greater than 1.5. Concerning the neopulmonary tract, increased flow velocity was observed in 24%, primarily at the supravalvular level. Two patients with pulmonary annulus hypoplasia (z < -2) required early reintervention. Regarding clinical outcome, freedom from reintervention at 1, 5, and 10 years was, respectively, 98%, 96%, and 96% for TGA/IVS, versus 65%, 63%, and 63% for TGA/VSD. A VSD and aortic arch obstruction were significant predictors for reintervention. After arterial switch operation, the neoaortic root is usually enlarged, but with a growth pattern comparable to that of a normal population. The association of a VSD and major arterial root size discrepancy predisposes to both neoaortic valve dysfunction and root enlargement. Severe root dilation appears to be closely related to significant neoaortic valve regurgitation, mainly as a result of a time-depending and reciprocal process. Neopulmonary stenosis is a frequent finding, but rarely has clinical consequences. Because the factor "time" is the principal determinant of late neoaortic valve dysfunction and root dilation, strict serial surveillance after arterial switch operation is mandatory.

Reappraisal of Left Ventricular to Right Atrial (LV-RA) Shunt in Pediatric Patients With Isolated Perimembranous Ventricular Septal Defect

The purpose of this study was to investigate the follow-up results of perimembranous ventricular septal defect (VSD) with left ventricular to right atrial (LV-RA) shunt since infancy and to analyze the morphologic variations of this shunt. The study group comprised 232 consecutive pediatric patients with isolated perimembranous VSD and aneurysm, of whom 134 (58%) had LV-RA shunts. Follow-up echocardiography was performed to assess for the size of both the VSD and LV-RA shunt. There were no significant differences between groups in terms of sex, age at the initial echocardiography, follow-up period, number of patients with tricuspid regurgitation, and initial VSD size. There was a significant difference between groups in spontaneous closure (p=0.039). The event-free probability (no surgical repair of the defect) was not significantly different between the groups (p=0.129). Perimembranous VSD with LV-RA shunt in infancy is common and associated with less chance of spontaneous closure. Color Doppler echocardiography can greatly improves the diagnostic efficacy and assist in understanding the mechanisms leading to this particular anomaly.

Short- and mid-term outcomes of arrhythmia after transcatheter and surgical closure of membranous ventricular septal defects: a comparative analysis

To evaluate the short- and mid-term outcomes of arrhythmia in patients undergoing transcatheter and surgical closure of membraneous ventricular septal defect (VSD). 358 VSD patients, 161 male and 197 female, aged (11 +/- 8), underwent transcatheter closure and 50 sex, age, body weight, size of membranous VSD, and percentage of complicated membranous aneurysm-matched VSD patients underwent surgical closure. Electrocardiography was conducted 1, 3, 6, and 12 months after VSD closure. Except bundle branch block other kinds of arrhythmia were resolved in all the patients prior to discharge. The arrhythmias occurring in the patients who underwent transcatheter closure of VSD included complete right bundle branch block (CRBBB, 4 5%), incomplete right bundle branch block (IRBBB, 10.1%), left anterior fascicular block (LAFB, 2.8%), IRBBB complicated with LAFB (1.7%), and CRBBB complicated with LAFB (0.6%), while in the patients who underwent surgical closure included CRBBB (26%) and IRBBB (28%). At the end of 12 months of follow-up, of the 180 patients who had undergone interventional therapy 6 showed CRBBB (3.3%), 6 showed IRBBB (3.3%), 3 showed CRBBB complicated with LAFB (1.7%) and one showed third degree auriculo-ventricular block (0.56%) s, however, no significant change in the ECG findings occurred in the patients who had undergone surgical closure. Transcatheter occlusion of membraneous VSD is safer than surgical closure. IRBBB and LAFB caused by interventional therapy are benign, the majority of which may resolve itself 6 - 12 months after the procedure. However, CRBBB and CRBBB complicated with LAFB need a long-term follow-up.

The utility of the general practice research database to examine selected congenital heart defects: a validation study

The purpose of this research was (1) to validate that ventricular septal defect (VSD), tetralogy of Fallot (TOF), and coarctation of the aorta (COA) can be studied in the UK General practice research database (GPRD) and (2) to understand which of the available GPRD components (computerized medical records, questionnaires, and maternal/infant free text) provide maximal information about these heart defects. Using a practitioner questionnaire, the positive predictive value (PPV) of the computerized medical record for VSD, TOF, and COA were determined. Both infant and maternal free text was examined. Concordance between the infant free text information and questionnaires was calculated. The proportion of infant information captured in the maternal free text was determined. A 93% response rate was achieved. Based on questionnaire responses, an overall PPV of 93.5% was achieved (VSD = 95%, TOF = 90%, COA = 100%). Approximately half of the records contained infant free text information including information on the type and size of VSD, echocardiogram findings, and surgery. Concordance between the infant's free text and questionnaire information occurred in most of the cases (92-100%). The proportion of infant information in the maternal free text was low (4-19%). The GPRD computerized medical records are sufficient to assess VSD, TOF, and COA. This study confirms that maternal free text provides a low yield of limited information pertaining to the infants' defect, while the infant free text may provide an additional information usually obtainable from practitioner questionnaires. The information provided by an infant free text may limit the need for practitioner questionnaire validation.

Transcatheter closure of congenital ventricular septal defects: results of the European Registry

To report the experience of 23 tertiary referral European Centres on transcatheter closure of congenital ventricular septal defects (VSD). Implantation of transcatheter devices was attempted in 430 patients (pts) with congenital VSDs until July 2005. The following anatomic types were present: 119 muscular, 250 perimembranous, 16 multiple, 45 residual post-surgery. Median VSD size was 7 mm (range 3-22), fluoroscopy time 33 min (range 3-146). Devices implanted were Amplatzer muscular or membranous devices in 364, PDA devices in 12, ASD devices in seven, Starflex in seven, and coils in nine patients. Procedure was successful in 410 cases (95%). device embolization in five cases (surgery in two, catheter retrieval in three), aortic regurgitation in 14 cases (two of which requiring surgery), tricuspid regurgitation in 27 cases (no surgery was necessary), minor rhythm disturbances in 10 pts, death in one patient, complete heart block (cAVB) in 16 pts [perimembranous 12 of 250 (5%), muscular one of 119 (0.8%), residual post-surgery VSD three of 45 (6.7%)]. CAVB was transient in six patients, requiring permanent pace-makers in 10 cases (3.8%) (six early, four late). In the multivariate analysis, the only variable associated with a risk of the occurrence of complication was age (P=0.012) and weight (P=0.0035). In the univariate analysis, risk factors for the development of cAVB were, device type (P=0.03) and VSD location (P=0.05). After the multivariable Cox proportional hazards analysis, no risk factor was found. Transcatheter closure of congenital VSDs offers encouraging results. COMPLICATIONS are limited; the most relevant one seems to be the device related to cAVB in perimembranous VSD. More experience and long-term follow-up are mandatory to assess safety and effectiveness of this procedure as an alternative to conventional surgery.

Does patch closure of subarterial ventricular septal defect affect the growth of pulmonary valve?☆

Patch closure of the subarterial ventricular septal defect requires suture placement at the pulmonary annulus. We aimed to identify whether patch closure of subarterial ventricular septal defect would affect the growth of pulmonary annulus in comparison with that of perimembranous ventricular septal defect. Of 361 patients who underwent patch closure of ventricular septal defect from January 1992 to December 1999, 98 (51 subarterial, 47 perimembranous) had echocardiographic data available for measurement of both preoperative and postoperative (more than 5 years after operation) pulmonary and aortic annular diameters. The pulmonary/aortic annular diameter ratio and their growth rates in the subarterial group were compared with those in the perimembranous group. The perioperative variables correlated with the pulmonary annular growth in subarterial group were also identified. The mean follow-up duration was 7.2 years. Preoperative pulmonary/aortic annular diameter ratio was 1.45 (range, 0.94-2.31) in the subarterial group and 1.57 (range, 1.15-2.51) in the perimembranous group (p=0.059). The latest postoperative ratio was significantly lower in the subarterial group [subarterial: 1.02 (range, 0.77-1.41) vs perimembranous: 1.36 (range, 1.11-1.75), p<0.01]. Twenty-three patients (45%) in the subarterial group had the ratio less than 1. The pulmonary annular growth rate in the subarterial group was lower than that in the perimembranous group (subarterial: 0.34 mm/year, perimembranous: 1.03 mm/year, p<0.01). Preoperative pulmonary/aortic annular diameter ratio (r=0.885, p<0.01), age at operation (r=-0417, p<0.01), weight at operation (r=-0.357, p<0.05), and ventricular septal defect size (r=0.298, p<0.05) were found to have correlation with pulmonary annular growth in the subarterial group. Our data show that pulmonary annular growth after patch repair of subarterial ventricular septal defect is suboptimal compared with perimembranous ventricular septal defect. Careful attention must be paid to the possible late clinical implication caused by impaired pulmonary annular growth after patch repair of subarterial ventricular septal defect.

Feasibility and Accuracy of Real-time 3-Dimensional Echocardiographic Assessment of Ventricular Septal Defects

The aim of this study was to evaluate feasibility, accuracy, and clinical applicability of real-time (RT) transthoracic 3-dimensional (3D) echocardiography (3DE) in the determination of the position, size, and shape of a ventricular septal defect (VSD). In all, 34 patients (age: 2 months-46 years), who were scheduled for surgical closure of a VSD, were enrolled in the study. VSD localization, shape, and dimensions were assessed and compared with measurements performed by the surgeon. Acquisition of RT-3DE datasets was feasible in 30 of 34 (88%) patients. Duration of 3D data acquisition was 6 +/- 2 minutes. Reconstruction time was 23 +/- 16 minutes. Localization and number of VSD were determined correctly by RT-3DE in all patients. There was a good correlation for VSD measurements between RT-3DE and operation (r = 0.95). RT-3DE allows accurate determination of VSD size, shape, and location. The short acquisition time and acceptable reconstruction time make this technique clinically applicable.

Real-time 3-dimensional echocardiography in assessing atrial and ventricular septal defects: An echocardiographic-surgical correlative study

Objective The aim of this study is to explore the feasibility and the value of real-time 3-dimensional echocardiography (RT3DE) in quantitative evaluation of the size of atrial septal defect (ASD) and ventricular septal defect (VSD) and to correlate with the surgical findings. Methods Thirty eight patients with ASD and/or VSD were examined with RT3DE. Three-dimensional image data-base was post-processed using 3D work-station. The results were compared with the results measured by 2-dimensional echocardiography and surgical findings. Results RT3DE produced novel views of congenital septal defects and improved quantification of the size of the defect. The sizes obtained from 3DE have better correlation with surgical findings than diameter measured by 2-dimensional echocardiography ( r = 0.69 vs r = 0.92). Conclusions RT3DE offers additional special information in congenital heart disease without extending examining time, permits quantitative recording of septal defect dynamics, and enhances the understanding of complex cardiac anatomy and elucidation of the disease mechanism. It is a potentially valuable clinical tool for diagnosing and managing patients with congenital heart disease.

Ventricular septal defect closure in tetralogy of Fallot: the aortic rule

Ventricular septal defect (VSD) closure is an important part of the surgical repair of tetralogy of Fallot and related anomalies. Visual appreciation of the VSD size (either transinfundibular or transatrial) can be misleading. My colleagues and I describe a simple and precise way to predict the size and shape of the VSD patch before extracorporeal circulation: the patch should be circular with a diameter identical to that of the mid ascending aorta.

Device closure of muscular ventricular septal defects using the Amplatzer muscular ventricular septal defect occluder: Immediate and mid-term results of a U.S. registry

ObjectivesWe sought to report the results of a U.S. registry of device closure of congenital muscular ventricular septal defects (VSDs) using the new Amplatzer mVSD occluder (AGA Medical Corp., Golden Valley, Minnesota). BackgroundMuscular VSDs pose a significant surgical challenge with increased morbidity and mortality. MethodsData were prospectively collected from 83 procedures involving 75 patients who underwent an attempt of percutaneous (70 [93.3%] of 75) and/or perventricular (surgical) (6 [8.0%] of 75) device closure of hemodynamically significant muscular VSDs. The patients' median age was 1.4 years (range 0.1 to 54.1 years). Outcome parameters were procedural success, evidence of residual shunts on echocardiography, and occurrence of procedure-related complications. The median follow-up was 211 days (range 1 to 859 days). ResultsThe median size of the primary VSD was 7 mm (range 3 to 16 mm) and in 34 of 78 (43.6%) procedures, patients had multiple VSDs (range 2 to 7). The device was implanted successfully in 72 of 83 (86.7%) procedures. In 17 of 83 (20.5%) procedures, multiple devices were implanted (range 2 to 3). Procedure-related major complications occurred in 8 of 75 (10.7%) patients. Device embolization occurred in two patients and cardiac perforation in one patient. There were two (2.7%) procedure-related deaths. The 24-h postprocedural complete closure rate was 47.2% (34 of 72 patients), increasing to 69.6% (32 of 46 patients) at 6 months and 92.3% (24 of 26 patients) at 12 months. Six patients underwent successful closure using the perventricular surgical (beating heart) approach, with complete closure at day 1 in three patients and trivial/small residual shunts in the remainder of the patients. ConclusionsThe Amplatzer mVSD device (AGA Medical Corp.) offers excellent closure rates and low mortality when used to close congenital muscular VSDs. The device appears to be safe and effective.

Surgical Treatment of Ventricular Septal Defect Complicating Acute Myocardial Infarction. Experience of a North Italian Referral Hospital

The purpose of our study was to evaluate the clinical outcome of postinfarction ventricular septal defect (VSD) of patients referred to our institution for surgical treatment, by assessing the role of several operative, pre- and post-operative variables on mortality. The medical records of 58 consecutive patients (mean age 73±7 years), operated on after 14±12 days from the acute myocardial infarction were retrospectively reviewed and the data were analyzed. Associated procedures were left ventricular reconstruction in 13 patients and aortocoronary bypass grafting in 47 (81%). The overall operative, in-hospital mortality rate was 52% (75% in patients operated on within the first week and 16% if time from infarct to surgery was &gt;3 weeks). Time from AMI to surgery and time from hospital admission to operation were significantly shorter in nonsurvivors ( p=0.003 and 0.012, respectively). Other pre-operative variables significantly associated with mortality were: cardiogenic shock, pulmonary pressure, VSD diameter. In conclusion, time from AMI to operation appears to be a very important prognostic factor. However, size of VSD and hemodynamic conditions significantly influence the mortality. Moreover, concomitant procedures of revascularization can be safely performed, when required, as actually occurs in most cases.

Surgical treatment of ventricular septal defect complicating acute myocardial infarction. Experience of a north Italian referral hospital

The purpose of our study was to evaluate the clinical outcome of postinfarction ventricular septal defect (VSD) of patients referred to our institution for surgical treatment, by assessing the role of several operative, pre- and post-operative variables on mortality. The medical records of 58 consecutive patients (mean age 73±7 years), operated on after 14±12 days from the acute myocardial infarction were retrospectively reviewed and the data were analyzed. Associated procedures were left ventricular reconstruction in 13 patients and aortocoronary bypass grafting in 47 (81%). The overall operative, in-hospital mortality rate was 52% (75% in patients operated on within the first week and 16% if time from infarct to surgery was >3 weeks). Time from AMI to surgery and time from hospital admission to operation were significantly shorter in non-survivors ( p=0.003 and 0.012, respectively). Other pre-operative variables significantly associated with mortality were: cardiogenic shock, pulmonary pressure, VSD diameter. In conclusion, time from AMI to operation appears to be a very important prognostic factor. However, size of VSD and hemodynamic conditions significantly influence the mortality. Moreover, concomitant procedures of revascularization can be safely performed, when required, as actually occurs in most cases.

Morphology of single ventricle

Single ventricle is a group of abnormalities with atrioventricular alignment consisting of double inlet or common inlet ventricle (or, rarely, straddling tricuspid valve), in which there is only one ventricular sinus. Single left ventricles have a large morphologic left ventricle and a diminutive right ventricular infundibulum on the other side of a morphologic ventricular septum, thus forming an outlet chamber. Typically single left ventricles have transposition of the great arteries, i.e. pulmonary artery arising from the large left ventricle and aorta from the right ventricular outlet chamber. Various forms of outflow obstruction related to atrioventricular valve tissue, conal development or ventricular septal defect size are discussed. Single right ventricles have only a morphologic right ventricle with no outlet chamber. The majority are associated with abdominal heterotaxy syndrome, predominantly with asplenia. A number of conditions with similar hemodynamics but with one dominant ventricle and a second rudimentary ventricular sinus or with atrioventricular valve atresia are termed functional single ventricles and will be mentioned briefly for comparison with the true single ventricles.

Growth parameters and endocrine function in relation to echocardiographic parameters in children with ventricular septal defect without heart failure.

To determine the effect of ventricular function, size of ventricular septal defect (VSD), and endocrine function on linear growth in children with VSD, we studied 88 children with VSD over a period of 1 year. Growth was assessed by determining the height standard deviation scores (HtSDS) and growth velocity (GV) every 4 months. Two hundred age-matched normal children served as controls for the growth data. Endocrine evaluation was performed in 30 randomly selected children with VSD, and 20 age-matched children with constitutional delay of growth (CSS). Growth hormone (GH) response to clonidine provocation was evaluated and circulating free thyroxine (FT4) and insulin-like growth factor-I (IGF-I) concentrations measured. Echocardiographic evaluation of the different cardiac parameters including shunt size and shunt fraction (Qp/Qs) was performed using a colour-coded echodoppler. The HtSDS, body mass index (BMI), and mid-arm circumference (MAC) of children with VSD were significantly decreased compared to those for the normal control group. The dietary intake evaluated by the recall method, appeared to be adequate in the majority of these children (83/88). IGF-I concentrations were reduced in children with VSD (87.5 +/- 29 ng/ml) versus normal age-matched children (169 +/- 42 ng/ml). Basal and clonidine-stimulated GH concentrations were significantly higher in children with VSD (4.6 +/- 2.1 microg/l and 28.8 +/- 7.9 microg/l respectively) versus controls (17.8 +/- 4.2 microg/l). In these patients (n = 88) the HtSDS was correlated negatively with the size of the shunt (r = -0.793, p < 0.001), shunt fraction (Qp/Qs) (r = -0.76, p < 0.001), pulmonary mean gradient (r = -0.4, p = 0.006), and pulmonary maximum velocity (r = -0.32, p = 0.02). Growth velocity (GV) was correlated negatively with pulmonary maximum gradient (r = -0.3, p = 0.02), pulmonary maximum velocity (r = -0.37, p = 0.007), and pulmonary stroke volume (Qp) (r = -0.345, p = 0.01). The BMI and IGF-I concentrations were correlated significantly with the size of the shunt (r = -0.453, p < 0.01), Qp/Qs (r = -0.432, p < 0.01), HtSDS (r = 0.565, p < 0.01), and BMI (r = 0.435, p < 0.01). It appears that in patients with VSD, the size of the left-to-right shunt and the abnormal hemodynamics in the pulmonary circulation are important factors in the etiology of impaired growth. It is suggested that the hypermetabolic status of these patients compromise nutrition and this decreases IGF-I synthesis with subsequent slowing of linear growth and weight gain.

Noninvasive prediction of pulmonary artery pressure in patients with isolated ventricular septal defect.

Management of patients with isolated ventricular septal defect (VSD) requires information regarding pulmonary artery pressure (PAP). The purpose of this study was to evaluate the individual predictive value of noninvasive methods for assessment of PAP and to determine if any combination of techniques significantly improved their predictive power. We reviewed the clinical history, electrocardiogram, and echocardiogram of 31 patients (age 1.9 +/- 1. 73 years) who underwent catheterization for isolated VSD. Noninvasive data were compared for patients with mean PAP <20 mmHg (group 1) and those with mean PAP > or =20 (group 2) at catheterization. Fourteen (45%) patients were in group 1 and 17 (55%) in group 2. Doppler estimation of VSD gradient, right ventricular hypertrophy by echocardiogram, interventricular septal orientation, and VSD size had predictive value for elevated mean PAP (p < 0.01). All patients (n = 6) with normal findings in all four variables had normal PAP. All patients (n = 12) with at least three of four abnormal findings had elevated PAP. Six patients in group 1 had at least one variable that incorrectly predicted high PAP, whereas 3 patients with normal findings on three of the four variables nevertheless had elevated PAP. No single noninvasive variable accurately predicted PAP in all cases. However, normal findings for all four significant variables did predict normal PAP and suggest that cardiac catheterization is unnecessary in that setting. However, any other combination of normal and abnormal findings for the four significant variables did not reliably predict PAP and such patients may require catheterization to directly measure PAP.

Regression of right ventricular pressure in ventricular septal defect in infancy: a longitudinal color-flow Doppler echocardiographic study.

To determine the course of right ventricular pressure (RVP) in patients with isolated ventricular septal defect (VSD) and factors influencing it, unselected 148 infants were followed-up longitudinally with color-Doppler echocardiography from a median age of 1 month for 201 patient-years. The patients were divided into three groups by absolute echographic size of VSD: group I, </=4.0 mm; group II, >4 to </=7 mm; group III, >7 mm. Sixty percent belonged to group I. Muscular defects dominated in group I, perimembranous defects dominated in group II, and those with outlet extensions dominated in group III. Peak systolic RVP was obtained by Doppler-estimated difference between systolic brachial artery and peak gradient across the VSD. Initial RVP ranged between 15 and 95 mmHg and increased in parallel to the size of defect. According to the regression equations RVP decreased in general by 0.17 mmHg per month. This correlated significantly with the size of the defect. In group I, the rate of decrease was very fast and is best expressed by a log function of time (r = -0.67, r(2) = 0.45). In groups II and III the rate of decrease was less steep and had a greater variability. RVP normalized in 100% in those of group I and in 90% of group II, at median ages of 0.17 and 0.33 years, respectively. Median Q(p):Q(s) values were 1.5, 2.2, and 3.0 in groups I-III, respectively. The outcome depended on the size of VSD. Spontaneous closure was observed in 51% of group I, 10% of group II, and none of group III. The rate was higher in muscular defects. Congestive heart failure was present in 53% and 100% in groups II and III, respectively. Death rate was 2.03%, all in patients with large defects. It is concluded that the temporal course of RVP with time can be estimated fairly well by the regression equation presented in relation to the initial size of the VSD.

Magnetic resonance imaging of complex congenital heart disease.

Current MR techniques enable both anatomical and functional evaluations of the heart. Although it is rarely used as a primary diagnostic tool in pediatric cardiology, it can be used as a valuable adjunct to echocardiography and angiography. MRI is particularly useful in clarification of morphology of complex congenital heart diseases. It is the most accurate method of determination of visceral and atrial situs. It is easy to evaluate the systemic and pulmonary venous connections that are very important for the Fontan type of operation, especially in patients with visceral heterotaxy. It facilitates demonstration of diminutive pulmonary arteries in patients with pulmonary atresia. It clearly demonstrates juxtaposition of the atrial appendages that is often missed by echocardiography. The anatomy of the twisted atrioventricular connections is much more clear in MRI than in echocardiography. It enables en face imaging of ventricular septal defect that provides a surgical view. We find en face imaging particularly helpful in patients with double inlet left ventricle and transposition of the great arteries where the size of the ventricular septal defect governs the blood flow into the aorta. It is often advantageous to echocardiography in defining the type of univentricular atrioventricular connections by demonstrating the position and topology of the rudimentary chamber in difficult cases. In double outlet right ventricle, the spatial relationship of the ventricular septal defect to the great arterial valves can be clearly defined by visualizing the ventricular septal defect and the outlet septum in the same imaging plane.