Predictors of mitral annulus enlargement? A real-time three-dimensional transesophageal study.

BACKGROUND: Mitral annulus (MA) enlargement can be observed in various cardiac conditions but respective influence of left atrial (LA) and left ventricle (LV) size remained unclear. METHODS: In 120 patients who underwent a clinically indicated 3D-transesophageal-echocardiography, 30 atrial fibrillation (AF), 30 secondary mitral regurgitation (SMR), 30 primary myxomatous mitral regurgitation (PMR) and 30 mitral stenosis (MS), we evaluated the association between MA area (MA-area) and LA volume (LAvol) measured using the biplane area-length method, end-diastolic (LVEDV) and end-systolic (LVESV) volumes measured using the biplane Simpson method. MA-area was measured based on 3D datasets using QLab10. RESULTS: MA-area was correlated to LVEDV (r = 0.42, p < 0.0001), LVESV (r = 0.29, p = 0.001) but more markedly to LAvol (r = 0.62, p < 0.0001). Correlation between MA-area and LAvol was sustained in all subsets whereas MA-area was not correlated to LVEDV and LVESV in patients with SMR and with PMR (all p > 0.10). In multivariate analysis main predictors of MA-area were LAvol (p < 0.0001) and myxomatous etiology of MR (p = 0.0003) followed by LVEDV (p = 0.006) and LVESV (p = 0.02). CONCLUSION: In a population of patients with a wide range of LA/LV size related to various conditions, LA volume and myxomatous MR etiology appeared as main predictors of MA size whereas LV size had a more modest influence.

[Paradoxical embolism: Myth or reality?] / Embolie paradoxale : mythe ou réalité ?

Paradoxical embolism should be suspected in front of a clinical phenomenon of thromboembolism associated with an anatomical right-to-left shunt. Others potential cardiac sources of thromboembolism must be ruled out. Strokes constitute the most frequent clinical manifestations of paradoxical embolism. Right-to-left left shunts are in connection with intracardiac defects (atrial septal defect and patent foramen ovale) or pulmonary arteriovenous malformations. The probability that a discovered PFO is stroke-related can be evaluated by a score. Therapeutic approaches for secondary prevention of recurrent stroke include antithrombotic and/or percutaneous treatments. The choice strategy begins to be clearer with the recent results of randomized controlled studies.

Eclipsed mitral regurgitation: an unusual cause of acute heart failure.

AIMS: So far, a total of five patients with eclipsed mitral regurgitation (MR) have been reported in the literature by three different teams. The aim of this article was to detail clinical and echocardiographic characteristics, and outcome of patients presenting eclipsed MR. METHODS AND RESULTS: We defined eclipsed MR as spontaneous appearance, at rest, from 1 min to the next of an acute restriction in the motion of mitral leaflets preventing coaptation and leading to massive MR in patients with normal left ventricular end-diastolic diameter, left ventricular ejection fraction >45%, and baseline MR ≤2. Spontaneous regression occurred within 30 min, and no obvious trigger such as acute hypertension, new-onset arrhythmia, or myocardial ischaemia is present. Clinical data, ECG, echocardiographic data, surgery report, and follow-up status of six patients with eclipsed MR are reported: all were post-menopausal women with median age of 74 [57-80] years presenting hypertension (4/6), chronic kidney disease (5/6), or chronic anaemia (4/6). Five out of six patients experienced acute pulmonary oedema requiring hospitalization and underwent mitral valve replacement because of heart failure recurrence. Two patients died in the first days after surgery while the three others are free of symptoms at, respectively, 56, 18, and 10 months follow-up. CONCLUSION: Eclipsed MR is a clinical and echocardiographic syndrome responsible for heart failure with preserved EF. It is presently underdiagnosed and should be evoked in cases of recurrent acute pulmonary oedema without obvious trigger, in particular in patients presenting discordant evaluation of MR severity over time.

[Percutaneous approaches to mitral valve disease]. / Approches percutanées des valvulopathies mitrales.

Percutaneous approaches to mitral valve disease consist in modifications of existing surgical techniques, aiming to replicate the favourable outcomes of surgery, with less procedure-related risk, due to their less invasive nature. While some of these techniques are clearly indicated for the management of certain valve diseases, other appear as possible alternatives to surgery among patients deemed at high-risk or considered inoperable, or are still under clinical investigation. Major development of these percutaneous approaches is expected within the future, thus hopefully allowing treatment of a larger proportion of patients with mitral valve disease.

[Percutaneous exclusion of the left atrial appendage: perspectives]. / Exclusion percutanée de l'auricule gauche : perspectives.

With its high prevalence and well-known thromboembolic risk, atrial fibrillation (AF) is a crucial component of the 2010-2014 actions plan, ongoing in France to reduce the annual incidence of stroke. The stroke risk is stratified well with the CHA(2)DS(2)-VASc score. With the current guidelines, most patients with AF should be on oral anticoagulant regimen, a treatment recognized as effective but whose bleeding risks limit its use. In clinical practice, warfarin is often not prescribed in patients with high risk of stroke. Thus, the exploration of new ways in preventing thromboembolic events in patients with AF is needed. Beside new more convenient anticoagulant agents, the exclusion of the left atrial appendage recognized as main source of thrombi, may be an alternative in patients with both high risk of thrombotic and haemorrhagic events. Surgical experience showed that the results depend on the quality of the exclusion. For over the past 10 years, several percutaneous exclusion systems of the left atrial appendage have been developed. A randomized study (PROTECT AF) demonstrated the non-inferiority of the percutaneous exclusion in comparison with the warfarin. However, the place of this interventional therapy remains to be clarified, particularly the definition of the target population. This often multidisciplinary approach will have to be accompanied by a reduction of periprocedural complications, increase in rate of complete occlusion, and enough long clinical follow-up to assess the efficiency of this strategy.

An unusual cause of pacemaker-induced severe tricuspid regurgitation.

Pacemaker (PM) induced tricuspid regurgitation (TR) is a common echocardiographic finding. Although mild or moderate TR is frequently observed, severe TR is rare. We report the exceptional observation of a severe TR due to leaflet malcoaptation occurring late after PM implantation and in the following weeks after an aortic valve replacement. Our hypothesis is that the aortic valve surgery has been responsible for conformational changes between cardiac cavities, tricuspid valve and PM leads resulting in a severe TR.

[Patent foramen ovale percutaneous closure: indications, techniques and results]. / Fermeture percutanée des foramens ovales perméables: indications, techniques et résultats.

A patent foramen ovale is almost physiological (15% of the population) but can be associated with some pathological situations in which its closure can be considered. The only medical indication currently accepted is a right-left shunt without elevation of the right pulmonary pressure, whose most famous pattern is the rare platypnea-orthodeoxie syndrome. PFO may be responsible for diving decompression accidents. Before taking the decision of closing a PFO, each situation must be discussed on a case to case basis. In spite of the possible link between some kinds of migraine and PFO, according to current knowledge, there is no evidence of the efficiency of PFO closure in this situation. The secondary prevention of a cryptogenic ischaemic cerebrovascular attack on a young person with a PFO associated to a membranous septum aneurysm, is the most commonly considered indication, but we lack valid data for this indication. The PFO closing procedure is well codified and its success rate is close to 100%, with rare major complications. Residual permeability within the prosthesis ensuring the closure of the PFO decreases gradually to get under 15% after six months. The clinical result is often dramatic when treating right-left shunts. As far as the secondary prevention of cryptogenic ischaemic cerebro vascular attacks in young people is concerned, there might be some clinical benefit, but we are waiting for the results of ongoing randomized and scheduled studies.

[Intracardiac echography]. / Echographie intracardiaque.

The role of echocardiography during non-coronary interventions is of increasing importance. They include percutaneous closure of atrial septal defects (ASD) or patent foramen ovale (PFO), percutaneous balloon mitral valvuloplasty (PMV), septal alcoholization, or interventional procedures managing arrhythmia. In all cases, echographic monitoring enables to guide the procedures, optimize and assess their results and avoid complications. This role could even increase with the development of other interventional techniques such as left auricle appendage exclusion or the percutaneous treatment of valvular diseases. This article reviews this new approach and its value in interventional cardiology.

[A pitfall of transseptal catheterisation for percutaneous mitral commissurotomy: interruption of the inferior vena cava with azygos continuation]. / Piège du cathétérisme transseptal pour commissurotomie mitrale percutanée: l'interruption de la veine cave inférieure avec continuation azygos. A propos d'un cas et revue de la littérature.

Transseptal catheterisation is a widely used technique in interventional cardiology. The authors report the case of a 37 year old woman admitted for percutaneous mitral commissurotomy of a symptomatic rheumatic mitral stenosis in whom transseptal catheterisation was impossible because of a rare congenital anomaly: interruption of the inferior vena cava with azygos vein continuation.

[Echocardiography in the catheterization unit]. / L'échocardiographie en salle de cathétérisme.

Non-coronary interventional cardiology has for about ten years been undergoing significant development, with the arrival of new percutaneous procedures in various domains. Some of them have already been well validated, notably percutaneous mitral comissurotomy, percutaneous closure of inter-atrial (IA) communications and patent foramen ovale, trans-septal catheterisation, and alcohol septal ablation of hypertrophic obstructive cardiomyopathy. Other interventional techniques are still in the validation phase, such as the techniques for percutaneous occlusion of the left atrium, percutaneous implantation of valvular prostheses, or the new approaches to percutaneous treatment of mitral valvulopathy. The rapid development of these techniques has benefited widely from the use of echocardiography in the catheter suite, providing a very precise clarification of the anatomy and continuous guidance during procedures. This echocardiographic guidance provides optimal results for the interventional procedure and reduces the incidence of complications.

[Feasibility of percutaneous exclusion of the left atrial appendage: results of 11 cases]. / Faisabilité de l'exclusion percutanée de l'auricule gauche. A propos de 11 cas.

Atrial fibrillation is associated with a risk of cerebral embolism, the only proven effective prevention of which is anticoagulant therapy. There is no known alternative in cases with contra-indications to this treatment. Percutaneous exclusion of the left atrial appendage by the implantation of a prosthesis (PLAATO System, ev3 Inc., Plymouth, Minnesota) is a new approach to the prevention of these complications. The authors report the results observed in a series of 11 consecutive patients (7 men, mean age 72 +/- 9 years) in whom this procedure was proposed. All patients had atrial fibrillation for over 3 months, were at high risk and had contra-indications to oral anticoagulants. The implantation of the prosthesis was performed after treatment with aspirin and clopidogrel, under general anaesthesia radioscopy and transoesophageal echocardiographic guidance with success in 9 cases (1 implantation refused in the catheter laboratory and 1 failure). The only complication observed was transient ST elevation treated by emergency angioplasty. The echographic and angiographic criteria of success of left atrial appendage exclusion were fulfilled in all implanted patients. The hospital course was uncomplicated. One recurrence of stroke was observed at the second month: transoesophageal echocardiography confirmed the absence of thrombosis, of migration of the prosthesis and its impermeability in all the patients. After 7 +/- 5 months' follow-up, no other adverse event was observed. This new procedure is technically feasible. Despite encouraging results, its long-term efficacy in the prevention of thromboembolic complications of atrial fibrillation remains to be demonstrated.

[Intracardiac echocardiography during percutaneous closure of atrial septal defect and patent foramen ovale]. / Echographie intracardiaque au cours des fermetures percutanées de communication interauriculaire et foramen ovale perméable.

Intracardiac echocardiography is a new technique based on the use of ultrasonic diagnostic catheters. The most significant current experience has been obtained with the AcuNav catheter, with a "phased array" high frequency (5.5 to 10 mHz) detector, which obtains bidimensional echocardiographic views, coupled to pulsed and colour Doppler. Image acquisition is made from an intracardiac position, usually the right atrium. This review touches on the technical aspects of this method, applied to the examination of the intra-atrial septum, as well as the results currently obtained during inter-atrial communication and patent foramen ovale closure procedures. In effect it is in this field of application that intracardiac ultrasound has now found its niche, providing equivalent information to the reference technique of transoesophageal echocardiography. Intracardiac echocardiography allows complete examination of the inter-atrial septum and septal defects, as well as accurate surveillance of the positioning of percutaneous closure devices. An important advantage of intracardiac echocardiography is the possibility of avoiding a general anaesthetic, usually necessary with the transoesophageal route. At present, the main limiting factor to its systematic use is its high cost, linked to the single use catheters.

[New French recommendations for the prophylaxis of infectious endocarditis]. / Nouvelles recommandations françaises de prophylaxie de l'endocardite infectieuse.

New French recommendations on infective endocarditis (IE) prevention were recently published and mark a turning point in the history of antibiotic prophylaxis. Endocarditis is an evolving disease, and its clinical and microbiological profile dramatically changes over time. The French surveys that were conducted in 1991 and 1999 showed variations in underlying heart disease with a decrease in native valvular disease and an increase of IE in patients without previously known heart disease. Moreover, the distribution of responsible microorganisms dramatically changed over time, with a marked decrease of oral streptococci. In addition, some dogmas are now challenged. First of all, the part of responsibility of dental procedures is debated, as dental bacteraemia possibly responsible of endocarditis are more likely due to daily manoeuvres such as tooth brushing or chewing gum than to occasional dental procedures. Moreover, as suggested by case-control studies, efficacy--or lack of efficacy--of antibiotic prophylaxis is far from being clinically proved. For all these reasons, the proportion of theoretically avoidable endocarditis seems very low, and the benefit of largely and systematically applied antibiotic prophylaxis may be discussed, not only in terms of financial cost but also in terms of microbiological threat of emergence of antibiotic resistant bacteria. So, the general idea of those new recommendations was to maintain the principle and the modalities of antibiotic prophylaxis, but to limit its indications to situations at high benefit to risk ratio, i.e. procedures at high risk in patients at high risk. Depending on the situation, antibiotic prophylaxis may be either recommended or become optional and decision-making factors are defined. Furthermore, the importance of general prophylaxis was emphasised, concerning more specifically oral and cutaneous hygiene, and patients and practitioners' education, such as, for example, recommendations on blood cultures to be performed before any antibiotic treatment in case on fever occurring in a patient at risk during the 3 months following a procedure at risk.

[The value of contrast in stress echocardiography]. / Apport du contraste en échographie de stress.

Stress echocardiography is a well validated method of diagnosing myocardial ischaemia and viability. Its limitations are also well known, related to a subjective interpretation and lack of reproducibility. One of the solutions suggested to improve its diagnostic performance is the use of ultrasonic contrast agents which presents many advantages. In difficult patients, the left ventricular chamber may be opacified, both at rest and at peak effort with a significant improvement in the detection of the endocardial contour and in the reproducibility of the interpretation of the images. The diagnostic performance of stress echocardiography with contrast is less dependent on the conditions of observation. In addition, recent technical advances enable the same ultrasonic contrast agents to be used for the study of myocardial perfusion. The first clinical studies using these techniques report the feasibility of simultaneous analysis of wall motion abnormalities and myocardial perfusion on exercise. Further progress is expected to facilitate the interpretation and quantification of these investigations which should further increase the diagnostic value of stress echocardiography.

[Measurement of coronary reserve by high-frequency transthoracic Doppler ultrasonography: indications and results]. / Mesure de la réserve coronaire par Doppler transthoracique haute fréquence: indications et résultats.

Coronary flow reserve is the ability of coronary flow to increase above its basal value when the coronary vascular bed is maximally dilated. It is a global parameter of coronary flow, which is early altered in the presence of epicardial coronary artery stenosis or a coronary microcirculation disorder. Until now, clinical use of coronary flow reserve has been hampered by the lack of an easy, reliable and non-invasive method. Recently developed high-frequency transthoracic Doppler echocardiography now allows non-invasive assessment of coronary flow reserve. After an initial learning curve, it is possible to study coronary flow, essentially in the left anterior descending artery. Coronary flow reserve is expressed as the ratio of maximal hyperaemic to basal mean coronary velocity. Maximal hyperaemic flow is obtained with adenosine. Clinical applications of coronary flow reserve are numerous. Coronary flow reserve enables the assessment of hemodynamic relevance of a moderate coronary stenosis. Detection of coronary restenosis is also possible by repeated non-invasive measurement of coronary flow reserve. Moreover, evaluation of the microcirculation is of crucial importance in order to appreciate myocardial reperfusion following successful recanalisation on the infarct-related artery. Transthoracic Doppler echocardiography could allow identification of "no-reflow" by analysis of coronary flow pattern and coronary flow reserve. Furthermore, transthoracic Doppler echocardiography constitutes one of the only available and simple means to evaluate microcirculatory disorders (hypertension, diabetes,...). Finally, the possibility of non-invasive follow-up of arterial bypasses constitutes a major advantage of this technique.