The prevalence of ruptured chordae tendineae in the mitral valve prolapse syndrome

Vertebral osteomyelitis secondary to infective endocarditis detected by repeated magnetic resonance imaging: a case report

Background

Patients with infective endocarditis (IE) experience various symptoms, a major one being back pain, which is occasionally caused by concomitant vertebral osteomyelitis (VO). Magnetic resonance imaging (MRI) is generally used to detect VO; however, the sensitivity of detection using MRI is very low in the early stages of VO.

Case summary

A 60-year-old man visited our hospital with complaints of fever and persistent back pain over the past 7 days. A holosystolic heart murmur was auscultated, and an echocardiography revealed a vegetation on the posterior mitral leaflet. Blood cultures were positive for Streptococcus sanguinis. He was diagnosed with IE and treated with antimicrobials. A lumbar spine MRI on Day 1 showed no clear signs of vertebral infection, but the back pain continued and gradually worsened. Magnetic resonance imaging retest on Day 8 showed high signal intensity within the lumbar vertebral bodies and the disk on T2-weighted sequences, indicating VO. Intravenous antimicrobial therapy was extended, followed by oral antimicrobials, and a corset was put on to protect the lumbar spine to prevent bone degradation.

Discussion

For persistent back pain in IE patients, repeat MRIs at regular intervals of time can detect possible vertebral infection even if signs of vertebral infection were absent on the initial MRI.

Back to Basics: Key Physical Examinations and Theories in Patients with Heart Failure

Heart failure (HF) is a leading cause of hospitalization. Suitable pharmacologic management is critical. Distinct physical findings such as congestion and peripheral hypoperfusion need to be considered in selecting pharmacologic therapy. By applying the pretest probability and likelihood ratios of unique physical findings of HF to a Markov model, a definite posttest probability can be obtained. This article focuses on the findings of S3, jugular venous pressure, proportional pulse pressure, bendopnea, trepopnea, and various heart murmurs. Incorporating statistical precision in physical assessments, diagnoses of HF can be further refined, providing a sophisticated approach to evaluate patients hemodynamics status noninvasively.

Fluid-Structure Interaction Analysis of Ruptured Mitral Chordae Tendineae

The chordal structure is a part of mitral valve geometry that has been commonly neglected or simplified in computational modeling due to its complexity. However, these simplifications cannot be used when investigating the roles of individual chordae tendineae in mitral valve closure. For the first time, advancements in imaging, computational techniques, and hardware technology make it possible to create models of the mitral valve without simplifications to its complex geometry, and to quickly run validated computer simulations that more realistically capture its function. Such simulations can then be used for a detailed analysis of chordae-related diseases. In this work, a comprehensive model of a subject-specific mitral valve with detailed chordal structure is used to analyze the distinct role played by individual chordae in closure of the mitral valve leaflets. Mitral closure was simulated for 51 possible chordal rupture points. Resultant regurgitant orifice area and strain change in the chordae at the papillary muscle tips were then calculated to examine the role of each ruptured chorda in the mitral valve closure. For certain subclassifications of chordae, regurgitant orifice area was found to trend positively with ruptured chordal diameter, and strain changes correlated negatively with regurgitant orifice area. Further advancements in clinical imaging modalities, coupled with the next generation of computational techniques will enable more physiologically realistic simulations.

Morphological and mechanical properties of the posterior leaflet chordae tendineae in the mitral valve

A number of studies have investigated the morphological and mechanical properties of the chordae tendineae of the mitral valve, providing comparisons between basal, marginal, and strut chordae and between chordae at the anterior and posterior leaflets. This study contributes to the literature by comparing the failure load of the chordae tendineae attached to the three posterior leaflet scallops, the anterolateral scallop (P1), middle scallop (P2), and posteromedial scallop (P3) of the mitral valve. In all, 140 chordae isolated from 23 porcine hearts were tested. First, the cross-sectional diameters of all branches in each chorda were measured using a microscope. Next, after positioning the chorda in a tensile testing machine, a preload of 0.2 N was applied, and the chordal length was measured. Cyclic loading between 0 and 0.3 N, 10 times with a speed of 1.5 mm/s, was conducted, after which the machine travelled at 1.5 mm/s until the chorda broke. We found that P2 chordae were thicker than P1 and P3 chordae and longer than P1 chordae. P2 chordae failed at significantly higher loads than P1 and P3 chordae. For all three types of chordae, almost half of the failures occurred at the chordal branch that was closest to the leaflet.

Gross and histological features of excised portions of posterior mitral leaflet in patients having operative repair of mitral valve prolapse and comments on the concept of missing (= ruptured) chordae tendineae

OBJECTIVES

The aim of the study is to describe gross and histological features of operatively excised portions of mitral valves in patients with mitral valve prolapse (MVP).

BACKGROUND

Although numerous articles on MVP (myxomatous or myxoid degeneration, billowing or floppy mitral valve) have appeared, 2 virtually constant histological features have been underemphasized or overlooked: 1) the presence of superimposed fibrous tissue on both surfaces of the leaflets and surrounding many chordae tendineae; and 2) the absence of many chordae tendineae on the ventricular surfaces of the leaflets as the result of their being hidden (i.e., covered up) by the superimposed fibrous tissue.

METHODS

We examined operatively excised portions of prolapsed posterior mitral leaflets in 37 patients having operative repair.

RESULTS

Histological study of elastic-tissue stained sections disclosed that the leaflet thickening was primarily due to the superimposed fibrous tissue. All leaflets had variable increases in the spongiosa element within the leaflet itself with some disruption and/or loss of the fibrosa element and occasionally complete separation of it from the spongiosa element. Both the leaflet and chordae were separated from the superimposed fibrous tissue by their black-staining elastic membranes.

CONCLUSIONS

These findings demonstrate that the posterior leaflet thickening in MVP is mainly due to the superimposed fibrous tissue rather than to an increased volume of the spongiosa element of the leaflet itself. The superimposed fibrous tissue on both leaflet and chordae is likely the result of subsequent abnormal contact of the leaflets and chordae with one another. Chordal rupture (i.e., missing chordae) occurred in all 37 patients, but finding individual ruptured chords was rare.

Echocardiographic assessment of canine degenerative mitral valve disease

Degenerative mitral valve disease (MVD), the most common acquired heart disease in small-sized dogs, is characterized by valvular degeneration resulting in systolic mitral valve regurgitation (MR). Worsening of MR leads to several combined complications including cardiac remodeling, increased left ventricular filling pressure, pulmonary arterial hypertension, and myocardial dysfunction. Conventional two-dimensional, M-mode, and Doppler examination plays a critical role in the initial and longitudinal assessment of dogs affected by MVD, providing information on mitral valve anatomy, MR severity, left ventricular (LV) size and function, as well as cardiac and vascular pressures. Several standard echocardiographic variables have been shown to be related to clinical outcome. Some of these markers (e.g., left atrium to aorta ratio, regurgitation fraction, pulmonary arterial pressure) may also help in identifying asymptomatic MVD dogs at higher risk of early decompensation, which remains a major issue in practice. However, both afterload and preload are altered during the disease course. This represents a limitation of conventional techniques to accurately assess myocardial function, as most corresponding variables are load-dependent. Recent ultrasound techniques including tissue Doppler imaging, strain and strain rate imaging, and speckle tracking echocardiography, provide new parameters to assess regional and global myocardial performance (e.g., myocardial velocities and gradients, deformation and rate of deformation, and mechanical synchrony). As illustration, the authors present new data obtained from a population of 91 dogs (74 MVD dogs, 17 age-matched controls) using strain imaging, and showing a significant longitudinal systolic alteration at the latest MVD heart failure stage.

Surgical pathology and etiology of 278 surgically removed mitral valves with pure regurgitation in Thailand

INTRODUCTION

There are multiple causes of mitral regurgitation. Its etiology includes floppy valve, postinflammatory disease, infective endocarditis, and other disorders. Recently, there has been an increased tendency to remove only portions of the mitral valve, causing difficulty in the determination of etiology. Our objective was to study the pathology and etiology of mitral regurgitation from surgically removed specimens.

METHODS

Native mitral valve specimens surgically excised due to mitral insufficiency were examined. Etiology was determined according to macroscopic, microscopic, clinical, and operative findings.

RESULTS

Among 278 mitral valve specimens, 43% were classified as floppy valve, 31% as postinflammatory disease (presumably associated with rheumatic fever), 12% as infective endocarditis, and 14% as miscellaneous group. In floppy valves, diffuse myxoid change and chordal rupture were the main findings. In postinflammatory disease, moderate neovascularization and chronic inflammatory cell infiltration were most commonly found. Aschoff bodies were found in two cases. In infective endocarditis, gram-positive cocci were found in 70% of cases. In the miscellaneous group, three cases were related to Marfan syndrome and one case was related to papillary muscle necrosis. In comparison with postinflammatory disease, the posterior leaflet in the floppy valve had a significantly longer basal free-edge length, a more frequent chordal rupture, and an higher mean age of patients. Among completely and partially excised specimens with postinflammatory disease, there were no significant differences in microscopic findings.

CONCLUSION

The three most common etiologies in mitral regurgitation were floppy valve, postinflammatory disease, and infective endocarditis. Macroscopic, microscopic, clinical, and operative findings are important in the evaluation of etiology, especially in partially excised specimens.

Biomechanical and echocardiographic characterization of flail mitral leaflet due to myxomatous disease: further evidence for early surgical intervention

BACKGROUND

Flail mitral leaflet (FML) is a common complication of mitral valve prolapse, often leading to severe mitral regurgitation (MR) and left ventricular dysfunction. In the absence of timely surgical correction, survival is significantly impaired. Early recognition of FML and identification of risk factors is important because early intervention increases the chances of survival.

METHODS

We studied 123 patients undergoing mitral valve surgery for severe MR caused by myxomatous disease. Chart review, echocardiography, and tensile testing were performed.

RESULTS

Thirty-eight patients had FML, and 85 patients had non-flail mitral leaflet (non-FML). Patients with FML were younger (53.7 +/- 1.8 vs 59.3 +/- 1.4 years, P =.02), had more severe MR (3.89 +/- 0.04 vs 3.76 +/- 0.04, P =.02), were less likely to be in New York Heart Association class III or IV heart failure (5% vs 20%, P =.037), and were less likely to have bileaflet mitral valve prolapse (5% vs 38%, P <.001) than non-FML patients. Valve tissue from patients with FML had less stiff chordae (23.5 +/- 3.6 vs 59.1 +/- 11.7 Mpa, P =.006) that tended to have a lower failure stress (3.8 +/- 0.9 vs 9.6 +/- 2.2 Mpa, P =.07) and had more extensible leaflets (56.4% +/- 7.9% vs 42.9% +/- 2.7% strain, P =.04) compared with that of non-FML patients.

CONCLUSIONS

The development of FML may result from intrinsic tissue abnormalities and is associated with a distinct subset of the myxomatous population. Identification of such clinical characteristics in this population and knowledge of an implicit mechanical abnormality of valve tissue may further the argument for early surgical correction.

Mitral valve prolapse, panic disorder, and chest pain

Mitral valve prolapse is a common cardiac disorder that can readily be diagnosed by characteristic auscultatory and echocardiographic criteria. Although many diseases have been associated with mitral valve prolapse, most affected individuals have the primary form of the disorder. Mitral valve prolapse is an inherited condition commonly associated with myxomatous degeneration of the mitral valve and its support structures. Complications of mitral valve prolapse, including cardiac arrhythmias, sudden death, infective endocarditis, severe mitral regurgitation (with or without chordae tendineae rupture), and cerebral ischemic events, occur infrequently considering the wide prevalence of the disorder. Panic disorder is a specific type of anxiety disorder characterized by at least three panic attacks within a 3-week period or one panic attack followed by fear of subsequent panic attacks for at least 1 month. It too is a common condition with a prevalence and age and gender distribution similar to that of mitral valve prolapse. Panic disorder and mitral valve prolapse share many nonspecific symptoms, including chest pain or discomfort, palpitations, dyspnea, effort intolerance, and pre-syncope. Chest pain is the symptom in both conditions that most commonly brings the patient to medical attention. The clinical description of chest pain in patients with mitral valve prolapse is highly variable, possibly reflecting multiple etiologies. Chest pain in panic disorder is usually characterized as atypical angina pectoris and as such bears resemblance to the chest pain commonly described by patients with mitral valve prolapse. Multiple investigative attempts to elucidate the mechanism of chest pain in both conditions have failed to identify a unifying cause. Review of the literature leaves little doubt that mitral valve prolapse and panic disorder frequently co-occur. Given the similarities in their symptomatology, a high rate of co-occurrence is, in fact, entirely predictable. There is, however, no convincing evidence of a cause-effect relationship between the two disorders, nor has a single pathophysiologic or biochemical mechanism been identified that unites these two common conditions. Until specific biologic markers for these disorders are identified, it may be impossible to do so. The lack of a proven cause-and-effect relationship between mitral valve prolapse and panic disorder and the absence of a unifying mechanism do not diminish the clinical significance of the high rate of co-occurrence between the two conditions. Primary care physicians and cardiologists frequently encounter patients with mitral valve prolapse and nonspecific symptoms with no discernible objective cause who fail to respond to beta-blockade. Panic disorder should be considered as a possible explanation for symptoms in such patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Value of acceleration flows and regurgitant jet direction by color Doppler flow mapping in the evaluation of mitral valve prolapse

To clarify the role of color Doppler echocardiography in the evaluation of mitral valve prolapse, we studied 49 consecutive patients in whom the sites of mitral valve prolapse were confirmed at the time of operation. The study group consisted of 22 patients with anterior leaflet prolapse, 24 patients with posterior leaflet prolapse, and three patients with multiple scallop prolapse (one patient with both anterior leaflet and middle scallop prolapse, and two patients with both medial and lateral scallop prolapse). Two-dimensional echocardiographic diagnosis of anterior leaflet prolapse was correct in all patients. The diagnosis of posterior leaflet prolapse by two-dimensional echocardiography, however, was mistaken as anterior leaflet prolapse in 16 (13 patients with medial scallop prolapse and three patients with lateral scallop prolapse) of the 24 patients according to current diagnostic criteria for mitral valve prolapse. Eight patients with middle scallop prolapse were diagnosed correctly by two-dimensional echocardiography. Acceleration flows in the left ventricle were observed by color Doppler echocardiography in all 49 patients. The sites of acceleration flows detected by color Doppler echocardiography coincided with those of prolapse confirmed in all at the time of operation. There was a significant correlation between the maximum area of acceleration flow signals and severity of mitral regurgitation estimated by angiography. In the 13 patients with medial scallop prolapse and the three patients with lateral scallop prolapse, a regurgitant jet originated from a bulged portion of the posterior leaflet and was directed toward the opposite left atrial cavity to the bulged portion by short-axis images of color Doppler echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Mitral valve prolapse

Mitral valve prolapse is a common mitral valve disorder manifested clinically as a midsystolic click and/or a late systolic murmur (the click-murmur syndrome) and pathologically as billowing or prolapsing mitral leaflets (the floppy valve syndrome). Not only is it one of the two most common congenital heart diseases and the most common valve disorder diagnosed in the United States, but it is also prevalent throughout the world. Mitral valve prolapse may be associated with a variety of other conditions or diseases. Diagnosis of mitral valve prolapse should be made on clinical grounds and, if necessary, supported by echocardiography. The majority of patients with mitral valve prolapse suffer no serious sequelae. However, major complications such as disabling angina-like chest pains, progressive mitral regurgitation, infective endocarditis, thromboembolism, serious arrhythmias, and sudden death may occur. Unless these serious complications occur, most of the patients with mitral valve prolapse need no treatment other than reassurance, including those with atypical chest pain or palpitation unconfirmed by objective data. Therapy with a beta-blocker for disabling chest pain and/or arrhythmias and antiplatelet therapy for cerebral embolic events may be indicated. In occasional patients with significant mitral regurgitation surgery may be necessary.

Acute rupture of myxomatous mitral valve presenting as refractory cardiopulmonary arrest

A 59 year old white woman had an out of hospital sudden cardiac arrest. Resuscitation at the scene restored spontaneous pulse, blood pressure and respiration but cardiovascular collapse recurred within 30 minutes of hospital arrival. Medically refractory cardiogenic shock of unclear origin prompted the placement of an intraaortic balloon pump, and hemodynamic stabilization was achieved over several hours. Acute rupture of the chordae tendineae of myxomatous mitral valve was diagnosed as the cause of the cardiac arrest. Mitral valve replacement was performed and the patient made an uneventful recovery. This report describes the first known case of rupture of a myxomatous mitral valve presenting as sudden cardiac death. The differential diagnosis of sudden death in this disorder is reviewed, the role of mechanical circulatory assistance in refractory cardiac arrest is discussed and several interesting hemodynamic aspects of the case are considered.

Surgical pathology of the mitral valve: a study of 712 cases spanning 21 years

The gross surgical pathologic features of the mitral valve were reviewed in 712 patients who had undergone mitral valve replacement at our institution during 1965, 1970, 1975, 1980, and 1985. Among the 452 cases of mitral stenosis, either with or without mitral insufficiency, 99% were attributable to postinflammatory disease and 1% were related to congenital mitral stenosis. Among the 260 cases of pure mitral regurgitation, the two most common causes were a floppy valve (38%) and postinflammatory disease (31%). Moreover, a floppy valve was observed in 73% of the 59 examples of chordal rupture and in 38% of the 16 cases of infective endocarditis. Women accounted for 73% of the 452 cases of mitral stenosis and for 72% of the 530 cases of postinflammatory disease. In contrast, men accounted for 58% of the 260 cases of pure mitral regurgitation, including 76% of the floppy valves and 69% of the infected valves. During the 21 years spanned by the study, the relative frequency of postinflammatory mitral insufficiency progressively decreased, whereas that of floppy mitral valves increased. It is unclear whether aging, heredity, environmental factors, changes in the frequency of acute rheumatic fever, or changes in patient referral practices may account for this observation.

Frequency of complications of mitral valve prolapse in subjects aged 60 years and older

One hundred forty-five patients (74 women, 71 men), aged 60 years and older, with echocardiographically documented mitral valve prolapse were studied. One hundred sixteen patients had precordial systolic murmurs, 20 of whom were suspected of having mitral valve prolapse before the echocardiographic study. Infective endocarditis occurred in 7 patients, cerebral ischemic events in 13 and spontaneous rupture of chordae tendineae in 33. Four other patients had ruptured chordae tendineae associated with infective endocarditis. Congestive heart failure was present in 35 patients, 11 of whom had undergone mitral valve surgery.

Evidence for progression from mild to severe mitral regurgitation in mitral valve prolapse

Little information is available concerning the progression of mild to severe mitral regurgitation (MR) in patients with mitral valve prolapse (MVP). This study reports 86 patients, average age 60 years, who presented with cardiac symptoms, precordial systolic murmur, severe MR and a high incidence of MVP on echocardiography (57 of 75 [75%] ) and left ventriculography (61 of 84 [73%] ). Seventy-five surgically excised mitral valves appeared grossly enlarged and floppy. Histologic studies showed extensive myxomatous changes throughout the leaflets and chordae. Eighty patients had had precordial murmurs first described at average age 34 years, but the average age at which symptoms of cardiac dysfunction appeared was 59. However, once symptoms developed, mitral valve surgery was required within 1 year in 67 of 76 patients who had undergone surgery. Atrial fibrillation, present in 48 of 86 patients (56%), or ruptured chordae tendineae, present in 39 of 76 patients (51%), may have contributed to this rapid progression and deterioration. Additionally, 13 patients had a remote history of documented infective endocarditis. Twenty-eight patients had at least 1 type of serial clinical evaluation that indicated progressive MR in all 28 patients on the basis of changing auscultatory findings (24 of 26), progressive radiographic cardiomegaly (24 of 25), echocardiographic left atrial enlargement (4.3 to 5 cm in 11 patients) and angiographically worsening MR (14 of 15). Twenty-four of these patients had evidence of MVP on at least 1 of their initial studies. Thus, mild MR due to MVP and myxomatous mitral valves is a progressive disease in some patients with MVP.

Minimally symptomatic patients with ruptured chordae tendineae due to myxomatous degeneration of the mitral valve

Minimally symptomatic patients with ruptured chordae tendineae and severe mitral insufficiency due to myxomatous degeneration of the mitral valve are presented. This unique clinical subset of patients with mitral valve prolapse is described.

Prevalence and severity of mitral regurgitation in the mitral valve prolapse syndrome: a Doppler echocardiographic study of 80 patients

Doppler echocardiography was performed in 80 consecutive patients (22 men, 58 women), aged 38 +/- 16 years, who had mitral valve prolapse diagnosed by two-dimensional echocardiography. Of the 80 patients, 16 (20%) were asymptomatic and 11 (14%) had a normal physical examination (no click or murmur). The M-mode echocardiogram was negative for mitral valve prolapse in 11 patients (14%) and equivocal or nondiagnostic in 19 patients (24%). Mitral regurgitation was evaluated using pulsed mode Doppler echocardiography and was quantified by the mapping technique as minimal or mild when a holosystolic regurgitant jet was recorded just below the mitral valve into the left atrium, and as moderate or severe when the jet was detected at the mid- or distal left atrium. Mitral regurgitation was found in 55 (69%) of the 80 patients and it was minimal or mild in 47 patients (59%) and moderate or severe in 8 (10%). In 20 (36%) of the 55 patients with mitral regurgitation by Doppler technique, a systolic murmur was not detected and each of the 20 had only mild mitral regurgitation. Left atrial and left ventricular size were significantly smaller in patients with mild or no regurgitation as compared with the eight patients with moderate or severe regurgitation. These eight patients were all men (six over 50 years of age) who usually presented with dyspnea and a holosystolic murmur; the mitral valve prolapse was holosystolic by M-mode and involved both leaflets by two-dimensional echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Flail mitral valve syndrome: comparison with chronic mitral regurgitation of other etiologies

Thirty-nine patients with symptomatic severe mitral regurgitation (MR) were studied by cardiac catheterization and two-dimensional echocardiography (2DE) prior to mitral valve replacement. A flail mitral valve was found at surgery in 23 patients (group 1); 16 patients had intact chordae tendineae (chronic MR, group 2). No difference was found between groups 1 and 2 with regard to hemodynamic findings. Left atrial volumes in end systole (LAESV) and end diastole (LAEDV) were determined by 2DE from apical four- and two-chamber views with the use of a biplane area-length method and a light pen system. The LAESV and LAEDV measured 116 +/- 66 ml and 56 +/- 48 ml, respectively, in group 1, as compared with 185 +/- 101 ml and 105 +/- 62 ml in group 2 (p less than 0.025). Ten patients from group 1 with LAESV less than or equal to 100 ml (group 1A) were compared to the remaining 13 patients with LAESV greater than 100 ml (group 1B). Patients in group 1A had significantly smaller left ventricular volume and higher mean pulmonary wedge pressure, pulmonary artery, and left ventricular end-diastolic pressure compared to patients in groups 1B and 2 (p less than 0.05). Thus, a subset group of patients with flail mitral leaflets and smaller LAESV has hemodynamic features of acute MR, whereas the remainder with larger LAESV are indistinguishable from patients with chronic MR.

Mitral valve prolapse requiring surgery. Clinical and pathologic study

The clinical, hemodynamic, surgical, and pathologic findings in 30 patients who required mitral valvular surgery and who had a preoperative diagnosis of mitral valve prolapse were reviewed. The mean age of the patients was 59.5 years; 28 patients were over 45 years of age and 10 were over 60 years. Surprisingly, 20 were males. A long history of systolic murmur was common, whereas symptoms of heart failure were of abrupt onset. At the time of surgery, a local holosystolic murmur typical of mitral regurgitation was present, although a mid- to late systolic click was not heard in any of the patients. Electrocardiographic abnormalities were present in all patients, with 13 patients demonstrating atrial fibrillation. Only four patients had a normal heart size radiographically. Echocardiography confirmed the radiographic findings, in that 27 patients demonstrated left atrial and ventricular enlargement. All 29 patients undergoing cardiac catheterization and angiography demonstrated a prolapsing mitral valve with severe regurgitation. Surgical and pathologic examination revealed findings characteristic of a myxomatous valve in all patients, with 19 also demonstrating ruptured chordae tendineae. This study demonstrates that heart failure requiring valvular surgery occurs in a subset of patients with mitral valve prolapse. In this subset, males predominate and most are over 50 years of age. These patients may be asymptomatic for many years, demonstrating mild to moderate mitral valvular regurgitation, before heart failure develops.