Atrial Septal Defect Group Research Articles

The Poor Performance of RSR′ Pattern on Electrocardiogram Lead V1 for Detection of Secundum Atrial Septal Defects in Children

To assess the accuracy of RSR' patterns in lead V1 (RSR'-V1) in diagnosing atrial septal defects (ASDs) in children. Children who underwent an electrocardiogram (ECG) during 2010 were divided into 2 ECG groups: RSR'-V1 and normal (no RSR'-V1). Children who underwent an echocardiogram during 2010 were also divided into an ASD group and a normal echocardiogram group. The 4 groups were matched in a 2 × 2 table format where the RSR'-V1 was the "test" and ASD was the "disease." Sensitivity, specificity, positive/negative predictive values, and pre/post-test probabilities were calculated. There were 4658 ECG studies included in the analysis: 836 had RSR'-V1 and 3822 were normal without RSR'-V1. Of 4935 echocardiographic studies analyzed, 329 had an ASD and 4606 were normal; 1363 patients had both studies done during the study period. The ECG sensitivity for diagnosing an ASD was 36.1%, specificity was 80%, positive predictive value was 14.7%, and negative predictive value was 92.9% with an overall accuracy of 76.2%. Patients with ASD and RSR'-V1 were significantly older than patients with ASD and no RSR'-V1 pattern. RSR'-V1 is a poor screening test for the detection of ASD. It should not change the clinical suspicion or the decision to obtain an echocardiogram. Older children without RSR'-V1 on ECG are unlikely to have an ASD.

The Efficacy and Safety of Sildenafil in Patients With Pulmonary Arterial Hypertension Associated With the Different Types of Congenital Heart Disease

The difference in underlying pathophysiology in different congenital heart disease (CHD) may have an influence on clinical outcome. It remains unclear whether the effect of sildenafil on pulmonary arterial hypertension (PAH) varies in different types of CHD. The potential effect of sildenafil on pulmonary arterial hypertension related to CHD may be associated with shunt location. In this 12-week, prospective, open label, multicenter trial, 55 patients with CHD were divided into the 3 groups: atrial septal defects group (ASD, n = 15), ventricular septal defects group (VSD, n = 24), and patent ductus arteriosus group (PDA, n = 16). Exercise capacity, hemodynamic parameters, and arterial oxygen saturation were assessed at baseline and after sildenafil therapy (25 mg, 3 times daily). Six-minute walk distance significantly increased from 377.2 ± 68.7 m to 436.0 ± 70.4 m in patients with ASD, from 371.2 ± 66.0 m to 413.7 ± 83.1 m in VSD, and from 384.3 ± 90.2 m to 440.9 ± 71.8 m in PDA (P<0.01, respectively). Moreover, sildenafil also improved the pulmonary vascular resistance and pulmonary blood flow index in the 3 groups, whereas no significant changes in systemic vascular resistance and systemic arterial pressure were observed. However, arterial oxygen saturation was significantly improved in the ASD group only. The incidence of adverse events was similar among the 3 groups. Sildenafil therapy seems to be effective and safe for PAH secondary to ASD, VSD, and PDA, although some clinical and hemodynamic parameters were changed in a different manner among the 3 groups.

Infl uence of percutaneous transcatheter closure of an atrial septal defect on the atrioventricular conduction

Objective This study aimed at determining the eff ect of percutaneous ASD closure on the AV conduction. Percutaneous closure of ostium secundum atrial septal defects (ASDs) has been widely accepted and has become the standard treatment of this malformation. However, some complications have been reported. Because of the close proximity between the discs of the device and the atrioventricular (AV) node, atrioventricular conduction disturbances (AVCD) are a likely complication.Methods and results From the database of congenital heart disease, 46 patients (mean age 54 ± 12 y) who underwent percutaneous ASD closure and 46 patients who underwent a percutaneous patent foramen ovale (PFO) closure were matched according to age, gender and follow-up time. Demographic, clinical, biochemical, and ECG variables were compared.Before closure, the PR interval in the ASD group was signifi cantly longer than in the PFO group (169 ± 22 ms versus 158 ± 25 ms, P= 0.031), which persisted after a mean follow-up time of 4.5 years (180 ± 39 ms versus 163 ± 23 ms, P= 0.007). PR interval increased signifi cantly from closure to latest follow-up in the ASD (P= 0.038), but not in the PFO group (P= 0.058).Conclusions ASD patients presented with signifi cantly longer PR interval than PFO patients before closure. In contrast with the PFO group, the PR interval increased in the ASD group after medium-term follow-up. These fi ndings indicate the need for further follow-up after ASD repair in order to detect potential late AVCD.

Outcomes of inferior sinus venosus defect repair

Inferior sinus venosus defect is an unusual form of interatrial communication with few published data on surgical outcomes. We sought to compare outcomes of surgical repair of inferior sinus venosus defect with those of large secundum atrial septal defects. Patients undergoing surgical closure of an isolated interatrial defect were reviewed, and those with inferior sinus venosus defect were identified on the basis of predetermined anatomic criteria. For each case, 2 controls with secundum atrial septal defect, matched for age and year of surgery, were selected. Technical outcome scores and other perioperative outcomes were compared. Compared with the secundum atrial septal defect group (n = 90), the inferior sinus venosus defect group (n = 45) had worse technical outcome scores (P = .02), a higher rate of reintervention (9% vs 1%, P = .04), longer median total cardiopulmonary bypass (48 vs 39 minutes, P < .001) and crossclamp (29 vs 20 minutes, P < .001) times, and were more likely to stay more than 1 day in the intensive care unit (20% vs 8%, P = .04) and more than 3 days in the hospital (29% vs 13%, P = .03). Only 16 (36%) of the patients with inferior sinus venosus defect had a correct diagnosis preoperatively. Patients with an incorrect diagnosis had worse technical outcome scores than the secundum atrial septal defect group (P = .003), whereas those with a correct diagnosis had scores similar to those of the secundum atrial septal defect group (P = .55). Compared with patients with secundum atrial septal defect, patients with inferior sinus venosus defect have more residual defects and longer durations of cardiopulmonary bypass and hospitalization. Rates of misdiagnosis of inferior sinus venosus defect are high and associated with worse technical outcome scores. Accurate preoperative diagnosis of this lesion may lead to improved outcomes.

Cardiovascular magnetic resonance tagging of the right ventricular free wall for the assessment of long axis myocardial function in congenital heart disease.

BackgroundRight ventricular ejection fraction (RV-EF) has traditionally been used to measure and compare RV function serially over time, but may be a relatively insensitive marker of change in RV myocardial contractile function. We developed a cardiovascular magnetic resonance (CMR) tagging-based technique with a view to rapid and reproducible measurement of RV long axis function and applied it in patients with congenital heart disease.MethodsWe studied 84 patients: 56 with repaired Tetralogy of Fallot (rTOF); 28 with atrial septal defect (ASD): 13 with and 15 without pulmonary hypertension (RV pressure > 40 mmHG by echocardiography). For comparison, 20 healthy controls were studied. CMR acquisitions included an anatomically defined four chamber cine followed by a cine gradient echo-planar sequence in the same plane with a labelling pre-pulse giving a tag line across the basal myocardium. RV tag displacement was measured with automated registration and tracking of the tag line together with standard measurement of RV-EF.ResultsMean RV displacement was higher in the control (26 ± 3 mm) than in rTOF (16 ± 4 mm) and ASD with pulmonary hypertension (18 ± 3 mm) groups, but lower than in the ASD group without (30 ± 4 mm), P < 0.001. The technique was reproducible with inter-study bias ± 95% limits of agreement of 0.7 ± 2.7 mm. While RV-EF was lower in rTOF than in controls (49 ± 9% versus 57 ± 6%, P < 0.001), it did not differ between either ASD group and controls.ConclusionsMeasurements of RV long axis displacement by CMR tagging showed more differences between the groups studied than did RV-EF, and was reproducible, quick and easy to apply. Further work is needed to assess its potential use for the detection of longitudinal changes in RV myocardial function.

E0685 Evaluate right ventricular shape and function in patients with atrial septal defect by single-beat real-time three-dimensional echocardiography sRt3DE

ObjectiveThe current study was the first in China to investigate the value of single-beat real-time three-dimensional echocardiography (sRt-3DE) in assessing the shape and function of right ventricle in Patients with...

Different Determinants of Residual Tricuspid Regurgitation after Tricuspid Annuloplasty: Comparison of Atrial Septal Defect and Mitral Valve Prolapse

We analyzed 20 patients with atrial septal defect (ASD) who underwent tricuspid valve (TV) annuloplasty and ASD closure, 21 patients with mitral valve prolapse (MVP) who underwent mitral valve (MV) and TV annuloplasty, and 20 healthy controls. Severity of tricuspid regurgitation (TR) was assessed by maximal TR jet area/RA area (%TR) using echocardiography before and early after surgery. Before surgery, 2 groups of patients showed significantly greater RA area, TV annulus diameter, RV systolic pressure, and %TR than controls. %TR was significantly decreased after surgery, whereas residual TR was shown in 19% of the MVP group and 25% of the ASD group. Preoperative TV tethering height and %TR were significantly associated with postoperative %TR in the MVP group, whereas preoperative RV fractional area change, RV spherical index, and RV systolic pressure were significantly associated with postoperative %TR in the ASD group. Risk stratification after TV annuloplasty should take the structural abnormality into consideration.

Single Center Experience With a Low Volume Priming Cardiopulmonary Bypass Circuit for Preventing Blood Transfusion in Infants and Small Children

This retrospective study analyzed the current practice of blood transfusion-free open-heart surgery in 536 children weighing 5-20 kg undergoing surgery between 2004 and 2007. A miniaturized cardiopulmonary bypass (CPB) circuit was used (priming volume; 300 ml for the flow rate <1,500 ml/min; 550 ml for the flow rate of 1500-2300 ml/min). Modified ultrafiltration was routinely performed. Criteria for blood transfusion during CPB included a hematocrit of <20% and/or mixed venous oxygen saturation of <65%. Transfusion during CPB was avoided in 264 (49.3%) of the 536 patients (5-10 kg group, 29.0%; 11-15 kg group, 67.4%; 16-20 kg group, 80.8%). There was no neurological complication related to hemodilution. Multiple logistic regression analysis revealed that body weight, preoperative hematocrit, priming volume of CPB circuit, CPB time, and lowest hematocrit during CPB predict requirement of blood transfusion (p < 0.01). Transfusion rate was lowest in the atrial septal defect group (5.6%) and highest in tetralogy of Fallot group (78.7%), being associated with complexity of diagnosis and procedure required. Blood transfusion-free open-heart surgery may be achieved in the half of the patients weighing 5-20 kg, and further miniaturization of CPB circuit and refinement of perfusion strategy might reduce transfusion rate in patients <10 kg and/or with complex congenital heart disease.

Left Ventricular Torsion in Patients With Secundum Atrial Septal Defect

Recently, assessment of left ventricular (LV) torsional deformation has become an important approach for quantifying LV function. This study sought to evaluate LV torsion using speckle tracking imaging in patients with atrial septal defect (ASD). Basal and apical LV short-axis images were analyzed in 45 asymptomatic adults with isolated secundum ASD and 45 matched normal subjects. The apical rotation parameters were similar between 2 groups; however, the peak basal clockwise rotation was significantly depressed (-5.4 +/-2.8 degrees vs -6.9 +/-2.6 degrees , P<0.001) and time to the peak was significantly delayed (118.3 +/-18.8% vs 96.1 +/-12.6% of systolic period, P<0.001) in patients with ASD. The peak basal initial counterclockwise rotation in the ASD group was significantly higher (5.1 +/-3.3 degrees vs 1.8 +/-1.4 degrees , P<0.001) and longer (75.4 +/-26.7% vs 42.5 +/-24.4% of systolic period, P<0.001) than that in the control group. LV peak twist was also reduced significantly in patients with ASD (11.9 +/-5.9 degrees vs 14.6 +/-3.5 degrees , P<0.05) in comparison with the controls. LV systolic twist was significantly reduced in patients with ASD mainly because of the heterogeneous basal rotation.

Community Use of the Amplatzer Atrial Septal Defect Occluder: Results of the Multicenter MAGIC Atrial Septal Defect Study

The objective of this study was to determine the initial safety and results of unrestricted multi-institution routine community use of the Amplatzer Septal Occluder (ASO) for atrial septal defect (ASD) closure. A multicenter, nonrandomized prospective study was performed in 13 pediatric cardiology centers from November 2004 to September 2007. Data were collected at the time of cardiac catheterization and 1 day postimplant. Four hundred seventy-eight patients underwent cardiac catheterization for ASO device closure of an ASD. The median age was 6 years (range, <1-83 years), and the mean weight was 37.2 kg (range, 2.6-148 kg). Procedural success was 96% (458/478 patients), with deficient rims being the major single reason for failed implantation (9/20). Major and minor complication rates were 1.1% and 4.8%, respectively, and were not different between simple and complex ASD groups. Success at 24 h was 99.4% (333/335) in the simple ASD group and 100% (120/120) in the complex ASD group. The presence of large defects, the presence of multiple defects, the use of multiple devices, and a weight <8 kg were significantly associated with a residual shunt (small to moderate) at 24 h. In conclusion, the ASO device in routine clinical practice for simple and complex ASD closure has an immediate safety and effectiveness profile equal to that reported in the initial pivotal FDA trial for simple ASDs. Based on the evolution in care posed by the ASO and the lack of consensus on patient selection in complex ASDs, this study points out the need to redefine the optimal patient and possibly broaden the indications for device closure of ASDs.

Prevalence of Pericardial Effusions in Children With Large Atrial or Ventricular Septal Defect

Recently, a high percentage of adults with isolated secundum atrial septal defects (ASD) and ventricular septal defects (VSD) undergoing surgical repair had a circumferential pericardial effusion (PE), preoperatively. It was our impression that PEs are uncommon in children with unrepaired ASD or VSD. To evaluate this impression, we performed a retrospective study to determine the prevalence of PE in children with ASD compared with those with VSD and with children with normal cardiac anatomy. The preoperative echocardiograms of 90 patients with isolated surgical grade secundum ASDs, 75 patients with isolated VSDs, and 91 normal patients were reviewed to evaluate for the presence or absence of pericardial effusions and also the septal defect size. Only 1 patient (ASD group) of the total 256 had a global PE (0.4%). No large effusions were found in any group. Eighty-one children (32%) had any effusion present in the pericardial space. The prevalence of these small PEs was not significantly different between the ASD (36/90, 40%) and VSD (23/75, 31%, p=0.25) groups. The patients with ASD, however, had a significantly higher prevalence of PEs compared with the control group (22/91, 24%, p<0.03). In conclusion, the presence of global PEs in children with surgical grade ASD or patients with VSD is rare, unlike that reported in adults with the same lesions. Trace effusions are found more commonly in children with ASD than those in VSD or in normal children, which may herald a potential for larger effusions with a longer time before defect closure.

Interatrial Shunt Detected in Coronary Computed Tomography Angiography

To determine differential findings of patent foramen ovales (PFOs) and atrial septal defects (ASDs) demonstrating interatrial shunting on coronary computed tomography (CT) angiography. We retrospectively analyzed 15 cases of patients demonstrating a contrast jet from the left to the right atrium on CT and interatrial shunting on echocardiography. According to the echocardiography results, patients were divided into PFO (n = 10) or ASD (n = 5) groups. The contrast jet direction and atrial septum appearance on CT were compared between the 2 groups. The PFO group had a contrast jet flowing toward the inferior vena cava, and the atrial septum appeared channel-like. The ASD group had a contrast jet flowing perpendicular to the atrial septum in all but one of the patients, and the atrial septum appeared as a membrane with a hole. Atrial septal defects and PFOs can be differentiated using the characteristic direction of the contrast jet from the left to right atrium and the appearance of the atrial septum on coronary CT angiography.

Left and Right Atrial Myocardial Deformation Properties in Patients with an Atrial Septal Defect

Atrial septal defect (ASD) is a common form of congenital heart defect in adults, which affects all cardiac chambers. Atrial myocardial function in patients with ASD has not yet been clearly elucidated. The aim of this study was to investigate atrial myocardial deformation properties in patients with ASDs. The study involved 24 patients with a secundum type ASD, and 22 healthy subjects. Color Doppler myocardial imaging was used to measure left and right atrial myocardial systolic strain and strain rate values, together with peak systolic velocity, early velocity, and late diastolic velocity. There was no significant difference between the two groups with regard to age, gender, body mass index, heart rate, blood pressure, left atrial diameter, and ventricular function. The peak systolic atrial myocardial strain and strain rate values in each of the atrial walls studied were lower in the ASD group compared to those of the control group, but the difference reached statistical significance only in the case of the right atrial wall (right atrial strain: 48.0 +/- 32.7% vs 100.2 +/- 46.6%, P = 0.006; right atrial strain rate: 2.6 +/- 1.2/sec vs 3.8 +/- 1.2/sec, P = 0.024). The left to right cardiac shunt that results from ASD leads to a reduction in the right atrial myocardial longitudinal lengthening that occurs during ventricular ejection. These findings demonstrate that the reservoir function of the atrium is impaired and atrial stiffness increases in patients with ASDs.

Prolonged P wave duration in adults with secundum atrial septal defect: a marker of delayed conduction rather than increased atrial size?

Although atrial fibrillation is a frequent complication of an atrial septal defect (ASD) of the secundum type, the underlying mechanisms are poorly understood. Atrial conduction disturbances, manifested as a prolonged P-wave duration, have been suggested as a substrate for arrhythmia. Prolongation of the P-wave in unrepaired ASD has been demonstrated by means of the conventional ECG, but not by more sophisticated methods. The aim of the study was to analyse P-wave duration and morphology by high-resolution P-wave signal-averaged ECG (PSA-ECG) and to investigate potential atrial mechano-electrical interactions in adults with an unrepaired ASD. P-wave signal-averaged-ECG was obtained in 35 adult patients (age 53 +/- 15 years) with ASD and compared with an equal number of sex- and age-matched healthy controls. Right and left atrial sizes were assessed by echocardiography in the ASD group. P wave duration was significantly longer in the ASD group than in control subjects (148 +/- 16 vs. 128 +/- 15 ms, P < 0.0001). P-wave morphology did not differ significantly between patients and controls. There was no clear relation between P-wave duration and atrial size. Atrial septal defect in the adult is characterized by a prolonged P-wave duration, indicating delayed atrial conduction, which is not related to the enlargement of the atria but rather to conduction delay. The nature and potential reversibility of this warrant further investigation.

Evaluation of Exercise Capacity with Cardiopulmonary Exercise Testing and Type B Natriuretic Peptide Concentrations in Adult Patients with Patent Atrial Septal Defect

Adults with patent atrial septal defect (ASD) usually find their exercise capacity satisfactory, and therefore hesitate to accept proposed surgical treatment of the heart disease. The aim of our study was to evaluate both the exercise capacity, using the cardio-pulmonary stress test, and brain natriuretic peptide (BNP) levels in asymptomatic adults with ASD. Thirty-six patients with patent secundum type ASD (aged mean 44.7 ± 8.2 years) were studied. The control group consisted of 25 healthy subjects at the mean age of 45.6 ± 6.1 years. Echocardiography and CPST were performed and BNP levels measured in all subjects. Oxygen uptake (VO_{2 max}) was lower in ASD patients than in controls (22.1 ± 5.6 vs. 30.0 ± 6.8 ml/kg/min, p = 0.00001); the VE/VO₂ slope was elevated in ASD patients compared with healthy subjects (31.3 ± 6.6 vs. 26.9 ± 3.3, p = 0.001), and exceeded 34 in 5 patients. VO_{2 max} showed a negative correlation with the pulmonary to systemic flow ratio Qp:Qs (r = –0.46, p = 0.004), and a positive correlation was found between the VE/VO₂ slope and Qp:Qs (r = 0.32, p = 0.05). BNP levels were higher in the ASD group than in the controls (60.6 ± 49.9 vs. 32.6 ± 24.5 pg/ml, p = 0.02). BNP correlated positively with RV diameter and Qp:Qs (r = 0.38 and 0.39 respectively, p = 0.03) and negatively with maximum VO₂ (r = –0.5, p = 0.004) and VO₂% (r = –0.32, p = 0.07). Conclusions: Although most adult patients with ASD perceive their exercise capacity as satisfactory, objective assessment reveals that in fact it is significantly decreased. BNP levels are increased comparing to healthy individuals. Decreased exercise capacity and increased BNP levels seem to result from right ventricular volume overload.

Percutaneous versus surgical closure of secundum atrial septal defect: Comparison of early results and complications

Surgical closure of atrial septal defect (ASD) provides excellent results. Given the increasing popularity of percutaneous techniques, a comparison between the 2 methods is needed. Between December 1988 and June 2003, we performed 1284 procedures in 1268 consecutive patients with isolated secundum ASD. Five hundred and thirty-three patients underwent surgical repair of ostium secundum ASD (group A). Seven hundred and fifty-one consecutive patients underwent percutaneous ASD closure (group B). The following outcomes were studied: mortality, morbidity, hospital stay, and efficacy. There were no postoperative deaths. The overall rate of complications was higher in group A than in group B: 44% (95% CI 39.8%-48.2%) versus 6.9 % (95% CI 5%-8.7%) (P < .0001). Major complications were also more frequent in group A: 16% (95% CI 13%-19%) versus 3.6% (95% CI 2.2%-5.0%) (P = .002). Multiple logistic regression analysis showed that surgery was independently strongly related to the occurrence of total complication (odds ratio [OR] 8.13, 95% CI 5.75-12.20) and of major complications (OR 4.03, 95% CI 2.38-7.35). The occurrence of minor complications was independently related to surgery (OR 7.33, 95% CI 4.75-11.02), childhood (OR 1.52, 95% CI 1.01-2.34), and presence of systemic hypertension (OR 1.35, 95% CI 1.01-4.41). Hospital stay was shorter in group B (3.2 +/- 0.9 vs 8.0 +/- 2.8 days, P < .0001). Percutaneous ASD closure provides, in experienced hands and in highly specialized centers, excellent results with a lower complication rate and requires a shorter stay in hospital.

Backscatter evaluation of myocardial functional and textural findings in children with right ventricular pressure and/or volume overload

Integrated backscatter (IBS) analysis represents a recent echocardiographic technique for evaluating the textural and functional state of the right ventricular (RV) myocardium. We undertook our study to (1) define the potential impact of age or morphometric parameters (height, weight, and body surface area) on RV IBS indexes, and (2) compare RV IBS data among normal subjects and children with different conditions of RV overload. We studied 34 patients (mean age 14.6 ± 4.7 years) divided into 3 groups: 14 patients with RV volume overload related to moderate to large atrial septal defect (group I); (2) 10 patients with RV pressure overload due to transposition of the great arteries after the Mustard procedure (group II); and (3) 10 patients with RV volume and pressure overload due to pulmonary regurgitation and stenosis after corrective surgery for tetralogy of Fallot (group III). In addition, 20 children with structurally normal hearts were enrolled as the control group. The 4 groups were comparable with regard to age and morphometric parameters. IBS parameters were assessed as the magnitude of cyclic variation, determined as the difference between peak and nadir IBS values and the averaged myocardial IBS intensity. In the control group and group I, IBS parameters did not change significantly with age, height, weight, and body surface area. In contrast, in groups II and III, a significant correlation was found between cyclic variation and age at the study (p = 0.021, r = −0.71, and p = 0.006, r = −0.79, respectively). Furthermore, compared with the control group, cyclic variation and IBS intensity were significantly different only in groups II (p = 0.01 and p = 0.006, respectively) and III (both p <0.0001) but not in group I (p = 0.23 and p = 0.38, respectively). The lowest values of cyclic variation and the highest values of intensity were detected in group III patients. Thus, our data suggest that (1) in normal subjects, there is no correlation between RV IBS indexes and age or any morphometric parameters, and (2) IBS analysis is able to noninvasively detect differences in myocardial functional and textural properties in the presence of different conditions of RV overload.

Assessment of interventricular septal motion using colour tissue Doppler imaging in adult patients with atrial septal defect.

We aimed to characterize changes in interventricular septum (IVS) motion and any relationship between them and the pulmonary-to-systemic flow ratio (Qp/Qs) in adult patients with atrial septal defect (ASD). Patients and controls were studied using colour tissue Doppler imaging (TDI). The septum length (SL) and distance from the colour change point (CCP) on the IVS to the aortic valve (the CCP distance) were measured on parasternal long axis views. Values normalized for body surface area, and the CCP distance to SL ratio, were calculated. Qp/Qs values were correlated with CCP distance, normalized CCP distance and CCP distance:SL ratio. Statistically significant differences in CCP distance, normalized CCP distance and CCP distance:SL ratio were found between the two groups. In the ASD group, there was no correlation between Qp/Qs and the echocardiographic measurements. The point between the motions in two different directions from the IVS shifted toward the apex in ASD patients compared with controls, and may be a mechanism involved in paradoxical septal motion.

Echocardiographic assessment of the right ventricular stress-velocity relationship under normal and chronic overload conditions.

The effects of chronic volume or pressure overload on the velocity of right ventricular ejection have not been previously well defined. We hypothesized that, as formerly shown for the left ventricle, there would be a direct relationship between the velocity of ejection and an estimate of systolic wall stress. Echocardiograms of asymptomatic patients, not on cardiac medications, with either an isolated secundum atrial septal defect > or = 5 mm in diameter or isolated pulmonic stenosis with a peak instantaneous pressure gradient > or = 20 mmHg, were reviewed. Forty-one patients with an atrial septal defect and 34 with pulmonary stenosis met criteria, and were compared to age-matched normal controls. Total subjects were 127 with ages ranging from 1 day to 54 years. Right ventricular monoplane ejection fraction, ejection time corrected for heart rate (ETc), mean normalized systolic ejection rate (MNSERc) and meridianal peak-systolic wall stress (WSps) were measured. Compared to controls, ejection fractions were not significantly different, but WSps averaged 81% and 110% higher, ETc 8% and 9% longer, and MNSERc 5% and 9% slower in the atrial septal defect and pulmonary stenosis groups, respectively. Among all subjects WSps had a significant linear correlation with ETc (r = 0.61, P < 0.01), MNSERc (r =-0.46, P < 0.01), and ejection fraction (r =-0.19, P < 0.05). Increases in WSps cause an incremental slowing of MNSERc in the right ventricle, with a relationship that is linear over a wide range of normal and abnormal loading conditions.

Effect of catheter device closure of atrial septal defect on diastolic mitral annular motion

Atrial septal defect closure with the Amplatzer septal occluder has a negative effect on diastolic mitral annulus motion in terms of decreasing longitudinal septal annular motion and changing the relation between the annulus motion and mitral inflow.