Intensity of murmurs correlates with severity of valvular regurgitation

Deep Learning Algorithms to Detect Murmurs Associated With Structural Heart Disease

Background The success of cardiac auscultation varies widely among medical professionals, which can lead to missed treatments for structural heart disease. Applying machine learning to cardiac auscultation could address this problem, but despite recent interest, few algorithms have been brought to clinical practice. We evaluated a novel suite of Food and Drug Administration-cleared algorithms trained via deep learning on >15 000 heart sound recordings. Methods and Results We validated the algorithms on a data set of 2375 recordings from 615 unique subjects. This data set was collected in real clinical environments using commercially available digital stethoscopes, annotated by board-certified cardiologists, and paired with echocardiograms as the gold standard. To model the algorithm in clinical practice, we compared its performance against 10 clinicians on a subset of the validation database. Our algorithm reliably detected structural murmurs with a sensitivity of 85.6% and specificity of 84.4%. When limiting the analysis to clearly audible murmurs in adults, performance improved to a sensitivity of 97.9% and specificity of 90.6%. The algorithm also reported timing within the cardiac cycle, differentiating between systolic and diastolic murmurs. Despite optimizing acoustics for the clinicians, the algorithm substantially outperformed the clinicians (average clinician accuracy, 77.9%; algorithm accuracy, 84.7%.) Conclusions The algorithms accurately identified murmurs associated with structural heart disease. Our results illustrate a marked contrast between the consistency of the algorithm and the substantial interobserver variability of clinicians. Our results suggest that adopting machine learning algorithms into clinical practice could improve the detection of structural heart disease to facilitate patient care.

Valvular Heart Disease Emergencies: A Comprehensive Review Focusing on the Initial Approach in the Emergency Department

Valvular heart disease (VHD) is an increasing health problem worldwide. Patients with VHD may experience several cardiovascular-related emergencies. The management of these patients is a challenge in the emergency department, especially when the previous heart condition is unknown. Specific recommendations for the initial management are currently poor. This integrative review proposes an evidence-based three-step approach from bedside VHD suspicion to the initial treatment of the emergencies. The first step is the suspicion of underlying valvular condition based on signs and symptoms. The second step comprises the attempt to confirm the diagnosis and assessment of VHD severity with complementary tests. Finally, the third step addresses the diagnosis and treatment options for heart failure, atrial fibrillation, valvular thrombosis, acute rheumatic fever, and infective endocarditis. In addition, several images of complementary tests and summary tables are provided for physician support.

Watchful surgery in asymptomatic mitral valve prolapse

The most common organic etiology of mitral regurgitation is degenerative and consists of mitral valve prolapse (MVP). Volume overload because of mitral regurgitation is the most common complication of MVP. Advocating surgery before the consequences of volume overload become irreparable restores life expectancy, but carries a risk of mortality in patients who are often asymptomatic. On the other hand, the post-surgical outcome of symptomatic patients is dismal and life expectancy is impaired. In the present article, we aim to bridge the gap between these two therapeutic approaches, unifying the concepts of watchful waiting and early surgery in a "watchful surgery approach".

Mitral Valve Regurgitation Murmurs—Insights from Hemoacoustic Computational Modeling

Mitral regurgitation (MR) is the leakage of blood from the left ventricle into the left atrium during systole through a mitral valve that does not close fully. A systolic murmur is produced by MR and can be used to diagnose this disease. In the current study, we use hemoacoustic simulations to characterize the features of murmurs for a range of severities relevant to chronic MR. The incompressible Navier–Stokes equations are solved using an immersed boundary method to simulate the blood flow. The resultant pressure fluctuations on the lumen wall serve as the source for the murmur, and the murmur propagation through the thorax is modeled as a 3D elastic wave in a linear viscoelastic material. The resulting acceleration on the surface of the thorax is used as a surrogate for the measurement from a stethoscope, and these characteristics of the acceleration signal are examined in detail. We found that the intensity of the MR murmur is lower at the mitral point on the precordium, as compared with the aortic and pulmonic areas. This is somewhat counterintuitive but is supported by other studies in the past. We also found that the intensity of the murmur, as well as the break frequency, are well correlated with the severity of MR, and this information can be useful for automated auscultation and phonocardiographic applications.

Association between Cardiac Auscultation and Echocardiographic Findings in Warmblood Horses

Heart murmurs are detected frequently when auscultating horses and certain murmurs can usually be linked to specific valvular regurgitations. Limited information exists about the accuracy of these broad rules in warmblood horses and the influence of grade of the regurgitation and dimensional changes on murmur intensity. This study aims to clarify the accuracy of cardiac auscultation in warmblood horses and the influence of the grade of regurgitation and dimensional changes on the loudness of the murmur. In this retrospective study, 822 warmblood horses presented for cardiac examination in a large equine referral center in northern Germany underwent a thorough cardiac auscultation. In total, 653 of these revealed one or more heart murmurs. Most common auscultatory findings were left-sided systolic murmurs (68%) or left-sided diastolic murmurs (15%). On 635 of these horses, an echocardiographic examination was performed, revealing regurgitations of the mitral valve as the most common valvular regurgitation (77%) followed by regurgitations of the aortic valve (23%). Thirty-one percent of horses that underwent echocardiographic examination displayed dimensional changes of one or more compartments of the heart, with the left atrium being most affected (21%), followed by the left ventricle (13%). The main goal of this study was to link certain auscultatory findings with results of the echocardiographic examinations, trying to determine whether auscultation and echocardiography agreed on the valve affected, as well as to find out if loudness of the murmur coincided with grade of regurgitation and presence of dimensional changes. Agreement between auscultation and cardiac ultrasound was substantial (Kappa 0.74) if one or more murmurs and regurgitations were present and almost perfect (Kappa 0.94) if only one murmur and one regurgitation were found. Auscultation was particularly well suited for detection of left-sided systolic and diastolic murmurs, with 87% of left-sided systolic murmurs being caused by a mitral valve regurgitation and 81% of left-sided diastolic murmurs originating from an aortic valve regurgitation. We found a fair agreement between the grade of regurgitation and the respective murmur. Association was particularly good between mild regurgitations and low-grade murmurs, while differentiation between moderate to severe regurgitation based upon the loudness of the murmur was less reliable. Dimensional changes were usually linked to more severe regurgitations and higher-grade murmurs. However, a direct correlation between murmur intensity and the presence or severity of dimensional changes, independent of the grade of valvular regurgitation, could not be established in this cohort of horses.

The Evolving Epidemiology of Elderly with Degenerative Valvular Heart Disease: The Guangzhou (China) Heart Study

Aim

The present study was aimed at investigating the prevalence, incidence, progression, and prognosis of degenerative valvular heart disease (DVHD) in permanent residents aged ≥65 years from Guangzhou, China.

Methods

This was a prospective study based on community population. Over a 3-year span, we conducted repeated questionnaires, blood tests, and echocardiographic and electrocardiogram examinations (2018) of a random sample of initially 3538 subjects.

Results

The prevalence of DVHD increased with age, average values being 30.6%, 49.2%, and 62.9% in 65-74, 75-84, and ≥85 years of age, respectively. The incidence rate was 1.7%/year. Aortic stenosis was the result of DVHD, and the mean transvalvular pressure gradient increased by 5.6 mmHg/year. The increase of mild aortic stenosis was lower than that of more severe disease, showing a nonlinear development of gradient, but with great individual variations. Mortality was significantly increased in the DVHD group (HR = 2.49). Risk factors for higher mortality included age (χ² = 1.9, P < 0.05), renal insufficiency (χ² = 12.5, P < 0.01), atrial fibrillation (χ² = 12.2, P < 0.01), mitral regurgitation (χ² = 1.8, P < 0.05), and tricuspid regurgitation (χ² = 6.7, P < 0.05) in a DVHD population.

Conclusions

DVHD was highly prevalent among residents in southern China. With the progression of the disease, the mean transvalvular pressure gradient accelerated. DVHD was an independent predictor of death, and the mortality was higher in those with older age, renal insufficiency, atrial fibrillation, mitral regurgitation, and tricuspid regurgitation.

Severe acute mitral valve regurgitation in a COVID-19-infected patient

The ongoing SARS-CoV-2 (COVID-19) pandemic has presented many difficult and unique challenges to the medical community. We describe a case of a middle-aged COVID-19-positive man who presented with pulmonary oedema and acute respiratory failure. He was initially diagnosed with acute respiratory distress syndrome. Later in the hospital course, his pulmonary oedema and respiratory failure worsened as result of severe acute mitral valve regurgitation secondary to direct valvular damage from COVID-19 infection. The patient underwent emergent surgical mitral valve replacement. Pathological evaluation of the damaged valve was confirmed to be secondary to COVID-19 infection. The histopathological findings were consistent with prior cardiopulmonary autopsy sections of patients with COVID-19 described in the literature as well as proposed theories regarding ACE2 receptor activity. This case highlights the potential of SARS-CoV-2 causing direct mitral valve damage resulting in severe mitral valve insufficiency with subsequent pulmonary oedema and respiratory failure.

Clinical manifestations, diagnosis, and treatment of ischemic mitral regurgitation: a review

Ischemic mitral regurgitation (IMR) is a frequent complication after acute myocardial infarction (AMI) associated with a worse prognosis. The pathophysiological mechanisms of IMR are not fully understood, but it is known to be a complex process in which ventricular remodelling is the main causal factor. The various imaging techniques in cardiology and echocardiography fundamentally have contributed significantly to clarify the mechanisms that cause and progressively aggravate IMR. At present, different therapeutic options, the most important of which are cardio-surgical, address this problem. Nowadays the improvement in cardiac surgery and transcatheter therapies, have shown a therapeutic advance in IMR management. IMR is a predictor of poor prognosis in patients with heart failure and depressed left ventricular (LV) systolic function. However, it remains controversial whether mitral regurgitation (MR) in these patients is a consequence of dilation and dysfunction of the LV, or whether it contributes to worsening the prognosis of the ventricular dysfunction. Given that echocardiography has a fundamental reference role in the identification, graduation of severity and evaluation of the therapeutics used in the treatment of MR, we are going to focus on it over the rest of the imaging techniques. In contrast to primary MR the benefits of mitral surgery in patients with secondary MR are uncertain. Therefore, we will comment fundamentally on the role of mitral surgery in patients with IMR, with an update of the different surgical interventions available, without forgetting to mention the other therapeutic options currently available.

Sildenafil improves heart rate variability in dogs with asymptomatic myxomatous mitral valve degeneration

Myxomatous mitral valve degeneration (MMVD) causes an imbalance of sympathovagal activity resulted in poor cardiac outcomes. Phosphodiesterase-5 inhibitors have been revealed cardioprotective effect in patients with heart diseases. This study aimed to 1) compare the heart rate variability (HRV) between asymptomatic MMVD and healthy dogs and 2) assess long-term effects of sildenafil and enalapril on time- and frequency-domains analyzes. Thirty-four dogs with MMVD stage B1 or B2 and thirteen healthy dogs were recruited into the study. MMVD dogs were divided into 3 subgroups: control (n=13), sildenafil (n=12) and enalapril (n=9). HRV was analyzed from 1-hr Holter recording at baseline (D0) in all dogs and at 30, 90 and 180 days after treatment. The results showed that MMVD dogs had significant higher heart rate (HR), systemic blood pressures, the ratio of low to high frequency (LF/HF) and had significant decreased standard deviation of all normal to normal RR intervals (SDNN) and the percentage of the number of normal-to-normal sinus RR intervals with differences >50 msec computed over the entire recording (pNN50) when compared with healthy dogs (P<0.05). Neither time nor frequency domain parameters were different among subgroups of MMVD dogs at D0. After treatment with sildenafil for 90 days, both time- and frequency-domain parameters were significantly increased when compared with control and enalapril groups. This study demonstrated that sildenafil improves HRV in asymptomatic MMVD dogs suggesting that sildenafil should be used in the MMVD dogs to restore the sympathovagal balance.

Mitral Regurgitation and Increased Risk of All-Cause and Cardiovascular Mortality in Patients with Type 2 Diabetes

BACKGROUND

Mitral regurgitation is the most common heart valve disease in the general population, but little is known about the prevalence and prognostic implications of mitral regurgitation in patients with type 2 diabetes.

METHODS

We retrospectively analyzed the data from 814 outpatients with type 2 diabetes who had undergone a conventional echocardiography for clinical reasons during the years 1992-2007. Mitral regurgitation was evaluated by using an integrated multiparametric echocardiographic approach. The study outcomes were all-cause and cardiovascular mortality.

RESULTS

At baseline, 261 (32%) patients had mitral regurgitation (25% mild, 5% moderate, and 2% severe). Over a mean follow-up of 9 years, 120 (14%) patients died, 50 of them from cardiovascular causes. Compared with those without valve disease, patients with mild mitral regurgitation had a 3.3-fold increased risk of all-cause mortality, whereas those with moderate-to-severe mitral regurgitation had a 5.1-fold increased risk of all-cause mortality. Results remained statistically significant after adjustment for multiple potential confounders. Similar results were found for cardiovascular mortality.

CONCLUSIONS

Mitral regurgitation is a common pathologic condition in patients with type 2 diabetes and is independently associated with an increased risk of both all-cause and cardiovascular mortality, even if the severity of mitral regurgitation is mild.

Misconceptions and Facts About Mitral Regurgitation

Mitral regurgitation is a common heart valve disease. It is defined to be primary when it results from the pathology of the mitral valve apparatus itself and secondary when it is caused by distortion of the architecture or function of the left ventricle. Although the diagnosis and management of mitral regurgitation rely heavily on echocardiography, one should bear in mind the caveats and shortcomings of such an approach. Clinical decision making commonly focuses on the indications for surgery, but it is complex and mandates precise assessment of the mitral pathology, symptom status of the patient, and ventricular performance (right and left) among other descriptors. It is important for healthcare providers at all levels to be familiar with the clinical picture, diagnosis, disease course, and management of mitral regurgitation.

Clinical Use of Doppler Echocardiography in Organic Mitral Regurgitation: From Diagnosis to Patients' Management

Knowledge of mitral regurgitation (MR) is essential for any care provider, and not only for those directly involved in the management of cardiovascular diseases. This happens because MR is the most frequent valvular lesion in North America and the second most common form of valve disease requiring surgery in Europe. Furthermore, due to the ageing of the general population and the reduced mortality from acute cardiovascular events, the prevalence of MR is expected to increase further. Doppler echocardiography is essential both for the diagnosis and the clinical management of MR. In the present article, we sought to provide a practical step-by-step approach to help either performing a Doppler echocardiography or interpreting its findings in light of contemporary knowledge on organic (but not only) MR.

Real-time 3-dimensional dynamics of functional mitral regurgitation: a prospective quantitative and mechanistic study

Background

Three‐dimensional transthoracic echocardiography (3D‐TTE) with dedicated software permits quantification of mitral annulus dynamics and papillary muscle motion throughout the cardiac cycle.

Methods and Results

Mitral apparatus 3D‐TTE was acquired in controls (n=42), patients with left ventricle dysfunction and functional mitral regurgitation (LVD‐FMR; n=43) or without FMR (LVD‐noMR, n=35). Annulus in both normal and LVD‐noMR subjects displayed saddle shape accentuation in early‐systole (ratio of height to intercommissural diameter, 10.6±3.7 to 13.5±4.0 in normal and 9.1±4.3 to 12.6±3.6 in LVD‐noMR; P<0.001 for diastole to early‐systole motion, P=NS between those groups). In contrast, saddle shape was unchanged from diastole in FMR patients (10.0±6.4 to 8.0±5.2; P=NS, P<0.05 compared to both other groups). Papillary tips moved symmetrically towards to the midanterior annulus in control and LVD‐noMR subjects, maintaining constant ratio of the distances between both tips to midannulus (PtAR) throughout systole. In LVD‐FMR patients midsystolic posterior papillary tip to anterior annulus distance was increased, resulting in higher PtAR (P=0.05 compared to both other groups). Mechanisms of early‐ and midsystolic FMR differed between different etiologies of LV dysfunction. In patients with anterior MI and global dysfunction annular function and dilatation were the dominant parameters, while papillary muscle motion was the predominant determinant of FMR in patients with inferior MI.

Conclusions

Inadequate early‐systolic annular contraction and saddle‐shape accentuation in patients with impaired LV contribute to early–mitral incompetency. Asymmetric papillary tip movement towards the midanterior annulus is a major determinant of mid‐ and late‐systolic functional mitral regurgitation.

Dynamic Ischaemic Mitral Regurgitation and the Role of Stress Echocardiography

Objective:

This paper aims to explain the main mechanisms that cause ischaemic mitral regurgitation (MR), the pathophysiology, and the role played by stress echocardiography in the evaluation of the dynamic component of MR.

Introduction:

Chronic ischaemic MR is a frequent complication of myocardial infarction (MI), and is associated with a poor prognosis and outcome. The more the severity of ischaemic MR, the lower is the survival rate. In recent times, improvements in the management of the acute phase of MI, has increased the survival rate after MI. This, combined with an increase in the incidence of MI, will probably lead to a higher prevalence of ischemic MR in the next decades. As a consequence, ischaemic MR should be thoroughly understood and promptly identified. Furthermore, it is well recognized that ischaemic MR is dynamic. The best way to explore the dynamic nature of ischaemic MR is exercise stress echocardiography, and this test should probably be integrated in the evaluation and the management of patients with chronic ischaemic MR.

Conclusion:

Based on our experience, exercise stress echocardiography might be of interest in the following subsets of patients: 1) in patients with left ventricular (LV) dysfunction who present exertional dyspnea out of proportion to the severity of resting LV dysfunction or MR severity, 2) in patients in whom acute pulmonary oedema occurs without any obvious cause; 3) to unmask patients at high risk of mortality and heart failure 4) before surgical revascularization in patients with moderate ischaemic MR and, 5) following surgery, to identify persistence of pulmonary hypertension and explain the absence of functional class improvement.

Assessment and management of aortic valve disease in patients with left ventricular dysfunction

The onset of symptoms or left ventricular systolic dysfunction heralds a poor prognosis for patients with either aortic stenosis or aortic regurgitation. Echocardiography is the primary imaging modality for assessment of aortic valvular lesions. Cardiac catheterization is indicated to determine the severity of the aortic valve lesion when there is a discrepancy between the clinical findings and the results of echocardiography in patients with either symptoms or left ventricular dysfunction. For patients with low-gradient, low-output aortic stenosis, dobutamine provocation should be used to differentiate truly severe aortic stenosis from patients with a primary cardiomyopathy and low aortic valve area due to low forward flow. Aortic valve surgery improves myocardial performance by relief of ventricular afterload in both patients with severe stenosis and those with severe regurgitation. Surgery should be pursued in both patients with severe aortic stenosis and those with severe regurgitation regardless of the degree of left ventricular dysfunction.

Unilateral pulmonary edema: a rare initial presentation of cardiogenic shock due to acute myocardial infarction

Cardiogenic unilateral pulmonary edema (UPE) is a rare clinical entity that is often misdiagnosed at first. Most cases of cardiogenic UPE occur in the right upper lobe and are caused by severe mitral regurgitation (MR). We present an unusual case of right-sided UPE in a patient with cardiogenic shock due to acute myocardial infarction (AMI) without severe MR. The patient was successfully treated by percutaneous coronary intervention and medical therapy for heart failure. Follow-up chest Radiography showed complete resolution of the UPE. This case reminds us that AMI can present as UPE even in patients without severe MR or any preexisting pulmonary disease affecting the vasculature or parenchyma of the lung.

Mitral regurgitation: current trends in diagnosis and management

Mitral regurgitation is the most prevalent heart valve disorder in the United States. Individuals with mitral regurgitation may be asymptomatic or may present with dyspnea, orthopnea, fatigue, and/or heart rhythm disturbances. Long-standing mitral regurgitation causes chronic left ventricular volume overload, which leads to left ventricular dilation and contractile dysfunction. Without treatment, mitral regurgitation results in biventricular failure and death. Echocardiography is the preferred diagnostic test to assess the presence and severity of mitral regurgitation. Mitral valve surgery, the only effective treatment for patients with severe mitral regurgitation, is recommended early in the course of the disease to prevent the development of heart failure. Early recognition of mitral regurgitation and timely referral for mitral valve surgery significantly improve symptoms and long-term survival.

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.

Prevalence, characteristics, and outcomes of patients presenting with cardiogenic unilateral pulmonary edema

BACKGROUND

Cardiogenic unilateral pulmonary edema (UPE) is a rare entity, frequently leading to initial misdiagnosis. We sought to assess the prevalence of UPE and to determine its impact on prognosis compared with bilateral pulmonary edema.

METHODS AND RESULTS

We studied the characteristics and outcomes of patients admitted to our institution for cardiogenic pulmonary edema during an 8-year period. The study population included 869 consecutive patients. The prevalence of UPE was 2.1%: 16 right-sided UPE (89%) and 2 left-sided UPE (11%). In patients with UPE, blood pressure was significantly lower (P≤0.01), whereas noninvasive or invasive ventilation and catecholamines were used more frequently (P=0.0004 and P<0.0001, respectively). The prevalence of severe mitral regurgitation in patients with bilateral pulmonary edema and UPE was 6% and 100%, respectively (P<0.0001). In patients with UPE, use of antibiotic therapy and delay in treatment were significantly higher (P<0.0001 and P=0.003, respectively). In-hospital mortality was 9%: 39% for UPE versus 8% for bilateral pulmonary edema (odds ratio, 6.9; 95% confidence interval, 2.6 to 18; P<0.001). In multivariate analysis, unilateral location of pulmonary edema was independently related to death whatever the model used (adjusted odds ratio, 6.5; 95% confidence interval, 1.3 to 32; P=0.021 for model A; and adjusted odds ratio, 6.8; 95% confidence interval, 1.1 to 41; P=0.037 for model B).

CONCLUSIONS

Unilateral pulmonary edema represented 2.1% of cardiogenic pulmonary edema in our study, usually appeared as an opacity involving the right lung, and was always associated with severe mitral regurgitation. Unilateral pulmonary edema is related to an independent increased risk of mortality and should be promptly recognized to avoid delays in treatment.

Mitral valve regurgitation and 3D echocardiography

The mitral valve is a complex, dynamic and functional apparatus that can be altered by a wide range of disorders leading to stenosis or regurgitation. Surgical management of mitral valve disease may be difficult. Planned intervention may not always be feasible when the surgeon is faced with complex pathology that cannot be assessed fully by conventional 2D echocardiography. Transthoracic and transesophageal 3D echocardiography can provide a more reliable functional and anatomical assessment of the different valve components and evaluation of its geometry, which can aid the surgeon in planning a more suitable surgical intervention and improve outcomes. Although 3D echocardiography is a new technology, it has proven to be an important modality for the accurate assessment of valvular heart disease and in the future, it promises to be an essential part in the routine assessment of cardiovascular patients.

Samuel A. Levine and the history of grading systolic murmurs

Murmurs were described first by Laennec in 1819, after which the significance of a murmur became a matter of debate. By the late 19th century, many physicians regarded systolic murmurs as "organic," whereas others believed that they were often "functional." Samuel Levine became a central figure in separating functional from organic systolic murmurs. Freeman and Levine's 1933 study of 1,000 "noncardiac" subjects determined the frequency, cause, and significance of systolic murmurs. Murmurs were rated on a scale of 1 to 6 grades of intensity. Approximately 20% of their patients had grade 1 or 2 systolic murmurs. Hypertension, fever, tachycardia, and anemia were common factors, and the murmurs were considered functional because they would often disappear when these causes were controlled. Of 19 subjects with grade 3 or 4 murmurs, all were determined to have organic heart disease or anemia. Thus, louder systolic murmurs were found to be a significant finding, as were the cause, location, and effects of posture. They concluded that systolic murmurs often have an explanation and that their grade can be useful in the diagnosis and prognosis. They cautioned that a loud systolic murmur did not necessarily indicate a bad prognosis or even serious heart disease. Levine's system of grading a systolic murmur is valuable and persists into the 21st century.

[Postoperative acute mitral regurgitation. Unexpected finding after minor non-cardiac surgery]

This report describes the case of a 59-year-old man who was scheduled for general anesthesia with propofol, sufentanil and sevoflurane for removal of a metal implant. The patient was classified as American Society of Anesthesiologists (ASA) II status because of an asymptomatic mitral valve prolapse and medically treated arterial hypertension. During induction of narcosis a pulsoxymetrically measured inadequate increase in oxygen saturation after preoxygenation was noticed and a moderate respiratory obstruction occurred intraoperatively, but anesthesia was uneventfully completed and the patient was extubated. However, 3 h later the patient developed severe dyspnea, hypoxia, tachycardia and arterial hypotension. Physical examination revealed a new grade 4/6 systolic murmur radiating to the axilla and X-ray showed bilateral pulmonary edema. Neither electrocardiographic nor biochemical manifestations of acute myocardial infarction were identified but transthoracic echocardiography revealed fluttering of the posterior leaflet of the mitral valve with grade III regurgitation and dilation of the left atrium. Coronary angiography was normal and left ventriculography confirmed severe mitral regurgitation. Mitral valve repair was successfully performed 22 h after presentation of symptoms. Mitral regurgitation is a common finding on echocardiography, seen to some degree in over 75% of the population. The etiology of mitral valve insufficiency which can be caused by pathologic changes of one or more of the components of the mitral valve, including the leaflets, annulus, chordae tendineae, papillary muscles, or by abnormalities of the surrounding left ventricle and/or atrium are discussed. Rupture of mitral chordae tendineae is infrequent and causes acute hemodynamic deterioration and needs corrective surgery. Valve replacement should be performed only if mitral valve repair is not possible. Echocardiography is an invaluable tool in determining the severity of regurgitation, the integrity of the mitral valve apparatus, the extent of left ventricular enlargement, and the ejection fraction. Acute mitral valve regurgitation caused by a rupture of chordae tendineae should be considered in the differential diagnosis of perioperative acute pulmonary edema.

[Ischemic mitral regurgitation: contributions of exercise echocardiography and new therapeutic perspectives]

The ischemic mitral regurgitation is defined by a left ventricular muscle disease affecting the function of normal mitral valve leaflets. This kind of mitral regurgitation is founded in about 20% of the ischemic cardiomyopathy and is attributed to the remodelling of the left ventricular shape. Its development is associated to a significantly worse prognosis. Frequently this ischemic mitral regurgitation will be associated to episode of acute heart failure decompensation. Its diagnosis is sometimes challenging as the degree of regurgitation might be extremely variable and affected by loading conditions. Echocardiography and especially exercise stress echocardiography has been demonstrated as an extremely powerful tool for its diagnosis and the prognostic evaluation. Its treatment should include the pharmacological treatment of the chonic heart failure and we are still waiting data in regard to the prognostic role of surgical mitral valvuloplastie. Works are still ongoing.

High Prevalence of Clinically Silent Severe Mitral Regurgitation in Patients with Heart Failure: Role for Echocardiography

Mitral regurgitation (MR) is common in patients with congestive heart failure (CHF) and has adverse effects on prognosis. In view of the altered hemodynamics in CHF, we examined the accuracy of auscultation for its detection in CHF with reduced systolic function. We examined 370 patients on stable heart failure therapy enrolled in our CHF clinic, if they had a physical examination by one of the two senior cardiologists and an echocardiogram within 2 weeks after the physical examination. The MR murmur was graded 0 to 6 on physical examination. MR was graded 0 to 4 on echocardiography using standard echocardiographic criteria. The left ventricular (LV) ejection fraction was 21 +/- 12% and age was 65 +/- 15 years. By echocardiography MR was present in 345 patients (94%), being 1+ in 162 (44%), 2+ in 80 (22%), 3+ in 54 (15%), and 4+ in 51 (14%). The frequency of an audible MR murmur by physical examination was 4% in 1+ MR, 11% in 2+ MR, 13% in 3+ MR, and 37% in 4+ MR. The audibility of MR murmur was not related to age, sex, body size, LV size, ejection fraction, or left atrial size. In conclusion, grade 3 or 4+ MR is present in one third of patients with CHF and reduced ejection fraction, and is inaudible in three quarters of them by physical examination. Echocardiography is needed for its detection. Audibility of MR murmur cannot be predicted by body size, LV size, or LV function in these patients.

Valvular heart diseases

Patients who have valvular heart disease coming for surgery present many challenges to the anesthesiologist. Over the past 3 decades there has been a persistent improvement in our understanding of the pathophysiology of valvular heart disease and in the surgical techniques for correcting it. With the development of efficient and safe noninvasive monitoring of cardiac function, new surgical techniques, better designs of prosthetic valves, and the development of useful guidelines for choosing the proper timing of surgical intervention, patients who have valvular disease with varying physiology can be encountered in the perioperative period. The perioperative physician has to be aware of the varying effects of hemodynamic variables on this subpopulation of patients.

Chronic Development of Ischaemic Mitral Regurgitation during Post-Infarction Remodelling

BACKGROUND/AIMS

Mitral regurgitation (MR) following myocardial infarction (MI) may be a (sub)acute complication which independently predicts reduced survival. We sought to evaluate the chronic development of MR as potential consequence of left-ventricular (LV) remodelling, the latter being a long-term process.

METHODS AND RESULTS

Retrospectively, 103 post-MI patients were included according to a standardised Doppler echocardiogram <3 months following MI (20 +/- 25 days post-MI) and a follow-up examination >6 months after the first examination (5.1 +/- 3.1 years post-MI). Patients were clinically followed up for 7.6 +/- 2.7 years. Group I patients were defined as those showing new development or deterioration in one of three grades of MR, and group II those without this criterion (MR grade acute 0.17 vs. 0.27, p = 0.7, and chronic 1.53 vs. 0.19, p < 0.0001). Patient characteristics were similar in respect of age, gender, size and location of infarction. However, group I patients had coronary artery disease with more vessels involved. With regard to echocardiographic parameters of significantly enlarged LV chamber size in group I vs. group II, the significant decrease in LV performance was more pronounced and occurred concomitant with a higher degree of symptomatic congestive heart failure and greater need for heart failure medications in group I. Mortality in group I patients was 39 versus 9% in group II patients (p = 0.0002), approximating an odds ratio of 6.4697 (95% confidence interval: 2.211-18.931).

CONCLUSION

First of all, this retrospective study indicates that MR may be detected in patients after MI during a long-term follow-up most probably due to geometric distortions of LV remodelling resulting in a significantly higher mortality. Since this process is known to become irreversible at a certain point, serial echocardiography may help to detect MR in post-MI patients and thus pave the way for appropriate treatment.

Mitral regurgitation after myocardial infarction: a review

Mitral regurgitation after myocardial infarction is the result of multifactorial processes involving local and global left ventricular remodeling. The prevalence of mitral regurgitation varies from 11% to 59%. Published studies differ greatly in design, inclusion criteria, duration of follow-up, and technique of mitral regurgitation assessment. However, they consistently indicate that mitral regurgitation after myocardial infarction carries an adverse prognosis with increased risk of death and heart failure independently of previously known indicators of risk after myocardial infarction. Mitral regurgitation is often clinically silent; therefore, it should be systematically evaluated by echocardiography. Standard color Doppler imaging is a highly sensitive method to detect even mild degrees of ischemic mitral regurgitation. One unique advantage of echocardiography is that it accurately quantifies the severity of mitral regurgitation by measuring the effective regurgitant orifice area and the regurgitant volume using Doppler methodology. Therefore, the evaluation should include precise quantification of the degree of mitral regurgitation to best appraise the ensuing risk. Current medical options rely chiefly on angiotensin converting enzyme-inhibitors and beta-blocker therapy, and surgical approaches offer future promise. Both categories of therapeutic approaches should be evaluated by randomized controlled trials.

Cardiac murmurs: echocardiography in the assessment of patients requiring antibiotic prophylaxis for dental treatment

BACKGROUND

Traditionally patients who indicate that they have a heart murmur or who indicate that they have had rheumatic fever are given antibiotic prophylaxis for dental treatment. This is commonly done without further assessment of the patient's actual endocarditis risk. Echocardiography is a non-invasive method of assessing cardiac valve function and haemodynamics.

METHODS

Consecutive patients who were referred to a private practice oral and maxillofacial surgeon for dentoalveolar surgery and indicated that they had a cardiac problem and usually had antibiotic prophylaxis, were evaluated. Those with a clear indication for prophylaxis, for example had prosthetic heart valves or previous infective endocarditis, received antibiotic prophylaxis. Where there was uncertainty, they were referred for an echocardiogram, and if abnormal, a formal cardiology review.

RESULTS

Three hundred and seventy patients out of approximately 20 000 (1.85 per cent) indicated that they had a cardiac murmur and usually received antibiotic prophylaxis for dental treatment between 1 February 1997 and 1 February 2005. Two hundred and sixty-two (71 per cent) were female and 108 (29 per cent) were male; age range 0.7 to 98 years, average 37.6 years. Two hundred and seventy (72 per cent) had normal hearts with no indication for antibiotic prophylaxis. Of the 100 (28 per cent) patients with abnormal findings, they were on average older; 49.5 years, range 0.7 to 87 years. Of these, 50 (14 per cent) met current indications for antibiotic prophylaxis.

CONCLUSION

Patients who present for dental treatment indicating that they require antibiotic prophylaxis for cardiac condition need to be fully evaluated. In this study only 50 of 370 patients (14 per cent) required antibiotic prophylaxis. The remaining 320 (86 per cent) would have no benefit but a risk of adverse reaction to the antibiotic.

Long-term outcome of patients with heart failure and dynamic functional mitral regurgitation

AIMS

In patients with heart failure and chronic ischaemic mitral regurgitation (MR), the mortality risk is related to the quantified severity of MR at rest and its dynamic changes during exercise. The impact of dynamic MR on long-term mortality, hospital admission for heart failure, and major adverse cardiac events has never been investigated.

METHODS AND RESULTS

We prospectively studied 161 patients with chronic ischaemic left ventricular (LV) dysfunction and at least mild MR who underwent quantitative measurement of the effective regurgitant orifice (ERO) of MR at rest and during semi-supine exercise test and who were followed up for 35+/-11 months. The 20 patients who underwent surgery were censored at the time of operation. Of the 141 patients who were treated medically, 23 died, 22 required hospitalization for heart failure, 4 had nonfatal myocardial infarction, and 11 developed unstable angina. By multivariate analysis, an exercise-induced increase in ERO by > or =13 mm(2) and a greater increase in transtricuspid pressure gradient during exercise emerged as predictors of mortality and of hospital admission for heart failure. MR severity under basal conditions (ERO> or =20 mm(2)) was an independent predictor of only cardiac death. Greater LV volumes at rest and lack of contractile reserve during exercise were additional independent markers of poor outcome.

CONCLUSION

In patients with ischaemic heart disease and LV dysfunction, large exercise-induced increases in MR identify patients at high risk of morbidity and of death.

Contribution of ischemic mitral regurgitation to congestive heart failure after myocardial infarction

OBJECTIVES

The purpose of this study was to define the contribution of ischemic mitral regurgitation (IMR) to the occurrence of congestive heart failure (CHF) after myocardial infarction (MI).

BACKGROUND

After MI, CHF is a frequent and serious complication, but its determinants and, particularly, the role of IMR are poorly defined.

METHODS

We analyzed 173 asymptomatic patients with previous Q-wave MI (>16 days) with echocardiographic quantitation of IMR (measuring effective regurgitant orifice [ERO] and regurgitant volume). The 102 patients with IMR were matched to 71 patients without IMR for age (71 +/- 11 years vs. 68 +/- 9 years; p = 0.11), gender (76% vs. 82% males; p = 0.41), and left ventricular ejection fraction (EF) (37 +/- 14% vs. 36 +/- 11%; p = 0.92).

RESULTS

Five-year rates of CHF and of CHF or cardiac death (CD) were 36 +/- 5% and 52 +/- 5%, respectively. Independent determinants of CHF were EF, sodium plasma level, and presence and degree of IMR (p < 0.0001). Five-year CHF rates were 18 +/- 5% without mitral regurgitation (MR), 53 +/- 7% with IMR, 46 +/- 9% with ERO 1 to 19 mm(2) and 68 +/- 12% with ERO > or =20 mm(2) (all p < 0.0001). The adjusted relative risk of CHF was 3.65 (95% confidence interval [CI] 1.86 to 7.75) for IMR presence and 4.42 (95% CI 1.9 to 10.5) for ERO > or =20 mm(2). The adjusted relative risk of CHF/CD was 2.97 (95% CI 1.77 to 5.16) for IMR presence and 4.4 (95% CI 2.4 to 8.2) for ERO > or =20 mm(2).

CONCLUSIONS

After MI, incidence of CHF and of CHF/CD are high even in patients with no or minimal symptoms at baseline and are higher in patients with IMR. Congestive heart failure is independently determined by larger ERO of IMR. These data suggest that detecting and quantifying IMR is essential for risk stratification after MI. Value of IMR treatment in improving post-MI outcome should be investigated.

Heart failure and death after myocardial infarction in the community: the emerging role of mitral regurgitation

BACKGROUND

In case series, mitral regurgitation (MR) increased the risk of death after myocardial infarction (MI), yet the prevalence of MR, its incremental prognostic value over ejection fraction (EF), and its association with heart failure and death after MI in the community is not known.

METHODS AND RESULTS

The prevalence of MR and its association with heart failure and death were examined among 1331 patients within a geographically defined MI incidence cohort between 1988 and 1998. Echocardiography was performed within 30 days after MI in 773 patients (58%), and MR was present in 50% of cases, mild in 38%, and moderate or severe in 12%. Among patients with MR, a murmur was inconsistently detected clinically. After 4.7+/-3.3 years of follow-up, 109 episodes of heart failure and 335 deaths occurred. There was a graded positive association between the presence and severity of MR and heart failure or death. Moderate or severe MR was associated with a large increase in the risk of heart failure (relative risk 3.44, 95% CI 1.74 to 6.82, P<0.001) and death (relative risk 1.55, 95% CI 1.08 to 2.22, P=0.019) among 30-day survivors independent of age, gender, EF, and Killip class.

CONCLUSIONS

In the community, MR is frequent and often silent after MI. It carries information to predict heart failure or death among 30-day survivors independently of age, gender, EF, and Killip class. These findings, which are applicable to a large community-based MI cohort, suggest that the assessment of MR should be included in post-MI risk stratification.

[Determinants and prognosis of ischemic mitral regurgitation]

Ischemic mitral regurgitation (IMR) is mitral regurgitation (MR) due to complications of coronary artery disease. Two mechanisms can be individualized. Acute MR secondary to ruptured papillary muscle is a rare but often fatal complication of myocardial infarction. We focus on functional MR, much more common, which occurs without any intrinsic valve disease. It was often underrated because of low murmur intensity but is observed between 15 and 20% after a myocardial infarction. The presence and degree of the regurgitation are related to local left ventricular remodeling. The apical and posterior displacement of papillary muscles leads to excess valvular tenting which in turn, in association with loss of systolic annular contraction, determines the severity of the regurgitation. IMR presence is associated with an excess mortality. The mortality risk is directly related to the degree of the regurgitation and a regurgitant volume > or = 30 ml or an effective regurgitant orifice > or = 20 mm2 define a high-risk group. In current clinical practice, IMR is mainly corrected with ring annuloplasty. However, this technique does not correct local alterations of left ventricular remodeling and its benefits on long-term outcome remains to be demonstrated.

Left ventricular remodeling and functional mitral regurgitation: mechanisms and therapy

Myocardial damage that results in dysfunction and remodeling changes left ventricular shape and size. Mitral competence requires the functional integrity of all components of the mitral apparatus. Progressive remodeling ultimately leads to geometric distortion of multiple elements of the mitral apparatus, resulting in functional mitral regurgitation (MR). In this article, we examine the mechanisms of functional MR in the remodeled ventricle. Surgical treatment should aim to correct all abnormalities of the mitral apparatus. These include (1) revascularization of viable myocardium, (2) reduction of ventricular volume and restoration of shape, (3) realignment of papillary muscles, and (4) reduction of annular orifice size.