evaluation of prosthetic valve dysfunction by three‑dimensional ... · 2018. 11. 21. ·...

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54 © 2018 Heart India | Published by Wolters Kluwer - Medknow Subhash Chaudhari, Jayesh Prajapati 1 , Naman Shastri 2 , Iva Patel 3 , Sharad Jain 1 , Sibasis Sahoo 1 , Vijay Gupta 4 Department of Cardiology, Solar Hospital, Departments of 1 Cardiology, 3 Research and 4 Nuclear Medicine, UN Mehta Institute of Cardiology and Research Center, Civil Hospital Campus, 2 Department of Cardiac Anaesthesia, Sal Hospital and Medical Institute, Ahmedabad, Gujarat, India Address for correspondence: Dr. Jayesh Prajapati, Department of Cardiology, UN Mehta Institute of Cardiology and Research Center, Civil Hospital Campus, Asarwa, Ahmedabad ‑ 380 016, Gujarat, India. E‑mail: [email protected] ABSTRACT Background: Three‑dimensional (3D) echocardiography (echo) and transesophageal echo images enable visualization of valvular anatomy from unique orientations with improved spatial relationships not previously seen with two‑dimensional (2D) echo. Materials and Methods: Patients who fulfilled the criteria had undergone detailed evaluation of prosthetic valve dysfunction. Prosthetic valve dysfunction patients with stable hemodynamic were included and 3D echo findings were compared with 2D echo. Results: A total of 10 males and 25 females were evaluated in the study. Two females and one male had bioprosthetic, three males and two females had tilting disc valve, while 21 females and six males had bileaflet mechanical valve. 3D echo had shown abnormal motion of leaflets in seven male and 21 female patients compared to 2D echo. Abnormal valvular calcification was demonstrated in a total of 23 patients on 3D echo. Valve sewing‑ring integrity and motion were found abnormal in two male and two female patients in 3D echo. Prosthetic valve dehiscence and thrombus were better seen in five and 15 patients, respectively, on 3D echo. On 3D echo, pannus was better seen in one male and two females. 3D echo defined exact site and size of vegetation better than 2D echo in two female patients. Conclusions: Real‑time 3D imaging allows clinically useful visualization of prosthetic valve components such as leaflets, rings, and struts of all prosthetic valves, irrespective of position. “En face” view of the valve has proven useful in the assessment of prosthetic valve endocarditis, paravalvular regurgitation, and prosthesis dysfunction. 3D echo imaging plays an important role in device closure. Keywords: Prosthetic valve dysfunction, three-dimensional echocardiography, two-dimensional echocardiography INTRODUCTION Approximately 280,000 valve substitutes are implanted worldwide each year. Of them, approximately half are mechanical valves and half are bioprosthetic valves. [1,2] Despite the marked improvements in valve technology and surgical skill, the outcome of patients undergoing valve replacement is affected by prosthetic valve hemodynamics, durability, and thrombogenicity. Three‑dimensional (3D) echocardiography (echo) with Doppler is the method of choice for noninvasive evaluation of prosthetic valve function. By their design, almost all replacement valves are obstructive compared with normal native valves. The degree of obstruction varies with the type and size of the valve. Thus, it may be difficult to differentiate obstructive hemodynamics due to valve design from that due to mild obstruction as observed after pathologic changes and from prosthesis‑patient mismatch. Further, because of shielding and artifacts, the insonation of valve and, in particular, of regurgitant jets associated with the valve may be difficult. [3‑6] Evaluation of prosthetic valve dysfunction by three‑dimensional echocardiography Access this article online Website: www.heartindia.net Quick Response Code DOI: 10.4103/heartindia.heartindia_1_18 How to cite this article: Chaudhari S, Prajapati J, Shastri N, Patel I, Jain S, Sahoo S, et al. Evaluation of prosthetic valve dysfunction by three- dimensional echocardiography. Heart India 2018;6:54-60. This is an open access journal, and arcles are distributed under the terms of the Creave Commons Aribuon-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creaons are licensed under the idencal terms. For reprints contact: [email protected] Original Article [Downloaded free from http://www.heartindia.net on Tuesday, June 19, 2018, IP: 27.109.14.146]

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Page 1: Evaluation of prosthetic valve dysfunction by three‑dimensional ... · 2018. 11. 21. · Shastri2, Iva Patel3, Sharad Jain1, Sibasis Sahoo1, ... of Chi‑square test of categorical

54 © 2018 Heart India | Published by Wolters Kluwer - Medknow

Subhash Chaudhari, Jayesh Prajapati1, Naman Shastri2, Iva Patel3, Sharad Jain1, Sibasis Sahoo1, Vijay Gupta4

Department of Cardiology, Solar Hospital, Departments of 1Cardiology, 3Research and 4Nuclear Medicine, UN Mehta Institute of  Cardiology  and  Research  Center,  Civil  Hospital  Campus, 2Department of Cardiac Anaesthesia, Sal Hospital and Medical Institute, Ahmedabad, Gujarat, India

Address for correspondence: Dr. Jayesh Prajapati, Department of Cardiology, UN Mehta Institute of Cardiology and Research Center, Civil Hospital Campus, Asarwa, Ahmedabad ‑ 380 016, Gujarat, India. E‑mail: [email protected]

ABSTRACTBackground: Three‑dimensional (3D) echocardiography (echo) and transesophageal echo images enable visualization of valvular anatomy from unique orientations with improved spatial relationships not previously seen with two‑dimensional (2D) echo.

Materials and Methods: Patients who fulfilled the criteria had undergone detailed evaluation of prosthetic valve dysfunction. Prosthetic valve dysfunction patients with stable hemodynamic were included and 3D echo findings were compared with 2D echo.

Results: A total of 10 males and 25 females were evaluated in the study. Two females and one male had bioprosthetic, three males and two females had tilting disc valve, while 21 females and six males had bileaflet mechanical valve. 3D echo had shown abnormal motion of leaflets in seven male and 21 female patients compared to 2D echo. Abnormal valvular calcification was demonstrated in a total of 23 patients on 3D echo. Valve sewing‑ring integrity and motion were found abnormal in two male and two female patients in 3D echo. Prosthetic valve dehiscence and thrombus were better seen in five and 15 patients, respectively, on 3D echo. On 3D echo, pannus was better seen in one male and two females. 3D echo defined exact site and size of vegetation better than 2D echo in two female patients.

Conclusions: Real‑time 3D imaging allows clinically useful visualization of prosthetic valve components such as leaflets, rings, and struts of all prosthetic valves, irrespective of position. “En face” view of the valve has proven useful in the assessment of prosthetic valve endocarditis, paravalvular regurgitation, and prosthesis dysfunction. 3D echo imaging plays an important role in device closure.

Keywords: Prosthetic valve dysfunction, three-dimensional echocardiography, two-dimensional echocardiography

INTRODUCTION

Approximately 280,000 valve substitutes are implanted worldwide each year. Of them, approximately half are mechanical valves and half are bioprosthetic valves.[1,2] Despite the marked improvements in valve technology and surgical skill, the outcome of patients undergoing valve replacement is affected by prosthetic valve hemodynamics, durability, and thrombogenicity.

Three‑dimensional (3D) echocardiography (echo) with Doppler is the method of choice for noninvasive evaluation of prosthetic valve function. By their design, almost all replacement valves are obstructive compared with normal native valves. The degree of obstruction varies with the type and size of the valve. Thus, it may be difficult to differentiate obstructive hemodynamics due to valve design from that due

to mild obstruction as observed after pathologic changes and from prosthesis‑patient mismatch. Further, because of shielding and artifacts, the insonation of valve and, in particular, of regurgitant jets associated with the valve may be difficult.[3‑6]

Evaluation of prosthetic valve dysfunction by three‑dimensional echocardiography

Access this article online

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www.heartindia.net

Quick Response Code

DOI:

10.4103/heartindia.heartindia_1_18How to cite this article: Chaudhari S, Prajapati J, Shastri N, Patel I, Jain S, Sahoo S, et al. Evaluation of prosthetic valve dysfunction by three-dimensional echocardiography. Heart India 2018;6:54-60.

This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.

For reprints contact: [email protected]

Original Article

[Downloaded free from http://www.heartindia.net on Tuesday, June 19, 2018, IP: 27.109.14.146]

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While these earlier techniques enabled an improved visualization of valvular anatomy, acquisition of images was tedious and time‑consuming compounded by the requirement of extensive postprocessing to generate images. Further, the image quality was poor and was frequently affected by artifacts, thereby limiting its use.

Recent advancements in 3D have enabled the visualization of valvular anatomy from unique orientations with improved spatial relationships not previously possible with two‑dimensional (2D) echo.

This study aims to assess whether 3D mode can provide an incremental diagnostic and descriptive value over 2D mode in the assessment of prosthetic valve function.

MATERIALS AND METHODS

This prospective, observational study was conducted at U N Mehta Institute of Cardiology and Research Centre after approval by the Institutional Ethics Committee. From March 2012 to March 2014, 60 patients were identified to have prosthetic valve dysfunction. Of 60 patients, 25 had unstable hemodynamic condition, so they were excluded from the study. The remaining 35 patients who fulfilled the inclusion criteria underwent detailed evaluation by both 2D echo and 3D echo for prosthetic valve dysfunction. The findings were then compared.

Inclusion criteria for the studyFor prosthetic aortic valve dysfunction, one or more of the following 2D echo criteria were used:1.  Mean gradient: ≥20 mmHg2.  Acceleration time: ≥80 ms3. Effective valve orifice area (EOA) (cm2) ≤1.24. Doppler velocity index (DVI) <0.30 a. (velocity time integral [VTI] left ventricular outflow

tract [LVOT]/VTI prosthetic aortic valve)5. Presence of regurgitation jet >5 cm long or its base at

origin >1 cm at prosthetic valvular leak or paravalvular aortic regurgitation.

For prosthetic mitral valve (pr.MV) dysfunction, one or more of the following 2D echo criteria were used:1.  Peak early velocity (m/s) ≥1.92. Mean gradient (mmHg) >53.  Pressure half‑time (ms) ≥1304.  DVI: VTI pr.MV/VTI (LVOT) ≥2.25. EOA (cm2) <2.06. Presence of regurgitation jet >4 cm at prosthetic

valvular leak or paravalvular mitral regurgitation effective regurgitant orifice area (cm2) ≥0.20.

Exclusion criteriaThe patients of prosthetic valve dysfunction having unstable hemodynamics are excluded from this study.

EquipmentFor echo, we have used Philips iE33 equipment with 2D and 3D transthoracic echo (TTE) probe (X5‑1), 2D and 3D transesophageal echo (TEE) probe (X7‑2t).

All the statistical calculations were carried out using SPSS program version 20.0 (Chicago, IL, USA); the result of Chi‑square test of categorical data was expressed as frequency and percentage.

RESULTS

The echo findings of 35 patients who underwent detailed evaluation by both 2D and 3D echo were analyzed for prosthetic valve dysfunction. Table 1 shows the different characteristic of study population. Of 35 patients in the study, there were 10 males (28.6%) and 25 females (71.4%). There were 16 (45.7%) young patients (age range 20–40 years) comprising 3 out of 10 males (30%) and 13 out of 25 females (52%).

Among the 35 patients, 3 (8.57%) had aortic valve prosthesis, 25 (71.43%) had mitral valve prosthesis, and 7 (20%) had both aortic and mitral valve prosthesis.

Table 1: Different characteristics of the study population

Variables Total Male (n=10), n (%)

Female (n=25), n (%)

Age group among study population

20‑40 16 3 (30) 13 (52)>40 18 7 (70) 12 (48)

Site of prosthetic valve among the study population

Aortic valve 3 1 (10) 2 (8)Mitral valve 25 7 (70) 18 (72)Both 7 2 (20) 5 (20)

Type of prosthetic valve amongst the study population

Bioprosthetic valve 3 1 (10) 2 (8)Mechanical valve bileaflet 27 6 (60) 21 (84)Mechanical valve tilting disc

5 3 (30) 2 (8)

Mechanical valve ball and cage

0 0 0

LV function data among study population

Normal 32 7 (70) 25 (100)Abnormal 3 3 (30) 0

LV: Left ventricular

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Of the total prosthetic valves, 3 (8.5%) patients (2 females and 1 male) had bio pr.MV; 5 (14.2%) patients (2 females and 3 males) had tilting disc mechanical prosthetic valve; 27 (77.1%) patients (21 females and 6 males) had bileaflet mechanical prosthetic valve.

In this study, only 3 (30%) male patients had abnormal left ventricular function, and thus, majority of patients in this study had normal left ventricular function.

Thirty (85.71%) patients had adequate TTE acoustic window. Only 5 (14.3%) patients had inadequate transthoracic acoustic window. Two patients had chronic obstructive pulmonary disease and three patients had obesity; however, even with inadequate 2D imaging window in these five patients, we could get necessary information by 3D echo.

Table 2 highlights that during evaluation of prosthetic valve dysfunction using echo, 3D mode provides superior visualization than 2D mode. As compared to 2D mode echo, prosthetic valve dehiscence was better visualized in five patients (1 male and 4 females) on 3D mode. On 3D mode, thrombus was seen in 15 patients (4 males and 11 females) which was not seen on 2D mode echo. As compared to 2D mode echo, on 3D mode, pannus was better visualized in three patients (1 male and 2 females). Vegetation was seen in 2 (8%) female patients by both 2D and 3D echo. 3D echo defined exact site and size of vegetation better than 2D echo. Pseudoaneurysm was not seen in any of the cases in this study. In the present study, anticoagulation status among the study population was 6 (66%) male patients and 12 (52%) female patients had subtherapeutic prothrombin time.

Table 3 demonstrates that valve leaflet motion was abnormal in 28 patients (7 male and 21 female patients) on 3D echo as compared to 2D echo which showed abnormality in 21 patients (6 males and 15 females). Abnormal valvular calcification was demonstrated in 23 patients on 3D echo. While on 2D echo only 9 patients were found to have abnormal valvular calcification. Valve sewing‑ring integrity and motion was found abnormal in four patients on 3D echo which was not visualized on 2D echo.

DISCUSSION

Real‑time (RT) 3D imaging allows clinically useful visualization of prosthetic valve components such as the leaflets, rings and struts of all prosthetic valves, irrespective of position. This is especially useful for the assessment of mechanical mitral and aortic valves where 2D images are often of poor quality due to acoustic shadowing. In particular, the RT3D allows visualization of ventricular side of mitral prosthetic valves.

Prosthetic valve endocarditisWhile TTE has relatively high specificity for detecting vegetations, its sensitivity lies between 40 and 80%. RT3D has been shown to provide additional information in the evaluation of prosthetic valve endocarditis [Figures 1‑3].[7]

One study patient presented with postbio‑pr.MV replacement before 8 years was presented with history of prolong fever and dyspnea NYHA Class 3 for the last 4 months. On 3D echo [Figures 1‑3], vegetation and mitral valve effective regurgitation orifice were seen very clearly as compared to 2D echo.

Particularly, the “en face” view of prosthetic valves has been useful in the assessment of prosthetic valve endocarditis as it allows the identification of discrete valvular dehiscence together with associated regurgitation jets. The ability to

Table 3: Prosthetic valve apparatus evaluation in the study population

Variables Male (2D)

Female (2D)

Male (3D)

Female (3D)

Motion of leaflets (%)Normal 4 (40) 10 (40) 3 (30) 4 (16)Abnormal 6 (60) 15 (60) 7 (70) 21 (84)

Presence of calcification (%)

Normal 7 (70) 19 (76) 3 (30) 9 (36)Abnormal 3 (30) 6 (24) 7 (70) 16 (64)

Valve sewing‑ring integrity and motion (%)

Normal 10 (100) 25 (100) 8 (80) 23 (92)Abnormal 0 0 2 (20) 2 (8)

2D: Two‑dimensional, 3D: Three‑dimensional

Table 2: Prosthetic valve dysfunction mechanisms

Male (n=10), n (%) Female (n=25), n (%)2D 3D 2D 3D

DehiscenceNot seen 10 9 (90) 22 (88) 21 (84)Seen 1 (10) 3 (12) 4 (16)

ThrombosisNot seen 7 (70) 3 (30) 21 (84) 10 (40)Seen 3 (30) 7 (70) 4 (16) 15 (60)

Pannus formationNot seen 10 9 (90) 25 23 (92)Seen 1 (10) 2 (8)

Pseudoaneurysm formation

Not seen 10 10 25 25Seen

EndocarditisNot seen 10 10 23 (92) 23 (92)Seen 2 (8) 2 (8)

2D: Two‑dimensional, 3D: Three‑dimensional

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display valvular images in a surgical perspective allows for better communication with surgeons.

RT3D images can also assist in the differentiation of vegetation versus loose suture material, and the rocking motion of a partially dehisced valve is better appreciated on RT3D imaging.

Paravalvular regurgitationThe incidence of significant prosthetic paravalvular regurgitation causing heart failure and hemolytic anemia is 1%–5%, and the majority of prosthetic leaks generally occur in the 1st year postvalve replacement.[8]

RT3D TEE plays an important role in (1) the evaluation of paravalvular regurgitation (size and location); (2) guidance during interventions to treat significant paravalvular regurgitation; and (3) postinterventional assessment.

Assessment of paravalvular regurgitation2D TEE can miss significant findings as it only presents images from a thin imaging plane through the heart. 3D TEE

provides 3D images that can display the entire prosthetic valve, especially those in the aortic or mitral positions.[9] Specifically, the 3D zoom modality can provide en face views of both the mitral and aortic valves.

Dehiscence sites can be identified, with special attention to their location, shape, size, and area. Using multiplanar imaging, it is possible to quantify the area of the dehiscence [Figures 4‑6]. Full‑volume acquisition provides wider angle images with higher temporal resolution. After data acquisitions, data sets can be rotated, manipulated, and cropped to obtain optimal exposure of paravalvular leaks. The presence of paravalvular orifices can be confirmed with the use of three dimensional color flow.

One of the study patients presented with history of dyspnea for the last 2 months after 6 months of mitral mechanical valve replacement. Prosthetic valve regurgitation was seen moderate on 2D TTE [Figure 4], and severe on 2D TEE [Figure 4], but site of regurgitation was not clearly defined.

On 3D echo [Figure 5], real anatomical site and dimension of paravalvular regurgitation were defined. Patients had undergone surgical correction and successfully treated

Figure 4: Two‑dimensional transthoracic echocardiographic and two‑dimensional transesophageal echocardiographic images of paravalvular regurgitation. (a) Moderate paravalvular leak on two‑dimensional transthoracic echocardiography, (b) paravalvular leak on two‑dimensional transesophageal echocardiography. However, leak site is not defined on two‑dimensional echocardiographic study

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Figure 3: Three‑dimensional echocardiographic image of prosthetic valve vegetation. (a) Effective regurgitation orifice area of mitral bioprosthetic valve, (b) vegetation attached on mitral bioprosthetic valve leaflets

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Figure 2: Three‑dimensional echocardiographic image of prosthetic valve vegetation. (a and b) Large vegetation attached on mitral bioprosthetic valve leaflets and protruding from leaflets during valve closure

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Figure 1: Two‑dimensional echocardiographic image of prosthetic valve dysfunction. (a and b) Independent movement of vegetation attached on mitral bioprosthetic valve leaflets

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on 3D echo color Doppler [Figure 6]; we can differentiate paravalvular regurgitation from echo drop out.

It has been recently described that mitral valve dehiscences occur mainly in the posterior or lateral region and are very rarely located anteriorly.[10]

Prosthetic valve thrombosis versus pannusAlthough thrombus formation is frequently associated with valve obstruction, regurgitation, or embolism, it may be an incidental finding during imaging.[9]

The distinction between thrombus and pannus as the underlying etiology of obstruction is essential if thrombolytic therapy is contemplated. Recently, fibrinolytic therapy has emerged as an alternative to surgical treatment for obstructed left‑sided prosthetic valves and is considered the treatment of choice for tricuspid valve thrombosis.[11‑14] A thrombus area on TEE <0.85 cm2 confers a lower risk for embolic phenomena or death associated with thrombolysis.[15]

Compared with pannus formation, obstruction due to thrombus is associated with a short duration of symptoms and with a history of inadequate anticoagulation (international normalized ratio <2).

The combination of findings of a soft density on the prosthesis and an inadequate international normalized ratio

has reported positive and negative predictive values of 87% and 89%, respectively, for thrombus formation.[16]

Thrombi are in general larger and have a soft ultrasound density, similar to that of the myocardium. 3D echo evaluation better defines thrombus size and exacts location of thrombus as compared to 2D echo. Specific features for pannus formation include a small dense mass that in 30% of cases may not be distinctly visualized. Pannus formation is more common in the aortic position [Figure 7].

One study patient had undergone cinefluoroscopy [Figure 8] due to dyspnea NYHA Functional Class II and abnormal prosthetic valvular hemodynamic data, suggesting bileaflet prosthetic valve with stuck one leaflet. An image of this patient was displayed showing 3D echo advantage over 2D echo evaluation in prosthetic valve dysfunction.

LimitationsThis study is prospective, observational study; we had included patients who had presented with prosthetic valve dysfunction and in hemodynamic stable condition. This study population is very small, so large sample study is required.

Limitations of 3D TEE include poor visualization of anterior structures of the heart such as the aortic and tricuspid valve,

Figure 7: Two‑dimensional and three‑dimensional transesophageal echocardiographic images of pannus of the study patient. Pannus on aortic prosthetic valve not seen in two‑dimensional echocardiography and better seen on three‑dimensional transesophageal echocardiographic image

Figure 8: Three‑dimensional transesophageal echocardiographic images of pannus of the study patients. Pannus on aortic valve prosthesis causing stuck leaflet

Figure 6: Three‑dimensional echocardiography color Doppler image. (a) Severe paravalvular regurgitation on three‑dimensional color image shown by arrow, (b) severe paravalvular mitral leak on three‑dimensional color image. Ao: Aorta

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Figure 5: Three‑dimensional echocardiographic images of paravalvular regurgitation. (a and b) Transesophageal echocardiography defining actual location and size of mitral prosthesis paravalvular leak

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suboptimal images due to poor electro triggering in patients with arrhythmias, reduced spatial and temporal resolution with narrow angled acquisitions, as well tissue dropout.

Conventionally, 3D zoom mode provides images of high spatial resolution at the expense of temporal resolution with frame rates typically <10 Hz. This may hamper the ability to visualize fast moving structures such as vegetations and dynamic behavior of mitral rings. This limitation has been recently overcome with the introduction of new software that allows imaging at higher rates approaching 30 Hz.

Alternatively, another approach to increasing temporal resolution with frame rates >30 Hz is to use wide‑angle, full‑volume acquisition. However, the risk of stitch artifact may be increased due to the requirement for multiple cardiac samplings over four to seven beats. This usually results in artifacts in >70% of cases. Stitch artifact can be eliminated by briefly interrupting the respirator during image acquisition.

Tissue dropout may occasionally be interpreted as an anatomic defect while increasing the gain may result in blurry images. However, experience as well as combining information of several imaging planes and using color and Doppler information will help differentiate between a true defect and tissue dropout.

CONCLUSIONS

In the assessment of prosthetic valves, especially mechanical valves, RT3D imaging allows improved visualization over 2D techniques. One example of this is visualization of the mitral prosthetic valves from the ventricular perspective.

Another major advantage of RT3D imaging is the ability to display unique views not available from traditional 2D imaging. Specifically, the “en face view of valves” has proven useful in the assessment of prosthetic valve endocarditis, paravalvular regurgitation, and prosthesis dysfunction due to thrombus or pannus.

As well for paravalvular regurgitation, RT3D imaging plays an important role in determining the method of closure and in the case of catheter‑based device closure, guidance in the closure procedure.

For acquiring better 3D image, better 2D images must be acquired.

There are a few limitations to RT3D imaging such as poor visualization of anterior cardiac structures, poor temporal

resolution, and poor image quality in patients with arrhythmias and tissue dropout.

This is the initial learning experience of 3D echo in our institute. In the future with experience, this technology will be helpful for guiding interventional therapy for structural heart diseases.

Financial support and sponsorshipThis work was supported by U N Mehta Institute of Cardiology and Research Center itself and received no specific grant from any funding agency, commercial, or not‑for‑profit sectors.

Conflicts of interestThere are no conflicts of interest.

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