Diagnosis of congenital unicuspid aortic valve in adult population: the value and limitation of transesophageal echocardiography

BACKGROUND

This study aimed to assess the accuracy of two-dimensional echocardiography (echo) in diagnosing unicuspid aortic valve (UAV) and to determine echo features that could improve the diagnosis.

METHOD

We reviewed transthoracic/transesophageal echoes (TTE/TEE) from our hospital database for adult patients who had aortic valve surgery with a preoperative echo diagnosis of UAV or equivocal diagnosis of bicuspid aortic valve (BAV) BAV/UAV. Morphological characteristics of AV and ascending aortic dimensions were evaluated.

RESULTS

Nineteen patients were identified, 13 (11 Male, 2 Female, mean age 47 ± 10 years) had surgically confirmed diagnosis of UAV, six had BAV. The incidence of UAV was 2.6%. For diagnosing UAV, the sensitivity and specificity of TTE was 27% and 50% and those of TEE was 75% and 86%, respectively. For TTE, positive predictive value (PPV) was 60% and negative predictive value (NPV) was 20%. By TEE, PPV was 90% and the NPV was 67%. In UAV patients, 85% had severe aortic stenosis (mean gradient 45 ± 16 mmHg, AVA: 0.9 ± 0.2 cm²). 46% had ascending aorta aneurysm (mean aortic root, sinutubular junction, ascending aorta dimensions: 36 ± 3 mm, 31 ± 4 mm and 41 ± 8 mm). Patients with ascending aortic aneurysm were younger (41 ± 11 years vs. 52 ± 5 years, P < 0.05) All UAV were unicommissural with a posteriorly positioned commissural attachment, 69% were heavily calcified. Diagnostic accuracy was limited by quality of images, severity, and distribution of calcification.

CONCLUSION

TEE is the diagnostic modality of choice in UAV. Identifying several echo features may improve its diagnostic accuracy.

Validation of noninvasive measurements of cardiac output in mice using echocardiography

BACKGROUND

Although multiple echocardiographic methods exist to calculate cardiac output (CO), they have not been validated in mice using a reference method.

METHODS

Echocardiographic and flow probe measurements of CO were obtained in mice before and after albumin infusion and inferior vena cava occlusions. Echocardiography was also performed before and after endotoxin injection. Cardiac output was calculated using left ventricular volumes obtained from an M-mode or a two-dimensional view, left ventricular stroke volume calculated using the pulmonary flow, or estimated by the measurement of pulmonary velocity time integral (VTI).

RESULTS

Close correlations were demonstrated between flow probe-measured CO and all echocardiographic measurements of CO. All echocardiographic-derived CO overestimated the flow probe-measured CO. Two-dimensional image-derived CO was associated with the smallest overestimation of CO. Interobserver variability was lowest for pulmonary VTI-derived CO.

CONCLUSION

In mice, CO calculated from two-dimensional parasternal long-axis images is most accurate when compared with flow probe measurements; however, pulmonary VTI-derived CO is subject to less variability.

Real-time three-dimensional transesophageal echocardiography in patients with secundum atrial septal defects: outcomes following transcatheter closure

BACKGROUND

Successful transcatheter closure of atrial septal defects (ASDs) requires the accurate assessment of defect size and morphology. Assessment of ASD anatomy may be difficult by two-dimensional (2D) echocardiography. The aim of this study was to test the hypothesis that real-time three-dimensional (3D) transesophageal echocardiography (TEE) may provide more accurate morphologic assessment of ASDs than multiplane 2D TEE.

METHODS

Twenty-four patients with ASDs were imaged using 2D and real-time 3D TEE. ASD shape and size were assessed using 3D TEE retrospectively. Maximal ASD dimensions obtained by 3D TEE were compared with unstretched and balloon-stretched dimensions on 2D TEE. Planimetered defect area by 3D TEE was compared with area calculated using the ellipse formula from 2D imaging. Twenty of the 24 patients underwent transcatheter ASD closure. Closure device size was based on findings on 2D TEE. Follow-up was conducted by 2D transthoracic echocardiography.

RESULTS

Of the 24 ASDs, 6 (25%) were circular, 10 (42%) were oval, and 8 (33%) were complex in shape. The mean maximal dimension was larger by 3D TEE compared with 2D TEE (1.8 ± 0.8 vs 1.5 ± 0.6 cm; P < .05). There was no difference in the mean area measured by either modality, but for complex-shaped defects, area measured by 3D TEE was larger than that by 2D TEE (2.8 ± 1.3 vs 1.7 ± 1.4 cm(2); P < .05). Follow-up transthoracic echocardiography was available for 19 of the 20 patients undergoing transcatheter closure. Nine patients had residual right-to-left shunting 1 to 6 months after ASD closure, and the majority of these were complex in shape. In patients with residual shunting, ASD area by 3D TEE was 27% larger than by 2D TEE, whereas in patients without residual shunting, there was significantly less discrepancy between 3D and 2D areas (19%; P = .0027).

CONCLUSIONS

Three-dimensional TEE can identify ASD shape. Maximal dimensions on 3D TEE were well correlated with balloon-stretched 2D dimensions. Two-dimensional TEE can underestimate the area of complex-shaped ASDs, which may result in residual right-to-left shunting.

Growth hormone status predicts left ventricular mass in patients after cure of acromegaly

CONTEXT

Growth hormone excess and growth hormone deficiency (GHD) are both associated with increased cardiovascular morbidity. A specific acromegaly-related cardiomyopathy has been described, characterized in part by increased left ventricular mass (LVM). Growth hormone deficiency is associated with reduced LVM. Following cure of acromegaly with surgery or radiation therapy, GHD may develop; however, its effects on cardiac morphology and function in this population are not established.

OBJECTIVE

We hypothesized that the development of GHD in patients with prior acromegaly would be associated with cardiac morphologic and functional changes that differ from those in patients who are GH sufficient following cure of acromegaly.

DESIGN

A cross-sectional study was conducted in a Clinical Research Center. Study participants consisted of three groups of subjects (n=34): I. Cured acromegaly with GHD (n=15), II. Cured acromegaly with GH sufficiency (n=8), and III. Active acromegaly (n=11). Main outcome measures included cardiac morphology and function, using echocardiography parameters.

RESULTS

Mean age and BMI, 44.6 ± 2.3 years (SEM) and 30.7 ± 1.3 kg/m², respectively, were not different among the three groups. Mean peak GH values were: I. 2.8 ± 0.4 ng/ml; II. 30.1 ± 9.1 ng/ml (p=0.0002.) In group I, left ventricular mass, indexed to body surface area (LVMi), was within the normal range in all patients; moreover, left ventricular (LV) geometry was normal. At least 50% of patients in groups II and III had elevated LVMi, and in 50% of patients, LV geometry was abnormal, indicating pathologic hypertrophy. Ejection fraction was similar between all three groups. There were no significant differences in diastolic function.

CONCLUSIONS

Patients who develop GHD following cure of acromegaly do not demonstrate elevated LV mass, in contrast to patients with a history of acromegaly but normal GH levels or to patients with active acromegaly. This suggests that GH status after treatment of acromegaly correlates with LV mass, and that, in GH sufficient patients, reversal of remodeling may be slower than previously thought. These data suggest that it will be important to determine whether GH replacement alters left ventricular morphology over time.

Preload dependency of left ventricular torsion: the impact of normal saline infusion

BACKGROUND

left ventricular (LV) rotation results from contraction of obliquely oriented myocardial fibers. The net difference between systolic apical counterclockwise rotation and basal clockwise rotation is left ventricular torsion (LVT). Although LVT is altered in various cardiac diseases, determinants of LVT are incompletely understood.

METHODS AND RESULTS

LV end-diastolic volume, LV apical and basal rotation, peak systolic LVT, and peak early diastolic untwisting rate were measured by speckle-tracking echocardiography in healthy subjects (n=8) before and after infusion of a weight-based normal saline bolus (2.1±0.3 L). Saline infusion led to a significant increase in end-diastolic LV internal diameter (45.9±3.7 versus 47.6±4.2 mm; P=0.002) and LV end-diastolic volume (90.0±21.6 versus 98.3±19.6 mL; P=0.01). Stroke volume (51.3±10.9 versus 63.0±15.5 mL; P=0.003) and cardiac output (3.4±0.8 versus 4.4±1.5 L/min; P=0.007) increased, whereas there was no change in heart rate and blood pressure. There was a significant increase in the magnitude of peak systolic apical rotation (7.5±2.4° versus 10.5±2.8°; P<0.001) but no change in basal rotation (-4.1±2.3° versus -4.8±3.1°; P=0.44). Accordingly, peak systolic LVT increased by 33% after saline infusion (11.2±1.3° versus 14.9±1.7°; P<0.001). This saline-induced increase in LVT was associated with a marked increase in peak early diastolic untwisting rate (72.3±21.4 versus 136.8±30.0 degrees/s; P<0.001).

CONCLUSIONS

peak systolic LVT and peak early diastolic untwisting rate are preload-dependent. Changes in LV preload should be considered when interpreting results of future LVT studies.

Long-term anabolic-androgenic steroid use is associated with left ventricular dysfunction

BACKGROUND

Although illicit anabolic-androgenic steroid (AAS) use is widespread, the cardiac effects of long-term AAS use remain inadequately characterized. We compared cardiac parameters in weightlifters reporting long-term AAS use to those in otherwise similar weightlifters without prior AAS exposure.

METHODS AND RESULTS

We performed 2D tissue-Doppler and speckle-tracking echocardiography to assess left ventricular (LV) ejection fraction, LV systolic strain, and conventional indices of diastolic function in long-term AAS users (n=12) and otherwise similar AAS nonusers (n=7). AAS users (median [quartile 1, quartile 3] cumulative lifetime AAS exposure, 468 [169, 520] weeks) closely resembled nonusers in age, prior duration of weightlifting, and current intensity of weight training. LV structural parameters were similar between the two groups; however, AAS users had significantly lower LV ejection fraction (50.6% [48.4, 53.6] versus 59.1% [58.0%, 61.7%]; P=0.003 by two-tailed Wilcoxon rank sum test), longitudinal strain (16.9% [14.0%, 19.0%] versus 21.0% [20.2%, 22.9%]; P=0.004), and radial strain (38.3% [28.5%, 43.7%] versus 50.1% [44.3%, 61.8%]; P=0.02). Ten of the 12 AAS users showed LV ejection fractions below the accepted limit of normal (>or=55%). AAS users also demonstrated decreased diastolic function compared to nonusers as evidenced by a markedly lower early peak tissue velocity (7.4 [6.8, 7.9] cm/s versus 9.9 [8.3, 10.5] cm/s; P=0.005) and early-to-late diastolic filling ratio (0.93 [0.88, 1.39] versus 1.80 [1.48, 2.00]; P=0.003).

CONCLUSIONS

Cardiac dysfunction in long-term AAS users appears to be more severe than previously reported and may be sufficient to increase the risk of heart failure.

Galectin-3, cardiac structure and function, and long-term mortality in patients with acutely decompensated heart failure

AIMS

To determine the relationship between galectin-3 concentrations and cardiac structure in patients with acute dyspnoea, and to evaluate the impact of galectin-3 independent of echocardiographic measurements on long-term mortality.

METHODS AND RESULTS

One hundred and fifteen patients presenting to the emergency department with acute dyspnoea who had galectin-3 levels and detailed echocardiographic studies on admission were studied. Galectin-3 levels were associated with older age (r = 0.26, P = 0.006), lower creatinine clearance (r = -0.42, P < 0.001), and higher levels of N-terminal-proBNP (r = 0.39, P < 0.001). Higher galectin-3 levels were associated with tissue Doppler E/E(a) ratio (r = 0.35, P = 0.01), a lower right ventricular (RV) fractional area change (r = -0.19, P = 0.05), higher RV systolic pressure (r = 0.37, P < 0.001), and more severe mitral (r = 0.30, P = 0.001) or tricuspid regurgitation (r = 0.26, P = 0.005). In patients diagnosed with heart failure (HF), the association between galectin-3 and valvular regurgitation and RV systolic pressure persisted. In a multivariate Cox regression model, galectin-3 remained a significant predictor of 4-year mortality independent of echocardiographic markers of risk. Dyspnoeic patients with HF and galectin-3 levels above the median value had a 63% mortality; patients less than the median value had a 37% mortality (P = 0.003).

CONCLUSION

Among dyspnoeic patients with and without ADHF, galectin-3 concentrations are associated with echocardiographic markers of ventricular function. In patients with ADHF, a single admission galectin-3 level predicts mortality to 4 years, independent of echocardiographic markers of disease severity.

Diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia: proposed modification of the task force criteria

BACKGROUND

In 1994, an International Task Force proposed criteria for the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) that facilitated recognition and interpretation of the frequently nonspecific clinical features of ARVC/D. This enabled confirmatory clinical diagnosis in index cases through exclusion of phenocopies and provided a standard on which clinical research and genetic studies could be based. Structural, histological, electrocardiographic, arrhythmic, and familial features of the disease were incorporated into the criteria, subdivided into major and minor categories according to the specificity of their association with ARVC/D. At that time, clinical experience with ARVC/D was dominated by symptomatic index cases and sudden cardiac death victims-the overt or severe end of the disease spectrum. Consequently, the 1994 criteria were highly specific but lacked sensitivity for early and familial disease.

METHODS AND RESULTS

Revision of the diagnostic criteria provides guidance on the role of emerging diagnostic modalities and advances in the genetics of ARVC/D. The criteria have been modified to incorporate new knowledge and technology to improve diagnostic sensitivity, but with the important requisite of maintaining diagnostic specificity. The approach of classifying structural, histological, electrocardiographic, arrhythmic, and genetic features of the disease as major and minor criteria has been maintained. In this modification of the Task Force criteria, quantitative criteria are proposed and abnormalities are defined on the basis of comparison with normal subject data.

CONCLUSIONS

The present modifications of the Task Force Criteria represent a working framework to improve the diagnosis and management of this condition.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00024505.

Diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia: proposed modification of the Task Force Criteria

BACKGROUND

In 1994, an International Task Force proposed criteria for the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) that facilitated recognition and interpretation of the frequently nonspecific clinical features of ARVC/D. This enabled confirmatory clinical diagnosis in index cases through exclusion of phenocopies and provided a standard on which clinical research and genetic studies could be based. Structural, histological, electrocardiographic, arrhythmic, and familial features of the disease were incorporated into the criteria, subdivided into major and minor categories according to the specificity of their association with ARVC/D. At that time, clinical experience with ARVC/D was dominated by symptomatic index cases and sudden cardiac death victims-the overt or severe end of the disease spectrum. Consequently, the 1994 criteria were highly specific but lacked sensitivity for early and familial disease.

METHODS AND RESULTS

Revision of the diagnostic criteria provides guidance on the role of emerging diagnostic modalities and advances in the genetics of ARVC/D. The criteria have been modified to incorporate new knowledge and technology to improve diagnostic sensitivity, but with the important requisite of maintaining diagnostic specificity. The approach of classifying structural, histological, electrocardiographic, arrhythmic, and genetic features of the disease as major and minor criteria has been maintained. In this modification of the Task Force criteria, quantitative criteria are proposed and abnormalities are defined on the basis of comparison with normal subject data.

CONCLUSIONS

The present modifications of the Task Force Criteria represent a working framework to improve the diagnosis and management of this condition. Clinical Trial Registration clinicaltrials.gov Identifier: NCT00024505.

Cardiovascular screening in college athletes with and without electrocardiography: A cross-sectional study

BACKGROUND

Although cardiovascular screening is recommended for athletes before participating in sports, the role of 12-lead electrocardiography (ECG) remains uncertain. To date, no prospective data that compare screening with and without ECG have been available.

OBJECTIVE

To compare the performance of preparticipation screening limited to medical history and physical examination with a strategy that integrates these with ECG.

DESIGN

Cross-sectional comparison of screening strategies.

SETTING

University Health Services, Harvard University, Cambridge, Massachusetts.

PARTICIPANTS

510 collegiate athletes who received cardiovascular screening before athletic participation.

MEASUREMENTS

Each participant had routine history and examination-limited screening and ECG. They received transthoracic echocardiography (TTE) to detect or exclude cardiac findings with relevance to sports participation. The performance of screening with history and examination only was compared with that of screening that integrated history, examination, and ECG.

RESULTS

Cardiac abnormalities with relevance to sports participation risk were observed on TTE in 11 of 510 participants (prevalence, 2.2%). Screening with history and examination alone detected abnormalities in 5 of these 11 athletes (sensitivity, 45.5% [95% CI, 16.8% to 76.2%]; specificity, 94.4% [CI, 92.0% to 96.2%]). Electrocardiography detected 5 additional participants with cardiac abnormalities (for a total of 10 of 11 participants), thereby improving the overall sensitivity of screening to 90.9% (CI, 58.7% to 99.8%). However, including ECG reduced the specificity of screening to 82.7% (CI, 79.1% to 86.0%) and was associated with a false-positive rate of 16.9% (vs. 5.5% for screening with history and examination only).

LIMITATION

Definitive conclusions regarding the effect of ECG inclusion on sudden death rates cannot be made.

CONCLUSION

Adding ECG to medical history and physical examination improves the overall sensitivity of preparticipation cardiovascular screening in athletes. However, this strategy is associated with an increased rate of false-positive results when current ECG interpretation criteria are used.

PRIMARY FUNDING SOURCE

None.

Mechanism of decrease in mitral regurgitation after cardiac resynchronization therapy: optimization of the force-balance relationship

BACKGROUND

Cardiac resynchronization therapy (CRT) has been shown to reduce functional mitral regurgitation (MR). It has been proposed that the mechanism of MR reduction relates to geometric change or, alternatively, changes in left ventricular (LV) contractile function. Normal mitral valve (MV) function relies on a balance between tethering and closing forces on the MV leaflets. Functional MR results from a derangement of this force-balance relationship, and CRT may be an important modulator of MV function by its ability to enhance the force-balance relationship on the MV. We hypothesized that CRT improves the comprehensive force balance acting on the valve, including favorable changes in both geometry and LV contractile function.

METHODS AND RESULTS

We examined the effect of CRT on 34 patients with functional MR before and after CRT (209+/-81 days). MR regurgitant volume, closing forces on MV (derived from Doppler transmitral pressure gradients), including dP/dt and a factor (closing pressure ratio) expressing how long the peak closing gradient is maintained over systole (closing pressure ratio=velocity time integral/MR peak velocityxmitral regurgitation time), and dyssynchrony by tissue Doppler were measured. End-diastolic volume, end-systolic volume, mitral valve annular area (MAA) and contraction (percent change in MAA from end-diastole to midsystole), leaflet closing area (leaflet area during valve closure), and tenting volume (volume under leaflets to annular plane) were measured by 3D echocardiography. After CRT, end-diastolic volume (253+/-111 versus 221+/-110 mL, P<0.001) and end-systolic volume (206+/-97 versus 167+/-91 mL, P<0.001) decreased and ejection fraction (19+/-6 versus 27+/-9%, P<0.001) increased. MR regurgitant volume decreased from 35+/-17 to 23+/-14 mL (P<0.001), MAA from 11.6+/-3.5 to 10.5+/-3.1 cm(2) (P<0.001), leaflet closing area from 15.4+/-5 to 13.7+/-3.8 cm(2) (P<0.001), and tenting volume from 5.7+/-2.6 to 4.6+/-2.2 mL (P<0.001). Peak velocity (and therefore transmitral closing pressure) was more sustained throughout systole, as reflected by the increase in the closing pressure ratio (0.77+/-0.1 versus 0.84+/-0.1 before CRT versus after CRT, P=0.01); dP/dt also improved after CRT. There was no change in dyssynchrony or MAA contraction.

CONCLUSIONS

Reduction in MR after CRT is associated with favorable changes in MV geometry and closing forces on the MV. It does so by favorably affecting the force balance acting on the MV in 2 ways: reducing tethering through reversal of LV remodeling and increasing the systolic duration of peak transmitral closing pressures.

Unusual position of a prosthetic mitral valve

Extensive calcification of the mitral annulus in patients who require mitral valvereplacement presents a significant challenge to the surgeon. Several techniques, includingdebridement of the calcium, reconstruction of the annulus, and insertion of the prosthesis in a locationother than the annulus, have been used in such patients. We report the echocardiographictechniques used to evaluate the case of a woman with an unusually positioned prosthetic mitralvalve.