Cardiovascular magnetic resonance phase contrast imaging

Cardiovascular magnetic resonance (CMR) phase contrast imaging has undergone a wide range of changes with the development and availability of improved calibration procedures, visualization tools, and analysis methods. This article provides a comprehensive review of the current state-of-the-art in CMR phase contrast imaging methodology, clinical applications including summaries of past clinical performance, and emerging research and clinical applications that utilize today's latest technology.

Infective endocarditis involving an apparently structurally normal valve: new epidemiological trend?

Infective endocarditis (IE) has been increasingly diagnosed in patients without previously detected predisposing heart disease, but its clinical features have yet to be fully determined. A recent single-center study including echocardiographic images and surgical findings investigated the incidence of undiagnosed, clinically silent valvular or congenital heart diseases and healthcare-associated infective endocarditis (HAIE). The study confirmed that a large proportion of patients with IE have no previous history of heart disease. Analysis of underlying disease in these patients showed that undetected mitral valve prolapse was the most common disease, followed by an apparently structurally normal valve. The patients who developed IE of apparently structurally normal valves had different clinical characteristics and worse outcomes. IE involving a structurally normal valve was associated with both nosocomial and non-nosocomial HAIE, whereas community-acquired IE was more frequent than HAIE. The pathophysiologic mechanism involving the development of non-HAIE or community-acquired IE due to predominantly staphylococcal infection in an apparently structurally normal valve is not yet clearly understood. Structurally normal valves are not necessarily free of regurgitation or abnormal turbulence and, given the dynamic nature and fluctuating hemodynamic effects of conditions such as poorly controlled hypertension, end-stage renal disease, and sleep apnea, further investigation is necessary to evaluate the potential role of these diseases in the development of IE. An apparently normal-looking valve is associated with IE development in patients without previously recognized predisposing heart disease, warranting repartition of at-risk groups to achieve better clinical outcomes.

Galnt1 is required for normal heart valve development and cardiac function

Congenital heart valve defects in humans occur in approximately 2% of live births and are a major source of compromised cardiac function. In this study we demonstrate that normal heart valve development and cardiac function are dependent upon Galnt1, the gene that encodes a member of the family of glycosyltransferases (GalNAc-Ts) responsible for the initiation of mucin-type O-glycosylation. In the adult mouse, compromised cardiac function that mimics human congenital heart disease, including aortic and pulmonary valve stenosis and regurgitation; altered ejection fraction; and cardiac dilation, was observed in Galnt1 null animals. The underlying phenotype is aberrant valve formation caused by increased cell proliferation within the outflow tract cushion of developing hearts, which is first detected at developmental stage E11.5. Developing valves from Galnt1 deficient animals displayed reduced levels of the proteases ADAMTS1 and ADAMTS5, decreased cleavage of the proteoglycan versican and increased levels of other extracellular matrix proteins. We also observed increased BMP and MAPK signaling. Taken together, the ablation of Galnt1 appears to disrupt the formation/remodeling of the extracellular matrix and alters conserved signaling pathways that regulate cell proliferation. Our study provides insight into the role of this conserved protein modification in cardiac valve development and may represent a new model for idiopathic valve disease.

Serotonin markers show altered transcription levels in an experimental pig model of mitral regurgitation

Serotonin (5-hydroxytryptamine, 5-HT) signalling is implicated in the pathogenesis of myxomatous mitral valve disease (MMVD) through 5-HT1B receptor (R), 5-HT2AR and 5-HT2BR-induced myxomatous pathology. Based on increased tryptophan hydroxylase-1 (TPH-1) and decreased serotonin re-uptake transporter (SERT) in MMVD-affected valves, increased valvular 5-HT synthesis and decreased clearance have been suggested. It remains unknown how haemodynamic changes associated with mitral regurgitation (MR) affect 5-HT markers in the mitral valve, myocardium and circulation. Twenty-eight pigs underwent surgically induced MR or sham-operation, resulting in three MR groups: control (CON, n = 12), mild MR (mMR, n = 10) and severe MR (sMR, n = 6). The gene expression levels of 5-HT1BR, 5-HT2AR, 5-HT2BR, SERT and TPH-1 were analysed using quantitative PCR (qPCR) in the mitral valve (MV), anterior papillary muscle (AP) and left ventricle (LV). MV 5-HT2BR was also analysed with immunohistochemistry (IHC) in relation to histological lesions and valvular myofibroblasts. All 5-HTR mRNAs were up-regulated in MV compared to AP and LV (P <0.01). In contrast, SERT and TPH-1 were up-regulated in AP and LV compared to MV (P <0.05). In MV, mRNA levels were increased for 5-HT2BR (P = 0.02) and decreased for SERT (P = 0.03) in sMR vs. CON. There were no group differences in 5-HT2BR staining (IHC) but co-localisation was found with α-SMA-positive cells in 91% of all valves and with 33% of histological lesions. In LV, 5-HT1BR mRNA levels were increased in sMR vs. CON (P = 0.01). In conclusion, these data suggest that MR may affect mRNA expression of valvular 5-HT2BR and SERT, and left ventricular 5-HT1BR in some pigs.

Role of modern 3D echocardiography in valvular heart disease

Three-dimensional (3D) echocardiography has been conceived as one of the most promising methods for the diagnosis of valvular heart disease, and recently has become an integral clinical tool thanks to the development of high quality real-time transesophageal echocardiography (TEE). In particular, for mitral valve diseases, this new approach has proven to be the most unique, powerful, and convincing method for understanding the complicated anatomy of the mitral valve and its dynamism. The method has been useful for surgical management, including robotic mitral valve repair. Moreover, this method has become indispensable for nonsurgical mitral procedures such as edge to edge mitral repair and transcatheter closure of paravaluvular leaks. In addition, color Doppler 3D echo has been valuable to identify the location of the regurgitant orifice and the severity of the mitral regurgitation. For aortic and tricuspid valve diseases, this method may not be quite as valuable as for the mitral valve. However, the necessity of 3D echo is recognized for certain situations even for these valves, such as for evaluating the aortic annulus for transcatheter aortic valve implantation. It is now clear that this method, especially with the continued development of real-time 3D TEE technology, will enhance the diagnosis and management of patients with these valvular heart diseases.

Complication probability models for radiation-induced heart valvular dysfunction: do heart-lung interactions play a role?

Purpose

The purpose of this study is to compare different normal tissue complication probability (NTCP) models for predicting heart valve dysfunction (RVD) following thoracic irradiation.

Methods

All patients from our institutional Hodgkin lymphoma survivors database with analyzable datasets were included (n = 90). All patients were treated with three-dimensional conformal radiotherapy with a median total dose of 32 Gy. The cardiac toxicity profile was available for each patient. Heart and lung dose-volume histograms (DVHs) were extracted and both organs were considered for Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) NTCP model fitting using maximum likelihood estimation. Bootstrap refitting was used to test the robustness of the model fit. Model performance was estimated using the area under the receiver operating characteristic curve (AUC).

Results

Using only heart-DVHs, parameter estimates were, for the LKB model: D₅₀ = 32.8 Gy, n = 0.16 and m = 0.67; and for the RS model: D₅₀ = 32.4 Gy, s = 0.99 and γ = 0.42. AUC values were 0.67 for LKB and 0.66 for RS, respectively. Similar performance was obtained for models using only lung-DVHs (LKB: D₅₀ = 33.2 Gy, n = 0.01, m = 0.19, AUC = 0.68; RS: D₅₀ = 24.4 Gy, s = 0.99, γ = 2.12, AUC = 0.66). Bootstrap result showed that the parameter fits for lung-LKB were extremely robust. A combined heart-lung LKB model was also tested and showed a minor improvement (AUC = 0.70). However, the best performance was obtained using the previously determined multivariate regression model including maximum heart dose with increasing risk for larger heart and smaller lung volumes (AUC = 0.82).

Conclusions

The risk of radiation induced valvular disease cannot be modeled using NTCP models only based on heart dose-volume distribution. A predictive model with an improved performance can be obtained but requires the inclusion of heart and lung volume terms, indicating that heart-lung interactions are apparently important for this endpoint.

Early initiation of enzyme replacement therapy for the mucopolysaccharidoses

The mucopolysaccharidoses (MPS), a group of rare genetic disorders caused by defects in glycosaminoglycan (GAG) catabolism, are progressive, multi-systemic diseases with a high burden of morbidity. Enzyme replacement therapy (ERT) is available for MPS I, II, and VI, and may improve walking ability, endurance, and pulmonary function as evidenced by data from pivotal trials and extension studies. Despite these demonstrable benefits, cardiac valve disease, joint disease, and skeletal disease, all of which cause significant morbidity, do not generally improve with ERT if pathological changes are already established. Airway disease improves, but usually does not normalize. These limitations can be well understood by considering the varied functions of GAG in the body. Disruption of GAG catabolism has far-reaching effects due to the triggering of secondary pathogenic cascades. It appears that many of the consequences of these secondary pathogenic events, while they may improve on treatment, cannot be fully corrected even with long-term exposure to enzyme, thereby supporting the treatment of patients with MPS before the onset of clinical disease. This review examines the data from clinical trials and other studies in human patients to explore the limits of ERT as currently used, then discusses the pathophysiology, fetal tissue studies, animal studies, and sibling reports to explore the question of how early to treat an MPS patient with a firm diagnosis. The review is followed by an expert opinion on the rationale for and the benefits of early treatment.

Non-invasive determination of left ventricular workload in patients with aortic stenosis using magnetic resonance imaging and Doppler echocardiography

Early detection and accurate estimation of aortic stenosis (AS) severity are the most important predictors of successful long-term outcomes in patients. Current clinical parameters used for evaluation of the AS severity have several limitations including flow dependency. Estimation of AS severity is specifically challenging in patients with low-flow and low transvalvular pressure gradient conditions. A proper diagnosis in these patients needs a comprehensive evaluation of the left ventricle (LV) hemodynamic loads. This study has two objectives: (1) developing a lumped-parameter model to describe the ventricular-valvular-arterial interaction and to estimate the LV stroke work (SW); (2) introducing and validating a new index, the normalized stroke work (N-SW), to assess the global hemodynamic load imposed on the LV. N-SW represents the global hemodynamic load that the LV faces for each unit volume of blood ejected. The model uses a limited number of parameters which all can be measured non-invasively using current clinical imaging modalities. The model was first validated by comparing its calculated flow waveforms with the ones measured using Cardiovascular Magnetic Resonance (CMR) in 49 patients and 8 controls. A very good correlation and concordance were found throughout the cycle (median root mean square: 12.21 mL/s) and between the peak values (r = 0.98; SEE = 0.001, p<0.001). The model was then used to determine SW using the parameters measured with transthoracic Doppler-echocardiography (TTE) and CMR. N-SW showed very good correlations with a previously-validated index of global hemodynamic load, the valvular arterial impedance (), using data from both imaging modalities (TTE: r = 0.82, SEE = 0.01, p<0.001; CMR: r = 0.74, SEE = 0.01, p<0.001). Furthermore, unlike , N-SW was almost independent from variations in the flow rate. This study suggests that considering N-SW may provide incremental diagnostic and prognostic information, beyond what standard indices of stenosis severity and provide, particularly in patients with low LV outflow.

Pseudoxanthoma elasticum: cardiac findings in patients and Abcc6-deficient mouse model

Background

Pseudoxanthoma elasticum (PXE), caused by mutations in the ABCC6 gene, is a rare multiorgan disease characterized by the mineralization and fragmentation of elastic fibers in connective tissue. Cardiac complications reportedly associated with PXE are mainly based on case reports.

Methods

A cohort of 67 PXE patients was prospectively assessed. Patients underwent physical examination, electrocardiogram, transthoracic echocardiography, cardiac magnetic resonance imaging (CMR), treadmill testing, and perfusion myocardial scintigraphy (SPECT). Additionally, the hearts of a PXE mouse models (Abcc6^−/−) and wild-type controls (WT) were analyzed.

Results

Three patients had a history of proven coronary artery disease. In total, 40 patients underwent exercise treadmill tests, and 28 SPECT. The treadmill tests were all negative. SPECT showed mild perfusion abnormalities in two patients. Mean left ventricular (LV) dimension and function values were within the normal range. LV hypertrophy was found in 7 (10.4%) patients, though the hypertrophy etiology was unknown for 3 of those patients. Echocardiography revealed frequent but insignificant mitral and tricuspid valvulopathies. Mitral valve prolapse was present in 3 patients (4.5%). Two patients exhibited significant aortic stenosis (3.0%). While none of the functional and histological parameters diverged significantly between the Abcc6^−/− and WT mice groups at age of 6 and 12 months, the 24-month-old Abcc6^−/− mice developed cardiac hypertrophy without contractile dysfunction.

Conclusions

Despite sporadic cases, PXE does not appear to be associated with frequent cardiac complications. However, the development of cardiac hypertrophy in the 24-month-old Abcc6^−/− mice suggests that old PXE patients might be prone to developing late cardiopathy.

Direct or coincidental elimination of stable rotors or focal sources may explain successful atrial fibrillation ablation: on-treatment analysis of the CONFIRM trial (Conventional ablation for AF with or without focal impulse and rotor modulation)

OBJECTIVES

This study sought to determine whether ablation of recently described stable atrial fibrillation (AF) sources, either directly by Focal Impulse and Rotor Modulation (FIRM) or coincidentally when anatomic ablation passes through AF sources, may explain long-term freedom from AF.

BACKGROUND

It is unclear why conventional anatomic AF ablation can be effective in some patients yet ineffective in others with similar profiles.

METHODS

The CONFIRM (Conventional Ablation for AF With or Without Focal Impulse and Rotor Modulation) trial prospectively revealed stable AF rotors or focal sources in 98 of 101 subjects with AF at 107 consecutive ablation cases. In 1:2 fashion, subjects received targeted source ablation (FIRM) followed by conventional ablation, or conventional ablation alone. We determined whether ablation lesions on electroanatomic maps passed through AF sources on FIRM maps.

RESULTS

Subjects who completed follow-up (n = 94; 71.2% with persistent AF) showed 2.3 ± 1.1 concurrent AF rotors or focal sources that lay near pulmonary veins (22.8%), left atrial roof (16.0%), and elsewhere in the left (28.2%) and right (33.0%) atria. AF sources were ablated directly in 100% of FIRM cases and coincidentally (e.g., left atrial roof) in 45% of conventional cases (p < 0.05). During a median (interquartile range) of 273 days (138 to 636 days) after one procedure, AF was absent in 80.3% of patients if sources were ablated but in only 18.2% of patients if sources were missed (p < 0.001). Freedom from AF was highest if all sources were ablated, intermediate if some sources were ablated, and lowest if no sources were ablated (p < 0.001).

CONCLUSIONS

Elimination of stable AF rotors and focal sources may explain freedom from AF after diverse approaches to ablation. Patient-specific AF source distributions are consistent with the reported success of specific anatomic lesion sets and of widespread ablation. These results support targeting AF sources to reduce unnecessary ablation, and motivate studies on FIRM-only ablation.

Circulating plasma and platelet 5-hydroxytryptamine in carcinoid heart disease: a pilot study

BACKGROUND AND AIM OF THE STUDY

Carcinoid heart disease (CaHD) is a rare form of valvular heart disease in patients with carcinoid syndrome (CS). The role of 5-hydroxytryptamine (5-HT) in the pathogenesis of CaHD is unclear. The study aim was to evaluate the association between platelet 5-HT (5-HTplt) and plasma 5-HT (5-HTpls) and valvular dysfunction.

METHODS

Twelve patients with CaHD, 18 with CS and 10 'normal' subjects were recruited. Patients with CaHD underwent cardiac catheterization and echocardiography. 5-HTplt and 5-HTpls was sampled in blood from the femoral vein, right and left ventricle, and left antecubital fossa vein.

RESULTS

Levels of 5-HTpls and 5-HTplt were significantly higher in patients with CaHD (median 5-HTpls 325 nmol/l and 5-HTplt 18.9 nmol/10(9) platelets) and CS (median 5-HTpls 155 nmol/l and 5-HTplt 16.4 nmol/10(9) platelets) when compared to healthy controls (median 5-HTpls 9 nmol/l and 5-HTplt 3.7 nmol/10(9) platelets; p < 0.0001 and p = 0.003, respectively). There was a significant increase in 5-HTplt and 5-HTpls between the femoral vein and right heart (p = 0.007 and p = 0.0002, respectively). There was no significant difference in 5-HTplt or 5-HTpls between the right and left side of the heart, irrespective of the presence of a patent foramen ovale or of left-sided CaHD.

CONCLUSION

Plasma and platelet 5-HT levels are elevated in patients with CaHD. Despite exposure to similar levels of intracardiac plasma and platelet 5-HT, the development of valve dysfunction is heterogeneous. This suggests that individual heart valves have a susceptibility to the development of valvular dysfunction which is not related solely to plasma or platelet 5-HT levels.

Evaluation of cardiac functions with Doppler echocardiography in children with Down syndrome and anatomically normal heart

OBJECTIVE

To study the cardiac functions in Down syndrome children who did not have structural cardiac lesion by conventional and tissue Doppler echocardiography.

MATERIALS AND METHODS

A total of 85 children with Down syndrome without anatomic heart disease and 50 normal control children were subjected to the assessment of right and left ventricular functions by both two-dimensional and tissue Doppler echocardiography.

RESULTS

Children with Down syndrome had significantly higher left ventricular ejection fraction detected by two-dimensional echocardiography and left ventricular diastolic dysfunction detected by tissue Doppler than observed in the controls. In addition, children with Down syndrome also had right ventricular systolic and diastolic dysfunctions. Children with Down syndrome had significantly higher pulmonary artery systolic pressure than the control children. There was no significant difference in the cardiac functions between children with non-disjunction Down syndrome and those with the translocation type.

CONCLUSION

Despite an apparently normal heart, children with Down syndrome may have silent disturbed cardiac functions, which may be detected by two-dimensional or tissue Doppler echocardiography. This may have an important clinical implication, especially before involving Down syndrome children in surgery or strenuous exercise.

[Surgical therapeutic decision-making in elderly patients with heart valvular defects combined with lesions of coronary and brachiocephalic arteries]

Due to considerable incidence of combined cardiac and vascular pathology in elderly and aged patients with heart valve defects, of special importance is the problem regarding surgical therapeutic decision-making. The present article is aimed at considering the problems concerning possibility and feasibility of stagewise or simultaneous surgical correction in patients diagnosed as having cardiac valve defect and haemodynamically significant lesions of coronary and/or brachiocephalic arteries based on generalizing the results of international studies.

Regulatory T-cell deficiency in rheumatic heart disease: a preliminary observational study

BACKGROUND AND AIM OF THE STUDY

Autoimmunity plays an essential role in the pathogenesis of rheumatic heart disease (RHD). The CD4+CD25+ T cell (Tregs) is the chief regulator of autoimmunity, and is essential for the induction and maintenance of self-tolerance and prevention of autoimmunity. To date, the levels of Tregs in RHD have not been investigated. Hence, the study aim was to monitor levels of circulating Tregs in patients with RHD, and to determine whether these differ according to the extent of valvular involvement.

METHODS

A total of 100 adult patients with RHD and 50 age- and gender-matched controls were studied. Patients were subdivided according to the extent of left-sided valvular involvement. Those with echocardiographic evidence only of significant mitral valve disease were enrolled in the univalvular group, while those with significant involvement of both mitral and aortic valves were allocated to the multivalvular group. Levels of circulating Tregs were determined using flow cytometry.

RESULTS

Levels of Tregs in total lymphocytes and CD4+ T lymphocytes were significantly lower in RHD patients than in controls (3.55 +/- 2.28% versus 5.76 +/- 4.2%; p < 0.001, and 14.4 +/- 9.4% versus 18.6 +/- 10.4%; p = 0.011, respectively). Within the study group, the proportion of Tregs to total and CD4+ T lymphocytes was significantly lower in patients with multivalvular than with univalvular disease (2.7 +/- 1.52% versus 4.41 +/- 2.58%; p = 0.001 and 11.5 +/- 8.5% versus 17.4 +/- 9.4%; p = 0.001, respectively).

CONCLUSION

The present study was the first to demonstrate a significant deficiency of circulating Tregs in RHD patients; notably, the reduction was greater in patients with multivalvular than with univalvular involvement.

New method for quantifying and correcting underestimated cardiac Doppler blood flow velocities: in vitro and in vivo studies

This study was aimed to quantify the underestimation of cardiac Doppler measurements and to explore a method for correction. A dual pulse wave (PW)/Doppler tissue imaging (DTI) mode echocardiographic technique was used in the in vitro and in vivo studies. In the in vitro experiment, we have demonstrated how cardiac valvular motion might interfere with blood velocity estimation using conventional Doppler. When examining the participants, we observed that adding valvular annulus velocity to determine the relative velocity between blood and valvular annulus would result in an increment of 9.3 ± 1.3 cm/s and 6.3 ± 0.9 cm/s for aortic and pulmonary blood flow, 12.8 ± 1.9 cm/s and 8.9 ± 1.4 cm/s for mitral E and A wave, 12.9 ± 1.8 cm/s and 10.2 ± 2.4 cm/s for tricuspid E and A wave. The underestimations of the Doppler measurements markedly influence the hemodynamic parameters commonly used in the clinical practices and researches. This study provides a quantitative method for the correction and would make the Doppler measurement accurate.

Comparing pre- and post-operative Fontan hemodynamic simulations: implications for the reliability of surgical planning

Virtual modeling of cardiothoracic surgery is a new paradigm that allows for systematic exploration of various operative strategies and uses engineering principles to predict the optimal patient-specific plan. This study investigates the predictive accuracy of such methods for the surgical palliation of single ventricle heart defects. Computational fluid dynamics (CFD)-based surgical planning was used to model the Fontan procedure for four patients prior to surgery. The objective for each was to identify the operative strategy that best distributed hepatic blood flow to the pulmonary arteries. Post-operative magnetic resonance data were acquired to compare (via CFD) the post-operative hemodynamics with predictions. Despite variations in physiologic boundary conditions (e.g., cardiac output, venous flows) and the exact geometry of the surgical baffle, sufficient agreement was observed with respect to hepatic flow distribution (90% confidence interval-14 ± 4.3% difference). There was also good agreement of flow-normalized energetic efficiency predictions (19 ± 4.8% error). The hemodynamic outcomes of prospective patient-specific surgical planning of the Fontan procedure are described for the first time with good quantitative comparisons between preoperatively predicted and postoperative simulations. These results demonstrate that surgical planning can be a useful tool for single ventricle cardiothoracic surgery with the ability to deliver significant clinical impact.

Changes in heart valve structure and function in patients treated with dopamine agonists for prolactinomas, a 2-year follow-up study

OBJECTIVE

The use of ergot-derived dopamine agonists (DA) to treat patients with prolactinomas has not been associated with an increased risk of significant heart valve dysfunction. Accordingly, the present study evaluated whether the long-term use of DA for hyperprolactinaemia may be associated with increased risk of significant valvular heart disease.

METHODS

A total of 74 patients (mean age 48 ± 1·4 years, 23% male) with prolactinoma treated with DA for at least 1 year were evaluated with 2-dimensional echocardiography at baseline. After 2 years of follow-up, a repeat echocardiography was performed to evaluate significant changes in valvular heart structure (thickening, calcifications and leaflet motion abnormalities) and function (regurgitation or stenosis). Patients were classified according to treatment: patients treated with cabergoline (group 1: n = 45), and patients not treated with cabergoline (group 2: n = 29).

RESULTS

At 2-year follow-up, no significant valvular stenosis was observed in any patient. In addition, the prevalence of any significant valve regurgitation did not change significantly (from 12% to 15%, P = NS). However, there was a significant increase in the prevalence of valvular calcifications (from 48% to 58%, P = 0·004) and, particularly, in the prevalence of aortic valve calcifications (from 39% to 53%, P = 0·002). In a per-treatment-based analysis, the group of patients treated with cabergoline had significantly higher prevalence of aortic valve calcification at 2 years follow-up as compared to the group of patients not treated with cabergoline (63%vs 38%, P = 0·016).

CONCLUSIONS

The long-term therapy with DA (cabergoline) of patients with prolactinoma is associated with an increased prevalence of valvular calcification. However, these structural changes were not accompanied by an increased prevalence of valvular dysfunction.

Heart valve disease: investigation by cardiovascular magnetic resonance

Cardiovascular magnetic resonance (CMR) has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve disease and assessing the right ventricle. CMR has many advantages, including the ability to image in any plane, which allows full visualisation of valves and their inflow/outflow tracts, direct measurement of valve area (particularly for stenotic valves), and characterisation of the associated great vessel anatomy (e.g. the aortic root and arch in aortic valve disease). A particular strength is the ability to quantify flow, which allows accurate measurement of regurgitation, cardiac shunt volumes/ratios and differential flow volumes (e.g. left and right pulmonary arteries). Quantification of ventricular volumes and mass is vital for determining the impact of valve disease on the heart, and CMR is the 'Gold standard' for this. Limitations of the technique include partial volume effects due to image slice thickness, and a low ability to identify small, highly mobile objects (such as vegetations) due to the need to acquire images over several cardiac cycles. The review examines the advantages and disadvantages of each imaging aspect in detail, and considers how CMR can be used optimally for each valve lesion.

[Spectral analysis and LDB based classification of heart sounds with mechanical prosthetic heart valves]

Auscultation, the act of listening for heart sounds to aid in the diagnosis of various heart diseases, is a widely used efficient technique by cardiologists. Since the mechanical prosthetic heart valves are widely used today, it is important to develop a simple and efficient method to detect abnormal mechanical valves. The study on five different mechanical valves showed that only the case of perivalvular leakage could be detected by spectral estimation. Though it is possible to classify different mechanical valves by using time-frequency components of the signal directly, the recognition rate is merely 84%. However, with the improved local discriminant bases (LDB) algorithm to extract features from heart sounds, the recognition rate is 97.3%. Experimental results demonstrated that the improved LDB algorithm could improve classification rate and reduce computational complexity in comparison with original LDB algorithm.

Beta-blocker therapy for valvular disorders

Valvular disorders are common, and result in a neurohormonal milieu similar to the heart failure state. Although valve surgery is the therapy of choice in symptomatic severe lesions, many patients do not receive surgery for a variety of reasons. Beta-blockers have a role in the management of many patients with valvular disorders, especially in the case of patients with mitral stenosis, where they reduce the transmitral gradient. They may also serve as life-saving therapy in pregnant women with pulmonary edema. Other uses of beta-blockers include the reduction of valve-related hemolysis, the prevention of atrial fibrillation, and the relief of dynamic left and right ventricular outflow tract obstruction. The prevention of aortic root dilation, potentially with beta-receptor blockade, may reduce the risk of aortic insufficiency in Marfan syndrome, and also in those with bicuspid aortic valves or following the Ross procedure. In this review, the potential role of beta-blockers is explored for the treatment of severe mitral and aortic regurgitation and asymptomatic severe aortic stenosis.

Structural, ultrastructural and functional studies of human cardiac valve allografts that suffered an increment of the cryostorage temperature

Human cardiac valve allografts (HVAs) suffer injuries during the cryopreservation period. Here, we described structural, ultrastructural and functional damages suffered by HVAs after an increment of their cryostorage temperature (100 degree C). Two experimental groups of pulmonary and aortic HVAs were compared: cryopreserved (HVAcryo) and cryopreserved with temperature changes (HVAΔT). Transmission electron microscopy (TEM) was used to analyze valve fibroblasts and extracellular matrix morphology. Total collagen amount was estimated using two different methods and fibroblast viability was assessed measuring their oxygen consumption rate. Porcine heart grafts valves were used to set the techniques. Disorganized collagen network was seen in HVAΔT by TEM. Fibroblasts showed damages in the cellular membrane and many secretor vesicles. Mitochondria and chromatin were also altered. HVAΔT had less amount of collagen and fibroblasts showed an oxygen consumption rate markedly diminished compared to HVAcryo. The increment of 100 degree C suffered by HVAs caused damages that made them unsuitable for clinical purposes.

Valvular heart disease with the use of fenfluramine-phentermine

Exposure to the anorectic drug fenfluramine, alone or in combination with phentermine, a noradrenergic central nervous system stimulant, has been associated with unusual cardiac valvular morphology and resultant regurgitation of the left- and right-sided heart valves. The prevalence of significant valvular disease associated with the use of these anorectic drugs is reported to be as high as 23%. Herein, we report the occurrence of multivalvular disease and pulmonary hypertension associated with fenfluramine-phentermine use, discovered in an obese 59-year-old woman before expected gastric bypass surgery.

[Changes of the endothelial function and cardiac valves in patients with reactive arthritis]

Our investigations showed endothelium's malfunction and changes of the cardiac valves in patients with reactive arthritis, which could be precondition of the cardiac failure development in these patients.

Assessment of cardiac valve dysfunction in patients receiving cabergoline treatment for hyperprolactinaemia

OBJECTIVE

Cabergoline is a highly effective medical treatment for patients with hyperprolactinaemia. There is an increased risk of valvular heart disease in patients receiving cabergoline for Parkinson's disease. This study examined whether cabergoline treatment of hyperprolactinaemia is associated with a greater prevalence of valvulopathy.

DESIGN

Cross-sectional, two-dimensional echocardiographic study performed by a single echocardiographer.

PATIENTS

Seventy-two patients (median age 36 years, 19 men) receiving cabergoline for hyperprolactinaemia, and 72 controls prospectively matched for age, sex and cardiovascular risk factors. Measurements Assessment of valvular mobility, regurgitation and morphology.

RESULTS

Median cumulative dose exposure for cabergoline was 126 (58-258) mg, and patients had received cabergoline for 53 (26-96) months. The frequency of mild mitral regurgitation was identical (5/72, 7%) in patient and control groups. Mild aortic regurgitation was not significantly different between groups (4/72 [controls] vs 2/72 [patients], P = 0.681). There was only one case of tricuspid regurgitation, which was mild and observed in a cabergoline-treated patient. Nodular thickening of the right coronary cusp, noncoronary cusp or left coronary cusp of the aortic valve was observed at a similar frequency in both groups. There were no cases of extensive thickening of any valvular leaflet.

CONCLUSION

Our data demonstrates that there is no association between cabergoline treatment for hyperprolactinaemia and valvulopathy. This study therefore supports continued use of low-dose cabergoline for patients with hyperprolactinaemia.