Usefulness of real-time three-dimensional echocardiography for evaluation of myectomy in patients with hypertrophic cardiomyopathy

A Case Report of Asymmetry of Systolic Anterior Motion of the Mitral Valve, a Not Widely Well-Known but Practically Important Echocardiographic Presentation in Hypertrophic Cardiomyopathy

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Echocardiography is useful for evaluating LVOT obstruction in patients with HCM.

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Asymmetry of SAM in patients with HCM is not a well-known presentation.

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This patient had asymmetry of SAM, resulting in a narrow laterally located LVOT.

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In a patient with asymmetry of SAM, LVOT gradient should be estimated carefully.

Live/real time three-dimensional transesophageal echocardiographic assessment of ventricular septal volume and mass before and after myectomy in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. In patients resistant to medical management, myectomy is the surgical procedure of choice to reduce the symptoms of left ventricular outflow obstruction. Two-dimensional transesophageal echocardiography (2DTEE) has become part of the operative procedure by decreasing the incidence of postoperative complications. However, because of the three-dimensional geometry of left ventricular outflow tract, it is unable to comprehensively assess the location and severity of the obstruction and to provide accurate guidance during myectomy. In this study, 10 patients with HCM underwent live/real time three-dimensional transesophageal echocardiography (3DTEE) intra-operatively to measure the volume of the resected septum. This volume correlated well with the volume of the resected septal muscle directly obtained using a graduating cylinder containing water (r = 0.9, P < 0.000). 3DTEE may be potentially used as an adjunct to guide the surgeon in performing an adequate myectomy with a lower incidence of residual obstruction and complications such as an iatrogenic ventricular septal defect.

In vivo measurement of mitral leaflet surface area and subvalvular geometry in patients with asymmetrical septal hypertrophy: insights into the mechanism of outflow tract obstruction

BACKGROUND

Analyzing the determinants of systolic anterior motion of the mitral valve and consequent left ventricular outflow tract (LVOT) obstruction in patients with asymmetrical septal hypertrophy requires a comprehensive 3-dimensional analysis of mitral leaflet (ML) area, papillary muscle (PM) geometry, and the distribution of left ventricular hypertrophy.

METHODS AND RESULTS

Real-time 3-dimensional echocardiography was performed in 47 patients with asymmetrical septal hypertrophy and 32 normal controls. Patients included 20 with resting LVOT obstruction (group I) and 27 without (group II). Customized software (Omni 4D) provided a validated measure of ML surface area, LVOT area, mitral annular area and nonplanarity, LVOT hypertrophy index by topography (percent area with wall thickness >16 mm), and 3-dimensional PM positions relative to annulus. ML area was more than twice as large in group I than normal and 1.4 times normal in group II (P<0.001). Group I patients were also characterized by higher LVOT hypertrophy index and medial and anterior displacements of both PMs, resulting in a shorter inter-PM distance. Independent determinants of LVOT obstruction were indexed total ML area (adjusted odds ratio, 5.651; 95% confidence interval, 1.573 to 20.304; P=0.008) and inter-PM distance (adjusted odds ratio, 0.416; 95% confidence interval, 0.203 to 0.854; P=0.0169). Minimal LVOT area during systole correlated well with peak LVOT pressure gradient (R(2)=0.83, P<0.001); its independent determinants were left ventricular end-systolic volume (P=0.0183), indexed total ML area (P=0.0108), inter-PM distance (P=0.0378), annular height (P=0.0047), and LVOT hypertrophy index (P=0.0098).

CONCLUSIONS

Myocardium is not the only tissue affected in patients with asymmetrical septal hypertrophy, and primary changes of the mitral apparatus, including ML area increase and PM displacement, are independent determinants of LVOT obstruction and provide a comprehensive mechanism that determines leaflet slack and anteriorly directed motion. Abnormal PM-mitral valve geometry assessed by real-time 3-dimensional echocardiography can provide reasonable new targets for individualized intervention.

[Evaluation of the mitral valve by transthoracic real-time three-dimensional echocardiography]

Recently, echocardiography is the most widely used routine non-invasive diagnostic method, with which morphology and function of the mitral valve can be characterized. The aim of this review is to demonstrate the role of one of the newest echocardiographic developments, the transthoracic real-time three-dimensional echocardiography in the evaluation of mitral valve.

[The role of real-time three-dimensional echocardiography in the evaluation of hypertrophic cardiomyopathy]

Hypertrophic cardiomyopathy is a relatively common hereditary disorder, which is associated with cardiac morphologic and functional alterations. Echocardiography is a non-invasive, simple and easy-to-learn method to evaluate patients with cardiomyopathy. The aim of this review paper is to demonstrate the possible diagnostic role of one of the newest echocardiographic development, the real-time 3-dimensional echocardiography in the evaluation of hypertrophic cardiomyopathy.

Echocardiography in hypertrophic cardiomyopathy: the role of conventional and emerging technologies

Hypertrophic cardiomyopathy is a relatively common inherited cardiomyopathy that is occasionally challenging to differentiate from hypertensive heart disease and athlete hearts on the basis of morphologic or functional abnormalities alone. Echocardiography has traditionally played a preeminent role in the diagnosis, formulation of management strategies, and the prognostication of this complex disease. In this review, we briefly profile the utility and pitfalls of established echocardiographic modalities and discuss the evolving role of novel echocardiographic imaging modalities such as tissue Doppler, Doppler-based strain, 2-dimensional strain (speckle tracking imaging), and 3-dimensional imaging in the assessment of hypertrophic cardiomyopathy.

Direct measurement of left ventricular outflow tract by transthoracic real-time 3D-echocardiography increases accuracy in assessment of aortic valve stenosis

BACKGROUND

Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter.

METHODS

We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from systolic LVOT areas. These results were compared to area values obtained by M-mode LVOT-diameters (area=pi(*)(d/2)(2)). In addition, the calculated aortic valve orifices were compared to invasive measurements or direct planimetry in the transthoracic or transesophageal examination.

RESULTS

Two independent observers found a reduction in LVOT area during systole (p<0.001). Often a more ellipsoid-like shaped LVOT resulted at end-systole which was shown by a reduction (p<0.001) of the LVOT longitudinal to oblique axis ratio. 3D-TTE determination of aortic valve orifice areas (mean difference: -0.04+/-0.09 cm(2)) showed a lesser deviation from the invasively or planimetrically measured areas than conventionally calculated LVOT areas (mean difference: -0.1+/-0.1 cm(2)) using the continuity equation (p<0.001).

CONCLUSIONS

The tested transthoracic 3D-echocardiography technique offers non-invasive measurement of the LVOT and aortic valve area based on the continuity equation during systole and thus improves accuracy and, additionally, agreement of aortic valvular area determination with invasive and direct measurements.

Real-time 3-dimensional echocardiography – can there be one more dimension?

A kardiológiai betegek ellátásában a noninvazív vizsgáló módszereknek alapvető jelentőségük van. Elméletileg a szív akkor vizsgálható tökéletesen, ha természetének megfelelően három dimenzióban rögzítjük a szívciklus szerint. A második generációs, immár real-time (vagyis valós idejű) háromdimenziós echokardiográfok elméletileg optimális lehetőséget nyújtanak a cardialis struktúrák háromdimenziós elemzésére. Real-time 3-dimenziós echokardiográfia során pontosan mérhetők a kamrai és pitvari térfogatok, valamint a kamrai izomtömeg. A billentyűk és a congenitalis abnormalitások ‘en-face’ vizsgálhatók. Használhatóságát terheléses protokollok alkalmazása mellett igazolták. A jelen összefoglaló közlemény célja a módszer bemutatása, lehetséges előnyeinek tisztázása a jelenleg még fennálló technológiai korlátok bemutatásával együtt.

Asymmetry of Systolic Anterior Motion of the Mitral Valve in Patients with Hypertrophic Obstructive Cardiomyopathy: A Real-time Three-dimensional Echocardiographic Study

By geometric analysis of real-time 3-dimensional echocardiography performed in 39 patients with hypertrophic obstructive cardiomyopathy and definite systolic anterior motion of the mitral valve, we found that the angle between the mitral annular plane and basal portion of the anterior mitral valve leaflet, and the angle between the basal portion of the anterior leaflet and its tip portion measured in the medial and central anteroposterior planes, were significantly smaller than those in the lateral plane. The distance between the interventricular septum and the anterior mitral valve tip in the medial and central plane was also significantly smaller than that in the lateral plane. The lateral distance between the interventricular septum and the anterior mitral valve tip was the only independent determinant of left ventricular outflow tract pressure gradient by multiple stepwise regression analysis. In conclusion, systolic anterior motion of the mitral valve develops predominantly in the medial side, resulting in laterally located narrow left ventricular outflow tract opening in patients with hypertrophic obstructive cardiomyopathy.

[Update in cardiac imaging techniques. Echocardiography and magnetic resonance imaging]

This article is a review of the main developments in cardiac imaging techniques reported in publications during 2005. Recent advances in digital technology have led to steadily increasing reliance on imaging techniques in the management of cardiovascular disease. We discuss advances in two techniques that fall under the remit of the echocardiography working group: echocardiography and magnetic resonance imaging.

Real-Time Three-Dimensional Echocardiography Is Useful in the Evaluation of Patients with Atrioventricular Septal Defects

OBJECTIVE

We sought to determine whether three-dimensional echocardiography (3DE) is useful in the evaluation of patients with atrioventricular septal defect (AVSD).

BACKGROUND

Recent advances in 3DE have enhanced its practicality. We assessed whether 3DE provided new information compared to 2DE among patients with AVSD.

METHODS

We retrospectively reviewed 52 3DE datasets from 51 patients (median age: 4.6 years, range 0-30 years; median BSA: 0.6 m2, range 0.2-1.9 m2) with any type of AVSD during a 1-year period. 3DE findings were compared to 2DE and surgical reports. For each study, AVSD was classified by 2DE as one of the following: unrepaired balanced defect, repaired balanced defect with residual lesions, repaired balanced defect without residual lesions, or unbalanced defect. 3DE was graded as (1) Additive: 3DE resulted in a new finding or changed diagnosis; (2) Useful: While useful, 3DE did not result in new findings or changed diagnosis; or (3) Not useful.

RESULTS

3DE on unrepaired balanced AVSD and repaired AVSD with residual lesions was more often additive/useful (33/36; 92%) than on repaired AVSD without residual lesions or unbalanced AVSD (9/16 (56%), P=0.009). 3DE was additive or useful in all three patients with unbalanced AVSD being considered for biventricular repair. Useful information obtained by 3DE included: precise characterization of mitral regurgitation and cleft leaflet, substrate for subaortic stenosis, valve anatomy, and presence and location of additional septal defects.

CONCLUSION

3DE provides useful and additive information in unrepaired balanced AVSD, repaired AVSD with residual lesions, and unbalanced AVSD under consideration for biventricular repair.