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

Importance of exercise capacity in predicting outcomes and determining optimal timing of surgery in significant primary mitral regurgitation

BACKGROUND

In primary mitral regurgitation (MR), exercise echocardiography aids in symptom evaluation and timing of mitral valve (MV) surgery. In patients with grade ≥3 primary MR undergoing exercise echocardiography followed by MV surgery, we sought to assess predictors of outcomes and whether delaying MV surgery adversely affects outcomes.

METHODS AND RESULTS

We studied 576 consecutive such patients (aged 57±13 years, 70% men, excluding prior valve surgery and functional MR). Clinical, echocardiographic (MR, LVEF, indexed LV dimensions, RV systolic pressure) and exercise data (metabolic equivalents) were recorded. Composite events of death, MI, stroke, and congestive heart failure were recorded. Mean LVEF was 58±5%, indexed LV end-systolic dimension was 1.7±0.5 mm/m(2), rest RV systolic pressure was 32±13 mm Hg, peak-stress RV systolic pressure was 47±17 mm Hg, and percentage of age- and gender-predicted metabolic equivalents was 113±27. Median time between exercise and MV surgery was 3 months (MV surgery delayed ≥1 year in 28%). At 6.6±4 years, there were 53 events (no deaths at 30 days). On stepwise multivariable survival analysis, increasing age (hazard ratio of 1.07 [95% confidence interval, 1.03 to 1.12], P<0.01), lower percentage of age- and gender-predicted metabolic equivalents (hazard ratio of 0.82 [95% confidence interval, 0.71 to 0.94], P=0.007), and lower LVEF (0.94 [0.89 to 0.99], P=0.04) independently predicted outcomes. In patients achieving >100% predicted metabolic equivalents (n=399), delaying surgery by ≥1 year (median of 28 months) did not adversely affect outcomes (P=0.8).

CONCLUSION

In patients with primary MR that underwent exercise echocardiography followed by MV surgery, lower achieved metabolic equivalents were associated with worse long-term outcomes. In those with preserved exercise capacity, delaying MV surgery by ≥1 year did not adversely affect outcomes.

Prevalence of mitral valve prolapse in Stickler syndrome

The prevalence of mitral valve prolapse in Stickler syndrome has been reported to be much higher than in the general population. As a result, it has been recommended that all patients with Stickler syndrome undergo routine echocardiography and have antibiotic prophylaxis prior to surgery. The purpose of this study was to evaluate the prevalence of mitral valve prolapse in a large cohort of UK patients with Stickler syndrome in whom the clinical diagnosis has been confirmed by molecular genetic analysis. Probands and pedigrees were identified from the Vitreoretinal Service database according to previously published criteria. Ophthalmic, skeletal, audiometric, and orofacial features were assessed. Affected individuals underwent a full cardiological examination including auscultation and two-dimensional echocardiography. Mutation analysis of the COL2A1 and COL11A1 genes was carried out. Seventy-eight patients from 25 pedigrees were studied. Mutation analysis confirmed the clinical diagnosis in every pedigree. No patient was found to have clinical evidence of cardiovascular disease and no patient had significant mitral or other valvular prolapse on echocardiography. These data from a large cohort of UK patients with proven Stickler syndrome do not suggest an increased incidence of mitral valve prolapse over and above that found in the general population. Routine echocardiography screening and use of preoperative antibiotics are unnecessary and should be reserved for those individual cases where there is clear clinical indication.

Mitral valve prolapse in the general population: the benign nature of echocardiographic features in the Framingham Heart Study

OBJECTIVE

The aim of this study was to examine the echocardiographic features and associations of mitral valve prolapse (MVP) diagnosed by current two-dimensional echocardiographic criteria in an unselected outpatient sample.

BACKGROUND

Previous studies of patients with MVP have emphasized the frequent occurrence of echocardiographic abnormalities such as significant mitral regurgitation (MR) and left atrial (LA) enlargement that are associated with clinical complications. These studies, however, have been limited by the use of hospital-based or referral series.

METHODS

We quantitatively studied all 150 subjects with possible MVP by echocardiography and 150 age- and gender-matched subjects without MVP from the 3,491 subjects in the Framingham Heart Study. Based on leaflet morphology, subjects were classified as having classic (n = 46), nonclassic (n = 37), or no MVP.

RESULTS

Leaflet length, MR degree, and LA and left ventricular size were significantly but mildly increased in MVP (p < 0.0001 to 0.004), with mean values typically within normal range. Average MR jet area was 15.1 +/- 1.4% (mild) in classic MVP and 8.9 +/- 1.5% (trace) in nonclassic MVP; MR was severe in only 3 of 46 (6.5%) subjects with classic MVP, and LA volume was increased in only 8.7% of those with classic MVP and 2.7% of those with nonclassic MVP.

CONCLUSIONS

Although the echocardiographic characteristics of subjects with MVP in the Framingham Heart Study differ from those without MVP, they display a far more benign profile of associated valvular, atrial, and ventricular abnormalities than previously reported in hospital- or referral-based series. Therefore, these findings may influence the perception of and approach to the outpatient with MVP.

Evaluation of collagenase-induced mitral valve regurgitation in dogs

OBJECTIVE

To investigate the hemodynamic changes induced by injecting collagenase into the mitral valve to induce mitral valve regurgitation (MVR) in dogs.

ANIMALS

9 healthy Beagles.

PROCEDURE

Dogs were randomly assigned to 3 groups: control (saline [0.9% NaCl] solution; n = 3), single collagenase injection (C1; 3), and 2 collagenase injections (C2; 3). Open-heart surgery was performed, and saline or collagenase solutions were injected into the mitral valve. Before and weekly for 11 weeks after surgery, radiography, echocardiography, and phonocardiography were performed. Mean pulmonary arterial pressure and mean pulmonary arterial wedge pressure (mPAWP) were measured before and 11 weeks after surgery. Postmortem examinations were performed after dogs were euthanatized.

RESULTS

No changes were detected in the control group during the 11-week follow-up period. A systolic murmur and MVR developed 1 week after surgery in groups C1 and C2. The murmur changed from a protosystolic to a pansystolic murmur, and left atrial diameter and the left atrial-to-aortic root diameter ratio increased with time. Mean pulmonary arterial pressure and mPAWP were greater 11 weeks after surgery in groups C1 and C2, compared with presurgery values. During necropsy, tissue loss was detected in the mitral valve at the site of collagenase injection. Degree of regurgitation corresponded to lesion size.

CONCLUSIONS AND CLINICAL RELEVANCE

Injection of collagenase into the mitral valve of healthy dogs induced MVR, and dogs with MVR developed progressive hemodynamic changes without acute overload. Collagenase-induced MVR may be an appropriate model for evaluation of prognostic markers of idiopathic MVR in dogs.

Increased endothelin-receptor density in myxomatous canine mitral valve leaflets

In dogs and humans, myxomatous mitral valve disease results in mitral valve prolapse and mitral regurgitation. Diseased leaflets display endothelial damage, which in turn might lead to subendothelial growth through release of paracrine mediators such as endothelin-1. The aim of the study was to investigate the presence and distribution of endothelin receptors and relate these to the presence and severity of myxomatous valve disease in the dog. Valves with clear macroscopic signs of disease were taken at postmortem from five old dogs. Control valves without macroscopic signs of disease were taken from five young dogs. Endothelin receptors in the leaflets were examined by using radiolabeled endothelin-1 detected by autoradiography. The endothelin-receptor density was graded semiquantitatively. To determine disease severity, adjacent sections stained with periodic acid-Schiff (PAS)/Alcian blue were examined histologically. The leaflet thickness was measured, and the mucopolysaccharide deposition, collagen degeneration, and fibrosis were graded semiquantitatively. Diseased areas displayed high endothelin-receptor densities; normal-looking areas showed low densities. The endothelin-receptor density within as well as on the leaflets correlated positively with all four measures of disease severity in the distal most affected third of the cusps, suggesting that endothelin plays a pathogenetic role in canine myxomatous mitral valve disease.

Relationship between severity of mitral regurgitation and prognosis of mitral valve prolapse: echocardiographic follow-up study

We investigated the relation between the severity of mitral regurgitation and the development of complications and cardiac events by using two-dimensional and color Doppler echocardiography in 229 consecutive patients with mitral valve prolapse. The frequency of moderate and severe mitral regurgitation was significantly higher in patients with a prolapsed posterior leaflet (61%) than in patients with a prolapsed anterior leaflet (25%), and the older the patient, the greater the severity of mitral regurgitation. The occurrence of complications, such as atrial fibrillation, congestive heart failure, and chordal rupture, was significantly greater in prolapsed posterior leaflet cases than in prolapsed anterior leaflet cases, and the occurrence was closely associated with the degree of severity of mitral regurgitation. Multiple logistic regression analysis showed that the severity of mitral regurgitation is a strong prognostic indicator for developing complications. Furthermore in a subgroup of 49 patients tracked for a mean of 4.8 years, the new development of complications was significantly higher in patients who showed a progression in the severity of mitral regurgitation (52%) that in patients without progression in severity (8%). The initial severity of mitral regurgitation was related to the occurrence of cardiac events (mitral valve replacement, infective endocarditis, cerebral embolism and death). The data indicated that the progression of mitral regurgitation is closely associated with the development of complications and cardiac events and suggest that the severity of mitral regurgitation is an important prognostic indicator for the development of complications and cardiac events in patients with mitral valve prolapse.

Predisposing factors for severe mitral regurgitation in idiopathic mitral valve prolapse

To elucidate predisposing factors for severe mitral regurgitation (MR) in idiopathic mitral valve prolapse (MVP), 124 MVP patients were classified into the following categories: 55 with isolated clicks (click group), 35 with a late-systolic murmur (late-SM group), and 34 with a holosystolic murmur (holo-SM group). Their clinical and echocardiographic findings were compared with those of 26 patients with spontaneous chordal rupture (rupture group). In 22 patients in the click group, 24 in the late-SM group, and 22 in the holo-SM group, follow-up studies were performed for a mean of 4.5 years (range 1 to 13.5). The mean age was youngest in the click group and oldest in the rupture group. The click and late-SM groups showed a female predominance, but the holo-SM and rupture groups showed a male predominance. There was no difference in the incidence of systemic hypertension among the 4 groups. Most patients in the click and late-SM groups had anterior leaflet prolapse. In the holo-SM and rupture groups, however, the incidence of posterior leaflet involvement was significantly increased. The incidence of thickened mitral valve increased in order of the click (8%), late-SM (21%), holo-SM (38%), and rupture (50%) groups. Six patients in the holo-SM group developed chordal rupture with severe MR during the follow-up period. In the click and late-SM groups, however, there were no complications and no development into a holo-SM. Thus, aging, male sex, posterior leaflet prolapse, thickened mitral valve, and holo-SM were found to be important predisposing factors for severe MR in idiopathic MVP.

Ventricular arrhythmia factors in mitral valve prolapse

To assess the prevalence of ventricular arrhythmias and late potentials (LPs) in mitral valve prolapse (MVP) and to identify clinical, ECG, and echocardiographic markers of spontaneous ventricular arrhythmias, we studied 58 consecutive patients (mean age 46.6 +/- 17.8 years; 29 males, 29 females) with MVP diagnosed by echocardiography. Patients underwent ambulatory ECG recording (n = 58), exercise stress test (n = 56), signal-averaged ECG (n = 58), and programmed ventricular stimulation (n = 52). Ten patients (17.2%) had spontaneous nonsustained ventricular tachycardia (NSVT), 26 patients (44.8%) had premature ventricular contractions (PVCs), Lown grade > or = 3 during 24-hour ECG, and 19 had Lown grade > or = 3 PVCs during exercise stress test; 13 patients had LPs (22.4%). We provoked sustained VT in one case and NSVT in ten cases. Patients with complex ventricular arrhythmias during 24-hour ECG and exercise stress test were older and more often had mitral regurgitation. There was a statistical correlation between the presence of LPs and spontaneous VT (46.1% vs 8.9%; P < 0.005) and induced ventricular arrhythmias (50% vs 12.8%; P < 0.005). No correlation was found between spontaneous ventricular arrhythmias and thickness or posterior displacement of the mitral valve. In conclusion, complex ventricular arrhythmia (especially VT) and LPs are frequent in MVP. Patient age and mitral regurgitation seem to be determinant factors of complex ventricular arrhythmias in MVP. On signal-averaged ECG, absence of LPs seems to be a good additional marker to identify MVP patients without spontaneous VT. On the other hand, programmed ventricular stimulation does not appear valuable in determining a MVP subgroup with a high risk of ventricular arrhythmias.

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)

Relation of echocardiographic morphology of the mitral apparatus to mitral regurgitation in mitral valve prolapse: assessment by Doppler color flow imaging

Few data exist regarding the relationship of valvular anatomy and coaptation to the presence of mitral regurgitation (MR) in patients with mitral valve prolapse (MVP). Therefore this study was undertaken to assess the ability of two-dimensional echocardiographic features of mitral valve morphology to predict the presence, direction, and magnitude of MR as assessed by color Doppler flow imaging. MR was present in 21 of 46 patients with MVP on two-dimensional echocardiography. Echocardiograms were specifically evaluated for leaflet apposition, leaflet morphology, and mitral anulus diameter. Color flow images were analyzed for presence of MR, direction of the regurgitant jet, and area encompassing the largest jet visible in any view. Abnormal mitral leaflet coaptation on two-dimensional echocardiography was strongly associated with the presence of MR (p = 0.003), being present in 15 of 21 patients with as compared with 5 of 25 patients without MR. Similarly, mitral leaflet thickness and MR were closely associated (p = 0.0035), with the latter being present in 9 of 30 patients with normal and 12 of 16 patients with excessive leaflet thickness. MR jet direction tended to be anterior to central with posterior leaflet prolapse and posterior or central with anterior leaflet prolapse (p = 0.02). Maximal jet area of MR tended to be larger in patients with compared with those without mitral annular dilatation (5.4 +/- 2.3 versus 2.1 +/- 1.9 cm2, p = 0.001), and in those with abnormal rather than normal leaflet thickness (4.5 +/- 2.7 versus 2.0 +/- 1.6 cm2, p = 0.009). Thus the presence, direction, and size of MR jets in MVP are related to structural abnormality of the mitral apparatus on echocardiography.

The spectrum of mitral regurgitation in idiopathic mitral valve prolapse: a color Doppler study

To characterize the spectrum of mitral regurgitation in mitral valve prolapse, one hundred patients were studied by color Doppler flow mapping. The findings were correlated with the clinical presentation and with the possible complications. Mitral regurgitation was absent in 46 patients, mild in 26 patients, moderate in 18 patients and severe in 10 patients. The jet orientation was central in 15 patients, antero-medial in 13 patients and postero-lateral in 26 patients. The regurgitation was early systolic in 7 patients, late systolic in 20 patients and holosystolic in 27 patients. A good agreement was observed between the color flow patterns and the presence, timing and radiation of a murmur. Systolic clicks were not predictors of the presence or the severity of regurgitation. The grade of mitral regurgitation was positively correlated with, age, left heart enlargement and valvular redundancy. No sex difference was observed. The prevalence of serious arrhythmias or cerebral ischemic events was not significantly increased when a regurgitation was present.

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)

Independent pulsed Doppler mapping techniques. Limitations in the prediction of the angiographic severity of mitral regurgitation

Pulsed Doppler mapping of the flow disturbance of mitral insufficiency is commonly employed to estimate the severity of regurgitation. We re-examined the customary pulsed Doppler criterion of relative depth of jet penetration (MR ratio) in 50 patients undergoing left ventriculography and found a modest correlation (r = 0.70) between Doppler and angiographic estimates of regurgitant grade. The MR ratio did not provide statistically significant separation between adjacent angiographic grades 1+ to 3+ (scale 0 to 4+). However, when the data were re-analyzed for the subset of 36 patients with pure mitral regurgitation the correlation between Doppler and angiographic estimates of regurgitant grade improved dramatically (r = 0.88) and MR ratio provided statistically significant separation between all angiographic grades with the sole exception of the distinction between 1+ and 2+ regurgitation. The presence of restriction of the regurgitant orifice in the remaining 14 patients with relative mitral inflow obstruction may result in a nozzle effect on the regurgitant jet which alters the relationship between depth of jet penetration and severity of regurgitation. In this latter group of patients independent pulsed Doppler mapping techniques may provide inaccurate estimates of the angiographic severity of mitral regurgitation.

Exercise first-pass radionuclide assessment of left and right ventricular function and valvular regurgitation in symptomatic mitral valve prolapse

The changes in right ventricular (RV) and left ventricular (LV) function and in regurgitant fractions on first-pass exercise radionuclide angiography (RNA) were assessed in 29 consecutive patients with symptomatic mitral valve prolapse (MVP). The mean right ventricular ejection fraction (RVEF) was 35 +/- 8% at rest and 46 +/- 15% after exercise (p less than 0.001). The mean left ventricular ejection fraction (LVEF) was 62 +/- 11% at rest and 74 +/- 13% after exercise (p less than 0.001). Seven of 29 patients had an abnormal RV response and 6 had an abnormal LV response. Eight had abnormal wall motion after exercise. A total of 12/29 patients (41%) had one or more abnormalities. The mean left-sided regurgitant fraction before exercise was 27 +/- 17% in 21/29 patients (72%) and 31 +/- 21% after exercise (p = ns). An additional 5 patients (17%) developed left-sided regurgitation after exercise. These findings indicate that wall motion abnormalities and abnormal RVEF and LVEF responses to exercise occur in symptomatic MVP patients. In addition, 26/29 (89.6%) had left-sided regurgitation after exercise. Since the presence of a murmur did not correlate with the presence of mitral regurgitation by RNA, then symptomatic patients with MVP should have first-pass exercise RNA to assess the presence of regurgitation at rest and after exercise. Antibiotic prophylaxis is recommended in MVP patients with systolic murmurs or with regurgitation. Since patients without murmurs can have regurgitation, further study is necessary to determine the need for endocarditis prophylaxis in these patients.

Temporal resolution of mitral regurgitation in patients with mitral valve prolapse: a phonocardiographic and Doppler echocardiographic study

To assess the timing and duration of mitral regurgitation in mitral valve prolapse, 20 patients with a mid-systolic click or late systolic murmur, or both (Group 1) and 16 patients with a pansystolic murmur with late systolic accentuation (Group 2) were studied with phonocardiography and echocardiography including various Doppler techniques. The subjects' ages ranged from 15 to 73 years. Mitral valve prolapse with mitral regurgitation was observed in 15 of 20 patients in Group 1 and in all 16 patients in Group 2. M-mode Doppler color echocardiography demonstrated a mitral regurgitant signal throughout systole and isovolumic relaxation in all but 1 of these 31 patients regardless of the pattern of the systolic murmur. The regurgitant signal was recorded after the click in only one patient with mitral valve prolapse in Group 1. Two of the five patients in Group 1 without two-dimensional echocardiographic findings of mitral valve prolapse had the early systolic signal of mitral regurgitation. The timing and duration of the mitral regurgitant signal detected in patients in Group 1 with pulsed or continuous wave Doppler ultrasound varied with the site of the sample volume or beam direction. In the patients in Group 2, however, the signal was demonstrated throughout systole and isovolumic relaxation by both Doppler methods. Compared with M-mode Doppler color echocardiography, therefore, pulsed and continuous wave Doppler methods were less sensitive and thus inadequate to investigate the timing and duration of mitral regurgitation in mitral valve prolapse, especially in patients with a mid-systolic click or a late systolic murmur, or both, who had mild or eccentric mitral regurgitant jets.(ABSTRACT TRUNCATED AT 250 WORDS)

Causes of false-negative auscultation of regurgitant lesions: a Doppler echocardiographic study of 294 patients

Few data are available regarding the prevalence and causes of false-negative auscultation (mis-auscultation) of aortic (AR), mitral (MR), or tricuspid regurgitation (TR), and there are no such data that are relevant when the patient's pretest probability of having regurgitation is unknown. The authors therefore studied 294 patients examined by pulsed Doppler echocardiography. On 755 examinations (2.57 examinations per patient), Doppler velocity patterns typical of AR, MR, or TR were found in 63, 96, and 49 patients, respectively. For all three murmurs, mis-auscultation was the rule, rather than the exception, with sensitivities of auscultation ranging from 0 to 37%, depending (but weakly) on the site of the murmur and the years of training of the observer. Specificity of auscultation was high (85% to 100%). The factors associated with the mis-auscultation of AR were poor image quality in the echocardiograms, absence of cardiomegaly, and less experience of the examiner. The probability of missing MR increased in the presence of coronary artery disease (CAD) or if the examiner had less experience. The likelihood of missing TR by auscultation was increased by CAD, obesity, chronic obstructive pulmonary disease, or the absence of cardiomegaly. This study suggests that there is a high prevalence of "silent" murmurs, and that not hearing a regurgitant murmur does not suffice to rule out the presence of regurgitation.

Lifetime risk for patients with mitral valve prolapse of developing severe valve regurgitation requiring surgery

Severe mitral regurgitation requiring surgery is the most common life-threatening complication of mitral valve prolapse (MVP) and is due to progressive myxomatous change in the valve. We identified all residents of New South Wales, Australia, who had mitral valve surgery for myxomatous valve disease during 1982 and, using these data and the adult population statistics from 1982, estimated the cumulative risk of valve surgery in patients with MVP. In 1982, 50 of the 5.36 million New South Wales residents required surgery for this complication of MVP. Of the 50, 36 were men and 14 were women, which was significantly different from the population sex distribution (p less than 0.02) for mean age +/- SD of 60 +/- 11 years (range, 26-78 years). Using our previously determined 4% prevalence of adult MVP in New South Wales, we estimated the number of male and female patients with MVP at risk for each 5-year age interval and calculated age-specific event rates. The results show that the cumulative risk is minimal below the age of 50 years but then rises steeply, particularly in men. The risks in men aged 50, 60, and 70 years (with 95% confidence intervals) were 1:202 (130-448), 1:53 (37-82), and 1:28 (22-41), respectively. In women, the risk was less than half that in men (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of auscultation with two-dimensional and Doppler echocardiography in patients with suspected mitral valve prolapse

Auscultation was compared to two-dimensional echocardiography (2D echo) and Doppler ultrasonography in 140 consecutive patients referred for evaluation for suspected mitral valve prolapse (MVP) to asses the precision of the two diagnostic methods. Ninety patients (64%) had midsystolic clicks, of which 42 (47%) had MVP by echocardiography; 6 patients (4%) had MVP by 2D echo but no click on examination. In 15 (17%) of the 90 patients, a click was heard only in the standing or squatting positions and 2D echo did not detect prolapse in the supine position in 10 (67%) of the 15. With auscultation as the reference standard for MVP, 2D echo has a sensitivity of 47% and a specificity of 89%. Of the 140 patients, 51 (36%) had systolic murmurs; Doppler detected mitral and/or tricuspid regurgitation in 26 (50%). In 23 (16%) patients, there was Doppler evidence of mitral or tricuspid regurgitation even though systolic murmurs were not heard. Auscultation shows a 53% sensitivity and 73% specificity for systolic murmurs, using Doppler ultrasonography as the reference standard. Of 48 patients with MVP by 2D echo, 15 (13%) had associated mitral regurgitation by Doppler. The results indicate that 2D echo and Doppler ultrasonography should be interpreted in concert with auscultation for the diagnosis of mitral valve prolapse and for therapeutic decision making.

Reconsideration of echocardiographic standards for mitral valve prolapse: lack of association between leaflet displacement isolated to the apical four chamber view and independent echocardiographic evidence of abnormality

Mitral valve prolapse by current echocardiographic criteria can be diagnosed with surprising frequency in the general population, even when preselected normal subjects are examined. In most of these individuals, however, prolapse is present in the apical four chamber view and absent in roughly perpendicular long-axis views. Previous studies have shown that systolic annular nonplanarity can cause apparent prolapse in the four chamber view without actual leaflet displacement above the most superior points of the anulus, and there is evidence for such nonplanarity in vivo. It is then reasonable to ask whether superior leaflet displacement limited to the four chamber view has any pathologic significance or complications. The purpose of this study, therefore, was to address the following hypothesis: that patients with superior leaflet displacement confined to the four chamber view have no higher frequency of associated echocardiographic abnormalities than do patients without displacement in any view. Such abnormalities, which would provide independent evidence of mitral valve pathology or dysfunction, include leaflet thickening, left atrial enlargement and mitral regurgitation. Leaflet displacement was measured in the parasternal long-axis and apical four chamber views in 312 patients who were studied retrospectively and selected for the absence of forms of heart disease other than mitral valve prolapse. Leaflet thickness and left atrial size were measured and mitral regurgitation was graded. Patients with leaflet displacement limited to the four chamber view were no more likely to have associated abnormalities than were patients without displacement in any view (0 to 2% prevalence, p greater than 0.5). In contrast, patients with leaflet displacement in the long-axis view were significantly more likely to have associated abnormalities (12 to 24%, p less than 0.005), the frequency of which increased with the extent of leaflet displacement in that view (p less than 0.0001). These results suggest that displacement limited to the apical four chamber view is, in general, a normal geometric finding unassociated with echocardiographic evidence of pathologic significance.

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)

The athlete's heart syndrome

The athlete's heart is a benign condition, associated with physiologic alterations that can be detected on physical and laboratory examination. Echocardiography is a particularly useful technique is quantitating cardiac adaptation to exercise training and in screening for cardiovascular disorders that can be deleterious to the athlete. Cardiomyopathies are common causes of sudden death in young athletes, and myocarditis in physically-active young military recruits. Coronary disease is usually implicated in middle-aged athletes such as distance runners. Recent well-publicized deaths in several athletes have focused more attention on the need to detect Marfan's syndrome and cocaine use. Published guidelines such as the 16th Bethesda Conference and recent medical advances like new antihypertensive and antiarrhythmic drugs assist the clinician in counseling and managing athletes with cardiovascular disorders.

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.

Value and limitations of color Doppler flow mapping in the detection and semiquantification of valvular regurgitation

We compared color Doppler flow mapping data to angiographic data in 294 patients with suspected valvular regurgitation. Thirty-one patients had rheumatic mitral regurgitation and 37 had mitral regurgitation due to mitral valve prolapse by angiography. Ten patients had no angiographic regurgitation (4 rheumatic, 6 prolapse). The remaining patients included 86 with suspected aortic regurgitation and 130 with suspected tricuspid regurgitation. Angiographically 74 had aortic regurgitation and 111 tricuspid regurgitation. The maximum size of regurgitant jets was evaluated in each patient by color flow mapping. The width of the jets was also taken into consideration. In 29 of the 31 with rheumatic regurgitation and 67 of the 74 with aortic regurgitation by angiography, abnormal regurgitant signals were detected by color flow mapping. In both rheumatic mitral regurgitation and aortic regurgitation, color Doppler estimation of the jets correlated well with angiographic grading. The regurgitant jets in these regurgitation were not eccentric. In the 37 with mitral regurgitation in mitral valve prolapse by left ventriculography, abnormal jets were detected in 35 by color flow mapping. However, the regurgitant jets were eccentric and color Doppler estimation of the jets correlated poorly with angiographic grading. In patients with tricuspid regurgitation, color Doppler grading of regurgitation correlated poorly with right ventriculographic grading. A color Doppler underestimation was observed in 48%. In conclusion, color Doppler flow mapping is useful in the noninvasive detection and semiquantification of rheumatic mitral regurgitation and aortic regurgitation having non-eccentric jets, although this technique often underestimates the severity of regurgitation in mitral valve prolapse.

Pulsed Doppler echocardiographic evaluation of valvular regurgitation in patients with mitral valve prolapse: comparison with normal subjects

Pulsed Doppler echocardiography was used to determine prospectively the prevalence of mitral, aortic, tricuspid and pulmonary regurgitation in 80 consecutive patients with mitral valve prolapse and 85 normal subjects with similar age and sex distribution. Mitral valve prolapse was defined by posterior systolic displacement of the mitral valve on M-mode echocardiography of 3 mm or more (40 patients), the presence of one or more mid- or late systolic clicks (61 patients), or both. Mitral regurgitation, detected by pulsed Doppler techniques in 53 patients with prolapse, was holosystolic in 24, early to mid-systolic in 6, late systolic in 15 and both holosystolic and late systolic behind different portions of the valve in 8. Definitive M-mode findings were present in only 27 of the 53 patients, and only 21 had mitral regurgitation audible on physical examination. Tricuspid regurgitation was evident by pulsed Doppler echocardiography in 15 patients (holosystolic in 9, early to mid-systolic in 1, late systolic in 4 and both holosystolic and late systolic in 1); 12 of these 15 patients, including all with an isolated late systolic pattern, had an echocardiographic pattern of tricuspid prolapse, but none had audible tricuspid regurgitation. A Doppler pattern compatible with aortic regurgitation was recorded in seven patients, all without echocardiographic aortic valve prolapse and only two with audible aortic insufficiency. A Doppler shift in the right ventricular outflow tract in diastole, suggestive of pulmonary regurgitation, was recorded in 16 of the 78 patients with an adequate Doppler examination: only 1 of the 16 had audible pulmonary insufficiency. Of the 85 normal subjects without audible regurgitation, pulsed Doppler examination detected mitral regurgitation in 3 subjects (holosystolic in 1 and early to mid-systolic in 2), aortic regurgitation in none, tricuspid regurgitation in 9 (holosystolic alone in 8 and both holosystolic and late systolic in 1) and right ventricular outflow tract turbulence compatible with pulmonary insufficiency in 15. The prevalence of valvular regurgitation, detected by pulsed Doppler echocardiography, is high in patients with mitral valve prolapse. Regurgitation may involve any of the four cardiac valves and is clinically silent in the majority of patients. The prevalence rates of mitral and aortic regurgitation are significantly higher in patients with mitral prolapse than in normal subjects, suggesting that alterations in underlying valve structure in the prolapse syndrome may indeed be responsible for this regurgitation.(ABSTRACT TRUNCATED AT 400 WORDS)