Real Time Three-Dimensional Stress Echocardiography Advantages and Limitations

Exploring heart dissection techniques for enhancing anatomical education: a pilot study to replicate transthoracic echocardiography

PURPOSE

For novice learners, converting two-dimensional (2D) images of echocardiography to three-dimensional (3D) cardiac structures is deemed challenging. This study aimed to develop an accurate dissection method of the heart to reproduce the transthoracic echocardiographic views on cadavers and elucidate new educational methods in human anatomy dissection courses.

METHODS

A total of 18 hearts were used in this study. After reflecting the anterior thoracic wall inferiorly, the hearts were excised from embalmed cadavers. Thereafter, three landmarks were set on the heart for each plane of the incision, and the hearts were incised to observe the three different echocardiographic views, which include the apical four-chamber view (A4C), parasternal long axis (PLAX) view, and parasternal short axis (PSAX) view at the papillary muscle level. If all structures for observation during routine echocardiography are clearly observed in each view, a successful incision is considered. All procedures and incisions were performed by the medical students. After a successful incision, hearts were returned to the original position in the pericardial sac for further observation.

RESULTS

The success rates of incision for each view were 83.3% (5/6 success cases), 83.3% (5/6 success cases), and 66.7% (4/6 success cases) in the A4C view, PLAX view, and PSAX view at the papillary muscle level, respectively.

CONCLUSION

This dissection method could probably be employed to reproduce transthoracic echocardiographic views on cadaveric hearts, which is beneficial for novice learners for a deeper understanding of the anatomy.

Early Diagnosis of Cardiovascular Diseases in Workers: Role of Standard and Advanced Echocardiography

Cardiovascular disease (CVD) still remains the main cause of morbidity and mortality and consequently early diagnosis is of paramount importance. Working conditions can be regarded as an additional risk factor for CVD. Since different aspects of the job may affect vascular health differently, it is important to consider occupation from multiple perspectives to better assess occupational impacts on health. Standard echocardiography has several targets in the cardiac population, as the assessment of myocardial performance, valvular and/or congenital heart disease, and hemodynamics. Three-dimensional echocardiography gained attention recently as a viable clinical tool in assessing left ventricular (LV) and right ventricular (RV) function, volume, and shape. Two-dimensional (2DSTE) and, more recently, three-dimensional speckle tracking echocardiography (3DSTE) have also emerged as methods for detection of global and regional myocardial dysfunction in various cardiovascular diseases and applied to the diagnosis of subtle LV and RV dysfunction. Although these novel echocardiographic imaging modalities have advanced our understanding of LV and RV mechanics, overlapping patterns often show challenges that limit their clinical utility. This review will describe the current state of standard and advanced echocardiography in early detection (secondary prevention) of CVD and address future directions for this potentially important diagnostic strategy.

Four-dimensional echocardiography area strain combined with exercise stress echocardiography to evaluate left ventricular regional systolic function in patients with mild single vessel coronary artery stenosis

BACKGROUND

The aim of this prospective study was to assess the diagnosis value of four-dimensional echocardiography area strain (AS) combined with exercise stress echocardiography to evaluate left ventricular regional systolic function in patients with mild single vessel coronary artery stenosis.

METHODS

Based on treadmill exercise load status, two-dimensional conventional echocardiography and four-dimensional echocardiography area strain were performed on patients suspected coronary artery disease before coronary angiogram. Thirty patients (case group) with mild left anterior descending coronary artery stenosis (stenosis <50%) and thirty gender- and age-matched patients (control group) without coronary artery stenosis according to the coronary angiogram results were prospectively enrolled.

RESULTS

All the patients had no left ventricular regional wall motion abnormality in two-dimensional echocardiography at rest and exercise stress. There was no significant difference in the 16 segmental systolic peak AS at rest between two groups. After exercise stress, the peak systolic AS_rest-stress at mid anterior wall (-7.00%±10.90% vs 2.80%±23.69%) and mid anterolateral wall (-4.40%±18.81% vs 8.80%±19.16%) were decreased, while increased at basal inferolateral wall (14.00%±19.27% vs -5.60%±15.94%) in case group compared with control group (P<.05).

CONCLUSIONS

In patients with mild single vessel coronary artery stenosis, the area strain was decreased at involved segments, while compensatory increased at noninvolved segments after exercise stress. Four-dimensional echocardiography area strain combined with exercise stress echocardiography could sensitively find left ventricular regional systolic function abnormality in patients with mild single vessel coronary artery stenosis, and locate stenosis coronary artery accordingly.

Assessment of image quality in real time three-dimensional dobutamine stress echocardiography: an integrated 2D/3D approach

BACKGROUND

Three-dimensional (3D) stress echocardiography is a relatively new technique offering the potential to acquire images of the entire left ventricle from 1 or 2 transducer positions in a time-efficient manner. Relative to two-dimensional (2D) imaging, the ability to quickly acquire full volume images during peak stress with 3D echocardiography can eliminate left ventricular (LV) foreshortening while reducing inter-operator variability. Our objectives were to (1) determine the practicality of a novel integrated 2D/3D stress protocol in incorporating 3D imaging into a standard 2D stress echocardiogram and (2) to determine whether the quality of imaging using the novel 2D/3D protocol was sufficient for interpretation.

METHODS

Twenty-five patients referred for stress echocardiography underwent an integrated 2D/3D image acquisition protocol. LV segments were scored from 0 (absent or no clear endocardial visualization) to 3 (excellent/full visualization of endocardial border) with each modality. 2D segment quality scoring was compared with 3D. An integrated score was compared with either 2D or 3D imaging alone.

RESULTS

Two-dimensional and 3D imaging were optimal for differing segments and the integrated protocol was superior to either modality alone. 3D imaging was superior in visualizing the anterior and anterolateral region of the base segments, compared to 2D imaging. 3D imaging was less useful for the base, the mid-inferior, and the inferoseptal segments, thus emphasizing the need to retain 2D imaging in stress echocardiography at this time.

CONCLUSION

The integrated 2D/3D protocol approach to stress echocardiography is technically feasible and maximizes image quality of dobutamine stress echocardiography, improving patient assessment.

Clinical application of three-dimensional echocardiography

Echocardiography is one of the most valuable diagnostic tools in cardiology. Technological advances in ultrasound, computer and electronics enables three-dimensional (3-D) imaging to be a clinically viable modality which has significant impact on diagnosis, management and interventional procedures. Since the inception of 3D fully-sampled matrix transthoracic and transesophageal technology it has enabled easier acquisition, immediate on-line display, and availability of on-line analysis for the left ventricle, right ventricle and mitral valve. The use of 3D TTE has mainly focused on mitral valve disease, left and right ventricular volume and functional analysis. As structural heart disease procedures become more prevalent, 3D TEE has become a requirement for preparation of the procedure, intra-procedural guidance as well as monitoring for complications and device function. We anticipate that there will be further software development, improvement in image quality and workflow.

Early effect of essential hypertension on the left ventricular twist-displacement loop by two-dimensional ultrasound speckle tracking imaging

OBJECTIVE

To investigate two-dimensional (2D) ultrasound speckle tracking imaging (STI) in the evaluation of the early changes in the left ventricular (LV) twist-displacement loop in patients with hypertension (EH).

METHODS

Sixty-five EH patients with left ventricular normal geometry (LVN) - including 33 cases with non-left atrial enlargement (NLAE) and 32 cases with left atrial enlargement (LAE) - along with 45 healthy individuals were enrolled in this study. Basal and apical 2D LV short-axis images were acquired and analyzed to obtain the LV rotation (LVrot) and LV radial displacement. Once the LV twist and LV radial displacement were calculated, an LV twist-displacement loop was constructed. Group comparisons between peak twist (Ptw), twist at mitral valve opening (MVOtw), untwisting rate (Utw R), systolic radial displacement (SD), systolic slope (SS), isovolumic relaxation radial displacement (IVRD) and isovolumic relaxation slope (IVRS) were performed.

RESULTS

(1) The Ptw and MVOTw were greater in the NLAE and LAE groups when compared to the normal group while the UTw R was lower in likewise comparison. (2) The LV twist was correlated to the radial displacement in systole and in the isovolumic relaxation period. The SS and IVRS were greater in the NLAE and LAE groups when compared to the normal group.

CONCLUSIONS

The LV twist-displacement loop can be reconstructed noninvasively by 2D ultrasound STI. EH affects the systolic and early diastolic component of the twist-displacement loop by increasing the LV twist and decreasing the LV untwisting respectively impairing LV relaxation. The assessment of the LV twist-displacement loop may be useful in the evaluation of early features of LV dysfunction in EH patients.