Journal of the American Society of Echocardiography - Articles in Press

Current Pediatric Nomograms Are Only One Source of Error for Quantification in Pediatric Echocardiography: What to Expect from Future Research - Corrected Proof

Massimiliano Cantinotti — 2013-05-17

I read with interest the article by Mawad et al. titled “A Review and Critique of the Statistical Methods Used to Generate Reference Values in Pediatric Echocardiography,” recently published in JASE, which highlights my group's previous observations pertaining to the limitations of current pediatric nomograms. There continues to be a need for more robust and accurate pediatric nomograms, with ongoing efforts to establish these at this time. Valid nomograms are needed to reduce errors in pediatric echocardiographic quantification.

Increased Aortic Pulse Wave Velocity as Measured by Echocardiography Is Strongly Associated with Poor Prognosis in Patients with Heart Failure - Corrected Proof

2013-05-14

Background: An increased aortic pulse wave velocity (PWV), a marker of arterial stiffness, is associated with poor prognosis in various diseases. In patients with heart failure (HF), an increased aortic PWV is associated with low peak exercise oxygen consumption, which is a strong risk factor of adverse clinical outcomes. However, it remains unknown if an increased aortic PWV predicts poor prognosis in patients with HF, independent of peak exercise oxygen consumption.Methods and Results: We enrolled 156 patients with HF and left ventricular ejection fraction <45%, who were followed up for a mean (SD) period of 36 ± 19 months. At baseline, all the patients underwent a complete echocardiography with aortic PWV as measured by Doppler ultrasonography and peak exercise oxygen consumption as measured by bicycle exercise testing with expiratory gas exchange monitoring. During the follow-up period, 20 patients (12.8%) died and 15 patients (9.6%) were hospitalized for worsening HF. In the Kaplan-Meier analysis, patients in the first tertile of aortic PWV had a lower risk of developing cardiac death or hospitalization (combined end point) than those in the second and third tertile combined (P < .001). In Cox regression analysis, increased aortic PWV (both as a continuous and categorical variable) was significantly associated with an increased risk of adverse clinical outcomes after adjustment for peak exercise oxygen consumption and other clinical risk factors (P < .05).Conclusions: Increased aortic PWV, as measured by echocardiography, independently predicted adverse clinical outcomes (cardiac death or hospitalization) among patients with HF.

Impact of Valvuloarterial Impedance on 2-Year Outcome of Patients Undergoing Transcatheter Aortic Valve Implantation - Corrected Proof

2013-05-13

Background: Elderly patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) often have increased calcification and fibrosis of the aorta. Indices that account for the severity of valvular obstruction and systemic vascular impedance may better assess total left ventricular afterload. The aims of the present study were to evaluate changes in valvuloarterial impedance (Zva), systemic arterial compliance, and systemic vascular resistance after TAVI and to investigate the prognostic value of these parameters.Methods: A total of 116 patients (49% men; mean age, 81 ± 8 years) with symptomatic severe aortic stenosis underwent TAVI. Zva, systemic arterial compliance, and systemic vascular resistance were measured at baseline and 1 and 12 months after TAVI. The primary end point was all-cause mortality.Results: After TAVI, there was a significant reduction in Zva (from 5.40 ± 1.52 mm Hg/mL/m2 at baseline to 4.13 ± 1.17 mm Hg/mL/m2 at 1 month and 4.35 ± 1.38 mm Hg/mL/m2 at 1 year, P < .001). Systemic arterial compliance (from 0.57 ± 0.27 to 0.57 ± 0.28 and 0.53 ± 0.27 mL/m2/mm Hg, P = .408) and systemic vascular resistance (from 1,938 ± 669 to 1,856 ± 888 and 1,871 ± 767, dyne·s·cm−5, P = .697) did not change significantly over time. During a median follow-up period of 25 months, survival rates of patients with baseline Zva ≥ 5 mm Hg/mL/m2 were lower compared with those with Zva < 5 mm Hg/mL/m2 (82% vs 91%, respectively, log-rank P = .04). On multivariate Cox proportional-hazards analysis, baseline Zva was independently associated with all-cause mortality (hazard ratio, 1.48; 95% confidence interval, 1.05–2.07; P = .025).Conclusions: In patients undergoing TAVI, there is a significant postprocedural reduction in Zva, but there is no reduction in systemic arterial compliance or vascular resistance. Baseline Zva is an independent predictor of overall mortality at 2-year follow-up.

Intrapulmonary Shunt Is a Potentially Unrecognized Cause of Ischemic Stroke and Transient Ischemic Attack - Corrected Proof

2013-05-13

Background: Ischemic stroke is a major cause of mortality and disability. Transient ischemic attack (TIA) is a harbinger of stroke. The etiology of stroke in as many as 40% of patients remains undetermined after extensive evaluation. It was hypothesized that intrapulmonary shunt is a potential facilitator of cerebrovascular accident (CVA) or TIA.Methods: Patients undergoing clinically indicated transesophageal echocardiography were prospectively enrolled. Comprehensive multiplane transesophageal echocardiographic imaging was performed and saline contrast done to assess for intrapulmonary shunt and patent foramen ovale.Results: Three hundred twenty-one patients with either nonhemorrhagic CVA (n = 262) or TIA (n = 59) made up the stroke group. Three hundred twenty-one age-matched and gender-matched patients made up the control group. Intrapulmonary shunt occurred more frequently in the stroke group (72 of 321) compared with the control group (32 of 321) (22% vs 10%, P < .0001). Intrapulmonary shunt was an independent predictor of CVA and/or TIA (odds ratio, 2.6; P < .0001). In subjects with cryptogenic CVA or TIA (n = 71), intrapulmonary shunt occurred more frequently (25 of 71) than in the control group (5 of 71) (35% vs 7%, P < .0001). Intrapulmonary shunt was an independent multivariate predictor of CVA or TIA in patients with cryptogenic CVA or TIA (odds ratio, 6.3; P < .005).Conclusions: These results suggest that intrapulmonary shunt is a potentially unrecognized facilitator of CVA and TIA, especially in patients with cryptogenic CVA and TIA. Future studies assessing the prognostic significance of intrapulmonary shunt on cerebral vascular event recurrence rates in patients after initial CVA or TIA would be of great interest.

The Assessment of Atrial Function in Single Ventricle Hearts from Birth to Fontan: A Speckle-Tracking Study by Using Strain and Strain Rate - Corrected Proof

2013-05-13

Background: Single ventricle (SV) exercise performance is impaired and limited by reduced ventricular preload reserve. The atrium modulates ventricular filling, and enhancement of atrial compliance can increase cardiac performance. We aimed to study atrial mechanics in SV hearts across staged surgical palliation compared with healthy children by using novel speckle-tracking echocardiography techniques.Methods: A cross-sectional study of 81 patients with SV (1 day to 6.5 years) at 4 stages of surgical palliation (presurgery, 22; prebidirectional cavopulmonary anastomosis, 23; pre-Fontan, 22; post-Fontan, 14). The dominant atrium was assessed with speckle-tracking echocardiography for active (εact), conduit (εcon), and reservoir (εres) strain; strain rate (SR); and εact/εres ratio before each stage of surgical palliation. Findings were compared with the left atrium of 51 healthy children (1 day to 5.5 years).Results: Single ventricle atrial size was increased (P < .01), and atrial εres was decreased (P < .01) compared with healthy controls. SV atrial εcon (P < .01) and SRcon (P < .0001) was decreased, increased εact persisted (P < .05), and εact/εres was increased (P < .001) between surgical stages. Although the expected maturational trend of increasing εcon, decreasing εact, and εact/εres occurred in SV, they lagged behind healthy maturational changes (P < .0001).Conclusion: Single ventricle atrium is dilated, has deceased compliance, decreased early diastolic emptying, and increased reliance on active atrial contraction for ventricular filling. This deviates from normal early childhood maturational changes and appears to parallel those of an atrium facing early ventricular diastolic dysfunction.

Regional Difference of Microcirculation in Patients with Asymmetric Hypertrophic Cardiomyopathy: Transthoracic Doppler Coronary Flow Velocity Reserve Analysis - Corrected Proof

2013-05-06

Objective: To evaluate, by noninvasive coronary flow velocity reserve (CFVR), whether patients with asymmetric hypertrophic cardiomyopathy (HC), with or without left ventricular outflow tract obstruction, demonstrate significant regional differences of CFVR.Methods: We evaluated 61 patients with HC (27 men; mean age 49 ± 16 years), including 20 patients with hypertrophic obstructive cardiomyopathy (HOCM) and 41 patients without obstruction (HCM). The control group included 20 age- and sex-matched subjects. Transthoracic Doppler echocardiography CFVR of the left anterior descending coronary artery (LAD) and the posterior descending coronary artery (PD) were performed, including calculation of relative CFVR as the ratio between CFVR LAD and CFVR PD.Results: Compared with the controls, all the patients with HC had lower CFVR LAD (2.12 ± 0.53 vs 3.34 ± 0.67; P < .001) and CFVR PD (2.29 ± 0.49 vs 3.21 ± 0.65; P < .001). CFVR LAD in HOCM group in comparison with the HCM group was significantly lower (1.93 ± 0.42 vs 2.22 ± 0.55; P = .047), due to higher basal diastolic coronary flow velocities (0.40 ± 0.09 vs 0.33 ± 0.07 m/sec; P = .002), with similar hyperemic diastolic flow velocities (0.71 ± 0.16 vs 0.76 ± 0.19 m/sec; P = .330), respectively. There was no significant difference in CFVR PD between patients with HOCM and those with HCM (2.33 ± 0.46 vs 2.27 ± 0.50; P = .636), respectively. Relative CFVR was lower in the HOCM group compared with the HCM group (0.84 ± 0.16 vs 0.98 ± 0.14; P = .001). By multivariable regression analysis, left ventricular outflow tract gradient was the independent predictor of CFVR LAD (B = −0.24; P = .008) and relative CFVR (B = −0.34; P = .016).Conclusions: CFVR LAD and relative CFVR were significantly lower in patients with HOCM compared with patients with HCM. Regional differences of CFVR are present only in patients with significant left ventricular outflow tract obstruction, which suggests that obstruction per se, by increasing wall stress in basal conditions, leads to higher basal diastolic coronary flow velocities and results in lower CFVR in LAD compared with PD.

Decremental Left Ventricular Deformation after Pulmonary Artery Band Training and Subsequent Repair in Ventriculoarterial Discordance - Corrected Proof

Heather Y. Sun, Fariborz Behzadian, Rajesh Punn, Theresa A. Tacy — 2013-04-29

Background: Patients with ventriculoarterial discordance, such as congenitally corrected and d-transposition of the great arteries, may undergo a morphologic left ventricular (LV) training strategy consisting of surgical pulmonary artery band (PAB) placement and subsequent anatomic repair to establish ventriculoarterial concordance. The purpose of this study was to characterize morphologic LV function and deformation longitudinally using speckle-tracking strain analysis in patients with ventriculoarterial discordance who underwent LV training.Methods: Twenty-nine patients (12 with d-transposition of the great arteries and 17 with congenitally corrected transposition of the great arteries) who underwent LV training with PAB placement were evaluated retrospectively. LV ejection fraction and global and regional longitudinal strain and strain rate were measured before and 7 ± 5 days after PAB placement and subsequent anatomic repair.Results: PAB placement caused reductions in the mean LV ejection fraction from 76.1 ± 10.2% to 66.7 ± 7.8% (P < .001), in mean global strain from −17.7 ± 9% to −13.3 ± 7.5% (P = .01), and in mean lateral wall strain from −23.3 ± 12.8% to −17.5 ± 10.3% (P = .01). After anatomic repair (a median of 21 months after PAB placement; range, 0.5–104 months), mean LV ejection fraction decreased further from 63.3 ± 8.6% to 52.4 ± 14.9% (P < .05). Mean global strain declined from −17.6% ± 4.4 to −12.6 ± 4% (P = .01), and mean lateral wall strain decreased from −18.2 ± 11.4% to −12.6 ± 5.3% (P = .04).Conclusions: In patients with ventriculoarterial discordance undergoing PAB placement for LV training and anatomic repair, the morphologic left ventricle demonstrated decremental systolic function and global longitudinal deformation acutely. Frequent functional assessment is warranted to understand long-term myocardial mechanics in these patients.

Restrictive versus Nonrestrictive Physiology Following Repair of Tetralogy of Fallot: Is There a Difference? - Corrected Proof

2013-04-29

Background: Long-term outcome in repaired tetralogy of Fallot (TOF) is related to chronic pulmonary insufficiency (PI), right ventricular (RV) dilation, and deterioration of RV function. The aim of this study was to characterize clinical differences between restrictive and nonrestrictive RV physiology in young patients with repaired TOF.Methods: Patients were prospectively enrolled from February 2008 to August 2009. Each had a clinic visit, brain natriuretic peptide assessment, exercise test, cardiac magnetic resonance study, and echocardiographic examination with assessment of regional myocardial mechanics. Consistent antegrade diastolic pulmonary arterial flow with atrial contraction identified restrictive RV physiology.Results: Twenty-nine patients (median age, 12 years; range, 8–33 years; nine male patients) were studied. Twelve had restrictive RV physiology. The median time since initial TOF repair was 12 years (range, 5–27 years). Restrictive physiology appeared more prevalent after transannular patch repair and was not influenced by other demographic features. The restrictive group had more PI (46% vs 28%, P = .002), larger RV end-diastolic volumes (128 vs 98 mL/m2, P = .046), but similar ejection fractions, brain natriuretic peptide levels, New York Heart Association classes, and exercise capacity. RV basal and mid free wall peak diastolic strain rate differed between groups, negatively correlating with exercise time and positively correlating with PI in patients with restrictive physiology.Conclusions: Restrictive RV physiology correlates with a larger right ventricle and increased PI after TOF repair but does not negatively affect other markers of myocardial health. Diastolic regional RV myocardial mechanics, particularly diastolic velocity and peak diastolic strain rate, differ for postoperative TOF patients with restrictive and nonrestrictive RV physiology; longitudinal study is necessary to understand the relationship of regional myocardial mechanics and patients' clinical status.

Prognostic Value of Left Atrial Volume in Asymptomatic Organic Mitral Regurgitation - Corrected Proof

2013-04-29

Background: Basal left atrial volume (LAV) indexed to body surface area (LAVI) predicts adverse events in patients with organic mitral regurgitation, but information is lacking regarding change in left atrial volume during follow-up.Methods: One hundred forty-four asymptomatic patients (mean age, 71 ± 12 years; 66% women; mean ejection fraction, 66 ± 4.8%) with moderate to severe mitral regurgitation were prospectively included, with a median follow-up period of 2.76 years (interquartile range, 1.86–3.48 years).Results: Fifty-four patients (37.50%) reached the combined end point of dyspnea and/or systolic dysfunction. Both basal and change in LAV were independently associated with the combined end point on multivariate analysis: for basal LAVI ≥ 55 mL/m2, odds ratio, 2.26 (95% confidence interval, 1.04–4.88; P = .038), and for change in LAV ≥ 14 mL, odds ratio, 7.32 (95% confidence interval, 3.25–16.48; P < .001), adjusted for effective regurgitant orifice area and deceleration time. Combined event-free survival at 1, 2, and 3 years was significantly less in patients with basal LAVI ≥ 55 mL/m2 (75%, 58%, and 43%) than in those with basal LAVI < 55 mL/m2 (95%, 89%, and 77%) (log-rank test = 15.38, P = .0001). The incidence of the combined end point was highest (88%) in patients with basal LAVI ≥ 55 mL/m2 and change in LAV ≥ 14 mL.Conclusions: Measurement of basal LAV and its increase during follow-up predict an adverse course in patients with moderate and severe asymptomatic mitral regurgitation. Hence, its assessment could be incorporated into the currently used algorithm for risk stratification and decision making in this group of patients.

Prognostic Value of Right Ventricular Two-Dimensional Global Strain in Patients Referred for Cardiac Surgery - Corrected Proof

2013-04-29

Background: Right ventricular (RV) function is a strong predictor of patient outcome after cardiac surgery. Limited studies have compared the predictive value of RV global longitudinal strain (RV-GLS) with tricuspid annular plane systolic excursion (TAPSE) and RV fractional area change (RVFAC) in this setting.Methods: The study included 250 patients (66 ± 13 years old, LVEF = 52% ± 12%) referred for cardiac surgery (EuroSCORE-II = 4.8% ± 8.0%). RV function before surgery was assessed by RV-GLS by using speckle-tracking analysis (3-segment from the RV free wall), RVFAC and TAPSE was compared with postoperative outcome defined by 1-month mortality.Results: Overall, 19 patients (7.6%) had RVFAC < 35%, 34 (13.6%) had TAPSE < 16 mm, and 99 (39.6%) had impaired RV-GLS > −21% (35% with normal RVFAC ≥ 35%). Postoperative death (n = 25) was higher in patients with abnormal RV-GLS > −21% (22% vs 3%; P < .0001), TAPSE < 16 mm (24% vs 8%; P = .007), and RVFAC < 35% (32% vs 9%; P = .001). Mortality was 3% in patients with preserved RV-GLS. In patients with preserved RVFAC ≥ 35% but abnormal RV-GLS, mortality was similar to that of those with RVFAC < 35% (20% vs 32%; P = .12). Among RV systolic indexes, only RV-GLS was associated with patient outcome by multivariate analysis adjusted to EuroSCORE-II and cardiopulmonary bypass duration.Conclusions: RV-GLS is a sensitive marker of RV dysfunction and correlates with postoperative mortality.

Right Ventricular Regional Systolic Function and Dyssynchrony in Patients with Pulmonary Hypertension Evaluated by Three-Dimensional Echocardiography - Corrected Proof

2013-04-26

Background: The aim of this study was to evaluate right ventricular (RV) regional systolic function and dyssynchrony in patients with pulmonary hypertension (PH) using real-time three-dimensional echocardiography.Methods: Real-time three-dimensional echocardiographic images were acquired to obtain RV regional (inflow, body, and outflow) ejection fraction (EF) and time to minimum systolic volume in 70 patients with PH and 26 normal controls. Pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance measured by echocardiography in all subjects and by right heart catheterization in 17 patients were recorded.Results: Inflow EF and global EF were significantly lower in patients with PH than in controls (P < .05). Body EF was significantly decreased in patients with moderate (PASP, 50–69mm Hg) and severe (PASP ≥ 70 mm Hg) PH (P < .05). Outflow EF was significantly lowered in patients with severe PH (P < .001). The standard deviation of regional time to minimum systolic volume corrected by heart rate was significantly prolonged in patients with severe PH (P < .05). Inflow EF and global EF were negatively correlated with PASP (r = −0.731 and r = −0.769, respectively, P < .001) and with pulmonary vascular resistance (r = −0.789 and r = −0.801, P < .001).Conclusions: In patients with PH, RV inflow and global systolic function was impaired in inverse relationship with PASP and pulmonary vascular resistance. RV systolic synchronicity was impaired in patients with severe PH. Evaluation of RV regional systolic function using real-time three-dimensional echocardiography may play a potential role in the noninvasive assessment of the severity of PH.

Impact of Propofol Anesthesia Induction on Cardiac Function in Low-Risk Patients as Measured by Intraoperative Doppler Tissue Imaging - Corrected Proof

Hyun Suk Yang, Bong Gun Song, Jee Young Kim, Soo-Nyung Kim, Tae-Yop Kim — 2013-04-26

Background: Despite a few experimental studies showing a dose-dependent myocardial depressive effect of propofol anesthesia induction, few clinical data are available to determine its precise impact on myocardial function, probably because of its brevity and a lack of appropriate evaluation tools. The purpose of this study was to examine the impact of propofol-based anesthesia induction on left ventricular (LV) function using Doppler tissue and speckle-tracking imaging.Methods: In 19 low-risk patients with normal LV systolic and diastolic function undergoing noncardiac surgery (all women; mean age, 42 years), propofol bolus (2.0 mg/kg) was administered intravenously for anesthesia induction. LV ejection fraction, global peak systolic longitudinal strain, and tissue Doppler–derived indices of mitral annular velocity during systole (S′), early diastole (e′), and atrial contraction (a′) were determined by intraoperative transthoracic echocardiography before and 1, 3, and 5 min after propofol bolus (T0, T1, T2, and T3, respectively).Results: The following at T1, T2, and T3 were significantly less in magnitude than at T0: septal S′ (5.61, 5.61, and 5.51 vs 7.60 cm/sec, P < .001), lateral S′ (5.75, 5.89, and 5.94 vs 8.12 cm/sec, P < .001), septal e′ (10.10, 10.26, and 10.07 vs 11.4 cm/sec, P < .01), septal a′ (6.70, 6.21, and 6.13 vs 8.58 cm/sec, P < .01), lateral a′ (7.29, 6.81, and 6.85 vs 9.01 cm/sec, P < .01), and longitudinal strain (−19.36%, −19.71%, and −19.61% vs −22.28%, P < .001). LV ejection fraction was not significantly changed (P = .361).Conclusions: Propofol anesthesia induction diminished LV and atrial contraction in low-risk patients with prior normal LV function. Further studies are needed to understand the clinical implications, particularly for higher risk populations.

Frequent Periodic Leg Movement during Sleep Is Associated with Left Ventricular Hypertrophy and Adverse Cardiovascular Outcomes - Corrected Proof

2013-04-26

Background: Sleep disturbance caused by obstructive sleep apnea is recognized as a contributing factor to adverse cardiovascular outcomes. However, the effect of restless legs syndrome, another common cause of fragmented sleep, on cardiac structure, function, and long-term outcomes is not known. The aim of this study was to assess the effect of frequent leg movement during sleep on cardiac structure and outcomes in patients with restless legs syndrome.Methods: In our retrospective study, patients with restless legs syndrome referred for polysomnography were divided into those with frequent (periodic movement index > 35/hour) and infrequent (≤35/hour) leg movement during sleep. Long-term outcomes were determined using Kaplan-Meier and logistic regression models.Results: Of 584 patients, 47% had a periodic movement index > 35/hour. Despite similarly preserved left ventricular ejection fraction, the group with periodic movement index > 35/hour had significantly higher left ventricular mass and mass index, reflective of left ventricular hypertrophy (LVH). There were no significant baseline differences in the proportion of patients with hypertension, diabetes, hyperlipidemia, prior myocardial infarction, stroke or heart failure, or the use of antihypertensive medications between the groups. Patients with frequent periodic movement index were older, predominantly male, and had more prevalent coronary artery disease and atrial fibrillation. However, on multivariate analysis, periodic movement index > 35/hour remained the strongest predictor of LVH (odds ratio, 2.45; 95% confidence interval, 1.67–3.59; P < .001). Advanced age, female sex, and apnea-hypopnea index were other predictors of LVH. Patients with periodic movement index > 35/hour had significantly higher rates of heart failure and mortality over median 33-month follow-up.Conclusions: Frequent periodic leg movement during sleep is an independent predictor of severe LVH and is associated with increased cardiovascular morbidity and mortality.

Effect of Pharmacologic Increases in Afterload on Left Ventricular Rotation and Strain in a Rabbit Model - Corrected Proof

2013-04-22

Background: Assessment of left ventricular rotational mechanics and myocardial deformation may provide new insight into both systolic and diastolic function. However, the effects of increasing afterload on these measures of cardiac function are poorly understood. The aim of this study was to identify the changes in left ventricular function and rotational mechanics during increasing pharmacologic afterload.Methods: In 14 anesthetized rabbits, two-dimensional speckle-tracking echocardiographic images and left ventricular pressure-volume loops were acquired at baseline and during norepinephrine, phenylephrine, and vasopressin infusion at increasing doses. Maximal ventricular elastance, arterial elastance, ventricular-arterial coupling, dP/dt, the time constant of relaxation, and other hemodynamic parameters were determined.Results: An increase in dP/dtmax with norepinephrine and phenylephrine and a decrease with vasopressin at escalating doses were detected. Ventricular-arterial coupling was preserved with norepinephrine and phenylephrine but decreased with vasopressin (P < .05). Apical rotation, rotational rate, and strain were preserved during the norepinephrine and phenylephrine infusions but were reduced with vasopressin (P < .05). Apical rotation and circumferential strain were significantly correlated with both ventricular-arterial coupling (r = 0.84 and r = 0.81) and dP/dtmax (r = −0.81 and r = −0.77). High-dose vasopressin decreased the diastolic time constant of relaxation and dP/dtmin while reducing apical untwisting rate.Conclusions: Pharmacologic increases in afterload with vasopressin resulted in greater derangements in ventricular-arterial coupling and cardiac performance compared with norepinephrine and phenylephrine. Rotation and strain correlated well with invasively determined measures and can be used to assess afterload-induced alteration in cardiac function.

Comparison of Factors Associated with Carotid Intima-Media Thickness in the Multi-Ethnic Study of Atherosclerosis (MESA) and the Heinz Nixdorf Recall Study (HNR) - Corrected Proof

2013-04-22

Background: The measurement of carotid intima-media thickness (CIMT) is a valid method to quantify levels of atherosclerosis. The present study was conducted to compare the strengths of associations between CIMT and cardiovascular risk factors in two different populations.Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) and the Heinz Nixdorf Recall Study (HNR) are two population-based prospective cohort studies of subclinical cardiovascular disease. All Caucasian subjects aged 45 to 75 years from these cohorts who were free of baseline cardiovascular disease (n = 2,820 in HNR, n = 2,270 in MESA) were combined. CIMT images were obtained using B-mode sonography at the right and left common carotid artery and measured 1 cm starting from the bulb.Results: In both studies, age, male sex, and systolic blood pressure showed the strongest association (P < .0001 for each) for a higher CIMT. The mean of mean far wall CIMT was slightly higher in MESA participants (0.71 vs 0.67 mm). Almost all significant variables were consistent between the two cohorts in both magnitude of association with CIMT and statistical significance, including age, sex, smoking, diabetes, cholesterol levels, and blood pressure. For example, the association with systolic blood pressure was (ΔSD = 0.011; 95% confidence interval, 0.0009 to 0.014) per mm Hg in MESA and (ΔSD = 0.010; 95% confidence interval, 0.005 to 0.021) per mm Hg in HNR. This consistency persisted throughout the traditional (Framingham) risk factors.Conclusions: A comparison of the associations between traditional cardiovascular risk factors and CIMT across two culturally diverse populations showed remarkable consistency.

Localized Transvalvular Pressure Gradients in Mitral Bileaflet Mechanical Heart Valves and Impact on Gradient Overestimation by Doppler - Corrected Proof

2013-04-22

Background: It has been reported that localized high velocity may be recorded by continuous-wave Doppler interrogation through the smaller central orifices of bileaflet mechanical heart valves (BMHV) and that this may result in overestimation of the transvalvular pressure gradient (TPG). However, the prevalence and clinical relevance of this phenomenon remain unclear, particularly for BMHVs in the mitral position. The objective of this in vitro study was to assess the presence and magnitude of localized high velocity in mitral BMHVs as well as its impact on TPG overestimation by Doppler.Methods: Nine BMHVs were tested under nine different flow conditions (volumes and flow waveforms) in a simulator specifically designed to assess mitral valve hemodynamics. Flow velocity was measured at three different locations (leading edge, midleaflets, and trailing edge) within the central and lateral orifices of the BMHVs using pulsed-wave Doppler. TPG was measured by pulsed-wave and continuous-wave Doppler and by catheterization.Results: The maximum flow velocity occurred within the central orifice of the BMHV in 61% of the 81 tested conditions. This locally higher velocity within the central orifice predominantly occurred at the leading edge of the prosthesis. Doppler overestimated mean TPG by an average of 5% to 10% compared with catheterization. The magnitude of the localized high velocity and ensuing overestimation of TPG by Doppler was more important at higher mitral flow volumes (P < .0001) as well as in BMHVs with smaller internal ring diameters (P < .0001).Conclusions: This study shows that the flow velocity distribution within the three orifices of mitral BMHVs is not uniform and that higher velocity occurs more frequently, but not always, within the inflow aspect of the central orifice. In most mitral BMHVs and flow conditions, this localized high-velocity phenomenon causes small overestimation of TPGs (<2 mm Hg and <10%) by Doppler and is thus not clinically relevant. However, in small mitral BMHVs exposed to high flow rates, the overestimation of TPG due to localized high velocity could become more important and overlap with the range of gradients found in patients with prosthesis dysfunction or prosthesis-patient mismatch.

Right Ventricular Function Is a Determinant of Long-Term Survival after Cardiac Resynchronization Therapy - Corrected Proof

2013-04-22

Background: Right ventricular (RV) dysfunction is a marker of poor prognosis in patients with heart failure. The aim of this study was to investigate the impact of RV function on the long-term outcomes of patients undergoing cardiac resynchronization therapy (CRT).Methods: A total of 120 consecutive patients treated with CRT according to guideline criteria were followed over 5 years. Comprehensive echocardiographic analyses of RV function and radial and longitudinal mechanical left ventricular dyssynchrony were performed at baseline and 6 months after implantation. RV function was evaluated by two-dimensional longitudinal strain of the free wall, fractional area change, tricuspid annular plane systolic excursion, and tricuspid annular systolic velocity. Long-term follow-up events were defined as all-cause mortality, heart transplantation, or assist device implantation.Results: Long-term events occurred in 38 patients. Among the studied variables for RV function, RV strain < 18% had the highest sensitivity (79%) and specificity (84%) to predict a poor outcome after CRT (area under curve, 0.821; P < .0001). When adjusted for confounding baseline variables of ischemic etiology, mechanical dyssynchrony, left ventricular end-systolic volume, mitral regurgitation, and medical therapy, RV dysfunction remained independently associated with outcomes, indicating a 5.7-fold increased risk for hard events (P < .0001).Conclusions: Preserved RV function as assessed by speckle-tracking strain imaging appears to be an independent predictor of long-term event-free survival after CRT.

Comprehensive Analysis of Left Ventricular Geometry and Function by Three-Dimensional Echocardiography in Healthy Adults - Corrected Proof

2013-04-22

Background: Recent European Association of Echocardiography and American Society of Echocardiography guidelines on three-dimensional echocardiography state that normal values of left ventricular (LV) parameters for age and body size remain to be established.Methods: In 226 consecutive healthy subjects (125 women; age range, 18–76 years), comprehensive three-dimensional echocardiographic analyses of LV parameters were performed, and values were compared with those obtained by conventional echocardiography.Results: Upper reference values (mean + 2 SDs) for three-dimensional LV end-diastolic and end-systolic volumes were 85 and 34 mL/m2 in men and 72 and 28 mL/m2 in women, respectively. Indexing LV volumes to body surface area did not eliminate gender differences. Lower reference values (mean − 2 SDs) for ejection fraction were 54% in men and 57% in women and for stroke volume were 25 and 24 mL/m2, respectively. Upper reference values for LV mass were 97 g/m2 in men and 90 g/m2 in women and for end-diastolic sphericity index were 0.49 and 0.48, respectively. Significant age dependency of LV parameters was identified and reported across age groups. Three-dimensional echocardiographic LV volumes were larger, ejection fraction was similar, and LV stroke volume and mass were significantly smaller in comparison with the corresponding values obtained by conventional echocardiography.Conclusions: The investigators report a comprehensive analysis of LV geometry and function using three-dimensional echocardiography in a relatively large cohort of healthy Caucasian subjects with a wide age range. These may serve to establish age-specific and gender-specific reference ranges, which are crucial for the routine implementation of three-dimensional echocardiography to detect LV remodeling and dysfunction in clinical practice.

Mitral Valve Dynamics in Severe Aortic Stenosis before and after Aortic Valve Replacement - Corrected Proof

2013-04-18

Background: The aortic and mitral valves are anatomically linked through a fibrous continuity. The investigators hypothesized that severe aortic stenosis (AS) would alter this fibrous continuity, affecting both the mitral valve and left ventricular function, and that mitral valve function would be altered after aortic valve replacement (AVR). The aim of this study was to evaluate the impact of AS and its treatment with surgical AVR on the mitral valve.Methods: Three-dimensional transesophageal echocardiography (using a Philips iE33 system) was performed on 49 patients: 20 controls with normal valves and left ventricular function, 20 with AS and normal left ventricular function studied before and after AVR, and nine with systolic heart failure and normal valves. Custom software tracked the aortic and mitral valves in three-dimensional space, allowing automated measurements of aortic and mitral annular (MA) morphology throughout the cardiac cycle.Results: Patients with AS before AVR had reduced MA velocities. After AVR, aortic and MA areas were significantly smaller throughout the cardiac cycle compared with controls and pre-AVR values. MA displacement was reduced after AVR and in patients with systolic heart failure compared with those with AS and controls.Conclusions: Dynamic MA function is changed with AS and after AVR through alterations in the aortic-mitral fibrous continuity. The prosthetic valve ring results in reduced aortic and MA areas, which could affect blood flow in and out of the left ventricle. These changes suggest that the design of future prosthetic aortic valves should be more flexible to preserve the function of the aortic-mitral fibrous continuity.

Left Ventricular False Tendons: Anatomic, Echocardiographic and Pathophysiologic Insights - Corrected Proof

Jeffrey J. Silbiger — 2013-04-18

Left ventricular (LV) false tendons are chordlike structures that traverse the LV cavity. They attach to the septum, to the papillary muscles, or to the free wall of the ventricle but not to the mitral valve. They are found in approximately half of human hearts examined at autopsy. Although it has been more than 100 years since their initial description, the functional significance of these structures remains largely unexplored. It has been suggested that they retard LV remodeling by tethering the walls to which they are attached, but there are few data to substantiate this. Some studies have suggested that false tendons reduce the severity of functional mitral regurgitation by stabilizing the position of the papillary muscles as the left ventricle enlarges. LV false tendons may also have deleterious effects and have been implicated in promoting membrane formation in discrete subaortic stenosis. This article reviews current understanding of the anatomy, echocardiographic characteristics, and pathophysiology of these structures.

Assessment of Intraventricular Time Differences in Healthy Children Using Two-Dimensional Speckle-Tracking Echocardiography - Corrected Proof

2013-04-18

Background: Parameters describing intraventricular time differences are increasingly assessed in both adults and children. However, to appreciate the implications of these parameters in children, knowledge of the applicability of adult techniques in children is essential. Hence, the aim of this study was to assess the applicability of speckle-tracking strain–derived parameters in children, paying special attention to age and heart rate dependency.Methods: One hundred eighty-three healthy subjects (aged 0–19 years) were included. Left ventricular global peak strain, time to global peak strain, and parameters describing intraventricular time differences were assessed using speckle-tracking strain imaging in the apical two-chamber, three-chamber, and four-chamber views (longitudinal strain) and the parasternal short-axis view (radial and circumferential strain). Parameters describing intraventricular time differences included the standard deviation of time to peak strain and differences in time to peak strain between two specified segments. Age and heart rate dependency were evaluated using regression analysis, and intraobserver and interobserver variability were tested.Results: Acquisition and analysis of longitudinal six-segment time-strain curves was successful in 94.8% of subjects and radial and circumferential time-strain curves in 89.5%. No clinically significant linear relation was observed between age or heart rate and parameters describing intraventricular time differences. The coefficient of variation of time to global peak strain parameters was <10, while it was >10 for parameters describing intraventricular time differences.Conclusions: The feasibility of speckle-tracking strain analysis in children is relatively good. Furthermore, no linear relation was observed between age or heart rate and parameters describing intraventricular time differences. However, the limited reproducibility of some parameters describing intraventricular time differences will confine their applicability in clinical practice.

A Novel and Simple Method Using Pocket-Sized Echocardiography to Screen for Aortic Stenosis - Corrected Proof

2013-04-18

Background: Pocket-sized echocardiography may serve as an initial tool to screen for aortic stenosis (AS). The purpose of this study was to evaluate the usefulness of a novel and simple method using pocket-sized echocardiography to screen for AS.Methods: Subjects (n = 130) with systolic ejection murmur or known AS were studied. After physical examination, each aortic cusp's opening was visually scored using pocket-sized echocardiography as follows: 0 = not restricted, 1 = restricted, or 2 = severely restricted. The sum of the scores was defined as the visual AS score. On the basis of high-end echocardiography, an aortic valve area index <0.60 cm2/m2 and an aortic valve area index of 0.60 to 0.85 cm2/m2 were considered to indicate severe and moderate AS, respectively.Results: For diagnosing severe AS (n = 27), a visual AS score ≥4 had sensitivity of 85% and specificity of 89%. For diagnosing moderate to severe AS (n = 57), a visual AS score ≥3 had sensitivity of 84% and specificity of 90%. The areas under the receiver operating characteristic curves for diagnosing severe and moderate to severe AS with a visual AS score (0.946 and 0.936, respectively) were slightly larger than those for a skilled physical examination (0.917 and 0.898, respectively) (P = NS for both) but were significantly larger than for an aortic valve calcification score also obtained using pocket-sized echocardiography (areas under the curve, 0.816 [P = .0015] and 0.827 [P = .0001], respectively).Conclusions: A novel and simple method using pocket-sized echocardiography is useful for rapid grading of AS in subjects with systolic ejection murmur.

Echocardiographic Methods, Quality Review, and Measurement Accuracy in a Randomized Multicenter Clinical Trial of Marfan Syndrome - Corrected Proof

2013-04-12

Background: The Pediatric Heart Network is conducting a large international randomized trial to compare aortic root growth and other cardiovascular outcomes in 608 subjects with Marfan syndrome randomized to receive atenolol or losartan for 3 years. The authors report here the echocardiographic methods and baseline echocardiographic characteristics of the randomized subjects, describe the interobserver agreement of aortic measurements, and identify factors influencing agreement.Methods: Individuals aged 6 months to 25 years who met the original Ghent criteria and had body surface area–adjusted maximum aortic root diameter (ROOTmax) Z scores > 3 were eligible for inclusion. The primary outcome measure for the trial is the change over time in ROOTmax Z score. A detailed echocardiographic protocol was established and implemented across 22 centers, with an extensive training and quality review process.Results: Interobserver agreement for the aortic measurements was excellent, with intraclass correlation coefficients ranging from 0.921 to 0.989. Lower interobserver percentage error in ROOTmax measurements was independently associated (model R2 = 0.15) with better image quality (P = .002) and later study reading date (P < .001). Echocardiographic characteristics of the randomized subjects did not differ by treatment arm. Subjects with ROOTmax Z scores ≥ 4.5 (36%) were more likely to have mitral valve prolapse and dilation of the main pulmonary artery and left ventricle, but there were no differences in aortic regurgitation, aortic stiffness indices, mitral regurgitation, or left ventricular function compared with subjects with ROOTmax Z scores < 4.5.Conclusions: The echocardiographic methodology, training, and quality review process resulted in a robust evaluation of aortic root dimensions, with excellent reproducibility.

Changes in Left Atrial Mechanics Following Pericardiectomy for Pericardial Constriction - Corrected Proof

2013-04-05

Background: Although impaired left ventricular (LV) filling in constrictive pericarditis (CP) is attributable to external constraints by a tethered pericardium, impaired left atrial (LA) function can further impair LV filling. Previous studies focused on the impact of a tethered pericardium on LV diastolic behavior, but its impact on LA function has been largely overlooked. The objectives of this study were to evaluate LA mechanics in CP and to assess the impact of pericardiectomy on LA mechanics.Methods: A total of 52 patients with CP (mean age, 57 ± 12 years) and 19 control subjects were studied retrospectively. All patients with CP underwent echocardiography before (median, 12 days; interquartile range, 5–34 days) and after pericardiectomy (median, 20 days; interquartile range, 5–64 days). Global LA longitudinal strain (ε) was calculated, which included peak negative ε (εnegative), peak positive ε (εpositive), and the sum of those values, total LA ε (εtotal), using speckle-tracking echocardiography with Velocity Vector Imaging. The regional difference of LA ε between the septal and lateral walls was assessed before and after the procedure.Results: Patients with CP showed depressed global LA εnegative, LA εtotal, and LA εpositive compared with controls. LA contractile (global LA εnegative) and reservoir functions (global LA εtotal) showed significant increases after pericardiectomy. Regional analysis revealed that the improvement in LA function after surgery was more apparent in lateral segments, while the regional function of septal walls was depressed after surgery.Conclusions: Patients with CP have impaired LA mechanics, presumably because of the constrictive tethering process involving the left atrium. Speckle-tracking echocardiography showed consistent results of changes in LA mechanics with conventional echocardiographic parameters early after the procedure. Regional ε analysis aided in recognition of the impact of constrictive tethering and pericardiectomy on LA function.

Patterns of Aortic Dilatation in Bicuspid Aortic Valve–Associated Aortopathy - Corrected Proof

Clarence Khoo, Christopher Cheung, John Jue — 2013-04-05

Background: Bicuspid aortic valves (BAVs) are associated with aortopathy. Recent studies suggest that aortic dilatation is more likely to be seen with left-right coronary cusp fusion (type I) compared with right-noncoronary cusp fusion (type II). The aim of this study was to investigate the association between BAV morphology and patterns of aortopathy.Methods: Aortic dimensions and BAV morphology were obtained retrospectively from archived cine loops of 581 consecutive patients with BAVs and 277 matched normal controls from the Vancouver General Hospital echocardiography database. Patient demographics and other echocardiographic parameters were extracted from the database.Results: The study population was composed of 71% type I BAVs (415 patients) and 26% type II BAVs (149 patients). Aortic dilatation was present in 30% of the population. Type I BAV was associated with increased dimensions indexed to body surface area at the sinus of Valsalva compared with type II BAV. No difference in proximal ascending aortic dimension was seen between different BAV morphologies. The pattern of dilatation with type I BAV was more likely to be at the level of the annulus or sinus of Valsalva compared with type II BAV (62% vs 33%, P = .002). Type I BAV was an independent predictor of proximal aortic dilatation (odds ratio, 3.42; 95% confidence interval, 1.07–10.9).Conclusions: Type I BAV is associated with a greater likelihood of dilatation at the annulus and sinus of Valsalva. There is relative sparing of this region of the aorta in patients with type II BAVs. Individuals with different BAV morphologies may require different strategies of aortopathy surveillance.