Ventricular Outflow Tract Diameter Research Articles

Sleep: A Window Into Autonomic Control in Children Born Preterm and Growth Restricted.

Preterm birth and fetal growth restriction (FGR) are both associated with risk of hypertension in adulthood. Mechanisms leading to this pathology are unclear. In children aged 5-12 years, who were born preterm and FGR, we used sleep as a tool to assess autonomic control with assessment of cardiovascular structure and function. Eighteen children born preterm and FGR, 15 children born preterm with appropriate birth weights for gestational age (AGA), and 20 AGA term-born children were studied. Children underwent overnight polysomnography with the addition of continuous noninvasive blood pressure (Finometer™). Spectral measures of heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity were assessed and overnight urinary catecholamine levels measured. Echocardiographic studies (Vivid7, GE Healthcare) were performed and vascular compliance assessed (Miller Instruments™). Statistical comparisons were adjusted for age and body size. Compared to term children, preterm AGA children had increased high frequency HRV (p < .05) and BPV (p < .05) during sleep, reflecting increased parasympathetic activation and blood pressure changes related to respiration. Preterm FGR children had smaller left ventricular lengths, ascending aorta, and left ventricular outflow tract diameter (p < .05 for all) and vascular compliance was positively correlated with gestational age (r2 = 0.93, p < .05). FGR combined with preterm birth did not alter autonomic control but altered heart structure in children. In contrast, preterm birth alone altered autonomic control but had no change in heart structure. These changes in children born preterm and FGR may contribute, in part, to increased risk of cardiovascular disease later in life but by different mechanisms.

Comparison of valve performance of the mechanically expanding Lotus and the balloon-expanded SAPIEN3 transcatheter heart valves: an observational study with independent core laboratory analysis.

The Lotus and SAPIEN3 are second-generation transcatheter heart valves, which are designed to minimize paravalvular aortic regurgitation (PAR) after transcatheter aortic valve replacement (TAVR). We sought to compare both devices for valve performance and with emphasis on PAR by independent core laboratory analysis. A total of 162 (79 Lotus and 83 SAPIEN3) consecutive patients (51% female, 80 ± 8 years, Logistic EuroSCORE 14.8 ± 9.4%) who underwent TAVR because of aortic stenosis were included. Patients with aortic valve-in-valve treatment were excluded. Pre-discharge echocardiograms were analysed by an independent core laboratory using the Valve Academic Research Consortium 2 criteria. There were no differences in baseline and procedural characteristics, except for a larger aortic annulus and sizing indices in SAPIEN3-treated patients and frequency of post-dilatation (0% in Lotus and 13.1% in SAPIEN3). Both valves have similar mean residual gradient, indexed effective orifice area and Doppler velocity index when adjusted to valve size. The frequency of mild (13.9% vs. 31.3%) and at least moderate (1.3% vs. 3.6%) PAR was less after Lotus than after SAPIEN3 implantation (P = 0.02). Multi-slice computed tomography-based annulus and left ventricular outflow tract diameters, calcification and percentage of oversizing were not different between those with or without mild or more PAR. On multivariate analysis, the use of Lotus valve was associated with less (odds ratio OR, 0.41, P = 0.03) occurrence of PAR. Overall, haemodynamic performance was comparable between the Lotus and SAPIEN3 valves. Lotus valve required less oversizing and was associated with less PAR than SAPIEN3.

Evaluate Energy Loss Changes within Left Ventricle in 4 Patients with Obstructive Hypertrophic Cardiomyopathy after Modified Morrow Procedure Using Vector Flow Mapping

To evaluate the changes of left ventricle energy loss (EL) in patients with obstructive hypertrophic cardiomypoathy (HOCM) after modified morrow procedure using vector flow mapping (VFM), and to explore its clinical value in evaluating the operation effect. Retrospectively analyzed the data from four patients with HOCM treated by modified morrow procedure. Measure the echocardiographic parameters before and after surgery, respectively, and EL of LV was analyzed frame by frame using color Doppler images of a standard apical three-chamber dynamic view on an offline VFM workstation. The average EL of LV isovolumetric contraction phase, ejection phase, isovolumetric relaxation phase and filling phase were calculated. Compared with preoperative condition, 1). echocardiographic parameters: the left ventricular outflow tract (LVOT) diameter and left ventricular end-systolic volume were obviously increased, the LVOT gradient and the thickness of ventricular septum were significantly decreased, the differences were obviously significant (P < 0.05). Systolic anterior motion (SAM) disappeared in all cases. 2). EL value changes: During isovolumetric contraction phase and filling phase, averaged EL values were markedly increased in patient 1 and patient 2 and markedly decreased in patient 4, in patient 3 it was increased a little. During isovolumetric relaxation phase and ejection phase, averaged EL values were markedly increased in patient 1 and patient 2 and markedly decreased in patient 3 and patient 4. As a whole the variation trend was that the EL values in patient 1 and patient 2 increased greatly, but decreased greatly in patient 3 and patient 4. After modified Morrow procedure, even the normal conditions and echocardiographic parameters were significantly improved in HOCM patients, an increased energy loss may lead to worse outcomes, EL might be an new index for precise and quantitative assessment of intracardiac flow dynamics under different pathophysiology conditions.

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.

Combination of ECG and Echocardiography for Identification of Arrhythmic Events in Early ARVC

ObjectivesThe aim of this study was to investigate early markers of arrhythmic events (AEs) and improve risk stratification in early arrhythmogenic right ventricular cardiomyopathy (ARVC). BackgroundAEs are frequent in patients with ARVC, but risk stratification in subjects with early ARVC is challenging. MethodsEarly ARVC disease was defined as possible or borderline ARVC diagnosis according to the ARVC Task Force Criteria 2010. We performed resting and signal averaged electrocardiogram (ECG). Using echocardiography, we assessed right ventricular (RV) outflow tract diameter and right ventricular basal diameter (RV diameter). Global longitudinal strain and mechanical dispersion (MD) from strain echocardiography were assessed in both the right and left ventricle. AEs were defined as documented ventricular tachycardia, cardiac syncope, or aborted cardiac arrest. ResultsOf 162 included subjects with ARVC (41 ± 16 years of age, 47% female), 73 had early ARVC, including mutation positive family members not fulfilling definite ARVC diagnosis. AEs occurred in 15 (21%) subjects with early ARVC. Those with AEs in early disease had larger RV diameter (40 ± 4 mm vs. 37 ± 5 mm), more pronounced RVMD (39 ± 15 ms vs. 26 ± 11 ms), and more pathological signal averaged ECGs compared with those without AEs (all p ≤ 0.05). Adding measurements of RV diameter and RVMD to electrical parameters improved identification of subjects with AEs compared with electrical parameters alone (p = 0.05). ConclusionsECG parameters, RV diameter, and RVMD were markers of previous arrhythmic events in patients with early ARVC. A combination of electrical and echocardiographic parameters improved identification of subjects with AEs in early ARVC disease.

Aortic root dimensions are predominantly determined by genetic factors: a classical twin study.

Previous studies using transthoracic echocardiography (TTE) observed moderate heritability of aortic root dimensions. Computed tomography angiography (CTA) might provide more accurate heritability estimates. Our primary aim was to assess the heritability of theaortic root with CTA. Our secondary aim was to derive TTE-based heritability and compare this with the CTA-based results. In the BUDAPEST-GLOBAL study 198 twin subjects (118 monozygotic, 80 dizygotic; age 56.1 ± 9.4years; 126 female) underwent CTA and TTE. We assessed the diameter of the left ventricular outflow tract (LVOT), annulus, sinus of Valsalva, sinotubular junction and ascending aorta. Heritability was assessed using ACDE model (A additive genetic, C common environmental, D dominant genetic, E unique environmental factors). Based on CTA, additive genetic effects were dominant (LVOT: A = 0.67, E = 0.33; annulus: A = 0.76, E = 0.24; sinus of Valsalva: A = 0.83, E = 0.17; sinotubular junction: A = 0.82, E = 0.18; ascending aorta: A = 0.75, E = 0.25). TTE-derived measurements showed moderate to no genetic influence (LVOT: A = 0.38, E = 0.62; annulus: C = 0.47, E = 0.53; sinus of Valsalva: C = 0.63, E = 0.37; sinotubular junction: C = 0.45, E = 0.55; ascending aorta: A = 0.67, E = 0.33). CTA-based assessment suggests that aortic root dimensions are predominantly determined by genetic factors. TTE-based measurements showed moderateto no genetic influence. The choice of measurement method has substantial impact on heritability estimates. • Aortic root dimensions are determined by genetic and environmental effects. • Transthoracic echocardiography (TTE) demonstrated moderate to no genetic effects on aortic root dimensions. • Computed tomography angiography might provide more accurate heritability estimates compared to TTE. • Three-dimensional imaging techniques are needed to reliably quantify aortic root dimensions.

Paravalvular leak after transcatheter aortic valve implantation: is it anatomically predictable or procedurally determined? MDCT study

To investigate the determinants of paravalvular leak (PVL) occurring after transcatheter aortic valve implantation (TAVI). One hundred and eight patients with severe symptomatic aortic stenosis (mean age 75.5±11.8 years, 72.2% male) underwent contrast-enhanced electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) then successful TAVI. The following parameters were determined in the late systolic phase: annular and left ventricular outflow tract (LVOT) diameters, annular perimeter, ellipticity index, annular area, indexed annular area, LVOT perimeter, annulus/LVOT perimeter difference ratio, the LVOT to ascending aorta angle (< LVOT-AO). In the diastolic phase, the extent of calcification of the aortic valve (AVC) was assessed visually and graded semi-quantitatively as grade I, II, and III at the annulus, LVOT, and aortic cusps levels. Pre-discharge transthoracic echocardiography (TTE) was performed, and the PVL was graded as grade I, II, and III. The area-dependent device-annulus sizing ratio was calculated. Absence of PVL was observed in 44.44% of the patients, 30.56% had grade I PVL, 25% of the patients had grade II or above, and any PVL was observed in 55.56%. There was no statistically significant association between the degree of PVL and the extent or the distribution of AVC, aortic annulus diameters, ellipticity index, annulus/LVOT perimeter difference ratio or < LVOT-AO. The frequency of PVL was not significantly different with the use of balloon-expandable or self-expandable valves. A larger transcatheter heart valve (THV)/annulus sizing ratio was associated with a lower incidence and degree of PVL (p<0.001); there was no detectable PVL with a mean sizing ratio of 14.89±7.29, and grade I PVL occurred with a mean sizing ratio 12.43±0.84, while PVL of grade II or above occurred using the mean sizing ratio -0.42±5.57. The procedure-related THV/annulus sizing ratio was an important determinant of the degree of PVL after TAVI, whereas the MDCT-derived anatomical measurements of the aortic root and AVC were not predictors of PVL.

Echocardiographic Predictors of Left Ventricular Outflow Tract Obstruction following Repair of Atrioventricular Septal Defect.

Left ventricular outflow tract obstruction (LVOTO) is a common complication following surgical repair of atrioventricular septal defect (AVSD). We sought to determine predictors of LVOTO based on echocardiograms performed prior to initial repair of AVSD. Of the 415 children that had repair of AVSD from 2003 to 2012, 17 children were identified with LVOTO that required surgical intervention. Thirty-four patients with repaired AVSD and no LVOTO served as controls. Patient demographics, cardiac surgery type, and echocardiogram results at last follow-up were collected. Off-line analysis of the echocardiogram prior to AVSD repair was done to obtain: left ventricular outflow tract (LVOT) and interventricular septal diameter, chordae across LVOT, aortoseptal angle, left ventricular (LV) inflow/outflow length ratio, inferior displacement of the atrioventricular (AV) valve, atrioventricular valve index (AVVI) and presence of coarctation of the aorta. The LVOTO group had significantly smaller indexed LVOT diameters (P < .001), increased likelihood of chordae crossing the LVOT (P = .010), decreased LV inflow/outflow length ratio (P < .001), decreased AVVI (P = .014) and increased presence of coarctation of the aorta (P = .003) compared to control patients. A multiple logistic regression model including presence of chordae in the LVOT [OR 5.32, 95% CI: (1.24-22.78, P = .024] and an indexed LVOT diameter ≤2.5 cm/m2 [OR 5.41, 95% CI: (1.15-25.39) P = .032] demonstrated each to be independently associated with the development of LVOT obstruction (area under the receiving operating curve = 0.77). Chordae across the LVOT and an indexed LVOT diameter of ≤2.5 cm/m2 are associated with a higher risk of development of LVOTO following repair of AVSD. Identification of these risk factors on echocardiogram prior to initial AVSD repair can be useful in evaluating for future risk of LVOTO and the need for closer clinical follow-up.

Assessment of right heart function in preeclampsia by echocardiography.

Preeclampsia (PE) is a multisystemic disorder characterized by hypertension and proteinuria that is specific to pregnancy and associated with maternal and fetal morbidity-mortality. To assess right heart structure and function in PE by echocardiography using conventional and tissue Doppler techniques. In total, 67 women with untreated PE and 46 matched healthy pregnant women were included. PE was defined according to the ACOG (2002) criteria. Right and left heart functions were evaluated using transthoracic two-dimensional (2D) echocardiography with color Doppler and tissue Doppler imaging techniques. Right ventricular basal and outflow tract diameters and free wall thickness, right atrial end-systolic maximum diameter, and area were significantly higher in the PE group than the control group (p<0.05). Tricuspid annular plane systolic excursion, isovolumic acceleration time, tissue Doppler-derived tricuspid lateral annular systolic velocity (S'), right ventricle fractional area change, and myocardial performance index (Tei) were significantly lower in the PE group than the controls (p<0.05). PE does not only affect the left side of the heart but also the right side. This finding may open new scenarios, because right ventricular dysfunction may also be responsible for PE-related morbidity.

SUBSTITUTION OF LEFT VENTRICULAR OUTFLOW TRACT DIAMETER WITH BODY SURFACE AREA

Measurement of the left ventricular outflow tract (LVOT) diameter is a key parameter in the calculation of stroke volume, aortic valve area and mitral valve area on transthoracic echocardiography (TTE). We had observed that the numeric value for body surface area (BSA) reported in m2 frequently

Prevalence and risk factors for pulmonary arterial hypertension in end-stage renal disease patients undergoing continuous ambulatory peritoneal dialysis

Background: Pulmonary arterial hypertension (PAH) is a major complication in renal failure patients, but very little information is available on the cardiovascular parameters in these patients. The prevalence and risk factors for PAH were systematically evaluated in patients with end-stage renal diseases (ESRD) undergoing continuous ambulatory peritoneal dialysis (CAPD). Methods: Between January 2010 and January 2014, 177 ESRD patients (85 males and 92 females) undergoing CAPD therapy were recruited. General data, biochemical parameters and echocardiographic findings were collected and PAH risk factors studied. Results: Study participants consisted of 65 patients (36.52%) with PAH (PAH group) and 112 patients without PAH (non-PAH group). The interdialytic weight gain, systolic blood pressure and diastolic blood pressure (DBP), mean arterial pressure and hypertensive nephropathy incidence in the PAH group were significantly higher than the non-PAH group (all p < 0.05). There were significant differences between PAH group and non-PAH group in C-reactive protein-positive rate, N-terminal pro-brain natriuretic peptide (NT-proBNP), hemoglobin, prealbumin and serum albumin levels (all p < 0.05). Compared with non-PAH group, PAH group showed significant increases in right ventricular internal diameter (RVID), right ventricular outflow tract diameter (RVOTD), main pulmonary artery diameter, left atrial diameter (LAD), left ventricular end-diastolic diameter, interventricular septal thickness, left ventricular mass index, early diastolic mitral annulus velocity and valve calcification incidence (all p < 0.05), and decreased left ventricular ejection fraction (LVEF), tricuspid annulus plane systolic excursion (TAPSE) and early diastolic blood flow peak and mitral annulus velocity (E/E’) (all p < 0.05). Logistic regression analysis revealed that DBP, NT-proBNP, LAD, RVID, RVOTD, LVEF, TAPSE and E/E’ are major risk factors for PAH. Conclusion: We observed a high incidence of PAH in ESRD patients undergoing CAPD. Logistic regression analysis revealed that DBP, NT-proBNP, LAD, RVID, RVOTD, LVEF, TAPSE and E/E’ are high-risk factors for PAH in ESRD patients undergoing CAPD.

Evaluation of Echocardiographic Systolic Parameters in Pre-Eclamptics and Normotensives Women.

Early detection of changes in cardiovascular echocardiographic systolic parameters and their comparison with normotensives women. This was a hospital-based prospective case-control study carried out in Department of Obstetrics and Gynaecology in S.M.S Medical College, Jaipur, during the period from February 2013 to December 2014. In total, 100 women were enrolled in the study after applying inclusion and exclusion criteria. All women underwent two-dimensional echocardiography at rest. Cardiac systolic parameters were recorded and studied. Mean LVEDV in the PIH group was 75.71±4.8 versus 71.08±5.6ml in the control group, and the difference was statistically significant. Mean stroke volume was higher in the PIH group as compared to the control group, and the difference was statistically significant (59.83±7.4 vs. 52.48±6.4ml/min). Mean aortic root diameter in the PIH group was 2.188±1.04cm as compared to the 1.866±1.06cm in the control group which was statistically significant. Mean left ventricular outflow tract diameter was slightly higher in the PIH group as compared to the controls although the P value was not significant (2.37±1.06 and 1.99±1.08cm). Mean total vascular resistance was found to be higher in the PIH group as compared to the controls, and the difference was statistically significant (1389±57.04 vs. 1286±45.01 dynes/sec/cm(-5)). Systolic parameters get worsened in pre-eclamptics. Early detection of change in these parameters could help to identify high-risk women who are prone to develop cardiovascular morbidity in later life.

Echocardiographic assessment of aortic valve annular and left ventricular outflow tract diameter in conscious and anesthetized adult sheep prior to prosthetic aortic valve implantation.

Prosthetic heart valve implantation is commonly performed in patients that have valvular heart disease. Prior to clinical evaluation of newly developed prostheses, preclinical animal studies are performed for the assessment of both acute and chronic valvular function. Commonly, one size of valve is used in these preclinical studies, which can present difficulties with the implantation procedure and assessing valve function. Due to these potential problems, we developed a preoperative screening assessment in potential ovine candidates for prosthetic aortic valve implantation. By determining if there is a correlation between conscious and anesthetized echocardiographic examinations, an improvement in surgical confidence can predict that the animal is deemed a suitable candidate for a particular size of prosthetic valve for implantation prior to subjecting the animal to anesthesia and surgery. A total of 53 crossbred sheep (Ovis aries), male and female, 10-37 months of age, weighing between 41 and 77 kg, underwent conscious echocardiography and a subset of 29 of these animals underwent echocardiographic assessment under anesthesia for a preoperative valve size comparison in these animals prior to surgical prosthetic aortic valve implantation. Using 2D echocardiographic assessment, left ventricular outflow tract (LVOT) dimensions were assessed. The mean paired difference between anesthetized and conscious LVOT diameter measurement was -0.87 mm (p = 0.0066, standard deviation 1.598, 95% confidence interval, -0.4796, -0.26378, n = 29). This pilot study evaluation revealed that conscious echocardiographic assessment can play a role preoperatively in selecting potential candidates for surgical prosthetic aortic valve implantation, thereby minimizing the potential in prosthetic-native annular mismatching, which can contribute to altered LVOT function.

Application of micro transesophageal echocardiography (micro-TEE) in neonat and infant cardiac surgery

Objective To evaluate the value of phased array probe of transesophageal echocardiography miniature (micro-TEE) in the neonatal and infant cardiac surgery intraoperation. Methods Micro-TEE probe was used in children with weight ≤5 kg undergoing cardiac surgery to detect the atrial and ventricular cavity size, the left and right ventricular outflow tract diameter were detected by transthoracic echocardiography(TTE) 3-7 d after operation, and compared with the measured value immediately after the TEE. Results Before and after intubation, airway index not statistically significant (P>0.05). Preoperative TEE and TTE inspection results were consistent with intraoperative diagnosis. Postoperative TEE measuring intracardiac structural data (each room, chamber size and left and right ventricular outflow tract diameter) and postoperative TTE measurement value representing the difference was not statistically significant(P>0.05). Conclusions Micro TEE intraoperative guardianship of low birth weight infants is safe and feasible, and can supplement and improve the preoperative diagnosis, and can accurately and timely evaluate postoperative curative effect. Key words: Echocardiography, transesopheageal; Infant, low birth weight; Cardiac surgical procedures

Abstract 16866: Depressed Biventricular Outputs in Fetuses of Diabetic Mothers When Standardized to Estimated Fetal Weight

Background: Although the results of maternal diabetes on the newborn heart are well described, in-utero cardiovascular effects of maternal diabetes and obesity are not as well understood. Hypothesis: Echocardiographically derived measures of right and left heart flow volumes in fetuses of diabetic mothers (FDM) and fetuses of obese mothers (FOM) differ from those of normal fetuses. Methods: We prospectively enrolled 264 normal fetuses, 30 FDM and 49 FOM for prenatal research echocardiography. Estimated fetal weight (EFW) based norms for aortic and pulmonary valve velocity time integrals (AVVTI, PVVTI), right and left ventricular outflow tract diameters (LVOTD, RVOTD), aortic and pulmonary valve stroke volume (AVSV, PVSV), and cardiac output (LVCO, RVCO) were derived from the 264 control group fetuses using nonlinear regression to a Gompertz growth function. Z values for each parameter were determined, then analyzed using a non-paired two-tailed t-test to compare the three groups. Results: The mean ± SD EFW (g) for normal fetuses, FDM and FOM were 1610 ± 1201, 964 ± 694 and 1075 ± 1013; respective mean gestational ages (weeks) were 28.1±1.3, 25.3± 5, and 25 ± 6.6. The table shows mean Z value comparisons of VTI, OTD, SV and CO for the RV and LV in the three groups. Conclusions: FDM have significantly lower right and left heart stroke volumes and outputs than other fetuses matched for size, while FOM did not have demonstrable right or left heart stroke volume or cardiac output changes relative to normal fetuses. Similar to their relationship with gestational age, normal right and left ventricular stroke volumes and outputs follow a non-linear correlation with estimated fetal weight. Flow volumes in macrosomic fetuses may be better normalized to EFW rather than to gestational age. Reduced placental blood flow and ventricular compliance changes may be contributing to depressed biventricular cardiac output in FDM.

A MATCHED-PAIRED COMPARATIVE ANALYSIS OF THE HEMODYNAMICS OF THE TRIFECTA AND PERIMOUNT AORTIC BIOPROSTHESES

A MATCHED-PAIRED COMPARATIVE ANALYSIS OF THE HEMODYNAMICS OF THE TRIFECTA AND PERIMOUNT AORTIC BIOPROSTHESES

A validation study of electrical cardiometry in pregnant patients using transthoracic echocardiography as the reference standard

To validate electrical cardiometry (EC) in pregnant patients using transthoracic echocardiography (TTE) as the reference standard. To improve EC accuracy via a one-time, measurement of left ventricular outflow tract (LVOT) diameter. 44 non-laboring, resting women with singleton, viable pregnancies underwent simultaneous EC and TTE measurements. Data were analyzed using Bland-Altman analysis. Entry multiple regression with stepwise elimination was used to develop a model for improved prediction of stroke volume by TTE (SVTTE) using EC. Bootstrapping and an 11-fold cross validation were used to test the model. Heart rate by TTE and EC had a mean bias of 3.3beats/min and mean percentage error of 10.7%. Envelope time and left ventricular ejection time had a mean bias of -4.9ms and mean percentage error 12.7%. Stroke volumes by the two techniques had a mean bias of 15.6mL and mean percentage error of 43.7%. A model, SVEC_Modified, predicting SVTTE was developed using LVOT area, stroke volume by electrical cardiometry and weight. SVTTE and SVEC_Modified had a mean bias of -0.83mL and mean percentage error of 22%. EC accurately measures heart rate and duration of systole when compared with TTE. Stroke volume measurements correlate but have a high bias and percentage error. Knowledge of LVOT area, by a one-time, measurement with TTE, could improve prediction of stroke volume by EC.

Improving the accuracy of effective orifice area assessment after transcatheter aortic valve replacement: validation of left ventricular outflow tract diameter and pulsed-wave Doppler location and impact of three-dimensional measurements.

Echocardiographic calculation of effective orifice area (EOA) after transcatheter aortic valve replacement is integral to the assessment of transcatheter heart valve (THV) function. The aim of this study was to determine the most accurate method for calculating the EOA of the Edwards SAPIEN and SAPIEN XT THVs. One hundred intraprocedural transesophageal echocardiograms were analyzed. To calculate the post-transcatheter aortic valve replacement left ventricular outflow tract (LVOT) stroke volume (SV), four diameters were measured using two-dimensional echocardiography: (1) baseline LVOT diameter (LVOTd_PRE), (2) postimplantation LVOT diameter, (3) native aortic annular diameter, and (4) THV in-stent diameter. Four corresponding areas were planimetered by three-dimensional echocardiography. Two LVOT velocity-time integrals (VTI) were measured with the pulsed-wave Doppler sample volume at (1) the proximal (apical) edge of the valve stent or (2) within the valve stent at the level of the THV cusps. LVOT velocity-time integral with the sample volume at the proximal edge of the valve stent was used with the LVOT and aortic annular measurements above, whereas in-stent VTI was paired with the in-stent THV diameter to yield eight different SVs. Right ventricular outflow tract (RVOT) SV was calculated using RVOT diameter and RVOT VTI and was used as the primary comparator. Transaortic VTI was obtained by continuous-wave Doppler, and EOA calculations using each SV measurement were compared with (1) EOA calculated using RVOTSV and (2) planimetered aortic valve area using three-dimensional echocardiography (AVAplanimetry3D). Post-transcatheter aortic valve replacement EOA calculated using LVOTd_PRE was not significantly different from EOA calculated using RVOTSV (1.88±0.33 vs 1.86±0.39cm(2), P=.36) or from AVAplanimetry3D (1.85±0.28, P=.38, n=34). All other two-dimensional EOA calculations were statistically larger than EOA calculated using RVOTSV. All three-dimensional echocardiography-based EOA calculations were statistically different from AVAplanimetry3D. The most accurate EOA after implantation of a balloon-expandable THV is calculated using preimplantation LVOT diameter and VTI.

Sutureless Aortic Valve Prosthesis Sizing: Estimation and Prediction Using Multidetector-Row Computed Tomography.

The sutureless prostheses may facilitate minimally invasive aortic valve replacement because of easy and fast deployment. However, correct device sizing remains a crucial step of this procedure, which may be difficult and time consuming in minimal invasive approaches. We sought to analyze the accuracy of contrast-enhanced preoperative multidetector-row computed tomography (MDCT) in predicting the size of the prosthesis to be implanted in patients undergoing aortic valve replacement through a right anterior minithoracotomy (RAMT). From January 2011 to September 2013, 235 patients underwent aortic valve surgery as sole procedure with implantation (Sorin Perceval S) in RAMT. Inclusion criterion for this study was presence of preoperative multidetector-row computed tomography (MDCT) with contrast enhancement and Doppler echocardiography. A preoperative MDCT was used to measure the aortic annulus as the diameter derived from either the area (aD) or the circumference (cD) of the virtual basal ring, left ventricular outflow tract (LVOT) diameter derived either from the area (aLVOT) or the circumference (cLVOT). Multidetector-row CT was reviewed by a single operator who was blind to implanted valve size. The operator measured the aortic annulus and LVOT in multiplanar reconstruction modality. Aortic annular diameter and LVOT diameter were retrieved from echocardiographic records. Predictive models were built based on logistic regression; outcome variable was the sutureless valve size, and covariates (annular and LVOT measurements) were used as single and multivariate predictors. A classification tree was built and then pruned with limited nodes to be able to obtain better predictive performance. We identified 54 patients who had preoperative contrast-enhanced MDCT. Seven patients received a size S, 21 received a size M, and 26 received a size L prosthesis. The mean age of the patients at the time of intervention was 76.3 ± 6.8 years, and the mean logistic EuroSCORE was 10.4% ± 8.7%. Echocardiographic measurements showed lower accuracy compared to MDCT measurements. Echocardiographic LVOT measurement was 61.11% to predict the valve size, whereas annulus measurement was 53.7%. The aLVOT from MDCT had an accuracy of approximately 62.96%, and cLVOT had 64.81% predictive accuracy. Aortic annulus perimeter cD had the highest accuracy to predict the valve size [62.96%, under the curve, 0.61] followed by aortic annular surface aD having an accuracy of approximately 70.37% (under the curve, 0.75). Classification tree models, after pruning with 4 nodes, increased their accuracy (83.33%), and it was easy to interpret and possibly to implement for clinical use. Multidetector-row CT-derived estimates seem to have higher predictive value for valve size determination in patients undergoing RAMT with the Perceval S prosthesis, thus facilitating this delicate procedure and preventing the selection of wrong candidates. Possibly for precise aortic annulus measurement, contrast-enhanced MDCT is preferable.

Incidence and Predictors of Pacemaker Implantation in Patients Undergoing Transcatheter Aortic Valve Replacement.

Transcatheter aortic valve replacement (TAVR) has emerged as an alternative treatment for patients with symptomatic aortic stenosis who are at high risk for surgical aortic valve replacement. The development of conduction abnormalities is a major complication in the postprocedural period of TAVR. The objective of this study was to investigate the development of postprocedural conduction abnormalities and the requirement of permanent pacemaker (PPM) implantation in patients undergoing TAVR. Data from 137 consecutive patients who underwent TAVR (Edwards SAPIEN valve, Edwards Lifesciences, Irvine, CA, USA) between June 2008 and October 2012 were reviewed. Patients with prior history of PPM (n = 27) were excluded. The role of various predictors for pacemaker implantation after TAVR, including the valve index (calculated as [valve size/left ventricular outflow tract diameter] × 100) was investigated. A total of 31/110 (28.2%) patients required implantation of a PPM after TAVR. The median time to implantation of a PPM was 5 days after the procedure. The development of postprocedural complete heart block was the most common indication for implantation of a PPM (16/31; 51.6%). On multivariate analysis, the presence of preexisting right bundle branch block (RBBB) was found to be a strong predictor of PPM implantation after TAVR (adjusted odds ratio: 4.87; 95% confidence interval: 1.29-18.46, P = 0.020). Using the receiver operated curve analysis, a cut-off value of valve index of 128 was found to be a strong predictor for PPM implantation with a sensitivity of 73% and specificity of 61% (c statistic = 0.68). This study identified the presence of prior RBBB and a valve index of 128 as important risk factors for PPM implantation after TAVR. A larger implanted valve size relative to left ventricular outflow tract diameter leads to a greater compression of the intrinsic conduction system, increasing the need for pacemaker placement.