Mitral valve E point-septal separation as an index of left ventricular function with valvular heart disease

Epidemiology of heart disease in English Bull Terriers and echocardiographic characteristics of mitral valve abnormalities

OBJECTIVES

To present the prevalence and distribution of heart disease as well as echocardiographic findings in English Bull Terriers.

MATERIALS AND METHODS

One hundred and one English Bull Terriers were retrospectively included to evaluate the prevalence and distribution of heart disease. Secondly, a retrospective study on mitral valve abnormalities was performed on three groups: a control group (n=120, 19 breeds) used to establish reference intervals for mean transmitral gradient; a healthy English Bull Terriers group (n=25) and an English Bull Terriers group with mitral valve abnormalities (n= 18). Healthy English Bull Terriers for which mitral inflow parameters were not obtainable and English Bull Terriers with other types of heart disease were excluded.

RESULTS

The prevalence of heart disease in English Bull Terriers was 65% (66/101), with mitral valve abnormalities (47%, 47/101) and aortic stenosis (29%, 29/101) being most common. The cut-off value for normal mean transmitral gradient was 3.5 mmHg in the control group. The mean transmitral gradient for healthy English Bull Terriers was higher than for other dog breeds. Healthy English Bull Terriers had a smaller mitral valve area and mitral annulus diameter compared with dogs with a similar body surface area. A high heart rate, smaller mitral valve area, mitral regurgitation, and volume overload are associated with increased mean transmitral gradient in English Bull Terriers with mitral valve abnormalities.

CLINICAL SIGNIFICANCE

We suggest that mitral valve area, mitral annulus diameter and mean transmitral gradient measurements should be included in the echocardiographic protocol for English Bull Terriers.

Estimation of Cardiac Systolic Function Based on Mitral Valve Movements: An Accurate Bedside Tool for Emergency Physicians in Dyspneic Patients

OBJECTIVES

The purpose of this study was to determine the success of mitral valve movements in the estimation of left ventricular ejection fraction (LVEF).

METHODS

Adult patients whose principal symptom was dyspnea were included in this prospective observational study. The distance from the anterior mitral valve (AMV) to the interventricular septum (IVS) during early diastole was measured first in B-mode in the parasternal long axis (PLAX) named parasternal long axis-anterior leaflet septal separation. Second, the AMV-IVS distance was measured in M-mode in the PLAX named E-point septal separation. Third, AMV-IVS distance was measured in B-mode in the apical 4-chamber view named apical 4-chamber view-anterior leaflet septal separation. Finally, maximum distance between the 2 mitral leaflets in the apical 4-chamber view was measured and named mitral valve leaflet separation. Comprehensive echocardiography was performed by an experienced cardiologist. Correlation was calculated between mitral valve measurements and LVEF. Cutoff values were determined using receiver operating characteristic curves and the chi-square test.

RESULTS

A total of 118 patients were included in the study. Parasternal long axis-anterior leaflet septal separation, E-point septal separation, and apical 4-chamber view-anterior leaflet septal separation were highly correlated with LVEF (correlation coefficient, -0.848, -0.833, and-0.822 [P < .001]). Parasternal long axis-anterior leaflet septal separation values less than 2.30 mm, E-point septal separation values less than 2 mm, and mitral valve leaflet separation values greater than 25.15 mm exhibited a 100% negative predictive value in excluding reduced LVEF. Parasternal long axis-anterior leaflet septal separation values less than 4.95 mm, EPSS values less than 5.85 mm, apical 4-chamber view-anterior leaflet septal separation values less than 6.95 mm, and mitral valve leaflet separation values greater than 24.05 mm exhibited a 100% negative predictive value in excluding severe reduced LVEF.

CONCLUSIONS

Mitral valve measurement methods may be useful in predicting LVEF or values thereof as a complementary method of diagnosing challenging patients on echocardiographic images.

Echocardiographic Applications of M-Mode Ultrasonography in Anesthesiology and Critical Care

Proficiency in echocardiography and lung ultrasound has become essential for anesthesiologists and critical care physicians. Nonetheless, comprehensive echocardiography measurements often are time-consuming and technically challenging, and conventional 2-dimensional images do not permit evaluation of specific conditions (eg, systolic anterior motion of the mitral valve, pneumothorax), which have important clinical implications in the perioperative setting. M-mode (motion-based) ultrasonographic imaging, however, provides the most reliable temporal resolution in ultrasonography. Hence, M-mode can provide clinically relevant information in echocardiography and lung ultrasound-driven approaches for diagnosis, monitoring, and interventional procedures performed by anesthesiologists and intensivists. Although M-mode is feasible, this imaging modality progressively has been abandoned in echocardiography and is often underutilized in lung ultrasound. This article aims to comprehensively illustrate contemporary applications of M-mode ultrasonography in the anesthesia and critical care medicine practice. Information presented for each clinical application will include image acquisition and interpretation, evidence-based clinical implications in the critically ill and surgical patient, and limitations. The present article focuses on echocardiography and reviews left ventricular function (mitral annular plane systolic excursion, E-point septal separation, fractional shortening, and transmitral propagation velocity); right ventricular function (tricuspid annular plane systolic excursion, subcostal echocardiographic assessment of tricuspid annulus kick, outflow tract fractional shortening, ventricular septal motion, wall thickness, and outflow tract obstruction); volume status and responsiveness (inferior vena cava and superior vena cava diameter and respiratory variability [collapsibility and distensibility indexes]); cardiac tamponade; systolic anterior motion of the mitral valve; and aortic dissection.

Emergency echocardiography

Emergency echocardiography refers to the use of cardiac ultrasound to address critical and time-sensitive clinical questions during the initial evaluation and treatment of the critically ill patient presenting to the emergency department. The information obtained can be pivotal to a physician's clinical decision making and can guide further diagnostic or therapeutic interventions. This article provides an evidence-based discussion of the common uses of emergency transthoracic echocardiography, as well as its benefits and limitations in the current practice of emergency medicine.

Mitral valve E-point septal separation as an indicator of ejection fraction in patients with reversed septal motion

The mitral valve E-point septal separation (EPSS) is widely used as an M-mode echocardiographic indicator of normal or abnormal left ventricular ejection fraction. Other M-mode echocardiographic estimates of left ventricular function (eg, fractional shortening) have limited utility in the presence of abnormal septal motion. The utility of EPSS was investigated in predicting a normal or abnormal ejection fraction in 27 patients with reversed septal motion, and to compare these results with 103 patients with normal septal motion. It was determined that EPSS is valid as an indicator of the presence of a normal or abnormal ejection fraction regardless of abnormalities of septal motion.

Sensitivity of cross-sectional echocardiography in detection of impaired global and regional left ventricular function: prospective study

In order to establish the sensitivity and specificity of cross-sectional echocardiography for detection of global and regional left ventricular function a prospective study was performed in 80 patients suspected of having coronary artery disease. Twenty four hours before heart catheterization, cross-sectional echocardiograms were recorded in the apical RAO-equivalent view and high quality echocardiograms were obtained in 71/80 patients (89%). M-mode echocardiograms of the left ventricle could be performed in 56/71 patients (79%). Based on normal values sensitivity and specificity of cross-sectional echocardiography were calculated in comparison to cineventriculography. For fractional shortening (normal value greater than 25%) sensitivity measured 46% and specificity 93%, and when the E-point septal separation was measured (normal value less than 7 mm), sensitivity increased to 73% and specificity was 84%. For detection of increased end-diastolic volume (less than 155 ml) sensitivity reached 84% and specificity 98% and for increased end-systolic (less than 70 ml) volume it was 86 and 97%, respectively. A depressed left ventricular ejection fraction (greater than 49%) was found with a sensitivity of 93% and specificity of 100%. Regional left ventricular wall motion, analyzed by an area method, revealed for anterior wall motion a sensitivity of 68% and a specificity of 94%, whereas for posterior wall motion sensitivity reached 80% and specificity 96%. Regression equation between the number of pathological segments and left ventricular ejection fraction for cineventriculography was given by Y = -4.06 X + 73.4, r = 0.93 and for cross-sectional echocardiography by Y = -3.69 X + 62.6, r = 0.85. We conclude that cross-sectional echocardiography can be used as a screening method to detect impaired left ventricular function. It is superior to M-mode echocardiography. Reduced regional function of the posterior wall can be found with high sensitivity, but depressed motion of the anterior wall may be overlooked.

Widened E point septal separation in a normal pediatric population

To determine the age and gender distribution of the E point septal separation (EPSS), M-mode echocardiograms were obtained from 121 normal subjects aged four months to 82 years. A small but consistent age factor was found. In subjects less than age 20, EPSS was 3.0 +/- 2.6 mm, whereas in those greater than 20 years, EPSS was 1.4 +/- 1.8 (p less than .001). In females EPSS did not vary appreciably at different ages. By contrast, in males EPSS increased with age, peaking between ages 15 and 19 and then decreasing. Between ages 10 and 19, EPSS was significantly wide in males than in females. Thus, EPSS is wide in male adolescents than in adults. The cause for this phenomenon is unclear, but judging from its age and gender distribution, it may be related to the effect of androgens on the myocardium.