Sudden,Severe Mitral Insufficiency

Five male patients with sudden, severe mitral insufficiency due solely to ruptured chordae tendineae or papillary muscle had an abrupt onset of symptoms of left and right heart failure and the sudden appearance of a harsh, widely propagated apical pansystolic murmur. None had a history of rheumatic fever. All were in sinus rhythm and had but mild left atrial and ventricular enlargement. Giant left atrial “v” waves were characteristic and exceeded pulmonary artery pressure in two instances.In contrast, when ruptured chordae tendineae were superimposed on chronic rheumatic mitral insufficiency, females predominated and there was a long history of disability. Atrial fibrillation, less elevation of left atrial pressure, and marked left atrial and ventricular enlargement were characteristic. These latter patients closely resembled patients with chronic rheumatic mitral insufficiency alone.It is concluded that the syndrome of sudden, severe mitral insufficiency develops if ruptured chordae tendineae occur on a previously normal or insignificantly diseased mitral valve. If ruptured chordae tendineae are superimposed on chronic rheumatic mitral insufficiency, the syndrome resembles that seen in the latter alone.     

Recommended Criteria for Cardiac Catheterization in Patients with Aortic Valve Disease

Criteria for selection of patients with aortic valve disease for cardiac catheterization are described, based on a study of 81 cases. Children with aortic stenosis warrant catheterization at the time when the clinical diagnosis is made, but in adults this examination may be deferred until symptoms appear or left ventricular hypertrophy is recognized. In patients with pure aortic insufficiency catheterization may be deferred until symptoms appear. When severe stenosis and insufficiency co-exist, the valve is usually heavily calcified. Thirty-seven per cent of patients with aortic valve disease have co-existing mitral lesions and these patients are usually women, are fibrillating and, as a rule, have atrial enlargement in contrast to those with aortic valve disease only. On rare occasions, patients with mitral valve disease have clinically silent but angiographically demonstrable aortic insufficiency; therefore, aortography should precede open-heart correction of a mitral lesion so as to detect minor degrees of aortic insufficiency.     

Exuberant accessory mitral valve tissue with possible true parachute mitral valve: a case report

ABSTRACT: INTRODUCTION: A parachute mitral valve is defined as a unifocal attachment of mitral valve chordae tendineae independent of the number of papillary muscles. Data from the literature suggests that the valve can be distinguished on the basis of morphological features as either a parachute-like asymmetrical mitral valve or a true parachute mitral valve. A parachute-like asymmetrical mitral valve has two papillary muscles; one is elongated and located higher in the left ventricle. A true parachute mitral valve has a single papillary muscle that receives all chordae, as was present in our patient. Patients with parachute mitral valves during childhood have multilevel left-side heart obstructions, with poor outcomes without operative treatment. The finding of a parachute mitral valve in an adult patient is extremely rare, especially as an isolated lesion. In adults, the unifocal attachment of the chordae results in a slightly restricted valve opening and, more frequently, valvular regurgitation. CASE PRESENTATION: A 40-year-old Caucasian female patient was admitted to a primary care physician due to her recent symptoms of heart palpitation and chest discomfort on effort. Transthoracic echocardiography showed chordae tendineae which were elongated and formed an unusual net shape penetrating into left ventricle cavity. The parasternal short axis view of her left ventricle showed a single papillary muscle positioned on one side in the posteromedial commissure receiving all chordae. Her mitral valve orifice was slightly eccentric and the chordae were converting into a single papillary muscle. Mitral regurgitation was present and it was graded as moderate to severe. Her left atrium was enlarged. There were no signs of mitral stenosis or a subvalvular ring. She did not have a bicuspid aortic valve or coarctation of the ascending aorta. The dimensions and systolic function of her left ventricle were normal. Our patient had a normal body habitus, without signs of heart failure. Her functional status was graded as class I according to the New York Heart Association grading. CONCLUSIONS: A recently published review found that, in the last several decades, there have been only nine adult patients with parachute mitral valve disease reported, of which five had the same morphological characteristics as our patient. This case presentation should encourage doctors, especially those involved in echocardiography, to contribute their own experience, knowledge and research in parachute mitral valve disease to enrich statistical and epidemiologic databases and aid clinicians in getting acquainted with this rare disease.     

Surgical Treatment of Mitral Insufficiency

Sixty-four patients with pure mitral insufficiency were operated upon. Thirty of them had torn chordae tendineae. It was possible to repair the mitral valve in 57 patients and there were five operative deaths. One patient had a femoral artery embolus and another had a cerebral embolus. The incidence of peripheral embolization was 4 per cent compared with 40 per cent reported for ball valve replacement.Forty-eight of the 57 patients with repair (84 per cent) were living and well with at most a grade II/VI apical systolic murmur up to seven and a half years after operation. There has been no evidence of recurrence in these patients.In approximately 90 per cent of patients with pure mitral insufficiency, repair should be performed. When feasible, repair is more satisfactory than valvular replacement, with not only excellent long-term results, but far less morbidity than is reported with ball valve replacement.     

Left heart catheterization; the clinical importance of findings

Left heart catheterization using the transbronchial route to obtain pressures in the left atrium and left ventricle was used successfully in 29 cases with no mortality or morbidity. It was found to be useful in differentiating between mitral stenosis and mitral insufficiency, as well as determining the amount of aortic stenosis present when there was involvement of the aortic valve. The technique was also helpful in determining which is the predominant lesion when there is a disease of the aortic and mitral valves. In two patients in a series of 29, data obtained by left heart catheterization forestalled operation on the basis of a mistaken diagnosis of mitral stenosis when actually no mitral valvular disease was present. In another eight patients, the predominant lesion was found to be mitral stenosis rather than mitral insufficiency as it was thought to be before catheterization. In two patients, who had only systolic murmurs, catheterization revealed mitral stenosis rather than mitral insufficiency. In four patients who were thought to have mixed valvular disease, left heart catheterization showed only aortic valvular disease.     

LEFT HEART CATHETERIZATION—The Clinical Importance of Findings

Left heart catheterization using the transbronchial route to obtain pressures in the left atrium and left ventricle was used successfully in 29 cases with no mortality or morbidity. It was found to be useful in differentiating between mitral stenosis and mitral insufficiency, as well as determining the amount of aortic stenosis present when there was involvement of the aortic valve. The technique was also helpful in determining which is the predominant lesion when there is a disease of the aortic and mitral valves.In two patients in a series of 29, data obtained by left heart catheterization forestalled operation on the basis of a mistaken diagnosis of mitral stenosis when actually no mitral valvular disease was present. In another eight patients, the predominant lesion was found to be mitral stenosis rather than mitral insufficiency as it was thought to be before catheterization. In two patients, who had only systolic murmurs, catheterization revealed mitral stenosis rather than mitral insufficiency. In four patients who were thought to have mixed valvular disease, left heart catheterization showed only aortic valvular disease.     

Is mitral valve repair safe procedure in elderly patients?

The aim of this randomized, prospective, study was to evaluate postoperative hospital mortality and morbidity after mitral valve repair by comparing two surgical techniques for resolving mitral valve insufficiency in elderly patients. In comparison were: mitral valve repair vs. mitral valve replacement in patients older than 70 years. In period from January 1st 2006 until August 30th 2009. Eighty patients with mitral valve disease, isolated or associated with other comorbidities, were scheduled for mitral valve repair or mitral valve replacement in our institution. Patients were randomized in two groups, one scheduled for mitral valve repair and another one for mitral valve replacement using the envelope method with random numbers. Results show no difference in hospital mortality and morbidity postoperatively in both groups. In group undergoing valve replacement we had one significant complication of ventricle rupture in emphatically calcified posterior part of mitral valve annulus. In conclusion we found no distinction in postoperative hospital mortality and morbidity after using one of two surgical techniques.     

冠心病合并缺血性二尖瓣关闭不全的手术方案探讨

目的:探讨适用于冠心病合并缺血性二尖瓣关闭不全的手术方法及临床效果,为心外科手术提供参考。方法:选取2012年2月至2013年5月在我院心脏外科接受手术治疗的冠心病合并缺血性二尖瓣关闭不全的患者31例。根据手术方式的不同,将所选病例分为二尖瓣成形术组和二尖瓣置换术组。术后随访6-24个月,观察并比较患者手术前后的左心房内径(LAD)、舒张末期直径(LVEDD)、收缩末期直径(LVESD)、左心室射血分数(LVEF)及二尖瓣返流面积。结果:围术期死亡1例,手术成功率为96.7%。30例成功获得随访,随访率为98.8%。二尖瓣成形术组并发症的发生率为22.7%,二尖瓣置换术组并发症的发生率为23.3%,两组术后并发症的发生率无显著差异(P0.05)。与手术前相比,两组患者术后的左心房内径变小,左室舒张末直径和收缩末直径增加,左室射血分数升高,二尖瓣反流面积缩少,差异显著且具有统计学意义(P0.05)。结论:对于冠心病合并重度缺血性二尖瓣关闭不全的患者行二尖瓣成形术或置换术应根据患者的实际情况和病理特点选择最佳的手术方案,以提高手术的成功率和安全性。     

A structural basis for the size-related mechanical properties of mitral valve chordae tendineae

It has been reported previously that the mechanical properties of mitral valve chordae tendineae vary with chordal size and type. The popularity of mitral valve repair and chordal transposition warrant a better understanding of this phenomenon. The objectives of this study were to characterize the size- and type-related variations in chordal mechanics and explain them from the ultra-structural viewpoint. A total of 52 porcine mitral valve chordae from eight hearts were mechanically tested. We found that thicker chordae were more extensible than thinner chordae (4.2+/-1.5%, 8.1+/-2.5%, 15.7+/-3.9% and 18.4+/-2.8% strain corresponding to chordae with cross-sectional areas of 0.1-0.5, 0.5-1.0, 1.0-2.0, and 2.0-3.0mm(2), respectively), and had lower moduli (90.1+/-22.3, 83.7+/-18.5, 66.3+/-13.5 and 61.7+/-13.3 MPa corresponding to the same chordae groups). Polarized light microscopy was used to measure collagen fibril crimp. Thicker chordae had smaller crimp period than thinner chordae (11.3+/-1.4 microm vs. 14.8+/-3.0 microm), and were thus more highly crimped. Thicker chordae could therefore extend to greater strain before lock-up. Transmission electron microscopy (TEM) was used to measure choral fibril ultra-structure. Thinner chordae had lower average fibril diameter than thicker chordae but greater average fibril density. The cross-sectional area occupied by fibrils, however, was found to be constant at 49+/-2% regardless of chordal size or type. The difference in moduli between thick and thin chordae can therefore be explained by differences in fibril packaging and hence fibril-to-fibril interactions. According to a simple fibril interaction model, chordae with smaller diameter fibrils will have a greater number of fibril-to-fibril interactions, and hence a greater modulus.     

Arrhythmia in patients with mitral valve prolapse]

An incidence of cardiac arrhythmias was evaluated in 119 patients with mitral valve prolapse. The disease was made basing on the results of clinical symptoms, echo-, angio- and phonocardiography. Electrocardiograms were recorded from the standard 12 lead and Holter technique for 24 hours in each patient to assess present arrhythmias. It was found that the most frequent cardiac arrhythmias accompanying mitral valve prolapse are ventricular extrasystolic contractions of Lown's class 1a and 1b. Only examination of strictly selected groups of patients (age groups with or without co-existing mitral valve insufficiency for adequate period of time) will facilitate precise evaluation of an incidence of different cardiac arrhythmias accompanying the underlying disease.     

The Preoperative Assessment of Multiple Valve Disease

Representative case histories are used to discuss the difficulties in preoperative assessment of patients with multiple valve disease and the dangers of correcting one lesion when two or more valves are seriously damaged. Errors fall into three broad categories: existing second valve disease (1) may not be suspected, (2) may be considered insignificant or (3) may be considered a consequence of the first.Recommendations are offered to minimize these errors. The four valves should be studied physiologically, no matter how “normal” the other three may appear to be clinically, whenever open-heart surgery is contemplated. In bivalvular disease angiographic methods are preferable to pressure studies, for data so obtained are not dependent on cardiac output. Mitral and tricuspid regurgitation can never be attributed with certainty to a more distal lesion but require direct examination at time of operation for assessment.     

Factitious Aortic Valve Insufficiency

One hundred consecutive aortograms, performed with careful attention to recommended technical details, were reviewed to identify cases of “factitious” aortic valve insufficiency, viz. aortic regurgitation seen during aortography for which there is no clinical evidence. Five patients with this condition were identified. Two of these subsequently underwent mitral valve replacement under cardiopulmonary by-pass. Aortic insufficiency was not detected during this procedure and the aortic valve appeared to be anatomically normal at postmortem examination. That factitious aortic insufficiency may exist should be remembered when aortography is used to differentiate aortic from pulmonary valve insufficiency.     

Bacterial endocarditis of the mitral valve associated with annual calcification.

Bacterial endocarditis, caused mainly by Staphylococcus aureus, was found at autopsy in five patients who had a calcified posterior mitral valve annulus. Clincopathologic correlation indicates that the infection should be suspected in elderly patients with a calcified mitral annulus, the murmur of mitral insufficiency, fever, anemia, polymorphonuclear leukocytosis and a positive blood culture, regardless of evidence of peripheral embolism or of another disease that could cause the last four features. Pertinent pathologic findings are a calcified mitral valve annulus, vegetations of bacterial endocarditis towards the base of the posterior leaflet associated with leaflet perforation and an annulus abscess, and no other valvular disease. The infection may develop on the atrial aspect of a leaflet ulcerated by the calcium mass or may begin on its ventricular aspect, subsequently perforating the leaflet and infecting its atrial surface.     

Course of experimental cardiac insufficiency under conditions of high altitude depending on the periods of adaptation

The data characterizing the compensatory hyperfunction of the circulation and respiration with dosaged insufficiency of the mitral valve in animals, depending on the periods of adaptation to high-altitude are presented. Unadapted animals with insufficiency of the mitral valve had more serious disorders of hemodynamic and gaseous exchange accompanied by stasis in the lesser and greater circulation. 52.9% of the animals died during the first days after the formation of the mitral defect. In animals adapted to the high altitude hypoxia the process coursed with less pronounced disturbances of circulation and respiration; 28.6% of the animals died.     

Stresses in the closed mitral valve: a model study

In the present model study on the closed mitral valve, tensile force in the chordae tendineae is related to transvalvular pressure using a mathematical model of mechanics of the closed mitral valve. Circumferential stress as well as bending stress in the valve leaflets were neglected. Without precisely knowing the mechanical properties of the leaflet material, geometry of the leaflets was estimated by applying Laplace's law, which relates leaflet stress to leaflet curvature. Independent of shape of the mitral valve orifice, under all circumstances tensile force in the chordae tendineae was calculated to be equal or greater than half the force exerted on the mitral valve orifice by the transvalvular pressure.     

比较老年与中青年二尖瓣腱索断裂的超声心动图特征和规律性

目的：比较老年二尖瓣腱索断裂（RMCT）患者与中青年RMCT患者的临床表现以及超声心动图特点,为老年RMCT患者的诊断和治疗提供依据。方法：选择年龄〉60岁的老年RMCT患者53例定义为老年组,年龄〈60岁的中青年RMCT患者57例定义为中青年组,使用经胸超声心动图（TTE）和经食道超声心动图（TEE）测量各组的心腔尺寸,观察二尖瓣活动形态以及腱索断裂的部位和程度,记录瓣膜的返流情况。结果：老年组中风心病仅占5．66％,而中青年组风心病患者占50．88％,差异有统计学意义（X2=27．221,P=0．000）。老年组多合并有多种慢性疾病,其中合并高血压者占83．02％,合并冠心病者占60．38％,合并2型糖尿病者占37．74％,均高于中青年组,其中合并高血压的差异有统计学意义（X2=-31．459,P=0．000）。老年组中心功能Ⅳ级的比例远高于中青年组,差异有统计学意义（X2=10．489,P=0．001）。老年组全心扩大、肺动脉高压的例数显著高于中青年组,差异有统计学意义（全心扩大：XZ=11．376,P=0．001;肺动脉高压：X2=-20．362,P=0．000）。老年组中二尖瓣细小腱索断裂的例数多于中青年组,差异有统计学意义（x2=9．799,P=0．002）,粗大腱索断裂的例数少于中青年组,差异有统计学意义（x2=11．118,P=0．001）。结论：合并有高血压、冠心病以及糖尿病等基础疾病的老年RMCT患者,应定期进行超声心动图的检查,同时给予合理的治疗,以降低心衰的发病率。     

A Pig Model of Ischemic Mitral Regurgitation Induced by Mitral Chordae Tendinae Rupture and Implantation of an Ameroid Constrictor

A miniature pig model of ischemic mitral regurgitation (IMR) was developed by posterior mitral chordae tendinae rupture and implantation of an ameroid constrictor. A 2.5-mm ameroid constrictor was placed around the left circumflex coronary artery (LCX) of male Tibetan miniature pigs to induce ischemia, while the posterior mitral chordae tendinae was also ruptured. X-ray coronary angiography, ECG analysis, echocardiography, and magnetic resonance imaging (MRI) were used to evaluate heart structure and function in pigs at baseline and one, two, four and eight weeks after the operation. Blood velocity of the mitral regurgitation was found to be between medium and high levels. Angiographic analyses revealed that the LCX closure was 10–20% at one week, 30–40% at two weeks and 90–100% at four weeks subsequent ameroid constrictor implantation. ECG analysis highlighted an increase in the diameter of the left atria (LA) at two weeks post-operation as well as ischemic changes in the left ventricle (LV) and LA wall at four weeks post-operation. Echocardiography and MRI further detected a gradual increase in LA and LV volumes from two weeks post-operation. LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline. Pathological changes were observed in the heart, which included scar tissue in the ischemic central area of the LV. Transmission electron microscopy highlighted the presence of contraction bands and edema surrounding the ischemia area, including inflammatory cell infiltration within the ischemic area. We have developed a pig model of IMR using the posterior mitral chordae tendineae rupture technique and implantation of an ameroid constrictor. The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients.     

The material properties of the native porcine mitral valve chordae tendineae: an in vitro investigation

The material properties of the mitral valve chordae tendineae are important for the understanding of leaflet coaptation configuration and chordal pathology. There is limited information about the mechanical properties of the chordae during physiologic loading. Dual camera stereo photogrammetry was used to measure strains of the chordae in vitro under physiologic loading conditions. Two high-speed, high-resolution cameras captured the movement of graphite markers attached to the central section of the chordae. A uniaxial test simulating the same loading conditions was conducted on the same chordae using the same markers. The maximum strain experienced during the cardiac cycle was 4.29% +/- 3.43%. The loading rate was higher at 75.3% +/- 48.6% strain per second than the unloading rate at -54.8% +/- -56.6% strain per second. The anterior lateral strut chordae had a higher maximum strain (5.7% +/- 3.8%) and loading rate (80.5% +/- 51.9% strain per second) than the posterior medial strut chordae (5.5% +/- 2.3% strain and 68.1% +/- 48.3% strain per second). The posterior medial strut chordae had a higher unloading rate (-68.5% +/- -59.1% strain per second) than the anterior lateral strut chordae (-44.9% +/- -57.2% strain per second). Although the anterior lateral and posterior medial strut chordae have a significantly different diameter and length, they experience a similar strain, strain rate, and tension. In conclusion, a non-destructive technique was developed to measure in vitro chordal strain in the mitral valve. This technique allows the investigation of the behavior of biological tissues under physiologic loading conditions.     

Mitral valve prolapse detected during hemodynamic studies

To estimate frequency of the posterior mitral valve leaflet prolapse in routinely performed left ventriculography, 1000 consecutive ventriculograms of the right anterior oblique projection were analyzed. A group of patients consisted of 511 women and 489 men at mean age 46,5 years. Clinical diagnosis of heart lesions, myocardial disease, pulmonary hypertension or arrhythmias were indications for hemodynamic studies. In the investigated group of patients, there were no patients with clinical diagnosis of the coronary artery disease. Prolapse of the posterior mitral valve leaflet was diagnosed in 59 patients. Idiopathic mitral valve prolapse was diagnosed in 10 patients. Prolapse of the posterior mitral valve leaflet was most frequent in atrial septal defect (16.6%), myocardial lesion (12.5%), and after mitral commissurotomy (8.9%). Posterior mitral valve leaflet prolapse is not a frequent anomaly in routinely performed left ventriculography. Relatively often occurrence of the mitral valve prolapse in atrial septal defect and only occasional in the aortic lesions and dilated cardiomyopathy seems to point out at a role of the left ventricle size in pathogenesis of this syndrome.