Observer variation in the echocardiographic diagnosis of mitral valve prolapse

Echocardiographic study of mitral valve prolapse in dachshunds

In this prospective echocardiographic study, we investigated the occurrence of mitral valve prolapse (MVP) in 60 dachshunds: 30 with mitral regurgitation (MR), 15 age-matched and 15 3-year-old controls without heart murmurs. To assess the MVP, video recorded sequences from the right parasternal long axis 4-chamber view were blindly evaluated by three observers. Of the 30 dogs with MR, 12 (40%) had severe MVP, 10 (33%) had mild MVP, and eight (27%) had a normal mitral valve. The clinical status of the dogs with MR correlated significantly with the severity of MVP, and these dogs had significantly worse MVP than age-matched controls, among which seven (47%) had mild MVP and eight (53%) had a normal mitral valve ( P < 0.01). In the group of 15 young dachshunds without heart murmurs, seven (47%) had mild MVP and eight (53%) had a normal mitral valve. The degree of MVP correlated significantly with the occurrence of arrhythmias, particularly severe sinus arrhythmia. We conclude that dachshunds with MR have a higher prevalence of MVP than controls, and that the severity of MVP is correlated with clinical status. The dogs with MVP and marked sinus arrhythmia might have autonomic dysfunction, analogous to findings in humans. Whether young dachshunds with MVP are predisposed to MR later in life must await the results of a longitudinal study.

Prevalence of mitral valve prolapse in Saudi sickle cell disease patients in Dammam - A prospective-controlled echocardiographic study

Mitral valve prolapse (MVP) is the most common valvular heart disease and there are numerous reports of a strong association with many conditions including sickle cell disease (SCD). Since SCD is very common in the Eastern Province of Saudi Arabia, we undertook a prospective controlled study to determine and compare the prevalence of MVP in the SCD patients with other groups of subjects. Three hundred and sixteen subjects (156 males and 160 females) were studied. They were divided into four groups based on their hematologic diagnoses - I SCD, II normal controls, III sickle cell traits, IV other anemias. The prevalence of MVP is 17.4% in Group I, 13.3% in Group II, 21.4% in Group III and 19.4% in Group IV. There was no statistically significant difference in the prevalence of MVP among the four study groups. In contrast to a previous study, these results show that the prevalence of MVP by echocardiographic criteria (M-mode and 2-dimensional) in SCD patients is the same as in the general population. We believe that mere case-reporting and lack of or inappropriate control in most of the clinical series are responsible for the wide range of conditions claimed to be associated with MVP.

Mitral regurgitation following first-time acute myocardial infarction--early and late findings by Doppler echocardiography

A total of 61 patients with first-time mild to moderate acute myocardial infarction and no reinfarction within the following 2 months were studied prospectively by Doppler echocardiography before hospital discharge and after 2 months to evaluate the prevalence of mitral regurgitation. Twenty-one age-matched healthy subjects served as controls. At baseline, the prevalence of Doppler-recorded mitral regurgitation was 74% and 29% in patients and controls, respectively. In the patients, the regurgitant flow measured by color flow Doppler was 1.04 cm2 (range 0.2-8 cm2) and occupied 7.5% (range 2-45%) of the left atrial area. Corresponding figures for controls were 0.35 cm2 (0.1-0.6) and 2.4% (0.7-4.5), respectively. On continuous wave Doppler, most patients (33/45) had Doppler signals similar to those of healthy controls. The prevalence of mitral regurgitation was about the same in anterior and inferior infarction (75 and 72% respectively). In the patients, the prevalence was similar after 2 months (79%) with minor changes in the Doppler characteristics of the regurgitation (regurgitant flow 1.12 cm2 and occupying 8.1% of left atrial area). The study demonstrates that in a group of patients with first-time mild to moderate myocardial infarction the prevalence of Doppler-recorded mitral regurgitation is high and mild in severity in the majority of the cases. The changes remain almost similar even after 2 months.

Utility of echocardiography in patients with suspected mitral valve prolapse

PURPOSE

Echocardiography has become a widely utilized test since its introduction into clinical medicine in the early 1970s. Although it has frequently been performed in patients suspected of having mitral valve prolapse (MVP), its usefulness in this setting has not been systematically studied. To investigate the use and value of echocardiography in patients suspected of having MVP, we conducted a prospective study in which physicians were interviewed before and after ordering echocardiographic testing for patients in whom there was a suspicion of MVP.

PATIENTS AND METHODS

The study population included consecutive patients referred to the echocardiography laboratory at Boston University Medical Center because of suspected MVP between January 1 and December 31, 1987. Two standardized telephone interviews were conducted with the physician most responsible for ordering the echocardiogram. The following information was obtained during the first interview, which was always conducted before the echocardiogram was performed: patient demographic and clinical data; the reason for ordering the echocardiogram; the physician's most likely clinical diagnosis; the physician's estimate of the likelihood that the patient had MVP; and the physician's proposed management plans. After the referring physician received the echocardiographic results, a second interview was conducted to determine changes in the most likely clinical diagnosis and management plans. The impact of the echocardiogram on diagnosis and management was evaluated by comparing physician responses before and after reception of echocardiographic results. Receiver operating characteristic (ROC) curves were constructed to assess the physician's skills at distinguishing patients with echocardiographic-documented MVP from those without MVP.

RESULTS

A total of 106 echocardiograms were ordered by 45 different physicians. More than 80% of all echocardiograms were ordered to address diagnostic or therapeutic concerns. On echocardiography, 47 (44%) patients were found to have MVP, six (6%) had mitral regurgitation without prolapse, and 53 (50%) had normal results. On the basis of the ROC curve analysis, the physician's ability to discriminate between patients with and without echocardiographic MVP varied significantly by physician specialty and practice setting. The echocardiographic results led to a change in diagnosis in 59 (56%) patients. A change in management occurred in 29 (27%) patients, with 25 of these 29 changes (86%) related to the initiation or discontinuation of antibiotics.

CONCLUSIONS

Echocardiography frequently alters diagnostic assessments and leads to therapeutic changes in some patients suspected of having MVP. However, the benefits of such changes have not yet been demonstrated.

Mitral valve dimensions and motion in Marfan patients with and without mitral valve prolapse. Comparison to primary mitral valve prolapse and normal subjects

To determine mitral valve and extravalvular findings associated with mitral valve prolapse (MVP) in patients with the Marfan syndrome, we compared mitral leaflet and anular dimensions and motion by computerized two-dimensional echocardiography in 53 Marfan patients (28 with M-mode echocardiographic MVP) to those in 48 adults with primary MVP and in 35 normal subjects. Mitral leaflet billowing occurred in 28 of 28 Marfan patients with M-mode MVP versus 24 of 48 with primary MVP (p less than 0.00005), 0 of 25 Marfan patients without M-mode MVP, and 0 of 35 normal subjects (both, p less than 0.0001). Billowing occurred on the first systolic frame in 8 of 28 Marfan-MVP patients, in whom posterior leaflet chordae arose abnormally from the posterior ventricular wall, and in no other subjects. These patients had large mitral valves and normal anular dynamics, whereas the remaining 20 Marfan-MVP patients had increased systolic anular expansion. Marfan-MVP patients were younger than those without MVP (29 +/- 12 vs. 38 +/- 15 years, p less than 0.02) and had lower body mass index (19.8 +/- 2.7 vs. 23.9 +/- 2.9 kg/m2, p less than 0.00005) and systolic blood pressure (120 +/- 20 vs. 133 +/- 20 mm Hg, p less than 0.05), similar to differences between primary MVP and normal subjects in body mass index (21.5 +/- 3.0 vs. 23.9 +/- 4.8 kg/m2, p less than 0.01) and systolic pressure (118 +/- 14 vs. 125 +/- 18 mm Hg, p less than 0.05). Marfan patients with and without MVP had similar arm span, arm span to height ratio, upper to lower segment ratio, and prevalence of ectopia lentis and thoracic bony abnormalities, but arachnodactyly was more frequent in those with MVP (82% and 48%, respectively; p less than 0.02). We conclude that 1) leaflet billowing occurs more uniformly in Marfan patients with MVP than in primary MVP, 2) MVP in Marfan patients may be due to either valve enlargement with distinctively abnormal chordal architecture or abnormal mitral anular distensibility, 3) Marfan patients with MVP have low body weight and systolic blood pressure, similar to primary MVP, and 4) Marfan patients with MVP more commonly have arachnodactyly but otherwise have similar skeletal and anthropometric characteristics to other Marfan patients.

Diagnostic reliability of M-mode echocardiography for detecting mitral valve prolapse in 50 consecutive panic patients

Fifty consecutive panic patients had M-mode echocardiographs read independently by two cardiologists with expertise in echocardiography. In this prospective study, there was poor interrater reliability (22 of 50; K = 0.11) for diagnosis of mitral valve prolapse (MVP). On repeat evaluation 10 months later there was also unacceptable intrarater reliability for each reader: 22 of 35 (K = 0.41) and 22 of 35 (K = 0.45). We conclude that M-mode echocardiography is clinically unreliable for establishing the diagnosis of mitral valve prolapse. These findings suggest that the variable reporting of M-mode-determined mitral valve prolapse in psychiatric populations may reflect differences among echocardiologists rather than differences in cardiac pathology. The clinical implications of these findings are discussed.

Ischemic stroke in young adults. I. Analysis of the etiological subgroups

An ischemic stroke (IS) group including 386 patients under 50 years old is analysed taking into account different etiological subgroups and comparing risk factors against a control group of 100 people. The series points out the presence of 66.1% patients included in the inconclusive-atherothrombosis group, of which 22.7% had defined criteria of atheromatosis, while 11.6% were diagnosed of lacunar infarct. 13.5% of cases were considered as cardiac origin embolisms, and 14.1% were affected of mitral valve prolapse. The migraine group includes 4.9% of the patients while 17.6% belong to the miscellaneous group. The comparison of each of these groups with the control group showed significant differences for family history of stroke, personal history of peripheral arteriopathy, tobacco, arterial hypertension and previous IS.

The medicalization of normal variants: the case of mitral valve prolapse

Mild mitral valve prolapse, hypoglycemia, irritable colon, and premenstrual syndrome are examples of anatomico-physiologic phenomena that largely overlap with normal. Such "overlap syndromes" become labeled disease entities by the medical community through a process called medicalization. This report uses mitral valve prolapse (MVP) to exemplify the effects of medicalization on patients, physicians, and society. Ascertainment bias and insufficient controlled clinical studies have led to the description of a clinical entity replete with false associations (e.g., mitral valve prolapse syndrome) and overly pessimistic prognostication (e.g., risk of sudden death or endocarditis), leading to clinical overreaction, overtreatment, and unnecessary induction of disability. Though some physical complications may be prevented by recognizing severe MVP, there is substantial risk of iatrogenic harm by attributing complex symptoms and illness behavior to mild MVP, which is probably a normal variant. A three-dimensional analysis of illness experience is presented that may be of use in conceptualizing the clinical approach to overlap syndromes such as mild MVP. Conservative criteria for the diagnosis of significant MVP have been developed at the National Institutes of Health. Treatment of patients with mild MVP must emphasize that it is a normal variant without serious consequences. Because the risks of overmedicalization are so substantial, the impact of diagnostic labels on individual patients and society must be analyzed continually.

Reassessment of echocardiographic criteria for diagnosis of mitral valve prolapse

Commonly used echocardiographic criteria for mitral valve prolapse (MVP) include a sizable proportion of persons whose hearts are normal. Nevertheless, the echocardiogram is generally used as an independent standard for the diagnosis of MVP despite lack of consensus on the criteria to be used and the probability of interobserver variability. Conversely, there is a relatively uniform consensus that classic auscultatory signs establish the diagnosis of MVP beyond reasonable doubt. Accordingly, in 148 patients referred for evaluation of known or suspected MVP, the echocardiographic patterns that coincide with diagnostic auscultatory signs were studied prospectively to compare those patterns with criteria commonly used for the echocardiographic diagnosis of MVP and to determine interobserver variability in echocardiographic interpretation. Eighty patients (54%) had a classic mid- to late systolic click or an apical late systolic murmur, or both. Eleven patients (7%) had the apical holosystolic murmur of mitral regurgitation with no discernible clinical or echocardiographic cause other than the consideration of MVP. Doppler echocardiography was performed in 80 of the 148 patients. The degree of superior systolic bowing of each mitral leaflet and the location of leaflet coaptation relative to the presumed plane of the mitral anulus were graded on apical 4-chamber and parasternal long-axis views. The only patterns absolutely specific for auscultatory MVP were: severe bowing of the anterior or posterior leaflet; coaptation of leaflets on the left atrial side of the anular plane; moderate to severe Doppler mitral regurgitation accompanied by any degree of leaflet bowing; and mild Doppler mitral regurgitation accompanied by moderate bowing of a leaflet.(ABSTRACT TRUNCATED AT 250 WORDS)