Non-ejection systolic clicks and mitral systolic murmurs in black schoolchildren of Soweto, Johannesburg

Echocardiographic screening for mitral valve prolapse in Turkish school children

We determined the frequency of mitral valve prolapse (MVP) in healthy Turkish school children using the current echocardiographic diagnostic criteria. This epidemiological survey was performed on 2550 school children. All children were screened with echocardiography and the family of children with MVP were also screened. The prolapse of mitral leaflets into left atrium ≥ 2 mm in parasternal long-axis view was used as diagnostic criteria. MVP was classified as classical or non-classical according to anterior mitral leaflet thickness. The thickness of anterior mitral leaflet, the extent of prolapse, and the presence of mitral regurgitation were evaluated. The children were also questioned about the associated symptoms. The prevalence of MVP was 1.25% in children with a mean age of 11.1 ± 2.9 years. The prevalence was 0.9%, 1.2%, and 1.6% in 5-9 years, 10-13 years, and 14-18 years of age, respectively. 43.7% of the cases were classical MVP. The frequency of auscultation findings was 34.3%. 11/34 children had mitral regurgitation. There was no statistically significant difference between classical MVP and non-classical MVP in terms of mitral regurgitation, physical examination findings, and symptoms. Anxiety (37.5%) was the most common symptom. The frequency of MVP in the first-degree relatives of children with MVP was 11/84 (13.1%). Most patients with MVP don't have auscultation findings and symptoms, therefore echocardiography is an important tool in the diagnosis of MVP. It is also reasonable to screen first degree relatives of MVP patients with echocardiography.

Prevalence of mitral valve prolapse and associated valvular regurgitations in healthy teenagers undergoing screening echocardiography

BACKGROUND

The true prevalence of mitral valve prolapse (MVP) in the population has been controversial.

OBJECTIVE

To evaluate the prevalence of MVP and associated valvular abnormalities in healthy teenage students.

METHODS

The Anthony Bates Foundation performed screening echocardiography in high schools across the United States. A total of 2072 students between 13 and 19 years of age were identified for the present study.

RESULTS

Total prevalence of MVP was 0.7%. The prevalence of MVP was significantly higher among female teenagers (nine of 690 female teenagers [1.3%] versus five of 1382 male teenagers [0.4%], P=0.01, OR 3.6, CI 1.21 to 10.70). The prevalence of mitral regurgitation (MR) and tricuspid regurgitation (TR) was higher in teenagers with MVP. MR occurred in five of 14 teenagers (35.7%) with MVP versus 15 of 2058 controls (0.7%) (P<0.001, OR 75.6, CI 22.6 to 252.5). TR occurred in one of 14 teenagers (7.1%) with MVP versus nine of 2058 controls (0.4%) (P<0.001, OR 17.5, CI 2.0 to 148.3).

CONCLUSION

The prevalence of MVP in this cohort of healthy teenage students was less than 1%. Furthermore, the prevalence of MVP was higher in female teenagers and was associated with a higher prevalence of MR and TR.

The genetics of mitral valve prolapse

Mitral valve prolapse (MVP) is a very common clinical condition that refers to a systolic billowing of one or both mitral valve leaflets into the left atrium. Improvements of echocardiographic techniques and new insights in mitral valve anatomy and physiology have rendered the diagnosis of this condition more accurate and reliable. MVP can be sporadic or familial, demonstrating autosomal dominant and X-linked inheritance. Three different loci on chromosomes 16, 11 and 13 have been found to be linked to MVP, but no specific gene has been described. Another locus on chromosome X was found to cosegregate with a rare form of MVP called 'X-linked myxomatous valvular dystrophy'. MVP is more frequent in patients with connective tissue disorders including Marfan syndrome, Ehlers-Danlos and osteogenesis imperfecta. The purpose of this review is to describe previous studies on the genetics and prevalence of MVP. The report warrants the need for further genetically based studies on this common, albeit not fully understood, clinical entity.

Mitral valve prolapse: now you see it; now you don't: recalling the discovery, rise and decline of a diagnosis

Mitral valve prolapse has been recognized as a clinical entity for only the past 50 years, although the auscultatory findings of this condition had been recognized since the mid-19th century. On the evidence of only a few autopsies, it was concluded that the basis for these were pleuropericardial adhesions. Left ventricular angiographic studies performed in the 1960s clearly documented the true nature of the condition, although it was not until the advent of echocardiography that large numbers of patients began to be referred for evaluation by this new technique. Because of the wide variety of symptoms in patients with suspected mitral valve prolapse, similar to those with other conditions, many patients with the latter were referred for evaluation and diagnosed with mitral valve prolapse because of misleading M-mode and then 2-dimensional criteria. It is now recognized, with the use of improved, more restrictive echocardiographic criteria, that the prevalence of the disorder is much less than previously believed. No test has been devised that will prove 100% sensitive and 100% specific for any disorder. In conclusion, this sobering fact should encourage the use of all modalities available, including clinical skills, to make proper diagnoses when these may be in doubt.

N-Linked glycans of proteins from mitral valves of normal pigs and pigs affected by endocardiosis

Endocardiosis, a degenerative and dystrophic process affecting cardiac valves and described in many mammalian species, is characterized by the accumulation of glycosaminoglycans, in particular hyaluronic acid, in the extracellular matrix. The glycoprotein patterns of pig mitral valves in normal animals and animals affected by endocardiosis were investigated. A different N-linked glycosylation pattern of glycoproteins was detected in affected valves compared with normal ones. In either normal or pathological species, the detected N-linked glycans were of the complex type. However, in samples from affected valves, sialic acid showed a prevalence of the alpha2,6 linkage to the galactosyl residue, whereas in normal samples the most frequent linkage was of the alpha2,3 type. In normal valves, the majority of complex oligosaccharides presented two outer branches with different degrees of fucosylation and sialylation, whereas in pathological samples we noted an increased number of glycans having up to four outer branches.

Implications of mitral valve prolapse in children with rheumatic mitral regurgitation

OBJECTIVES

This study was conducted to determine the longterm prognosis of children with mitral valve prolapse associated with isolated rheumatic mitral regurgitation.

BACKGROUND

Rheumatic fever may result in mitral valve prolapse, which sometimes leads to severe mitral regurgitation requiring surgical intervention during the active stage of rheumatic fever. However, the influence of mitral valve prolapse on the prognosis of patients with rheumatic mitral regurgitation remains largely unknown.

METHODS

From 1971 to 1991, 181 children who fulfilled the revised Jones criteria of rheumatic fever were identified from a rheumatic fever prevention program. Of the 181 patients, isolated mitral regurgitation was diagnosed in 123 at age 4 to 12 years. The diagnosis of mitral valve prolapse was based on echocardiographic findings. Actuarial event-free curves for persistent murmur, cardiac improvement and surgical intervention were drawn according to the Kaplan-Meier nonparametric estimation.

RESULTS

Evidence of mitral valve prolapse was shown in 37 (30%) of the 123 patients. Patients with mitral valve prolapse were more likely to have a larger cardiac size than those without mitral valve prolapse during the active stage of rheumatic fever. Although the cardiac status of patients with mitral valve prolapse may improve under adequate secondary prophylaxis, an actuarial analysis indicated that patients with mitral valve prolapse had a greater likelihood of murmur persistence and surgical intervention. This trend toward murmur persistence was observed even when patients with heart failure during the active stage of rheumatic fever were excluded from analysis.

CONCLUSIONS

The presence of mitral valve prolapse in children with isolated rheumatic mitral regurgitation may predict a less favorable outcome.

Mitral valve prolapse in childhood: the incidence and clinical presentations in different age groups

To elucidate the incidence and natural history of mitral valve prolapse (MVP) during childhood, we investigated a total of 4,238 children (aged from 1 day to 15 years) classified by age into 4 groups: Group 1:1 to 28-day-old full-term normal newborns (n = 108), Group 2: 6 to 18-month-old infants (n = 391), Group 3: 6 to 7-year-old children (n = 2,801), and Group 4: 12 to 15-year-old children (n = 938). The incidence of MVP was determined by videorecorded two-dimensional echocardiography in a double-blind method twice-over. There were 109 cases diagnosed as having MVP. The incidence rates of MVP were as follows: Group 1: 0%, Group 2: 0.25%, Group 3: 2.1% and Group 4: 5.1%. Arrhythmias were detected in 49% (27/55) by Holter ECG, and by exercise stress test in 4.7% (2/43). Eighty-three (77%) of 108 cases in Groups 3 and 4, excluding the 1 case in Group 2, showed no symptoms. Ventricular premature contraction (VPC) was the most common arrhythmia, and was benign in all cases. A mid-systolic click (MSC), late systolic murmur (LSM), MSC + LSM, and a pansystolic murmur were detected in 23.1%, 3.7%, 4.6% and 5.6%, respectively. Symptoms caused by MVP increased and appeared more apparently with age. Further prospective long-term follow-up studies to adulthood are necessary.

Ventricular arrhythmias in children with an apparently normal heart

Ventricular ectopy occurs frequently in normal children. In the presence of a normal heart, these arrhythmias, including asymptomatic, nonsustained ventricular tachycardia, carry a benign prognosis and are not associated with sudden, unexpected death. However, complex ventricular arrhythmias frequently indicate the presence of underlying cardiac disease; patients with such arrhythmias must undergo an appropriately thorough evaluation before decisions regarding prognosis and the need for therapy can be made.

Follow-up in mitral valve prolapse by phonocardiography, M-mode and two-dimensional echocardiography and Doppler echocardiography

To assess the serial phonocardiographic and echocardiographic change in patients with mitral valve prolapse (MVP), phonocardiograms and echocardiograms were reviewed retrospectively in 116 patients (48 men and 68 women, mean age 27 years) who had been determined to have MVP and were reexamined 4.3 years (range 1 to 14) later by phonocardiography and echocardiography between 1971 and 1988. Follow-up phonocardiograms showed periods when 5 of 18 patients with silent MVP developed mid- or late systolic clicks. Of 57 patients with mid- or late systolic clicks, 15 had silent MVP, 6 developed a late systolic murmur with or without systolic clicks and 1 developed a pansystolic murmur. Two of 9 patients with an isolated late systolic murmur developed a pansystolic murmur. M-mode echocardiograms showed that left atrial and left ventricular dimensions at end-diastole and end-systole increased in patients with systolic murmur (33 +/- 10 vs 35 +/- 11, 46 +/- 6 vs 50 +/- 7 and 29 +/- 4 vs 31 +/- 5 mm, respectively, all p less than 0.001) and no statistically significant changes in any of these dimensions were found in patients without a systolic murmur. The degree of MVP evaluated by the anteroposterior mitral leaflet angle on the 2-dimensional echocardiogram was more severe in patients with a systolic murmur than in patients without systolic murmur (157 +/- 12 vs 131 +/- 16 degrees, p less than 0.001). The degree of prolapse did not change during the follow-up periods. The number of patients with mitral regurgitation detected by pulsed Doppler echocardiography increased from 21 of 72 (29%) to 31 of 72 (43%).(ABSTRACT TRUNCATED AT 250 WORDS)

Mitral leaflet billowing and prolapse: its prevalence around the world

Primary mitral leaflet billowing, or so-called mitral valve prolapse, has become the most common valve anomaly in the United States and is also frequently found throughout the world. Its prevalence varies from less than 1% to 38%, differing not only between countries but also within the same country. The prevalence depends on whether the study is clinical or echocardiographic, based on autopsy or surgical material, or of hospital or non-care-seeking population. Other explanations for the varying prevalence are the age, sex and weight differences of the study population, imprecise terminology, the care with which auscultation and/or echocardiography are carried out and interpreted, and some selection biases. Although prevalent throughout the world, the condition is generally benign and can often be regarded as a normal variant. Among the complications of mitral valve prolapse, progressive mitral regurgitation and infective endocarditis are particularly noteworthy. Primary mitral valve prolapse is currently a leading cause of mitral regurgitation and also of infective endocarditis.

Clinical significance of the echocardiographic degree of mitral valve prolapse

To assess the clinical significance of the echocardiographic degree of mitral valve prolapse, we prospectively evaluated with Doppler echocardiography 245 consecutive patients referred with signs or symptoms consistent with a diagnosis of mitral valve prolapse. The echocardiographic degree of mitral valve prolapse was measured by a scoring system that incorporates an assessment of mitral systolic displacement from the M-mode as well as the two-dimensional long-axis and apical four-chamber views (range 0 to 9, 0 = no mitral valve prolapse). A structured questionnaire was used to record the frequency and severity of symptoms. Pulsed and continuous-wave Doppler echocardiography were performed to document mitral regurgitation and determine the ratio of peak early to atrial diastolic filling velocities. Patients were grouped according to the degree of mitral valve prolapse; 45 patients had no echocardiographic evidence of mitral valve prolapse. There was no statistically significant relationship between the mitral valve prolapse score and symptoms or left ventricular systolic or diastolic function. There was, however, a strong relationship between the echocardiographic degree of mitral valve prolapse and the presence of significant mitral regurgitation. Patients without echocardiographic evidence of mitral valve prolapse had a 4% incidence of mitral regurgitation, which was not significantly different than that of persons with mild degrees of prolapse (6%). However, the groups with the most marked degree of prolapse (scores of 6, 7, 8, and 9) had a significantly higher incidence of mitral regurgitation (20% and 60% respectively, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Mitral Valve Prolapse in Young Patients

In brief: From 1% to 5% of young individuals are found to have, on clinical or echocardiographic examination, a prolapsing mitral valve. The majority of these patients are asymptomatic, and require from the physician an explanation of this defect and reassurance that the condition usually remains mild. Beta-blocking drugs are prescribed for patients with disabling chest pain, dizziness, or palpitation, or if potentially serious rhythm disorders develop. Physicians caring for these young patients must manage each case individually and must remain mindful that the natural course studies come from a perspective of only 25 years.

Mitral valve prolapse: definition and implications in athletes

Mitral valve prolapse is probably the most common cardiac valve disorder, affecting approximately 5% of the population. Although it is genetically determined, its clinical manifestations do not usually become evident before adulthood. In the setting of a cardiology referral center, a mitral valve prolapse syndrome, consisting of nonspecific symptoms, repolarization changes on the electrocardiogram and arrhythmias, has been identified. However, doubt has recently been expressed about the existence of such a syndrome. The prognosis of mitral valve prolapse is generally favorable but infrequent complications do occur and include transient ischemic attacks, progression of mitral regurgitation with or without ruptured chordae tendineae, infective endocarditis and sudden death. The symptoms and the complications are not usually related to physical activity. A permissive attitude toward participation of patients with mitral valve prolapse in competitive athletics is probably warranted; however, it would appear reasonable to disqualify athletes with mitral valve prolapse in the following circumstances: history of syncope; disabling chest pain; complex ventricular arrhythmias, particularly if induced or worsened by exercise; significant mitral regurgitation; prolonged QT interval; Marfan's syndrome; and family history of sudden death.

Mitral valve prolapse in sickle cell disease: manifestation of a generalized connective tissue disorder

Previous studies have shown an association of sickle cell disease with generalized connective tissue disorders such as pseudoxanthoma elasticum. We recently documented an unexpectedly high prevalence of mitral valve prolapse, a connective tissue disorder, in sickle cell disease. To investigate this association, skin biopsies were analyzed from 32 sickle cell disease patients, 11 of whom had mitral prolapse. Total and type III collagen, collagen solubility, and uronic acid were not different between the patients with or without mitral prolapse (p greater than 0.05). Computerized morphometric quantitation of the volume fraction of elastic fibers was greater in sickle cell disease patients than in 10 normals (3.1 +/- 0.1 mean +/- SEM vs 2.0 +/- 0.3%; p less than 0.01) but less than in three patients with pseudoxanthoma elasticum (9.7 +/- 0.6%; p less than 0.001). Desmosine radioimmunoassay (an index of elastic fibers) was greater in sickle cell disease patients with mitral prolapse than those without (239.3 +/- 9.3 vs 171.7 +/- 25.4 ng/mg wet weight; p less than 0.02). Histopathologic grading showed a similar trend (p = 0.07). The combined probabilities of these three independent tests of elastic fiber quantity showed an increased elastic fiber concentration in mitral prolapse patients compared to those without mitral prolapse (p less than 0.02). Thus, there is no evidence for a specific collagen defect; rather, sickle cell disease appears to be associated with a spectrum of elastic tissue disorders, a feature that could predispose to mitral valve prolapse.

Mitral valve prolapse. Incidence and clinical course in a pediatric population

Mitral valve prolapse is a common finding in the pediatric population. Five percent (154/3100) of pediatric patients had clinical evidence of mitral valve prolapse. A positive family history and minor abnormalities on electrocardiograms were frequent. The vast majority of patients were asymptomatic and exhibited a benign clinical course.

The Mitral Valve Prolapse Syndrome in Athletes

In brief The mitral valve prolapse syndrome is prevalent in apparently normal people, including athletes. Symptoms, when present, range from chest pain and palpitations to anxiety neurosis. The typical finding on auscultation of the heart is a midsystolic click and/or a mid-to-late systolic high-frequency murmur. Cardiac arrhythmias are common and often do not require therapy. The exercise ECG shows ST segment depression in up to one fourth of patients. When drug therapy is necessary, beta blockers are usually selected. The overall prognosis is excellent. Sudden death, infectious endocarditis, and cerebral thromboembolic events are relatively rare.

Cerebral ischemia in young patients: it is associated with mitral valve prolapse and abnormal platelet activity in vivo?

The etiology of cerebrovascular disease (CDV) in young patients is difficult to establish if the common causes of a focal neurological deficit are excluded by appropriate investigations. Since in some observations prolapse of the mitral-valve (MVP), alterations of platelet function, or both have been linked with cerebral ischemic events, we studied the in vivo platelet release reaction and the incidence of MVP in 47 patients (12 males, 35 females) under 45 years of age with TIA or stroke of unknown cause and in an age- and sex-matched control group. The mean plasma beta-thromboglobulin (beta-TG) level of the patients (mean = 54.9 +/- 31.4 ng/ml) was significantly higher than that of the controls (mean = 20.6 /- 6.9 ng/ml, p less than 0.001). MVP was demonstrated in 13 of 47 patients in contrast to 4 of the controls (p less than 0.01). However, the beta-T levels of patients with MVP (n = 13, 52.9 +/- 25.5 ng/ml) did not differ from those of patients without MVP (n = 34, 55.7 +/- 33.7 ng/ml) significantly (p less than 0.4). Our results confirm that the incidence of MVP is higher in young patients with cerebral ischemia of unknown cause than in asymptomatic controls. The significantly elevated plasma beta-TG concentrations in the patient's group indicate an increased platelet activity in vivo. Since there was no significant difference between beta-TG levels of patients with and without MVP, the mitral-valve abnormality can not be the cause for the altered platelet activity.

Mitral valve prolapse

Mitral valve prolapse (MVP) now is a commonly recognized syndrome with an apparent prevalence of approximately 4-6%. It appears to occur more frequently in females and occasionally it is familial. In most instances, the syndrome is idiopathic, although it occurs in association with many other conditions, particularly Marfan's syndrome, rheumatic heart disease, coronary heart disease, congestive cardiomyopathy, ostium secundum atrial septal defect, Ehlers-Danlos syndrome or abnormalities of the thoracic cage. The majority of patients with the syndrome have minimal, if any, symptoms and have a benign course. When symptoms do occur, more frequently they are palpitations, chest pain, dyspnea on exertion or fatigue. Neuropsychiatric symptoms or even transient ischemic episodes may occur rarely. Very rarely, complications such as severe mitral regurgitation, arrhythmias or infective endocarditis may occur. Characteristically, patients have a midsystolic click, occasionally followed by a systolic murmur. The timing of the click and the onset of the murmur usually is variable, depending on the ventricular volume. The electrocardiogram frequently shows ST-T wave changes. The diagnosis usually can be confirmed by echocardiography or left ventricular angiography. Most patients with MVP require no treatment other than reassurance. If a systolic murmur is present, prophylaxis against infective endocarditis during dental work probably is useful. Patients with palpitations or chest pain usually respond well to treatment with propranolol. Patients with progressive severe mitral regurgitation require mitral valve replacement.

Innocent murmurs and third heart sounds in Black schoolchildren

Normal auscultatory findings were studied during a heart survey in which 12 050 Black schoolchildren, aged 2 to 18 years, were examined by cardiologists. Physiological third heart sounds were detected in 96 per cent of children, innocent systolic murmurs in 72 per cent, and innocent mid-diastolic murmurs in 0.27 per cent. The term 'innocent systolic murmur" was used for vibratory systolic murmurs (70%) and pulmonary ejection systolic murmurs (4.2%) but distinct separation of these two murmurs was often difficult. Vibratory systolic murmurs were present throughout the age range. Important features in differentiating innocent systolic murmurs from those caused by mild organic heart disease included the intonation, site of maximal intensity, timing in systole, and behaviour with postural change. Innocent mid-diastolic murmurs are short murmurs occurring immediately after the third heart sound in children, with no supportive evidence of organic heart disease.

Four year follow-up of black schoolchildren with non-ejection systolic clicks and mitral systolic murmurs

In 1972 we conducted a survey of 12,050 urban Black schoolchildren and detected 168 (prevalence rate of 14 per 1,000) with a non-ejection systolic click (NESC), a late systolic murmur, or both. The etiology of the mitral valve abnormality was unknown but we considered that a significant proportion might have early rheumatic heart disease. The auscultatory features four years later of 139 of the original 168 subjects as well as those of 139 age- and sex-matched controls are presented in this study. No cardiac abnormality was detected in as many as 55 of the subjects. Five children now had pansystolic murmurs but the mitral regurgitation was assessed as mild in four. Twenty-five (17.9 per cent) of the controls, 23 of whom had NESCs, had auscultatory features compatible with mitral valve prolapse. These findings do not support our earlier suggestion that a large number of the 1972 subjects have mild rheumatic heart disease. The results are in accord with other studies which have indicated that auscultatory features compatible with mitral valve prolapse are common in "normals" and also that the prognosis of the specific "billowing mitral leaflet syndrome" is generally benign.