Systolic Velocity Time Integral Research Articles

Patient-specific pulmonary venous flow characterization and its impact on left atrial appendage thrombosis in atrial fibrillation patients

BackgroundCardioembolic strokes are commonly occurred in non-valvular atrial fibrillation patients, with over 90% of cases originating from clot in left atrial appendage (LAA), which is believed to be greatly related with hemodynamic characters. Numerical simulation is widely accepted in the hemodynamic analysis, and patient-specific boundaries are required for realistic numerical simulations. MethodThis paper firstly proposed a method that maps personalized pulmonary venous flow (PVF) by utilizing the volume changes of the left atrium (LA) over the cardiac cycle. Then we used data from patients with atrial fibrillation to investigate the correlation between PVF patterns and hemodynamics within the LAA. Meanwhile, we conducted a fluid-structure interaction analysis to assess the impact of velocity- and time-related PVF parameters on LAA hemodynamic characters. ResultsThe analysis reveal that the ratio of systolic to diastolic peak velocity (VS/VD), and systolic velocity-time integral (VTI) showed a significant influence on LAA velocity in patients with atrial fibrillation, and the increases of velocity- and time-related parameters were found to be positively correlated with the blood update in the LAA. ConclusionsThis study established a method for mapping patient-specific PVF based on LA volume change, and evaluated the relationship between PVF parameters and thrombosis risk. The present work provides an insight from PVF characters to evaluate the risk of thrombus formation within LAA in patients with AF.

Echocardiographic findings for improved prenatal diagnosis of aortic coarctation with ventricular septal defect.

Accurate prenatal diagnosis of coarctation of the aorta (CoA) associated with ventricular septal defect (VSD) remains challenging. The objective of the study was to identify which Doppler and/or two-dimensional sonographic findings are most useful for predicting fetal CoA/VSD. A retrospective cohort study identified 35 fetuses with suspected CoA/VSD. Prenatal imaging characteristics included the right ventricular/left ventricular, pulmonary artery (PA)/aorta ratio, aortic isthmus (AOI) Z score, diastolic velocity-time integral (VTID), and systolic velocity-time integral (VTIS) at the AOI. The area under the receiver operating characteristic curve (AUC), integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were calculated. Significant differences in the PA/AO, VTID, VTID/VTIS, VTID/VTIS, VTID/(VTID + VTIS), and AOI Z score between the true CoA group and false positives were found. When associated with VSD, the VTID/VTIS and VTID/(VTID + VTIS) had the highest AUC (0.97, 95% confidence interval: 0.84-1.00), with 88.46% sensitivity and 100.00% specificity for predicting the true CoA. The AOI Z score had the highest sensitivity (92.31%). Adding the VTID/VTIS to the AOI Z score significantly improved the performance (IDI, 50%; NRI, 82%; P < 0.05), with an improvement in specificity (77.78% vs. 55.56%; non-Event P = 0.008) without sacrificing sensitivity (96.15% vs. 92.31%; Event P = 0.564). In fetuses with suspected CoA associated with VSD, the quantitativespectral Doppler metric aided accurate detection of the fetal CoA, with reduced false positives. The conventional AOI Z score plus spectral Doppler metric may improve the overall diagnostic accuracy of CoA/VSD.

Carotid Doppler Ultrasonography for Hemodynamic Assessment in Critically Ill Children.

An accurate assessment of cardiovascular performance is essential to predict and evaluate hemodynamic response to interventions. The objective of this prospective study was to assess whether point-of-care ultrasonography of the common carotid artery (CCA) can estimate the stroke volume (SV) and cardiac index (Ci) of critically ill children. Participants underwent Doppler ultrasonography of the left CCA and transthoracic echocardiography (TTE). Variables measured by TTE were SV and Ci. Carotid blood flow (CBF) was calculated based on both systolic velocity-time integral (CBF(s)) and total velocity-time integral (CBF(t)). Carotid corrected flow time(CFT)was also determined. A total of 50 children were enrolled. The median age and weight of participants were 36.0months and 14.2kg, respectively. Both CBF(s) and CBF(t) correlated very strongly with SV (ρ = 0.98 and 0.97, respectively) and Ci (ρ = 0.96 and 0.92, respectively). Agreement analysis showed low biases and clinically acceptable percentage errors between variables measured by TTE (SV and Ci) and those estimated by Doppler ultrasonography. Linear regression analysis revealed that the Ci of mechanically ventilated children can be estimated by the following equation: [Formula: see text]. CFT did not significantly correlate with SV or Ci (ρ = 0.27 and 0.05, respectively). Doppler ultrasonography of the left CCA is able to estimate the SV and Ci of critically ill children. Therefore, the CDU may be considered as an alternative for estimating Ci in critically ill children when TTE is not feasible or available.

Echocardiography and cardiac magnetic resonance in children with repaired tetralogy of fallot and their correlations with exercise capacity

Abstract Background Severe pulmonary regurgitation (PR) and progressive right ventricular (RV) dilation and disfunction are common in patients with repaired Tetralogy of Fallot (r-TOF) and should be carefully monitored during the follow up of these patients. In this contest, Echocardiography and Cardiac Magnetic Resonance (CMR) have a complementary diagnostic role. Purpose To correlate Echo and CMR parameters in children (&amp;lt;18 years) with r-TOF with at least moderate PR assessed by Echocardiography and to analyse which parameter was associated with peak oxygen consumption (Vo2). Methods Paediatric patients with r- TOF with at least moderate PR at the echo evaluation who underwent a CMR study within six months were included by using hospital databases. All patients underwent standard echo-Doppler study including RV end-diastolic area (RVEDA), end-systolic area (RVESA), fractional area change (FAC) and TAPSE; PR was assessed by Color Doppler, continuous-wave (CW) Doppler and derived parameters such as pressure half time (PHT), PR index, ratio of diastolic and systolic time-velocity integrals (DSTVI) of the main pulmonary artery. By speckle tracking we measured also RV global longitudinal strain (RVGLS) and right atrial strain (RAS). All the patients underwent CMR to assess PR and right ventricular volumes and ejection fraction (EF). Of these, 36 patients underwent cardiopulmonary exercise test (CPET). Results Fourty-six children (aged 13.7±3.0 years) were included. Echo derived RV areas correlated significantly with CMR RV volumes (r=0.72, p&amp;lt;0.0001). RVEDA &amp;gt;21.9 cm2/m2 had a good sensitivity (83.3%) and specificity (73.5%) to identify a RV end-diastolic volume (RVEDV) ≥150 ml/m2. No correlation was found among TAPSE, FAC, RVGLS and RVEF calculated by CMR nor between PHT, PR index and DSTVI and PR-RF. Only A' wave velocity showed a significant but modest correlation with CMR RF (r=0.57, p&amp;lt;0.0001). Flow reversal in pulmonary branches showed a sensitivity of 95.8% and a specificity of 59.1% to identify PR RF ≥35%. RVEF by CMR was preserved in all patients, while TAPSE was reduced in 78.2% and RVGLS in 60.8%. None of the CMR parameters correlated with peak Vo2. At the multivariate analysis RAS was the best independent predictor of peak Vo2 (p&amp;lt;0.0001). Conclusion In children, flow reversal in pulmonary branches identifies hemodynamically significant PR at CMR. RV area by echocardiogram is a valid first-line parameter to screen RV dilation. Our study suggests that, also for the RV, there is longitudinal systolic dysfunction in presence of preserved RV EF. RAS is the best predictor of peak Vo2 and should be added in the follow up of these patients. Funding Acknowledgement Type of funding source: None

1160 Which parameters do correlate better with functional exercise capacity in children with repaired Tetralogy of Fallot? An echo and CMR study

Abstract Background Severe pulmonary regurgitation (PR) and progressive right ventricular (RV) disfunction are common in patients with repaired Tetralogy of Fallot (r-TOF), and CMR has become the gold standard for PR and RV volumes assessment. However, in paediatric patients CMR use can be limited by the need for general anaesthesia. Purpose The aim of our study was to analyse a paediatric population (&amp;lt;18 years) of r-TOF with at least moderate PR (regurgitant fraction (RF) &amp;gt;20%), assessed by CMR and to assess which Echo or CMR parameter is associated with functional capacity evaluated by cardiopulmonary exercise test (CPET). Methods Consecutive r-TOF patients regularly followed at our Institution, with at least moderate PR (RF &amp;gt;20% by CMR), were included in the study. Echocardiographic and CMR studies were performed within six months. Echo study: PR was assessed by Color Doppler, continuous-wave (CW) Doppler and derived parameters such as pressure half time (PHT), PR index, ratio of diastolic and systolic time-velocity integrals (DSTVI) of the main pulmonary artery. RV end-diastolic area (RVEDA), end-systolic area (RVESA), right ventricle outflow tract (RVOT) end-diastolic area, fractional area change (FAC) and TAPSE were calculated. By speckle tracking analysis we measured also RV global longitudinal strain (RVGLS) and right atrial strain (RAS). CMR study: we evaluated PR as RF, end-diastolic and systolic volumes (RVEDV, RVESV) and right ventricle ejection fraction (RVEF). In addition, patients underwent CPET within one month from CMR and peak oxygen consumption (Vo2) values were measured. Results We studied 53 r-TOF patients (aged 13.8 ± 2.5 years, ranged between 7.1 and 17.6 years, male 57%, surgical repair at a mean age of 1.1 ± 0.75 years). Based on CMR data, 38 out of 53 had free PR (RF &amp;gt;35%) and nobody had &amp;gt; mild tricuspid regurgitation. We found a good correlation between RVEDA and CMR RVEDV (p &amp;lt;0.0001, r =0.73), which slightly improved adding RVOT area (p &amp;lt; 0.0001, r =0.75). RVEDA indexed (RVEDAi) &amp;gt; 21.3 cm2/mq was found to have a good sensitivity (83.3%, specificity 64.9%, AUC0.74) for RVEDV indexed (RVEDVi) &amp;gt;150 ml/mq. No correlation was found between TAPSE, FAC, RVGLS measured by echo and RVEF calculated by CMR. No correlation was found between echo Doppler parameters used to assess PR severity and PR RF measured by CMR. None of the CMR studied parameters (RV volumes, RVEF, RF) correlated with peak Vo2. Among the Echo parameters only RAS demonstrated a good correlation (p &amp;lt;0.0001, r =0.70) with peak Vo2. At the multivariate analysis including RAS, TAPSE, FAC, RVGLS, RVEF and RVEDV, RAS was the best independent predictor of peak Vo2 (p &amp;lt;0.0001). Conclusion Echo parameters studied to assess PR are unsatisfactory and showed no correlation with PR RF by CMR. RVEDAi is well correlated with CMR volumes. Right atrial strain is the best predictor of peak Vo2 in young patients with r-TOF and should be included in their follow up. Abstract 1160 Figure.

The Diastolic and Systolic Velocity-Time Integral Ratio of the Aortic Isthmus Is a Sensitive Indicator of Aortic Coarctation in Fetuses

Prenatal diagnosis of coarctation of the aorta (CoA) is challenging and is affected by high false-positive and false-negative rates. The aim of this study was to identify sonographic criteria to improve the identification of fetal CoA. A retrospective review was conducted of subjects with prenatal suspicion for CoA who also had postnatal follow-up. Sixty-nine fetuses were identified with possible CoA, and 47 normal fetuses were selected as control subjects. Retrospective measurements of right ventricular/left ventricular ratio, pulmonary artery/aorta ratio, aortic isthmus (AOI) Z score, diastolic velocity-time integral (VTID), and systolic velocity-time integral (VTIS) at the AOI were recorded. Receiver operating characteristic curve analysis identified the parameter most predictive of postnatal CoA. When comparing subjects with (n=31) and without (n=38) CoA, significant differences were detected for the AOI Z score, VTID, VTID/VTIS ratio, and VTID/(VTID+VTIS) ratio (P<.001). The areas under the receiver operating characteristic curve were 0.92, 0.92, 0.78, 0.74, 0.71, and 0.68 for the VTID/VTIS ratio, VTID/(VTID+VTIS) ratio, VTID, AOI Z score (sagittal view), AOI Z score (three-vessel tracheal view), and pulmonary artery/aorta ratio, respectively. There was a 25% (95% CI, 14%-35%) improvement in the area under the curve after adding the VTID/VTIS ratio to the basic model (AOI Z score [sagittal view]), and this ratio (after transformation) showed significantly better discrimination and reclassification ability for determining CoA. The pulmonary artery/aorta ratio, VTID, VTID/VTIS ratio, and VTID/(VTID+VTIS) ratio were stable throughout the normal fetal developmental period in this study. In cases with suspected prenatal diagnosis of CoA, evaluation of spectral Doppler measurements, such as the VTID/VTIS ratio, may enhance the accuracy of diagnosis with fetal echocardiography.

Usefulness of Intraprocedural Pulmonary Venous Flow for Predicting Recurrent Mitral Regurgitation and Clinical Outcomes After Percutaneous Mitral Valve Repair With the MitraClip

ObjectivesThe aim of this study was to determine the prognostic value of pulmonary venous (PV) flow during MitraClip implantation. BackgroundThe clinical significance of PV flow information during MitraClip implantation is unknown. MethodsA total of 300 patients who underwent MitraClip implantation and in whom the measurement of PV flow was completed using intraprocedural transesophageal echocardiography were retrospectively reviewed. The optimal threshold of the ratio of systolic velocity-time integral (Svti) to diastolic velocity-time integral (Dvti) ratio after MitraClip placement for major adverse cardiovascular events (all-cause death, redo MitraClip implantation, mitral valve surgery, and heart transplantation) during 12 months was assessed. The best cutoff ratio was 0.72. Patients were divided into 2 groups using this cutoff ratio (low Svti/Dvti, n = 91; high Svti/Dvti, n = 209). ResultsFollowing mitral regurgitation reduction by MitraClip placement, Svti increased in the both groups. The frequency of mitral regurgitation 3/4+ immediately after MitraClip implantation, at 1-month follow-up, and at 12-month follow-up was significantly higher in patients with low Svti/Dvti ratios than in those with high Svti/Dvti ratios (after MitraClip placement, 5.5% vs. 0%; p < 0.001; at 1 month; 26% vs. 5.2%; p < 0.001; at 12 months, 18% vs. 5.3%; p = 0.006). Major adverse cardiovascular events during 12 months were significantly higher in patients with low Svti/Dvti ratios than in those with high Svti/Dvti ratios (23% vs. 6.2%; p < 0.001). Multivariate analysis demonstrated that low Svti/Dvti ratio was significantly associated with major adverse cardiovascular events during 12 months after adjustment for age, baseline renal function, and mean transmitral pressure gradient (adjusted hazard ratio: 4.00; 95% confidence interval: 2.02 to 8.23; p < 0.001). ConclusionsPV flow information in the catheterization laboratory immediately after MitraClip implantation predicted recurrent mitral regurgitation and worse long-term outcomes.

Relation Between Pulmonary Venous Flow and Left Atrial Pressure During Percutaneous Mitral Valve Repair With the MitraClip

Pulmonary venous (PV) flow may provide valuable information in terms of the severity of mitral regurgitation and left atrial (LA) pressure. We sought to find PV flow determinants of LA pressure during MitraClip procedure. We analyzed 575 PV flows in 290 patients using transesophageal echocardiography before and after MitraClip procedure. We measured peak systolic velocity (Sv), diastolic velocity (Dv), systolic velocity time integral (Svti), diastolic velocity time integral (Dvti), and those systolic to diastolic ratio as PV flow parameters. Systolic PV flow velocity was lower than diastolic PV flow velocity before the procedure, but systolic PV flow velocity markedly increased after the procedure. Peak Sv/Dv ratio and Svti/Dvti ratio after the procedure were significantly higher than those before the procedure (peak Sv/Dv; 1.06 [inter-quartile range (IQR) 0.73 to 1.34] vs 0.32 [IQR 0.03 to 0.55], p <0.001, Svti/Dvti; 1.06 [IQR 0.76 to 1.61] vs 0.26 [IQR 0.02 to 0.51], p <0.001). Peak Sv/Dv ratio and Svti/Dvti ratio were negatively correlated with mean LA pressure and LA pressure V wave, respectively (peak Sv/Dv ratio; r = -0.50 and r = -0.59, Svti/Dvti ratio; r = -0.47 and r = -0.58, p <0.001). In receiver operating characteristics curve assessing the ability of PV flow to predict mean LA pressure ≥20 mm Hg after the successful procedure, the area under the curve of peak Sv/Dv ratio was 0.76 (p <0.001). Peak Sv/Dv ratio <0.98 best predicted LA pressure ≥20 mm Hg with 77% sensitivity and 71% specificity. In conclusion, systolic PV flow velocity immediately increased in response to mitral regurgitation reduction during MitraClip procedure. PV flow velocity, specifically systolic to diastolic ratio, was useful to evaluate invasively determined LA pressure.

Reduced stroke distance of the left ventricular outflow tract is independently associated with long-term mortality, inpatients hospitalized due to heart failure.

Reduced blood circulation is an important feature of heart failure, and Doppler stroke distance of the left ventricular outflow tract is a measure of forward stroke volume. Several echocardiographic parameters have known prognostic implications in heart failure, but the prognostic implications of stroke distance in relation to other parameters are insufficiently known. The aim was therefore to test the hypothesis that stroke distance is associated with five-year all-cause mortality, independently of other echocardiography variables, and that stroke distance has added long-term prognostic value. A cohort of 350 consecutive elderly patients, over 65years of age and mean 79·9±7·1years, hospitalized due to heart failure was studied. Patients with available echocardiography were included and images evaluated. Stroke distance was measured by tracing the systolic velocity time integral (VTI) of the pulsed wave Doppler in the left ventricular outflow tract. Other parameters were also estimated, such as left ventricular ejection fraction (LVEF), left ventricular mass, left atrial volume, early diastolic mitral velocity (E), deceleration time and mitral annulus tissue Doppler diastolic velocity (e') and pulmonary artery systolic pressure (PASP). Five-year all-cause mortality, assessed without missing data, was 67·7%. Multivariate analysis showed that stroke distance, E/e' and PASP were independently associated with mortality, but LVEF was not. Stroke distance was associated with long-term mortality, independently of other known echocardiographic prognostic factors in elderly patients hospitalized with heart failure. Only when stroke distance was excluded from analysis, LVEF became associated with mortality. Stroke distance had additive prognostic value.

Quantification of Aortic Valve Regurgitation by Pulsed Doppler Examination of the Left Subclavian Artery Velocity Contour: A Validation Study with Cardiovascular Magnetic Resonance Imaging

Reflux of the aortic regurgitation (AR) causes an increased diastolic reverse flow in the aorta and its branching vessels. We aimed to evaluate the feasibility and accuracy of Doppler measurements in the left subclavian artery (LSA) for quantification of AR in a cardiovascular magnetic resonance imaging (CMR) validation study. Systolic and diastolic flow profiles of the LSA (subclavicular approach) were evaluated prospectively by use of pulsed wave Doppler in 59 patients (55.5±15years; 44 men), 47 with a wide spectrum of AR and 12 as control group. Using CMR phase-contrast sequences (performed 1cm above the aortic valve), the AR was divided into three groups: mild, regurgitant fraction (RF)<20% (n=17); moderate, RF 20%-40% (n=10); and severe, RF>40% (n=20). The LSA Doppler-derived RF was calculated as the ratio between diastolic and systolic velocity-time integrals (VTI). Quality LSA Doppler signal could be obtained in all cases. Patients with CMR severe AR had higher values of LSA Doppler-derived RF (51%±9% vs 36%±11% vs 16%±8%; P<.0001). LSA Doppler showed a good correlation with CMR, with a sensitivity of 95%, specificity of 89%, and diagnostic accuracy for severe AR of 91.5%. Finally, Bland-Altman plots showed agreement in the group with moderate to severe AR (mean bias=-2.2%±8%, 95% CI, -17.7 to 13.3; P=.145) but differed in mild AR. Measurements of the RF for quantification of AR using LSA Doppler are comparable to those of CMR, highlighting the potential role of LSA Doppler as an adjunctive technique to assess the severity of AR.

Diagnostic value of Doppler echocardiography for identifying hemodynamic significant pulmonary valve regurgitation in tetralogy of Fallot: comparison with cardiac MRI

Quantification of pulmonary regurgitation (PR) is essential in the management of patients with repaired tetralogy of Fallot (TOF). We sought to evaluate the accuracy of first-line Doppler echocardiography in comparison with cardiac magnetic resonance imaging (MRI) to identify hemodynamic significant PR. Paired cardiac MRI and echocardiographic studies (n = 97) in patients with repaired TOF were retrospectively analyzed. Pressure half time (PHT) and pulmonary regurgitation index (PRi) were measured using continuous wave Doppler. The ratio of the color flow Doppler regurgitation jet width to pulmonary valve (PV) annulus (jet/annulus ratio) and diastolic to systolic time velocity integral (DSTVI; pulsed wave Doppler) were assessed. Accuracy of echocardiographic measurements was tested to identify significant PR as determined by phase-contrast MRI (PR fraction [PRF] ≥ 20%). Mean PRF was 29.4 ± 15.7%. PHT < 100 ms had a sensitivity of 93%, specificity 75%, positive predictive value (PPV) 92% and negative predictive value (NPV) 78% for identifying significant PR (C-statistic 0.82). PRi < 0.77 had sensitivity and specificity of 66% and 54%, respectively (C-statistic 0.63). Jet/annulus ratio ≥1/3 had sensitivity 96%, specificity 75%, PPV 92% and NPV 82% (C-statistic 0.87). DSTVI had sensitivity 84%, specificity 33%, PPV 84% and NPV 40%, (C-statistic 0.56). Combined jet/annulus ratio ≥1/3 and PHT < 100 ms was highly accurate in identifying PRF ≥ 20%, with sensitivity 97% and specificity 100%. PHT and jet/annulus ratio on Doppler echocardiography, especially when combined, are highly accurate in identifying significant PR and therefore seem useful in the follow-up of patients with repaired TOF.

Coronary Flow Parameters Assessed by Transesophageal Echocardiography in Patients with Coronary Artery Ectasia Baseline Measurements and the Effects of Intravenous Verapamil

Background and rationale: Coronary artery ectasia (defined as luminal dilatation 1.5 to 2 times the adjacent healthy coronary artery or the diameter of the corresponding coronary artery in the control group in case of diffuse ectasia) is an uncommon disorder, usually associated with underlying myocardial ischemia. Micro-circulatory dysfunction has been demonstrated as one possible mechanism to explain ischemia in this disorder. Calcium antagonists have been proven to relieve microvascular spasm. Aim of the study: To test the hypothesis that relieving microvascular spasm in patients with coronary artery ectasia, through intravenous administration of verapamil, may result in improvement of microvascular coronary flow as reflected by coronary flow parameters assessed by transesophageal echocardiography (TEE). Patients and methods: Thirty patients with angiographically documented coronary artery ectasia of the left anterior descending artery were prospectively enrolled in the current study. Ten patients with normal coronary arteries were included as controls. All forty patients underwent TEE using pulsed wave Doppler (PWD) to measure peak systolic and diastolic velocities (m/sec); systolic, diastolic and total velocity time integrals (cm); and the systolic, diastolic and total coronary blood flow (cm³/min) in the proximal LAD before and after intravenous injection of verapamil (0.1 mg/kg). Results: Resting systolic, diastolic, and total coronary blood flow (cm³/min) were significantly higher in patients with ectasia compared to normal subjects (60.83 ± 27.7 cm³/min versus 25.31 ± 9.01 cm³/min, p<0.001; 126.89 ± 49.22 cm³/min versus 53.15 ± 18.30 cm³/min, p<0.001; and 188.02 ± 70.36 cm³/min versus 78.46 ± 25.97 cm³/min, p<0.001). There was a trend, not reaching statistical significance, towards higher basal peak velocities in normal subjects compared to patients with ectasia. In patients with coronary artery ectasia, intravenous injection of verapamil resulted in an increase in all observed coronary flow parameters including: peak systolic velocity (m/sec) from 0.19 ± 0.05 to 0.21 ± 0.04, p=<0.05, peak diastolic velocity (m/sec) from 0.39 ± 0.11 to 0.48 ± 0.15, p=<0.001, systolic velocity time integral (cm) from 3.0 ± 1.05 to 3.38 ± 0.78, p=<0.05, diastolic velocity time integral (cm) from 6.22 ± 1.97 to 8.42 ± 2.09, p=<0.001; total velocity time integral (cm) from 9.22 ± 2.73 to 11.8 ± 2.64, p=<0.001, systolic coronary blood flow (cm³/min) from 60.83 ± 27.7 to 69.0 ± 22.7, p=<0.05, diastolic coronary blood flow (cm³/min) from 126.89 ± 49.22 to 173.01 ± 62.4 p=<0.001, and total coronary blood flow (cm³/min) from 188.02 ± 70.36 to 242.0 ± 81.82, p=<0.001. Conclusion: Intravenous administration of verapamil resulted in statistically significant improvement of coronary flow parameters in patients with coronary artery ectasia. Further studies are needed to confirm whether continued treatment with verapamil translates to symptomatic improvement in the clinical setting.

Longitudinal Validation of the Diastolic to Systolic Time-Velocity Integral Ratio as a Doppler-Derived Measure of Pulmonary Regurgitation in Patients with Repaired Tetralogy of Fallot.

Pulmonary regurgitation (PR) is a common residual lesion and major determinant of outcome following surgical repair for tetralogy of Fallot. We sought to longitudinally study a previously described echocardiographic index as a correlate of PR measured by cardiac magnetic resonance imaging (CMR). We conducted a retrospective longitudinal study of patients with baseline and follow-up echocardiogram and CMR. The baseline studies were obtained as part of a research protocol, while the follow-up studies were performed for clinical purposes. On echocardiogram, the ratio of diastolic and systolic time-velocity integrals (DSTVI) in the main pulmonary artery was calculated. The Wilcoxon matched-pairs signed-rank test was used to test for individual changes in PR on echocardiogram and CMR. A linear regression of pulmonary valve regurgitant fraction (RF) was fit on DSTVI to identify clinically meaningful cut points of DSTVI. Thirty-five subjects were included, age at follow-up 18.3±3.5years. The follow-up between consecutive CMRs was a median time of 60months (interquartile range 46-73). There was a moderate correlation between DSTVI and PR measured as RF by CMR (r=0.62, p=0.0001). A CMR RF of 20 and 40% (the boundaries between mild/moderate and moderate/severe PR) corresponded with DSTVI of 0.52 and 0.79 (95% CI 0.39; 0.66, and 0.69; 89), respectively. There was no significant change in either DSTVI (p=0.61) or PR (p=0.89) from baseline to follow-up. This study lends further credence to the DSTVI as an accurate reflection of PR. This index might become helpful in the routine echocardiographic assessment of PR. Further studies are needed to determine whether changes in RF by CMR result in changes in DSTVI.

Superior Mesenteric Arterial Flow Pattern is Associated with Major Adverse Events in Adults with Fontan Circulation.

Factors contributing to the failure of Fontan circulation in adults are poorly understood. Reduced superior mesenteric arterial (SMA) flow has been identified in pediatric Fontan patients with protein-losing enteropathy. SMA flow has not been profiled in an adult Fontan population and its association with adverse events is unknown. We aimed to examine associations between SMA flow patterns and adverse events in adult Fontan patients. We performed a retrospective review of adult Fontan patients who underwent echocardiograms between 2008 and 2014. SMA Doppler data included peak systolic and end-diastolic velocity and velocity time integral (VTI). Systolic/diastolic (S/D) ratio and resistive index were calculated. The relationship between SMA flow parameters and major adverse events (death or transplantation) was examined using proportional hazard Cox regression analyses. Kaplan-Meyer analysis was conducted to construct survival curve of patients with and without adverse events. 91 post-Fontan adult patients (76% systemic left ventricle, 20% atriopulmonary Fontan, mean age 27.9years) were analyzed. Adverse events occurred in nine patients (death=4, transplant=5). When compared with the non-event group, the event group had increased end-diastolic velocity [hazard ratio (HR) 1.5, 95% confidence interval (CI) 1.1-1.8; p=0.002], increased systolic VTI (HR 1.5, 95% CI 1.1-2.2, p=0.02), increased diastolic VTI (HR 1.7, 95% CI 1.2-2.4, p=0.004), decreased S/D velocity ratio (HR 0.32, 95% CI 0.14-0.71, p=0.006), decreased S/D VTI ratio (HR 0.76, 95% CI 0.61-0.97, p=0.02), and decreased resistive index (HR 0.29, 95% CI 0.14-0.60, p=0.0007). Increased end-diastolic velocity and VTI in mesenteric arterial flow, with lower systolic/diastolic ratio and resistive index, were associated with death and need for heart transplant in adult Fontan patients. The mesenteric hyperemic flow was also associated with clinical signs of portal venous outflow obstruction, suggesting the presence of vasodilatory state in end-stage adult Fontan circulation.

Transcatheter Replacement of Stenotic Aortic Valve Normalizes Cardiac-Coronary Interaction by Restoration of Systolic Coronary Flow Dynamics as Assessed by Wave Intensity Analysis.

Aortic valve stenosis (AS) can cause angina despite unobstructed coronary arteries, which may be related to increased compression of the intramural microcirculation, especially at the subendocardium. We assessed coronary wave intensity and phasic flow velocity patterns to unravel changes in cardiac-coronary interaction because of transcatheter aortic valve implantation (TAVI). Intracoronary pressure and flow velocity were measured at rest and maximal hyperemia in undiseased vessels in 15 patients with AS before and after TAVI and in 12 control patients. Coronary flow reserve, systolic and diastolic velocity time integrals, and the energies of forward (aorta-originating) and backward (microcirculatory-originating) coronary waves were determined. Coronary flow reserve was 2.8±0.2 (mean±SEM) in control and 1.8±0.1 in AS (P<0.005) and was not restored by TAVI. Compared with control, the resting backward expansion wave was 45% higher in AS. The peak of the systolic forward compression wave was delayed in AS, consistent with a delayed peak aortic pressure, which was partially restored after TAVI. The energy of forward waves doubled after TAVI, whereas the backward expansion wave increased by >30%. The increase in forward compression wave with TAVI was related to an increase in systolic velocity time integral. AS or TAVI did not alter diastolic velocity time integral. Reduced coronary forward wave energy and systolic velocity time integral imply a compromised systolic flow velocity with AS that is restored after TAVI, suggesting an acute relief of excess compression in systole that likely benefits subendocardial perfusion. Vasodilation is observed to be a major determinant of backward waves.

0470: Echocardiographic estimate of pulmonary vascular resistances: a validation in a non-selected population with pulmonary hypertension

Invasive hemodynamic procedures are still necessary to appreciate pulmonary hypertension characteristics. A few studies have adressed the issue of echocardiographic evaluation, but lack an external validation of their results with various settings and patients. The aim of our study was to appreciate the value of 2 published echocardiographic evaluations of pulmonary vascular resistances (PVR) based on tricuspid regurgitation maximal velocity (TRV) and right ventricular outflow tract systolic time velocity integral (TVI). All of the patients presenting during 2013 for invasive haemo-dynamic evaluation with a suspected pulmonary hypertension were prospec-tively included, with echocardiography being done within 24 hours of catheterization. The TRV/TVI and TRV2/TVI ratio and echographic estimations of PVR were compared with catheter values; predictive values to detect elevated PVR were assessed. 43 patients were included, 12 with atrial fibrillation, 16 with valvular disease, 14 with hypertrophic cardiopathy. Mean pulmonary pressure was 41±11 mmHg. TRV/TVI and TRV2/TVI were correlated with PVR (r=0.71 and r=0.78 respectively, p<0.01). Using TRV2/TVI, a cutpoint value of 0.98 had a specificity of 86% and a sensitiviy of 80% to predict PVR over 6 UW. Estimation of PVR with the previously published formula PVR = 5,19 TRV2/TVI - 0.4 was 100% correct to predict an PVR under 3 UW and 93% correct to predict an PVR over 6 UW. Our results confirm the value of echocardiographic measurement of TRV2/TVI to evaluate PVR in a routine fashion for a non-selected population with high pulmonary pressure (figure next page). Download : Download full-size imageAbstract 0470 – Figure: Bland and Altmann plot Abstract 0470 – Figure: Bland and Altmann plot

Correlation between pulmonary regurgitation and right ventricular myocardial performance index in TOF patients after surgical repair

Objective and aimResidual PR after repair of tetralogy of Fallot is an important determinant of the outcome of patients. Patients and methodsWe aim to assess severity of PR by PR index and diastolic/systolic time velocity integrals (DSTVI) and to correlate both of them to RVMPI, to detect which is more likely to reflect RV global function. This is a cross sectional study in which 33 patients with repaired TOF, and 46 controls were enrolled. For each patient full medical history and examination were obtained, conventional and tissue Doppler echocardiography were done, to measure pulmonary regurgitation by two indices: PR index and diastolic systolic time velocity integrals (DSTVI), to measure myocardial tissue velocities at the tricuspid annulus, to determine RVMPI, and to correlate it to the PR indices. Resultsour study included 33 patients with totally corrected TOF, and 46 controls, there were statistically significant differences in S′,E′,A′ velocities, and RVMPI between cases and controls, no statistically significant correlation between PR index, DSTVI and the RVMPI of the patients. ConclusionTissue Doppler RVMPI in patients after surgical repair of Fallot tetralogy is not correlated to the degree of PR measured by two indices: PR index and DSTVI, a new index that can assess severity of PR and correlate to RV functions is required.

Influence of Type of Aortic Valve Prosthesis on Coronary Blood Flow Velocity

Severe aortic valve stenosis is associated with high resting and reduced hyperemic coronary blood flow. Coronary blood flow increases after aortic valve replacement (AVR); however, the increase depends on the type of prosthesis used. The present study investigates the influence of type of aortic valve prosthesis on coronary blood flow velocity. The blood flow velocity in the left anterior descending coronary artery (LAD) and the right coronary artery (RCA) was measured intraoperatively before and after AVR with a stentless bioprosthesis (Sorin Freedom Solo; n = 11) or a bileaflet mechanical prosthesis (St. Jude Medical Regent; n = 11). Measurements were made with an X-Plore epicardial Doppler probe (Medistim, Oslo, Norway) following induction of hyperemia with an adenosine infusion. Preoperative and postoperative echocardiography evaluations were used to assess valvular and ventricular function. Velocity time integrals (VTI) were measured from the Doppler signals and used to calculate the proportion of systolic VTI (SF), diastolic VTI (DF), and normalized systolic coronary blood flow velocities (NSF) and normalized diastolic coronary blood flow velocities (NDF). The systolic proportion of the LAD VTI increased after AVR with the St. Jude Medical Regent prosthesis, which produced higher LAD SF and NSF values than the Sorin Freedom Solo prosthesis (SF, 0.41 ± 0.09 versus 0.29 ± 0.13 [P = .04]; NSF, 0.88 ± 0.24 versus 0.55 ± 0.17 [P = .01]). No significant changes in the LAD velocity profile were noted after valve replacement with the Sorin Freedom Solo, despite a significant reduction in transvalvular gradient and an increase in the effective orifice area. AVR had no effect on the RCA flow velocity profile. The coronary flow velocity profile in the LAD was significantly influenced by the type of aortic valve prosthesis used. The differences in the LAD velocity profile probably reflect differences in valve design and the systolic transvalvular flow pattern.

Frequency, Time Course, and Possible Causes of Right Ventricular Systolic Dysfunction after Cardiac Transplantation: A Single Center Experience

The frequency and causes of right ventricular (RV) systolic dysfunction early after cardiac transplantation are not well defined. We investigated the prevalence and causes of RV dysfunction in 27 heart transplant recipients, as measured by lateral tricuspid annular plane excursion (TAPSE) and fractional area change (FAC) at a mean of 15 ± 11 days after transplant. Tissue Doppler imaging was used to assess systolic time velocity integral (TVI) of the RV basal free wall. A subset of 22 patients had follow-up TAPSE measurement at 406 ± 121 days. RV systolic dysfunction, defined as TAPSE > 2 standard deviation (SD) below values in a control group, was present in 100% (27/27) of patients (P < 0.05). FAC was also significantly lower in patients compared with controls (P < 0.0001). TVI confirmed the presence of RV dysfunction in all 16 patients with both TAPSE and TVI (P < 0.05). Ischemic time (P = 0.017) and posttransplant tricuspid regurgitation (P = 0.024) were independent predictors of early RV dysfunction (r = 0.753). On follow-up, RV function improved in 15 of 22 patients but all patients remained with TAPSE > 2 SD below controls. This study showed that 100% of patients had reduced RV function early after transplant. Two thirds of patients had partial recovery of RV function during the first year. In all patients, however, RV function remained significantly lower than in controls.

Quantifying Pulmonary Regurgitation and Right Ventricular Function in Surgically Repaired Tetralogy of Fallot

Background— Patients with repaired tetralogy of Fallot are monitored for pulmonary regurgitation (PR) and right ventricular (RV) function. We sought to compare measures of PR and RV function on echocardiogram to those on cardiac magnetic resonance (CMR) and to develop a new tool for assessing PR by echocardiogram. Methods and Results— Patients with repaired tetralogy of Fallot (n=143; 12.5±3.2 years) had an echocardiogram and CMR within 3 months of each other. On echocardiogram, RV function was assessed by (1) Doppler tissue imaging of the RV free wall and (2) myocardial performance index. The ratio of diastolic and systolic time-velocity integrals measured by Doppler of the main pulmonary artery was calculated. CMR variables included RV ejection fraction, RV volumes, and pulmonary regurgitant fraction (RF). Pulmonary regurgitation was graded as mild (RF&lt;20%), moderate (RF=20–40%), and severe (RF&gt;40%). On CMR, RF was 34+17% and RV ejection fraction was 61+8%. Echocardiography had good sensitivity identifying cases with RF&gt;20% (sensitivity 97%; 95% CI: 92–99%) but overestimated the amount of PR when RF&lt;20% (false-positive rate 36%; 95% CI: 18–57%). The diastolic and systolic time-velocity integrals on echocardiogram showed moderate correlation with RF on CMR ( R =0.60; P &lt;0.0001). On CMR, RF of 20% and 40% corresponded with a diastolic and systolic time-velocity integral of 0.49 (95% CI: 0.44–0.56) and 0.72 (95% CI: 0.68–0.76), respectively. RV myocardial performance index correlated modestly with RV ejection fraction ( r =−0.33; P &lt;0.001). Conclusions— This study suggests that the diastolic and systolic time-velocity integrals ratio may make a modest contribution to the overall assessment of PR in patients with repaired tetralogy of Fallot and warrants further investigation. However, echocardiography continues to have a limited ability to quantify PR and RV function as compared with CMR.