Acute Valvular Regurgitation

Assessment and management of a 1.77-cm2 mitral leaflet perforation as a subclinical cause of mitral regurgitation

Anterior mitral valve perforations are commonly due to underlying infective endocarditis, which can lead to significant mitral valve insufficiency. In these cases, clinicians should have a high index of suspicion for infective endocarditis. After appropriate imaging, immediate surgical intervention is unequivocally the choice of management here for optimal patient outcomes.

Acute Mitral Regurgitation: The Dreaded Masquerader

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Acute MR is a rare but important etiology of unilateral pulmonary edema.

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Anterior leaflet flail can cause right upper lobe opacity.

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Early imaging with TTE can establish diagnosis and guide lifesaving intervention.

3D Biofabrication of Thermoplastic Polyurethane (TPU)/Poly-l-lactic Acid (PLLA) Electrospun Nanofibers Containing Maghemite (γ-Fe₂O₃) for Tissue Engineering Aortic Heart Valve

Valvular dysfunction as the prominent reason of heart failure may causes morbidity and mortality around the world. The inability of human body to regenerate the defected heart valves necessitates the development of the artificial prosthesis to be replaced. Besides, the lack of capacity to grow, repair or remodel of an artificial valves and biological difficulty such as infection or inflammation make the development of tissue engineering heart valve (TEHV) concept. This research presented the use of compound of poly-l-lactic acid (PLLA), thermoplastic polyurethane (TPU) and maghemite nanoparticle (γ-Fe₂O₃) as the potential biomaterials to develop three-dimensional (3D) aortic heart valve scaffold. Electrospinning was used for fabricating the 3D scaffold. The steepest ascent followed by the response surface methodology was used to optimize the electrospinning parameters involved in terms of elastic modulus. The structural and porosity properties of fabricated scaffold were characterized using FE-SEM and liquid displacement technique, respectively. The 3D scaffold was then seeded with aortic smooth muscle cells (AOSMCs) and biological behavior in terms of cell attachment and proliferation during 34 days of incubation was characterized using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and confocal laser microscopy. Furthermore, the mechanical properties in terms of elastic modulus and stiffness were investigated after cell seeding through macro-indentation test. The analysis indicated the formation of ultrafine quality of nanofibers with diameter distribution of 178 ± 45 nm and 90.72% porosity. In terms of cell proliferation, the results exhibited desirable proliferation (109.32 ± 3.22% compared to the control) of cells over the 3D scaffold in 34 days of incubation. The elastic modulus and stiffness index after cell seeding were founded to be 22.78 ± 2.12 MPa and 1490.9 ± 12 Nmm², respectively. Overall, the fabricated 3D scaffold exhibits desirable structural, biological and mechanical properties and has the potential to be used in vivo.

Simulation for transthoracic echocardiography of aortic valve

Simulation allows interactive transthoracic echocardiography (TTE) learning using a virtual three-dimensional model of the heart and may aid in the acquisition of the cognitive and technical skills needed to perform TTE. The ability to link probe manipulation, cardiac anatomy, and echocardiographic images using a simulator has been shown to be an effective model for training anesthesiology residents in transesophageal echocardiography. A proposed alternative to real-time reality patient-based learning is simulation-based training that allows anesthesiologists to learn complex concepts and procedures, especially for specific structures such as aortic valve.

Aortic Regurgitation Generates a Kinematic Obstruction Which Hinders Left Ventricular Filling

An incompetent aortic valve (AV) results in aortic regurgitation (AR), where retrograde flow of blood into the left ventricle (LV) is observed. In this work, we parametrically characterized the detailed changes in intra-ventricular flow during diastole as a result of AR in a physiological in vitro left-heart simulator (LHS). The loss of energy within the LV as the level of AR increased was also assessed. The validated LHS consisted of an optically-clear, flexible wall LV and a modular AV holder. Two-component, planar, digital particle image velocimetry was used to visualize and quantify intra-ventricular flow. A large coherent vortical structure which engulfed the whole LV was observed under control conditions. In the cases with AR, the regurgitant jet was observed to generate a "kinematic obstruction" between the mitral valve and the LV apex, preventing the trans-mitral jet from generating a coherent vortical structure. The regurgitant jet was also observed to impinge on the inferolateral wall of the LV. Energy dissipation rate (EDR) for no, trace, mild, and moderate AR were found to be 1.15, 2.26, 3.56, and 5.99 W/m³, respectively. This study has, for the first time, performed an in vitro characterization of intra-ventricular flow in the presence of AR. Mechanistically, the formation of a "kinematic obstruction" appears to be the cause of the increased EDR (a metric quantifiable in vivo) during AR. EDR increases non-linearly with AR fraction and could potentially be used as a metric to grade severity of AR and develop clinical interventional timing strategies for patients.

Acute Severe Aortic Regurgitation: Imaging with Pathological Correlation

Context:

Acute aortic regurgitation (AR) is an important finding associated with a wide variety of disease processes. Its timely diagnosis is of utmost importance. Delay in diagnosis could prove fatal.

Case Report:

We describe a case of acute severe AR that was timely diagnosed using real time three-dimensional (3D) transesophageal echocardiogram (3D TEE). Not only did it diagnose but also the images obtained by 3D TEE clearly matched with the pathologic specimen. Using this sophisticated imaging modality that is mostly available at the tertiary centers helped in the timely diagnosis, which lead to the optimal management saving his life.

Conclusion:

Echocardiography and especially 3D TEE can diagnose AR very accurately. Surgical intervention is the definitive treatment but medical therapy is utilized to stabilize the patient initially.

The Akt-mTOR axis is a pivotal regulator of eccentric hypertrophy during volume overload

The heart has two major modalities of hypertrophy in response to hemodynamic loads: concentric and eccentric hypertrophy caused by pressure and volume overload (VO), respectively. However, the molecular mechanism of eccentric hypertrophy remains poorly understood. Here we demonstrate that the Akt-mammalian target of rapamycin (mTOR) axis is a pivotal regulator of eccentric hypertrophy during VO. While mTOR in the heart was activated in a left ventricular end-diastolic pressure (LVEDP)-dependent manner, mTOR inhibition suppressed eccentric hypertrophy and induced cardiac atrophy even under VO. Notably, Akt was ubiquitinated and phosphorylated in response to VO, and blocking the recruitment of Akt to the membrane completely abolished mTOR activation. Various growth factors were upregulated during VO, suggesting that these might be involved in Akt-mTOR activation. Furthermore, the rate of eccentric hypertrophy progression was proportional to mTOR activity, which allowed accurate estimation of eccentric hypertrophy by time-integration of mTOR activity. These results suggested that the Akt-mTOR axis plays a pivotal role in eccentric hypertrophy, and mTOR activity quantitatively determines the rate of eccentric hypertrophy progression. As eccentric hypertrophy is an inherent system of the heart for regulating cardiac output and LVEDP, our findings provide a new mechanistic insight into the adaptive mechanism of the heart.

Cardiogenic Shock

Cardiogenic shock is the leading cause of morbidity and mortality in patients presenting with acute coronary syndrome. Although early reperfusion strategies are essential to the management of these critically ill patients, additional treatment plans are often needed to stabilize and treat the patient before reperfusion may be possible. This article discusses pharmacologic and surgical interventions, their indications and contraindications, management strategies, and treatment algorithms.

Clinical impact of aortic regurgitation after transcatheter aortic valve replacement: insights into the degree and acuteness of presentation

OBJECTIVES

The aim of this study was to determine the impact of the degree of residual aortic regurgitation (AR) and acuteness of presentation of AR after transcatheter aortic valve replacement (TAVR) on outcomes.

BACKGROUND

The degree of residual AR after TAVR leading to excess mortality remains controversial, and little evidence exists on the impact of the acuteness of presentation of AR.

METHODS

A total of 1,735 patients undergoing TAVR with balloon-expandable or self-expanding valves were included. The presence and degree of AR were evaluated by transthoracic echocardiography; acute AR was defined as an increase in AR severity of ≥1 degree compared with pre-procedural echocardiography.

RESULTS

Residual AR was classified as mild in 761 patients (43.9%) and moderate to severe in 247 patients (14.2%). The presence of moderate to severe AR was an independent predictor of mortality at a mean follow-up of 21 ± 17 months compared with none to trace (adjusted hazard ratio [HR]: 1.81, 95% confidence interval [CI]: 1.32 to 2.48; p < 0.001) and mild AR (adjusted HR: 1.68, 95% CI: 1.27 to 2.24; p < 0.001) groups. There was no increased risk in patients with mild AR compared with those with none to trace AR (p = 0.393). In patients with moderate to severe AR, acute AR was observed in 161 patients (65%) and chronic AR in 86 patients (35%). Acute moderate to severe AR was independently associated with increased risk of mortality compared with none/trace/mild AR (adjusted HR: 2.37, 95% CI: 1.53 to 3.66; p < 0.001) and chronic moderate to severe AR (adjusted HR: 2.24, 95% CI: 1.17 to 4.30; p = 0.015) [corrected]. No differences in survival rate were observed between patients with chronic moderate to severe and none/trace/mild AR (p > 0.50).

CONCLUSIONS

AR occurred very frequently after TAVR, but an increased risk of mortality at ∼2-year follow-up was observed only in patients with acute moderate to severe AR.

Revision of the Jones Criteria for the diagnosis of acute rheumatic fever in the era of Doppler echocardiography: a scientific statement from the American Heart Association

BACKGROUND

Acute rheumatic fever remains a serious healthcare concern for the majority of the world's population despite its decline in incidence in Europe and North America. The goal of this statement was to review the historic Jones criteria used to diagnose acute rheumatic fever in the context of the current epidemiology of the disease and to update those criteria to also take into account recent evidence supporting the use of Doppler echocardiography in the diagnosis of carditis as a major manifestation of acute rheumatic fever.

METHODS AND RESULTS

To achieve this goal, the American Heart Association's Council on Cardiovascular Disease in the Young and its Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee organized a writing group to comprehensively review and evaluate the impact of population-specific differences in acute rheumatic fever presentation and changes in presentation that can result from the now worldwide availability of nonsteroidal anti-inflammatory drugs. In addition, a methodological assessment of the numerous published studies that support the use of Doppler echocardiography as a means to diagnose cardiac involvement in acute rheumatic fever, even when overt clinical findings are not apparent, was undertaken to determine the evidence basis for defining subclinical carditis and including it as a major criterion of the Jones criteria. This effort has resulted in the first substantial revision to the Jones criteria by the American Heart Association since 1992 and the first application of the Classification of Recommendations and Levels of Evidence categories developed by the American College of Cardiology/American Heart Association to the Jones criteria.

CONCLUSIONS

This revision of the Jones criteria now brings them into closer alignment with other international guidelines for the diagnosis of acute rheumatic fever by defining high-risk populations, recognizing variability in clinical presentation in these high-risk populations, and including Doppler echocardiography as a tool to diagnose cardiac involvement.

Three patients with signs of acute flail mitral leaflet seen on emergency department echo: a critical constellation within the focused cardiac exam

Acute flail mitral leaflet is a time-sensitive, reversible cause of cardiogenic shock. Transthoracic echocardiography (echo) is increasingly becoming a vital tool for non-cardiologist physicians who treat patients with undifferentiated chest pain and dyspnoea. The sonographic abnormalities seen in acute flail mitral leaflet are within the boundaries of a focused echo. Individually, these findings are non-specific. As a constellation, however, they are highly suggestive of this disease process. We present a case series of three patients with acute flail mitral leaflet seen on emergency department echo along with a discussion of the findings and the disease itself.

Iatrogenic Mitral Valve Perforation following CABG and Aortic Valve Replacement: A Rare Complication detected by Post-bypass Transesophageal Echocardiography

Iatrogenic mitral valve perforation following aortic valve replacement is a rare complication. We present a case of anterior mitral leaflet perforation following coronary artery bypass grafting (CABG) and aortic valve replacement detected by intraoperative transesophageal echocardiography (TEE). A 57-year-old male patient with preoperative diagnosis of coronary artery disease, sclerodegenerative aortic valve with severe aortic stenosis and mild central mitral regurgitation (MR) underwent CABG and aortic valve replacement. A post bypass TEE in midesophageal long axis view showed an additional MR jet across the body of the anterior mitral leaflet. We present intraoperative TEE images with a discussion on role of TEE in detection of mitral valve perforation and surgical decision making.

Abbreviations

AVR: Aortic valve replacement C ABG: Coronary artery bypass grafting 2D: Two-dimensional MR: Mitral regurgitation TEE: Transesophageal echocardiography TTE: Transthoracic echocardiography

How to cite this article

Raj R, Mathew S, Puri GD. Iatrogenic Mitral Valve Perforation following CABG and Aortic Valve Replacement: A Rare Complication detected by Post-bypass Transesophageal Echocardiography. J Perioper Echocardiogr 2014;2(2):75-76.

Carotid intima media thickness and arterial stiffness in children with acute rheumatic fever

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) constitute important public health problems in developing countries. Inflammation is present both in the early and late stages of the diseases. Chronic inflammation is known to be associated with atherosclerosis. We hypothesize that subclinical atherosclerosis and arterial stiffness may increase due to the ongoing inflammation as well as the increased pulse pressure and left-ventricular systolic dysfunction in RHD. The purpose of the present study was to investigate carotid intima media thickness (CIMT) and carotid artery stiffness in patients with ARF. Forty patients in follow-up due to ARF in the age group of 7-16 years (disease duration 1-10 years) and 36 volunteered subjects with similar body mass index were included in the study. The subjects included in the present study were compared regarding M-mode echocardiographic parameters and CIMT as well as carotid arterial strain (CAS), carotid artery distensibility (CAD), beta stiffness index (βSI), and pressure-strain elasticity modulus (Ep) as carotid artery stiffness parameters. CIMT (0.52 ± 0.08 and 0.48 ± 0.07 mm, p = 0.01), βSI (5.29 ± 2.98 and 3.02 ± 1.30, p < 0.001), and Ep (426.53 ± 210.50 and 254.44 ± 104.69 p < 0.001) were increased, whereas CAS (0.11 ± 0.01 and 0.19 ± 0.09, p < 0.001) and CAD (10.27 ± 4.69 and 17.76 ± 14.41, p < 0.001) were decreased in patients with ARF compared with the control group. There was a positive correlation between pulse pressure and βSI (r = 0.25, p = 0.02) and Ep (r = 0.28, p = 0.01) in addition to a correlation between left atrial dilatation and CIMT (r = 0.55 p < 0.001) in patients with ARF. CIMT and carotid artery stiffness were increased in patients with ARF. Patients with ARF may have an increased risk of subclinical atherosclerosis and cardiovascular events.

Diffuse Alveolar Hemorrhage due to Acute Mitral Valve Regurgitation

Diffuse alveolar hemorrhage (DAH) can be caused by several etiologies including vasculitis, drug exposure, anticoagulants, infections, mitral valve stenosis, and regurgitation. Chronic mitral valve regurgitation (MR) has been well documented as an etiological factor for DAH, but there have been only a few cases which have reported acute mitral valve regurgitation as an etiology of DAH. Acute mitral valve regurgitation can be a life-threatening condition and often requires urgent intervention. In rare cases, acute mitral regurgitation may result in a regurgitant jet which is directed towards the right upper pulmonary vein and may specifically cause right-sided pulmonary edema and right-sided DAH. Surgical repair of the mitral valve results in rapid resolution of DAH. Acute MR should be considered as a possible etiology in patients presenting with unilateral pulmonary edema, hemoptysis, and DAH.

Nitric oxide synthase-3 promotes embryonic development of atrioventricular valves

Nitric oxide synthase-3 (NOS3) has recently been shown to promote endothelial-to-mesenchymal transition (EndMT) in the developing atrioventricular (AV) canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT) and NOS3^−/− mice at postnatal day 0. Our data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3^−/− compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3^−/− mice. These phenotypes were all rescued by cardiac specific NOS3 overexpression. To assess EndMT, immunostaining of Snail1 was performed in the embryonic heart. Both total mesenchymal and Snail1⁺ cells in the AV cushion were decreased in NOS3^−/− compared with WT mice at E10.5 and E12.5, which was completely restored by cardiac specific NOS3 overexpression. In cultured embryonic hearts, NOS3 promoted transforming growth factor (TGFβ), bone morphogenetic protein (BMP2) and Snail1expression through cGMP. Furthermore, mesenchymal cell formation and migration from cultured AV cushion explants were decreased in the NOS3^−/− compared with WT mice. We conclude that NOS3 promotes AV valve formation during embryonic heart development and deficiency in NOS3 results in AV valve insufficiency.

Role of echocardiography in guiding the optimal timing of surgery in infective endocarditis

Infective endocarditis (IE) is a complex cardiovascular infection with the potential for multiorgan complications. While early surgery can be life saving in IE patients with acute heart failure and acute valve regurgitation, the appropriate timing of surgery for embolic complications is less certain. The ongoing debate concerns the ideal timing of surgical therapy and stems primarily from a scarcity of therapeutic randomized controlled trials in this population. Based largely on the evidence from observational studies and expert consensus, the European Society of Cardiology has issued guidelines on the optimal surgical timing in IE. Nonetheless, selection bias in published studies and the clinical complexity of this disease entity continue to pose management challenges in the individual patient. In this review, we focus on the cardinal role of echocardiography as a diagnostic tool in patients with complicated IE and discuss the available evidence pertaining to the ideal timing of surgical intervention.

Acute aortic regurgitation due to aortic dissection confined to the sinus of Valsalva

A 34-year-old man with severe heart failure was diagnosed with acute aortic regurgitation (AR) by transthoracic echocardiography (TTE). However, this differential diagnosis was incomplete. Only transesophageal echocardiography (TEE) revealed an intimal flap, leading to a diagnosis of Stanford type A aortic dissection. No abnormal findings were observed in the ascending aorta by contrast-enhanced computed tomography (CT). Aortic dissection confined to the sinus of Valsalva has rarely been reported; however, TEE should still be considered for the differential diagnosis of acute AR, even if there is no evidence of dissection by TTE or contrast-enhanced CT.

Aortic root abscess presenting as pyrexia of unknown origin and the importance of echocardiography

Aortic root abscess in patients with aortic endocarditis is not uncommon. Aortic root abscess may cause persistent sepsis, worsening heart failure, conduction abnormalities, fistula formation, and an increased need for surgery. We present a young patient with aortic root abscess presenting as pyrexia of unknown origin. She had acute severe aortic and mitral regurgitation which produced very soft murmurs that were easily missed. This report reiterates that a high index of suspicion is needed in suspecting valvular endocarditis as well as a comprehensive transthoracic and transesophageal echocardiographic examination to diagnose complications like aortic root abscess.

From pressure overload to volume overload: aortic regurgitation after transcatheter aortic valve implantation

Severe aortic valve stenosis is a common valvular heart disease that is characterized by left ventricular (LV) pressure overload. A lasting effect of pressure overload is LV remodeling, accompanied by concentric hypertrophy and increased myocardial stiffness. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement for patients with severe symptomatic aortic valve stenosis and high surgical risk. Although TAVI has favorable hemodynamic performance, aortic valve regurgitation (AR) is the most frequent complication because of the specific technique used for implantation of transcatheter valves. During implantation, the calcified native valve is pushed aside, and the prosthesis usually achieves only an incomplete prosthesis apposition. As a consequence, the reported prevalence of moderate and severe AR after TAVI is 6% to 21%, which is considerably higher than that after a surgical valve replacement. Although mild AR probably has minor hemodynamic effects, even moderate AR might result in serious consequences. In moderate and severe AR after TAVI, a normal-sized LV with increased myocardial stiffness has been exposed to volume overload. Because the noncompliant LV is unable to raise end-diastolic volume, the end-diastolic pressure increases, and the forward stroke volume decreases. In recent years, an increasing number of patients have successfully undergone TAVI. Despite encouraging overall results, a substantial number of patients receive neither symptomatic nor prognostic benefits from TAVI. Aortic valve regurgitation has been considered a potential contributor to morbidity and mortality after TAVI. Therefore, various strategies and improvements in valve designs are mandatory to reduce the prevalence of AR after TAVI.

Post myocardial infarction cardiogenic shock: a review of current therapies

Cardiogenic shock is often a devastating consequence of acute myocardial infarction (MI) and portends to significant mortality and morbidity. Despite improvements in expediting the time to treatment and enhancements in available medical therapy and reperfusion techniques, cardiogenic shock remains the most common cause of mortality following MI. Post-MI cardiogenic shock most commonly occurs as a consequence of severe left ventricular dysfunction. Right ventricular (RV) MI must also be considered. Mechanical complications including acute mitral regurgitation, ventricular septal rupture, and ventricular free-wall rupture can also lead to cardiogenic shock. Rapid diagnosis of cardiogenic shock and its underlying cause is pivotal to delivering definitive therapy. Intravenous vasoactive agents and mechanical support devices may temporize the patient's hemodynamic status until definitive therapy by percutaneous or surgical intervention can be performed. Despite prompt management, post-MI cardiogenic shock mortality remains high.

Recommendations for the practice of echocardiography in infective endocarditis

Echocardiography plays a key role in the assessment of infective endocarditis (IE). It is useful for the diagnosis of endocarditis, the assessment of the severity of the disease, the prediction of short- and long-term prognosis, the prediction of embolic events, and the follow-up of patients under specific antibiotic therapy. Echocardiography is also useful for the diagnosis and management of the complications of IE, helping the physician in decision-making, particularly when a surgical therapy is considered. Finally, intraoperative echocardiography must be performed in IE to help the surgeon in the assessment and management of patients with IE during surgery. The current 'recommendations for the practice of echocardiography in infective endocarditis' aims to provide both an updated summary concerning the value and limitations of echocardiography in IE, and clear and simple recommendations for the optimal use of both transthoracic and transoesophageal echocardiography in IE.

Infective endocarditis: an update on the role of echocardiography

The evaluation of valvular and nonvalvular structures is of central importance in the diagnosis, management, and treatment of infective endocarditis (IE). The incidence of IE has remained constant due to changing substrate, with notably higher prevalence observed in the elderly. Mortality and morbidity continue to remain high, despite advances in medical and surgical treatment. This article reviews the technical and practical aspects of the use of echocardiography to evaluate patients with suspected IE.

Progress in the treatment of severe mitral regurgitation

Organic mitral regurgitation (MR) is prevalent in the general population. Disease progression, involving potentially irreversible left ventricular dysfunction, implies a poor prognosis for patients who do not receive appropriate treatment. Immediate rescue surgery is indicated in those with severe MR in whom subclinical left ventricular dysfunction is suggested by echocardiographic measurements or the presence of symptoms, however minor. Patients whose symptomatology is unclear should be evaluated by exercise testing. Not all forms of severe organic MR are the same: the presence of risk factors in patients with severe asymptomatic MR and preserved ventricular function indicates a suboptimal prognosis over the medium-to-long term and should prompt early mitral repair if there is a low surgical risk and the probability of a successful repair is >90-95%. The patient should be referred to a specialized surgical center if necessary. Appropriate training of surgeons in mitral repair is essential. Ischemic MR carries a worse prognosis and the risk of surgery is higher. Consequently, treatment decisions must be patient-specific and take into account the possibility of repair, the risk of surgery, and the need for concomitant surgical revascularization. New percutaneous approaches to mitral repair are being developed for selected patient groups.