Doppler Gradient Research Articles

Different Patterns of Cerebral and Muscular Tissue Oxygenation 10 Years After Coarctation Repair.

The purpose of this study was to assess whether the lower exercise tolerance in children after coarctation repair is associated with alterations in peripheral tissue oxygenation during exercise. A total of 16 children after coarctation repair and 20 healthy control subjects performed an incremental ramp exercise test to exhaustion. Cerebral and locomotor muscle oxygenation were measured by means of near infrared spectroscopy. The responses of cerebral and muscle tissue oxygenation index (cTOI, mTOI), oxygenated (O2Hb), and deoxygenated hemoglobin (HHb) as a function of work rate were compared. Correlations between residual continuous wave Doppler gradients at rest, arm-leg blood pressure difference and local oxygenation responses were evaluated. Age, length, and weight was similar in both groups. Patients with aortic coarctation had lower peak power output (Ppeak) (72.3 ± 20.2% vs. 106 ± 18.7%, P < 0.001), VO2peak/kg (37.3 ± 9.1 vs. 44.2 ± 7.6 ml/kg, P = 0.019) and %VO2peak/kg (85.7 ± 21.9% vs. 112.1 ± 15.5%, P < 0.001). Cerebral O2Hb and HHb had a lower increase in patients vs. controls during exercise, with significant differences from 60 to 90% Ppeak (O2Hb) and 70% to 100% Ppeak (HHb). Muscle TOI was significantly lower in patients from 10 to 70% Ppeak and muscle HHb was significantly higher in patients vs. controls from 20 to 80% Ppeak. Muscle O2Hb was not different between both groups. There was a significant correlation between residual resting blood pressure gradient and Δmuscle HHb/ΔP at 10–20W and 20–30W (r = 0.40, P = 0.039 and r = 0.43, P = 0.034). Children after coarctation repair have different oxygenation responses at muscular and cerebral level. This reflects a different balance between O2 supply to O2 demand which might contribute to the reduced exercise tolerance in this patient population.

Doppler gradients, valve area and ventricular function in pregnant women with aortic or pulmonary valve disease: Left versus right

ObjectiveLittle is known about the course of echocardiographic parameters used for the evaluation of valvular heart disease (VHD) during pregnancy, hampering interpretation of possible changes (physiological vs. pathophysiological). Therefore we studied the course of these parameters and ventricular function in pregnant women with aortic and pulmonary VHD. MethodsThe cohort comprised 66 pregnant women enrolled in the prospective ZAHARA studies or evaluated by an identical protocol who had pulmonary VHD or aortic VHD (stenosis/prosthetic valve). The control group comprised 46 healthy pregnant women. Echocardiography was performed preconception, during pregnancy and 1 year postpartum. Peak gradient, mean gradient, aortic valve area (AVA)/effective orifice area (EOA), left ventricular ejection fraction (LVEF) and right ventricular function (RVF; TAPSE) were assessed. ResultsPeak and mean gradients increased during pregnancy compared to preconception in women with aortic VHD and controls (p < 0.0125), but not in women with pulmonary VHD. AVA/EOA remained unchanged. Preconception and postpartum gradients were comparable in all groups. Mean LVEF was normal in pregnant women with VHD and controls. Mean TAPSE was lower (p < 0.001) in women with pulmonary VHD compared to women with aortic VHD and controls (<20 mm vs. ≥23 mm; p < 0.001). In women with pulmonary VHD a decrease of TAPSE was observed during pregnancy (p = 0.005). ConclusionPhysiological changes during pregnancy lead to increased Doppler gradients in women with aortic VHD. This increase was not found in women with pulmonary VHD, probably caused by impaired RVF. Therefore, evaluation of RVF during pregnancy might be important to prevent underestimation of the degree of stenosis.

Effect of Pressure Recovery on Pressure Gradients in Congenital Stenotic Outflow Lesions in Pediatric Patients—Clinical Implications of Lesion Severity and Geometry: A Simultaneous Doppler Echocardiography and Cardiac Catheter Correlative Study

Doppler pressure gradients (PGs) are routinely used as a surrogate for catheter peak-to-peak gradient (PPG) for referring pediatric patients with aortic stenosis (AS), pulmonary stenosis (PS), and coarctation of the aorta (CoA) for intervention but do not always predict the catheter PPG accurately, which results in misclassification of lesion severity. We hypothesized that recovered pressure (RP) accounts for the discrepancy between Doppler PG and catheter PPG. We aimed to study the occurrence of clinically significant RP in AS, PS, and CoA. Simultaneous Doppler and catheter PGs were prospectively measured in 82 patients (median age, 12.2months; weight, 7.5kg) with isolated AS (n=30), PS (n=24), and CoA (n=28), and agreement before and after correcting for RP were analyzed. RP was calculated from a fluid dynamic-based equation. Effects of lesion geometry on the magnitude of RP were analyzed. Recovered pressure-corrected Doppler peak instantaneous gradient (PIG) had significantly closer agreement and correlation with the catheter PPG (P<.001) than the uncorrected PIG and mean Doppler gradients. Recovered pressure-corrected Doppler PIG predicted PPG with high specificity and accuracy in all lesions (95% CI, 36%-97% and 85%-100%, respectively, P<.05 for both). RP magnitude was weakly related (r=0.33 to 0.47) to valve area and inversely related (r=-0.22 to -0.34) to downstream vessel area. Significant RP occurs in congenital AS, PS, and CoA, accounting for misclassification of lesion severity by Doppler PIG. The RP magnitude is at a maximum in mild to moderate stenotic outflow lesions, with small-size downstream vessels causing the most misclassification of lesion severity by Doppler PIG.

Atrial fibrillation is not an independent predictor of outcome in patients with aortic stenosis

ObjectivesTo examine the prognostic significance of atrial fibrillation (AF) versus sinus rhythm (SR) on the management and outcomes of patients with severe aortic stenosis (AS).Methods1847 consecutive patients with severe AS...

Correlation of Echocardiogram and Exercise Test Data in Children with Aortic Stenosis.

Previous pediatric exercise test criteria for aortic stenosis severity were based on cardiac catheterization assessment, whereas current criteria are based on echocardiographic valve gradients. We sought to correlate exercise test criteria with echocardiographic assessment of severity. We report 65 studies, 51 patients (mean age of 13 ± 4years; 75% males), with aortic stenosis (AS) who had a maximal exercise test between 2005 and 2016. We defined three groups based on resting mean Doppler gradient across their aortic valve: severe AS (n = 10; gradient of ≥ 40mmHg), moderate AS (n = 20; gradient 25-39mmHg), and mild AS (n = 35; gradient ≤ 24mmHg). We studied symptoms (chest pain) during exercise, resting electrocardiogram changes (left ventricular hypertrophy [LVH]), complex arrhythmias during exercise, change in exercise systolic blood pressure (SBP; delta SBP = peak SBP-resting SBP), exercise duration, work, echocardiogram parameters (LVH), and ST-T wave changes with exercise. Additionally, we compared work and delta SBP during exercise with 117 control males and females without heart disease. Severe AS patients have statistically significant differences when compared with mild AS in ST-T wave depression during exercise, LVH on resting electrocardiogram, and echocardiogram. There was a significant difference in delta SBP between severe AS and normal controls (delta SBP 21.6 vs. 46.2mmHg), and between moderate AS and normal controls (delta SBP 32 vs. 46.2mmHg). There were no significant complications during maximal exercise testing. Children with echocardiographic severe and moderate AS have exercise testing abnormalities. Exercise test criteria for severity of AS were validated for echocardiographic criteria for AS severity.

Inconsistency in aortic stenosis severity between CT and echocardiography: prevalence and insights into mechanistic differences using computational fluid dynamics

ObjectivesThe aims of this study were to evaluate the inconsistency of aortic stenosis (AS) severity between CT aortic valve area (CT-AVA) and echocardiographic Doppler parameters, and to investigate potential underlying...

Spatially truncated optical pumping cooling

We present both the theoretical description and experimental implementation of a novel cooling technique for ultracold atoms trapped in a confining potential. We call the technique ‘spatially truncated optical pumping cooling.’ By using the fact that the internal states of atoms can be manipulated by laser light focused on only part of a confined ultracold gas, high energy atoms can be preferentially selected and then slowed to achieve cooling without requiring the loss of any atoms. This technique uses cooling photons more efficiently on a per photon basis than Doppler or polarization gradient cooling, while having approximately the same degree of difficulty with regard to experimental implementation.

The Immediate Results of Percutaneous Balloon Aortic Valvuloplasty in Patients with Congenital Aortic Valvular Stenosis

Objective: To assess the immediate-term effectiveness of percutaneous balloon aortic valvuloplasty (PBAV) for congenital aortic stenosis (AS). Design: Early clinical and instrumental evaluation of 34 consecutive PBAV performed from 2001&nbsp;to 2007. Setting:&nbsp; A tertiary referral center for heart diseases (Ibn Al-Bitar Cardiac Center). Patients: Thirty-four patients with congenital valvular AS, twenty-five males and nine females. Interventions: PBAV using Tayshak balloons of different sizes and lengths. Main outcome measures:&nbsp; Doppler and peak to peak pressure gradient (PG) across the aortic valve (AV) before and after valvuloplasty, the percent of PG reduction post dilatation, left ventricular (LV) systolic and diastolic pressures before and after valvuloplasty, number of the aortic cusps, degree of aortic regurgitation (AR) before and after valvuloplasty, left ventricular systolic function before and after valvuloplasty, associated anomalies,&nbsp; and the need for emergency surgery were the main outcome measures. Results: The peak to peak instantaneous PG across the AV was reduced acutely from 102 ± 42.7 (20 - 200) mm Hg to 40 ± 25.5 (10- 140) mm Hg (p&lt;0.001), left ventricular systolic pressure was reduced from 196 ± 48.57 (70 – 280) mm Hg to 133 ± 35.45 (65 – 240) mm Hg (p&lt;0.001) and both are statistically significant. Three patients had inadequate relief of obstruction but in one of them it was mainly due to subaortic obstruction and two patients had severe AR, one of them with acute pulmonary edema and required surgical AV repair. PBAV produced a gradient reduction ≥&nbsp;50% in 29&nbsp;patients, six patients&nbsp;having a residual peak to peak gradient of &gt;50 mm Hg and in one of whom the remaining PG was 70 mm Hg which was mainly subvalvular (50 mm Hg). Six patients had bicuspid AV while the other patients had tricuspid valve. Six had associated anomalies. There was no mortality during the procedure. Severe AR reported in two&nbsp;patients and moderate AR occurred in five patients. One significant complication (acute pulmonary edema) occurred immediately after the dilatation and surgery was done for that patient after few days. Two serious complications occurred during the procedure which responded to routine resuscitation. There was a residual maximum Doppler gradient of &lt;&nbsp;30 mm Hg in 12&nbsp;patients, ≥&nbsp;60 mm Hg in four (one of them had mainly subvalvular gradient) and between 30 to 48 mm Hg in the others. Twenty one patients developed new AR (62%), in fourteen of them (41%) it was mild. Conclusions: PBAV is an effective procedure and offers a good palliation for congenital AS.

Evaluation of initial and medium-term follow-up results of balloon aortic valvuloplasty in severe aortic valve stenosis in newborns, infants and children in Alexandria, Egypt

Background: Aortic valve stenosis (AVS) represents 3%–7% of all congenital heart diseases. Balloon aortic valvuloplasty (BAoV) has been established as an alternative to surgery for therapy of AVS in infants and children; and has proven to be an effective method for decreasing the gradient between the left ventricle and the aorta. The objective of the study was to evaluate the initial and medium-term results of BAoV in newborns, infants and children with severe AS, treated at the Alexandria University Children’s Hospital.Methods: Thirty-seven newborns, infants and children with severe AS treated by B AoV between 2009 and 2017 were studied. They were followed-up for at least 1year post- ballooning by clinical and echocardiographic evaluation.Results: The mean AoV annulus diameter by echo was 13.1±4.4 mm and by angiographic measurement was 12.8±4.3 mm. The mean Doppler gradient across AoV was 91.8±14.7 mmHg, compared to mean catheter gradient of 66.1±13.4 mmHg. The mean inflated balloon diameter was 12.1±4.1 mm. The mean balloon/AoV annulus ratio by angiogram was 0.94±0.03 (0.88–1). The mean pressure gradient across the AoV post-ballooning was 21.5±6.9 mmHg by Doppler and was 10.3±4.7 mmHg by catheter, both were significantly less than pre-ballooning values (p&lt;0.001). The procedure was successful in all the cases. Only one case died. Post -ballooning aortic incompetence was moderate in 2 cases (5.4%) and severe in only one case (2.7%).Conclusions: Balloon aortic valvuloplasty is an effective and safe technique for relieving severe aortic valvular stenosis with acceptable morbidity and minimal mortality, particularly with the new catheter and balloon technology.

Long-term follow-up and outcomes of discrete subaortic stenosis resection in children.

Background:Studies of long-term outcomes of discrete subaortic stenosis (DSS) are rare. Therefore, we reviewed the long-term outcomes of subaortic membrane resection in children with isolated DSS over 16 years from a single institution.Materials and Methods:We retrospectively reviewed the records of patients (n = 27) who underwent resection of DSS between 2000 and 2017. Patients with major concomitant intracardiac anomalies were excluded. Indications for surgery were mean left ventricular outflow tract (LVOT), Doppler gradient >30 mmHg, and/or progressive aortic insufficiency.Results:The mean age at diagnosis was 3.77 ± 3.49 years (range, 0.25–13 years) and the mean age at surgery was 6.36 ± 3.69 years (range, 1–13 years). All patients underwent resection of subaortic membrane. The mean LVOT Doppler gradient decreased from 40.52 ± 11.41 mmHg preoperatively to 8.48 ± 5.06 mmHg postoperatively (P < 0.001). The peak instantaneous LVOT Doppler gradient decreased from 75.41 ± 15.22 mmHg preoperatively to 18.11 ± 11.44 mmHg postoperatively (P < 0.001). At the latest follow-up, the peak gradient was 17.63 ± 8.93 mmHg. The mean follow-up was 7.47 ± 3.53 years (median 6.33 years; range 2.67–16 years). There was no operative mortality or late mortality. Recurrence of subaortic membrane occurred in 7 (25.92%, 7/27) patients who underwent primary DSS operation. Four (14.81%, 4/27) patients required reoperation for DSS recurrence at a median time of 4.8 years (3.1–9.1 years) after the initial repair. Risk factors for reoperation were age <6 years at initial repair. Eighteen (66.66%, 18/27) patients had AI preoperatively and progression of AI occurred in 70.37% (19/27). This included 4 (22.22%, 4/18) patients who had worsening of their preoperative AI. Short valve-to-membrane distance was found to be prognostically unfavorable. One (3.7%, 1/27) patient had an iatrogenic ventricular septal defect, and 2 (7.4%, 2/27) patients had complete AV block following membrane resection.Conclusions:Resection of subaortic membrane in children is associated with low mortality. Higher LVOT gradient, younger age at initial repair, and shorter valve-to-membrane distance were found to be associated with adverse outcome. Recurrence and reoperation rates are high, and progression of aortic insufficiency following subaortic membrane resection is common. Therefore, these patients warrant close follow-up into adult life.

Left Atrial Size and Function in Patients With Congenital Aortic Valve Stenosis

Little information exists on left atrial (LA) function in healthy children and in patients with congenital aortic valve stenosis (AS). We sought to determine whether patients with significant congenital AS have detectable abnormalities in LA size and function compared with matched normal controls. Retrospective chart review and analysis of 2-dimensional echocardiographic images for phasic left atrial volumes (LAVs) and longitudinal LA strain by speckle tracking in children ≥1 years of age with ≥ moderate isolated congenital AS. LAVs and LA strain in AS cases were compared with age, gender, and body surface area-matched controls (healthy children with a normal echocardiogram). Between June 2004 and October 2012, there were 36 eligible AS cases [age 13 (range 3 to 27) years; 30 males] with a median maximal Doppler gradient of 63 (range 43 to 94) mm Hg. No significant interobserver and intraobserver differences were noted in the analyses of normal subjects. Significantly higher phasic body surface area-adjusted LAVs [preatrial contraction: p = 0.01; minimal: p = 0.04] and higher LA contractile function parameters [indexed active LA stroke volume: p = 0.03; peak negative strain p = 0.04] were noted in AS cases compared with matched controls. In conclusion, compared with normal, children with congenital AS have higher preatrial contraction and minimal phasic LA volumes and higher LA contractile function.

Disopyramide use in infants and children with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy has a range of clinical severity in children. Treatment options are limited, mainly on account of small patient size. Disopyramide is a sodium channel blocker with negative inotropic properties that effectively reduces left ventricular outflow tract gradients in adults with hypertrophic cardiomyopathy, but its efficacy in children is uncertain. A retrospective chart review of patients ⩽21 years of age with hypertrophic cardiomyopathy at our institution and treated with disopyramide was performed. Left ventricular outflow tract Doppler gradients before and after disopyramide initiation were compared as the primary outcome measure. Nine patients received disopyramide, with a median age of 5.6 years (range 6 days-12.9 years). The median left ventricular outflow tract Doppler gradient before initiation of disopyramide was 81 mmHg (range 30-132 mmHg); eight patients had post-initiation echocardiograms, in which the median lowest recorded Doppler gradient was 43 mmHg (range 15-100 mmHg), for a median % reduction of 58.2% (p=0.002). With median follow-up of 2.5 years, eight of nine patients were still alive, although disopyramide had been discontinued in six of the nine patients. Reasons for discontinuation included septal myomectomy (four patients), heart transplantation (one patient), and side effects (one patient). Disopyramide was effective for the relief of left ventricular outflow tract obstruction in children with hypertrophic cardiomyopathy, although longer-term data suggest that its efficacy is not sustained. In general, it was well tolerated. Further study in larger patient populations is warranted.

Tissue Doppler Assessment of Systolic Right Ventricular Function before and after Balloon Pulmonary Vulvuloplasty

AbstractBackground: The incidence of valvular pulmonary stenosis has been reported to be 0.6 to 0.8 per 1000 live births, and when associated with other congenital heart diseases as many as 50% of all patient with congenital heart diseases. The magnitude of right ventricular pressure and the pressure across the pulmonary valve are generally proportional to the degree of obstruction. Under usual circumstances, proportional right ventricular hypertrophy maintains normal pulmonary flow. If the normal output isn't maintained, right sided heart failure ensues. This occur in neonates with critical pulmonary stenosis and in patient with severe obstruction that occur in childhood or adulthood.Aim of Study: To assess the right ventricular systolic function by tissue Doppler in patients with critical valvular pulmonary stenosis before, immediately and three months after successful Balloon Pulmonary Valvuloplasty (BPV).Methods: This study is a prospective study, it included 20 patients with critical stenosis who attended to the Cardiology Department in Tanta University Hospital and subjected to balloon pulmonary valvuloplastyfrom August 2016 to March 2017. The patients are subjected to balloon valvuloplasty and full echocardiography assessment and tissue Doppler to the right ventricle.Results: The transcutaneous BPV showed high efficacy in reducing the pressure gradient across the pulmonary valve denoting successful and effective dilatation, where the max-imum pulmonary PG ranged from 68-120mmHg. With a mean ± SD value of 82.47±16.3 at base line, and 12-30mmHg with a mean value of 20.26±5.43 immediately after intervention, and 15-35mmHg, with a mean ± SD value of 22.37±5.05 mmHg three months after intervention. There was statistically significant decrease in maximum pulmonary PG immediately after BPV (p=0.001), but there was no statistically significant difference in the maximum pulmonary PG immediately after intervention and after three months. TAPSE ranged from 11- 16mm with a mean ± SD value of 13.48±1.43 at base line, and 13-17mm with a mean ± SD value of 15.87±1.08 imme-diately after intervention.and 20-24mm with a mean ± SD value of 21.74±1.163 three months after intervention. There was statistically significance increase in TAPSE immediately after intervention and also three months after intervention. Right Ventricular Systolic wave (RVs) ranged from 8-11cm/s with a mean ± SD value of 9.24±0.77 at base line, and 8-11 cm/s with a mean ± SD value of 9.24±0.67 immediately after intervention and ranged from 11-14cm/s with a mean ± SD value of 12.41±0.67 three months after intervention. There was no statistically difference in RVs before intervention and immediately after intervention but RVs was statistically significance increased after three months from both before intervention and immediately after intervention.Conclusion: BPV is safe and effective to relieve critical pulmonary stenosis. The balloon promotes advantageous changes in both, pulmonary annulus and pressure gradient across the RVOT, in addition, the Doppler gradient observation during the follow-up support the expectation that BPV is a curative therapy. The right ventricular systolic function changed favorably in children with moderately-severe pulmonary stenosis after successful balloon valvuloplasty. These changes provide a good insight for early intervention in the children with pulmonary stenosis to avoid progression to permanent cardiac deformation and heart failure.

Percutaneous transcatheter pulmonary valve replacement in children weighing less than 20 kg.

Since FDA approval of the Melody valve, transcatheter pulmonary valve replacement (TPVR) has been offered to an expanding population. Limited data exist regarding the safety and feasibility of TPVR in smaller patients. All patients weighing <20 kg who underwent catheterization for percutaneous TPVR at four centers were reviewed. Of the 51 patients reviewed, 43 (84%) had successful valve implantation and 8 (16%) were found not to be candidates due to access veins too small (n = 3), coronary artery/aortic root compression (n = 3), and RVOT too large (n = 2). The 43 patients who underwent successful percutaneous TPVR had a median age and weight of 5.8 years (3.3-10) and 17.7 kg (13.5-19.8), and most had tetralogy of Fallot (TOF). TPVR was performed via femoral vein (FV) access in 24 patients and internal jugular vein (IJV) access in 19 patients. Median weight in patients with IJV implant was 1.1 kg lower than those who underwent transfemoral implant (17.0 vs. 18.1 kg, P = 0.05). There were four adverse events: one iliac vein injury, one contained MPA tear, and two patients with post-procedure femoral vein bleeding. All patients were alive at recent follow-up, a median of 2.0 years (0.1-6.0) after TPVR. There was excellent valve function with mean Doppler gradients of 3-20 mm Hg, and trivial or mild pulmonary regurgitation in all but one patient. There were no RVOT reinterventions and no cases of endocarditis. Percutaneous TPVR can be safely performed in patients <20 kg. The procedure frequently requires IJV access, and access site/bleeding complications may be more common in this cohort.

Experimental Investigation of Left Ventricular Flow Patterns After Percutaneous Edge-to-Edge Mitral Valve Repair.

Mitral valve percutaneous edge-to-edge repair (PEtER) is a viable solution in high-risk patients with severe symptomatic mitral regurgitation. However, the generated double-orifice configuration poses challenges for the evaluation of the hemodynamic performance of the mitral valve and may alter flow patterns in the left ventricle (LV) during diastole. This in vitro study aims to evaluate the hemodynamic modifications following a simulated PEtER. A custom-made mitral valve was developed, and two configurations were tested: (i) a single-orifice valve with mitral regurgitation and (ii) a double-orifice mitral valve configuration following PEtER. The hemodynamic performance of the valve was evaluated using Doppler echocardiography and catheterization, while the flow patterns in the LV were investigated using particle image velocimetry (PIV). The tests were run at a stroke volume of 65 mL and a heart rate of 70 bpm. PEtER was found to significantly reduce the regurgitant volume (15 vs. 34 mL). There was a good agreement between Doppler and catheter transmitral pressure gradients (peak gradient: 9 vs. 7 mm Hg; mean gradient: 4 vs. 3 mm Hg) as well as an excellent agreement between maximal velocity measured by Doppler and PIV (1.60 vs. 1.58 m/s). Vortex development in the LV during diastole was significantly different after repair. PEtER significantly increased the amplitude of Reynolds and viscous shear stresses, as well as the number of high shear regions in the LV, potentially promoting thromboembolism events.

Resection of subaortic membrane for discrete subaortic stenosis.

We reviewed the long-term results of surgery for discrete subaortic membrane (SubAM) from a single institute. A retrospective review of medical records of all patients (n = 146) who underwent resection of a SubAM for discrete subaortic stenosis between 1990 and 2015 at the All India Institute of Medical Sciences, New Delhi, India was undertaken. Median age at surgery was 9.0 years (9 months-47 years). There was one early death. Preoperative peak left ventricular outflow tract (LVOT) Doppler gradient was 83.4 ± 26.2 mmHg (range: 34-169 mmHg). On preoperative echocardiography, aortic regurgitation (AR) was absent in 69 (47.3%), mild in 35 (24%), moderate in 30 (20.5%), and severe in 12 (8.2%). After surgery, the LVOT gradient was reduced to 15.1 ± 6.2 mmHg (P < 0.001). Fourteen patients (9.6%) who had residual/recurrent significant gradients are currently being followed-up or awaiting surgery. There was improvement in AR for operated patients with freedom from AR of 92.6 ± 0.03% at 15 years. Kaplan-Meier survival at 25 years was 93.0 ± 3.9% (95% confidence interval: 79.6, 97.7). Freedom from re-operation at 25 years was 96.9 ± 1.8%. Long-term results of surgery for discrete SubAM are good. Resection of the membrane along with septal myectomy decreases the risk of recurrence.

Echocardiographic assessment of pediatric semilunar valve disease.

We reviewed echocardiography literature for the assessment and management of semilunar valve disease in children. A search was performed within the National Library of Medicine using the keywords aortic stenosis (AS), aortic regurgitation, pulmonary stenosis (PS), and pulmonary regurgitation in children. The search was further refined adding the keywords-pediatric, neonates, echocardiographic definition, classification, evaluation. Thirty-eight studies were included. For stenotic lesions, there were sufficient consistencies between Doppler and invasive gradients (especially for PS), while other quantitative parameters used in adults showed significant limitations when applied to children. Heterogeneities remain in the range of Doppler measurements utilized to define mild vs moderate vs severe AS/PS, and to guide management. There is sufficient consensus regarding indications for interventions. In regurgitant lesions, there is weak evidence supporting the use of quantitative or semiquantitative parameters after correction for body surface area; clear indications for intervention are lacking. Because adult echocardiographic recommendations cannot be simply translated to the pediatric age, more specific pediatric guidelines and standards for the assessment of semilunar valve disease are needed.

Role of Transesophageal Echocardiography in the Diagnosis of Paradoxical Low Flow, Low Gradient Severe Aortic Stenosis.

Background and ObjectivesPrior studies indicate that up to 35% of cases of severe aortic stenosis (AS) have paradoxical low flow, low gradient despite preserved left ventricular ejection fraction (LVEF). However, error in left ventricular outflow tract (LVOT) diameter may lead to misclassification. Herein, we determined whether measurement of LVOT diameter by transesophageal echocardiography (TEE) results in reclassification of cases to non-severe AS.Subjects and MethodsPatients with severe AS with aortic valve area (AVA) <1 cm2 by transthoracic echocardiography (TTE) within 6 months were studied. Paradoxical low flow, low gradient was defined as mean Doppler gradient (MG) <40 mm Hg and stroke volume index (SVI) ≤35 mL/m2. Preserved LVEF was defined as ≥0.50.ResultsAmong 108 patients, 12 (15%) had paradoxical low flow, low gradient severe AS despite preserved LVEF based on TTE measurement. When LVOT diameter by TEE in 2D was used, only 5 (6.3%) patients had low flow, low gradient severe AS (p<0.001). Coefficients of variability for intraobserver and interobserver measurement of LVOT were <10%. However, the limits of agreement between TTE and TEE measurement of LVOT ranged from 0.43 cm (95% confidence interval [CI]: 0.36 to 0.5) to -0.31 cm (95% CI: -0.38 to -0.23).ConclusionTEE measured LVOT diameter may result in reclassification to moderate AS in some patients due to low prevalence of true paradoxical low flow, low gradient (PLFLG) severe AS.

Intravascular and hybrid intraoperative stent placement for baffle obstruction in transposition of the great arteries after atrial switch.

To report our experience with intravascular and hybrid intra-operative stent placement for baffle obstruction in patients with complete transposition of the great arteries (TGA) after the atrial switch (Mustard/Senning) operation. Venous baffle obstruction is a challenging complication after atrial switch operation in patients with TGA. Traditional treatment options include intravascular stenting or surgery. A retrospective analysis of Mayo Clinic's electronic medical record was completed to identify consecutive pediatric and adult patients with TGA after atrial switch who underwent baffle stent implantation from 1994 to 2015. Overall, 64 patients were referred for cardiac catheterization, in whom 47 (73%) were noted to have hemodynamic and angiographic evidence of baffle obstruction. A total of 20 patients mean age 33 (range: 8-46) years old underwent stent implantation of baffle stenosis at a mean of 33 (range: 7.5-45) years after initial atrial switch operation (Mustard, n = 19; Senning, n = 1). Overall, 27 baffles were stented in 20 patients via the following approaches: intravascular (17); hybrid surgical (3); staged intravascular & hybrid (2). Sites of stent placement were: superior vena cava (SVC) (13); inferior vena cava (IVC) (9); pulmonary venous baffle (5). Three patients had stent placement in the SVC and IVC baffles during the same procedure. Procedural adverse events occurred in 2/22 cases (9%) including creation of unintentional baffle leak (n = 1) and stent migration (n = 1). There was no procedure-related mortality. At follow-up (median 2, range 0.02-10 years), significantly improved NYHA class and mean Doppler baffle gradient were demonstrated (P < 0.05). Mild baffle re-stenosis (mean Doppler gradient; 2-3 mmHg) occurred in two patients who have not required re-intervention. Trivial baffle leak was noted in four patients. Baffle re-intervention was only occurred in one patient. One patient with pre-procedural Class IV symptoms died 3.5 months after stent implantation. This study is the largest reported experience of intravascular and intra-operative hybrid stent placement for patients with TGA after atrial switch. Transcatheter and minimally invasive hybrid intraoperative surgical stent placement are an effective strategy for relief of systemic and pulmonary venous baffle obstruction. © 2016 Wiley Periodicals, Inc.

Transcatheter Aortic Valve Replacement During Pregnancy

Transcatheter aortic valve replacement (TAVR) is an approved and widely accepted standard treatment for severe symptomatic aortic stenosis (AS) in high-risk surgical candidates.1 Severe symptomatic AS during pregnancy presents a difficult clinical challenge.2 A 22-year-old female patient presented to our service at 15 weeks’ gestation with congenital symptomatic AS. After a thoughtful heart team evaluation, TAVR was recommended to the patient and performed at 22 weeks’ gestation. The authors further explore and discuss the preprocedure planning and treatment decisions of this case. The heart team focused on the timing and special considerations needed to ensure the health and safety of the patient and fetus. With careful preprocedural planning, TAVR can be a low-risk treatment option during pregnancy and provide a reliable bridge to a healthy, term delivery. A 22-year-old pregnant female patient presented with severe symptomatic AS at 15 weeks’ gestation. The patient was 165 cm tall, weighed 74 kg with a body mass index of 27 kg/m2 and body surface area of 1.84 m2 at the time of presentation. The patient’s clinical history includes congenital bicuspid aortic valve disease, which required balloon aortic valvuloplasty (BAV) at the age of 9 years. Throughout young adulthood, she had been asymptomatic with high levels of activity. Her chief complaints on presentation were increased dizziness, dyspnea on exertion, and chest discomfort. Echocardiography demonstrated a normal ejection fraction, an aortic peak flow velocity of 4.04 m/s, an aortic valve mean gradient of 38.22 mm Hg, an aortic valve area of 1.0 cm2, and mild-to-moderate aortic insufficiency (AI). The ascending aorta was mildly enlarged (3.9 cm). There was mild narrowing of periductal isthmus with no Doppler gradient (Figure 1; Table 1). Stress echocardiography testing showed moderate AI and below-average exercise capacity. The patient completed 8 to 9 metabolic equivalents …