Evaluation of left ventricular ejection fraction by tissue locus imaging

The newly developed echocardiographic technique called "tissue locus imaging" (TLI) can visualize temporal series of images in a single picture by maintaining the display of previous images with a shading function; therefore, it can display the whole systolic shift of the mitral leaflets toward the apex in a single picture and can potentially offer useful information on left ventricular (LV) function. In 36 consecutive patients with varying degrees of LV dysfunction (15 with coronary artery disease, 9 with cardiomyopathy, 3 with hypertension, 2 with aortic stenosis, 1 with aortic regurgitation, and 6 controls), the systolic shift of the mitral leaflets (X) by TLI showed a significant correlation with the LV ejection fraction (Y) by 2-dimensional echocardiography (Y = 7.2 x+13, r(2) = 0.83, p <0.01). TLI enables the evaluation and visualization of LV systolic function by displaying the whole systolic shift of the mitral leaflets toward the apex.     

Transcatheter Interventions for Mitral Regurgitation: Multimodality Imaging for Patient Selection and Procedural Guidance

Transcatheter therapies to treat mitral regurgitation are rapidly developing. Currently, there are several devices commercially available to treat mitral regurgitation. The underlying cause of mitral regurgitation and specific anatomical aspects of the mitral valve and surrounding structures are considered when patients with symptomatic severe mitral regurgitation for transcatheter mitral valve therapies are selected. Multimodality imaging plays an important central role in the selection of patients, providing information about the mechanism of mitral regurgitation, the anatomy of the mitral valve and spatial relationships with the coronary sinus, the circumflex coronary artery and left ventricular outflow tract and to predict the procedural outcomes. During the transcatheter procedure, transesophageal echocardiography and fluoroscopy are key for monitoring the procedural steps to maximize the outcomes and minimize the complications. This paper provides a comprehensive review of the most important aspects to visualize in order to appropriately select patients for transcatheter mitral valve repair and replacement and to guide the procedure for the different transcatheter devices.     

Valvular Heart Disease in Aging Women

Elderly women are at risk for aortic and mitral valve disease that may be challenging to manage because of co-morbidities. Many reports focus on the evaluation and management of elderly patients, but only limited information that is directed specifically at women is available. Until more research can be completed, current guidelines offer updated recommendations for the diagnosis and treatment of significant valvular lesions. On-line and point-based risk assessment instruments are valuable tools for guiding treatment decisions in individual patients.     

Simple Way to Resolve the Range Ambiguity

Purpose: The purpose of this study was to test the hypothesis that with the range gate fixed, random adjustment of the pulse repetition frequency will offer a rapid and accurate way to avoid misinterpretation of range ambiguity. Background: Traditionally, to avoid the misdiagnosis of Doppler artifacts caused by range ambiguity, time must be spent on checking the flow patterns in the calculated phantom range gates. Methods: Twenty-four patients (mean age 64 ± 15 years, 15 men and nine women) with mitral regurgitation were included in the study. Pulsed Doppler evaluation was performed with sample volume initially at the shallow left ventricle and then, along the direction of ultrasonic beam, at the calculated range gate distal to the mitral valve to search for the high velocity Doppler signal. The highest velocity scale was initially selected. After detection of high velocity signal, the velocity scale was lowered to achieve the lower pulse repetition frequency. Results: For all patients, a high velocity regurgitant Doppler signal could be recorded both distal to the mitral valve and at the shallow left ventricle. Such signal persisted at the range gate distal to the mitral valve but disappeared at the range gate at the shallow left ventricle after manual adjustment of the velocity scale. The sensitivity, specificity, and accuracy of disappearance of the high velocity Doppler signal after adjustment of the pulse repetition frequency for confirmation of a phantom phenomenon are 100%, 100%, and 100%, respectively. Conclusions: Without the necessity of exact information about the pulse repetition frequency used, random adjustment of the pulse repetition frequency for the selected gate range is a rapid and exact method for initial differentiation of in situ from phantom signal in pulsed Doppler echocardiography.     

Concomitant Transcatheter Edge-to-Edge Treatment of Secondary Tricuspid and Mitral Regurgitation: An Expert Opinion

Secondary (functional) tricuspid regurgitation (sTR) is common in patients with mitral regurgitation (MR). Because combined valvular heart disease affects long-term survival, in comparison with isolated MR or tricuspid regurgitation, it is essential to offer patients adequate treatment. Despite considerable experience, no conclusive data are yet available on the prognostic impact of concomitant tricuspid valve surgery at the time of mitral valve surgery. Emerging transcatheter treatments offer the opportunity to treat both conditions (MR and sTR) simultaneously or in a stepwise fashion. This review provides a clinical overview on available data regarding the rationale for treatment of sTR in patients with relevant MR undergoing mitral transcatheter edge-to-edge repair, focusing on clinical and anatomical selection criteria.     

The double-orifice mitral valve. An evaluation by two-dimensional echocardiography and color echo-Doppler

Double-orifice mitral valve is an uncommon congenital heart defect. The isolated occurrence of this anomaly is exceptional and, more often, is encountered in association with other congenital cardiac abnormalities. Principal among these are the partial and complete forms of the atrioventricular canal. In this paper, we present two cases of double-orifice mitral valve. Our first case is associated with subaortic stenosis and coarctation of aorta. The second case is an isolated one resembling a severe mitral stenosis. As we know, the diagnosis of this rare anomaly by color-Doppler technique has not been previously reported. We believe this technique provides definite anatomical and functional information about double-orifice mitral valve.     

Intraoperative color Doppler assessment of mitral and tricuspid valvuloplasty

Conclusion Intraoperative color Doppler offers rapid and accurate information about the presence and severity of mitral regurgitation at the time of surgery. This technique provides instantaneous evaluation of the adequacy of mitral and tricuspid valvuloplasty and appears capable of predicting their postoperative outcome. This approach may ultimately allow for valve repair procedures to be performed in greater numbers of patients with better control over outcome and lower reoperation rates.     

Obstruction of the outflow tract of the left ventricle by accessory mitral valve tissue

Among the causes of left ventricular outflow tract obstruction, accessory mitral valve tissue is one of the last described and least studied. At present echocardiography permits a complete exploration of the atrioventricular valves as well as left ventricular outflow tract. In this study we evaluate the information obtained in four patients with two-dimensional echocardiography and color-coded Doppler by both transthoracic and transesophageal approaches. The information was compared with catheterization results. In none of the three cases in which hemodynamic study was performed, diagnostic angiographic images of the anomaly were obtained. Transesophageal echocardiography gave additional information about the mitral valve and subvalvular apparatus, the site of accessory tissue implantation and associated lesions.     

Echocardlographic evaluation of patients with mitral stenosis

Since the introduction of ultrasound technics to study the heart, echocardiographic evaluation of the mitral valve has become the most sensitive and specific noninvasive method for diagnosing mitral stenosis. Identification of the anterior mitral leaflet and the reduction of its velocity of motion was the first clinical application of M-mode echocardiography. Although simultaneous visualization of both mitral leaflets aids in the diagnosis of mitral stenosis, quantitation was not achieved until real-time imaging systems were developed to produce cross-sectional images of the mitral orifice. Currently, M-mode echocardiography remains the technic of choice for routinely diagnosing mitral stenosis. It is also useful in confirming mitral stenosis when associated abnormalities, such as aortic regurgitation, are present. Mitral orifice area is best determined with cross-sectional (two-dimensional) imaging systems. This method correlates well with hemodynamic parameters. Both methods offer the clinician serial evaluation before and after operative intervention.     

Transesophageal echocardiography in the selection of patients prior to percutaneous mitral valvuloplasty. Study of 71 consecutive patients]

We studied 71 consecutive patients with mitral stenosis candidates for mitral valvuloplasty by means of transthoracic (TTE) and transesophageal echocardiography (TEE). We compared the information obtained by the two methods with respect to: mitral valve morphology (echocardiographic score), severity of mitral regurgitation, prevalence of atrial thrombus and incidence of spontaneous contrast in the left atrium. The assessment of valvular thickening, mobility and calcification was similar by the two methods. The assessment of the subvalvular disease was significantly lower by TEE than the assessed by TTE (1.66 +/- 0.6 vs 2.12 +/- 0.5; p less than 0.001). The total "score" obtained by TEE was significantly lower than the "score" obtained by TTE (7.32 +/- 1.9 vs 7.88 +/- 1.8; p +/- 0.001), but when we classified the patients in groups according to the "score", there were no significant differences between the groups obtained by the two methods. We detected mitral regurgitation in 27 patients (38%) by TTE and in 36 (50%) by TEE. The difference in the quantification of the mitral regurgitation was no more than one grade in any case. Atrial thrombus were detected in 16 patients (22%) by TEE and in 2 patients by TTE. Spontaneous contrast was seen in 53 patients (75%) by TEE and in only 1 by TTE. We conclude that TEE is essential in detecting atrial thrombus, but does not provide any new information about mitral valve morphology and mitral regurgitation in the selection of patients for percutaneous mitral valvuloplasty.     

Transcatheter closure of paravalvular mitral prosthetic leak with resultant hemolysis

Reoperations for mitral prosthetic paravalvular leaks presenting with heart failure or hemolysis are associated with significant morbidity and mortality. Transcatheter options offer an attractive alternative, though the method is under evolution and outcome is varied. This report gives procedural details of transcatheter closure of mitral paravalvular leak with Amplatzer septal occluder device.     

Pitfalls and tips in Inoue balloon mitral commissurotomy

Balloon mitral commissurotomy is a safe and effective alternative therapeutic modality in selected patients with significant rheumatic mitral stenosis. Since its introduction in 1984, Inoue balloon mitral commissurotomy has gained wider acceptance over other balloon valvuloplasty techniques because it is technically less demanding and associated with fewer complications. Nevertheless, certain pitfalls which may make the procedure more difficult or create complications are sometimes encountered. In this article, we offer tips to facilitate a safe and expeditious execution of Inoue balloon mitral commissurotomy based on our experience with over 1,000 procedures. © 1996 Wiley-Liss, Inc.     

Evaluation by Doppler echocardiography of left ventricular diastolic function in acute graft rejection after heart transplantation

In order to study abnormalities of left ventricular diastolic function (LVDF) in heart transplant patients and their possible association with graft rejection, 21 patients who had recently undergone orthotopic heart transplantation were evaluated prospectively, on the day of endomyocardial biopsy, by pulsed and continuous Doppler echocardiography (DEC). Investigation of the LVDF consisted of pulsed DEC of the mitral valve in apical projection (4 cavities) with measurement of isovolumetric relaxation time (IVR), peak velocity of rapid ventricular filling (E), peak velocity of graft atrial contraction (A) and transmitral gradient decrease half-time (mitral T1/2). Each patients had 5 DEC examinations on average over a 2-month period. In patients with subsevere to severe rejection mitral T1/2 decreased significantly from 76.46 +/- 11.6 ms in the absence of rejection to 47 +/- 13.7 ms during rejection (P less than 0.001). When mitral T1/2 decreased by 25 p. 100 or more between two successive DEC, rejection was present in 89 p. 100 of the cases. It is concluded that Doppler echocardiographic studies of left ventricular diastolic function provide useful information in the follow-up of heart transplant recipients and offer hopes, in a not too distant future, of non-invasive detection of cardiac graft rejection.     

In vivo identification of mitral valve fibrosis and calcium by real-time quantitative ultrasonic analysis

Conventional echocardiography provides fundamental information about mitral valve morphology and function but has a relatively low specificity in evaluating valve calcific deposits, which is critical information for the preoperative decision to perform commisurotomy or replacement. In vitro radiofrequency ultrasonic quantitative analysis of the mitral valve has been demonstrated to be a reliable tool in identifying normal, fibrotic and calcific valves. This study evaluates quantitative ultrasound characterization of the mitral valve in vivo. Thirty-three patients, scheduled to undergo mitral valve replacement, and 20 normal subjects (10 young and 10 older control subjects) were studied with a 2.25-MHz transducer. Radiofrequency signal was analyzed by a microprocessor system (used with an M-mode commercially available echocardiograph) for on-line evaluation of ultrasonic backscatter with 8 bits of amplitude resolution, 40-MHz sampling rate and a 1-microsecond acquisition gate. The integrated value of the rectified radiofrequency signal amplitude was deemed the integrated backscatter index. The highest value recorded with the ultrasonic analysis from each valve was taken as representative and expressed as the percent value with respect to the pericardial integrated backscatter index value of that subject. The 33 excised mitral valves underwent histologic examination. Four groups were identified: young controls (group I, n = 10); older controls age-matched with patients (group II, n = 10); patients with fibrotic mitral valves (group III, n = 13); and patients with calcific mitral valves (group IV, n = 20).(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous Mitral Repair: Patient Selection,Results, and Future Directions

Percutaneous heart valve therapies are rapidly changing our approach to valvular heart diseases. Currently, mitral valve surgery is the treatment of choice for patients suffering from severe symptomatic mitral regurgitation. However surgery, because of its inherent risks, is not applicable to all patients, particularly for the elderly with comorbidities. Catheter-based mitral repair systems offer a new option to those high-risk patients. The edge-to-edge repair using the MitraClip device (Evalve, Menlo Park, CA), simulating the surgical Alfieri stitch via percutaneous approach proved to be a safe and feasible technique. This article discusses the currently available data for the MitraClip transcatheter mitral repair system.     

Urgent transcatheter aortic valve replacement for severe acute aortic regurgitation following open mitral valve surgery

Transcatheter aortic valve replacement (TAVR) is not currently approved for pure native valve aortic incompetence, and is typically performed on a compassionate basis in selected patients who are at high risk for conventional surgery. We describe the first use of TAVR to treat iatrogenic severe acute pure aortic incompetence following mitral valve surgery. A 71‐year‐old gentleman developed life‐threatening acute aortic regurgitation (AR) within hours of a very challenging fifth open heart mitral valve replacement. Careful inspection of echocardiographic and computed tomographic imaging identified the cause as a disrupted left coronary cusp at the commissure caused by the surgical mitral annular reconstruction. Medical management with afterload reduction failed with recurrent pulmonary edema, and a sixth open heart surgery was deemed prohibitively high risk. The lack of aortic annular calcium onto which anchors a transcatheter valve was a concern for TAVR. However, we postulated that the struts of the mitral valve bioprosthesis would offer some support to the TAVR valve. We opted for a self‐expanding system because of concerns about potential unfavorable interaction between the balloon onto which balloon‐expandable bioprosthesis is mounted and the struts of the mitral bioprosthesis, and because the Evolut R system has additional anchoring points at the crown which might enhance transcatheter valve stability in the non‐calcified annulus, compared with the Edwards Sapien system. Transfemoral TAVR, performed with a Medtronic Evolut R 34 mm system under general anesthesia and using moderately rapid ventricular pacing, was successful with minimal residual AR. On follow‐up 1 month later the patient was asymptomatic, and the aortic and mitral bioprostheses were functioning normally on echocardiogram.     

Percutaneous correction of acquired aortic stenosis and mitral insufficiency in adults

Aortic stenosis and mitral regurgitation are the most common valvular diseases in western countries. Surgical treatment, aortic valve replacement or mitral valve repair, is the treatment of choice. Innovative technologies could offer an alternative therapeutic option to the patients with increased operative risk. This article will report the early experience with these promising techniques as presented at the High-Tech 2004 meeting.     

The role of mitral annulus motion in left ventricular function.

The dynamics between mitral annulus motion and left ventricular function were studied. Thirty subjects (10 normals, 10 with severe cardiac failure and 10 with mitral regurgitation) were examined. Left ventricular long and short-axis dimensions were measured in a two-dimensional apical four-chamber image. A volume was calculated as defined by cardiac cyclic changes of mitral annulus in size and motion. This volume had the approximate geometric configuration of a truncuated cone and was covered by mitral annulus motion at enddiastole and endsystole. Left ventricular ejection fraction was calculated echocardiographically using the prolate ellipsoid/area-length method. The volume defined by mitral annulus motion was 24 ml in normals, 16 ml in patients with cardiac failure and 48 ml in patients with mitral regurgitation while the ejection fraction was 51%, 19% and 53% respectively. Comparison between the volume of the truncuated cone and the ejection fraction in all 30 subjects revealed a statistically significant correlation (p less than 0.01). Thus, the bigger the volume determined by the mitral annulus motion during systole, the larger portion of the left ventricle is "atrialized", and a higher ejection fraction follows. Mitral annulus motion may provide new information about cardiac mechanics in normal and abnormal conditions.     

Indications, types, results, and complications of valvular surgery

Results of long-term follow-up of new mechanical valves introduced in the 1980s and innovative new surgical techniques complementing repair of the mitral apparatus are discussed here. In addition, recent reports highlighting new information about the indications, types, results, and applications of valve surgery are described.