Richard L. Popp

Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation.

We evaluated the accuracy of a noninvasive method for estimating right ventricular systolic pressures in patients with tricuspid regurgitation detected by Doppler ultrasound. Of 62 patients with clinical signs of elevated right-sided pressures, 54 (87%) had jets of tricuspid regurgitation clearly recorded by continuous-wave Doppler ultrasound. By use of the maximum velocity (V) of the regurgitant jet, the systolic pressure gradient (delta P) between right ventricle and right atrium was calculated by the modified Bernoulli equation (delta P = 4V2). Adding the transtricuspid gradient to the mean right atrial pressure (estimated clinically from the jugular veins) gave predictions of right ventricular systolic pressure that correlated well with catheterization values (r = .93, SEE = 8 mm Hg). The tricuspid gradient method provides an accurate and widely applicable method for noninvasive estimation of elevated right ventricular systolic pressures.

Report of the American Society of Echocardiography Committee on Nomenclature and Standards in Two-dimensional Echocardiography.

The Committee recommends that when the transducer is placed in the suprasternal notch that it be referred to as in the suprasternal location. When the transducer is located near the midline of the body and beneath the lowest ribs, the transducer should be referred to as in the subcostal location. When the transducer is located over the apex impulse, the Committee recommends that this be referred to as the apical location. If the term apical is used alone, it will be assumed that this refers to a left-sided apical position. The area bounded superiorly by the left clavicle, medially by the sternum and inferiorly by the apical region will be referred to as the parasternal location. If the term parasternal is used alone, it will be assumed to be the left parasternal location. In those unusual situations in which the apex impulse is palpated on the right chest, a transducer placed over the right-sided apex impulse will be referred to as in the right apical location. The region bounded superiorly by the right clavicle, medially by the sternum and inferiorly by the right apical region will be referred to as the right parasternal location.

Late Pulmonary Sequelae of Bronchopulmonary Dysplasia

BACKGROUND Bronchopulmonary dysplasia is a chronic lung disease that often develops after mechanical ventilation in prematurely born infants with respiratory failure. It has become the most common form of chronic lung disease in infants in the United States. The long-term outcome for infants with bronchopulmonary dysplasia has not been determined. METHODS We studied the pulmonary function of 26 adolescents and young adults, born between 1964 and 1973, who had bronchopulmonary dysplasia in infancy. We compared the results with those in two control groups: 26 age-matched adolescents and young adults of similar birth weight and gestational age who had not undergone mechanical ventilation, and 53 age-matched normal subjects. RESULTS Sixty-eight percent of the subjects with bronchopulmonary dysplasia in infancy (17 of the 25 tested) had airway obstruction, including decreases in forced expiratory volume in one second, forced expiratory flow between 25 and 75 percent of vital capacity, and maximal expiratory flow velocity at 50 percent of vital capacity, as compared with both control groups (P less than 0.0001 for all comparisons). Twenty-four percent of the subjects with bronchopulmonary dysplasia in infancy had fixed airway obstruction, and 52 percent had reactive airway disease, as indicated by their responses to the administration of methacholine or a bronchodilator. Hyperinflation (an increased ratio of residual volume to total lung capacity) was more frequent in the subjects with a history of bronchopulmonary dysplasia than in either the matched cohort (P less than 0.0006) or the normal controls (P less than 0.0004). Six of the subjects who had bronchopulmonary dysplasia in infancy had severe pulmonary dysfunction or current symptoms of respiratory difficulty. CONCLUSIONS Most adolescents and young adults who had bronchopulmonary dysplasia in infancy have some degree of pulmonary dysfunction, consisting of airway obstruction, airway hyperreactivity, and hyperinflation. The clinical consequences of this dysfunction are not known.

Intracoronary ultrasound in cardiac transplant recipients. In vivo evidence of "angiographically silent" intimal thickening.

BackgroundAccelerated coronary atherosclerosis is a major factor limiting allograft longevity in cardiac transplant recipients. Histopathology studies have demonstrated the insensitivity of coronary angiography for detecting early atheromatous disease in this patient population. Intracoronary ultrasound is a new imaging techniquse that provides characterization of vessel wall morphology. The purpose of this study was to compare in vivo intracoronary ultrasound with angiography in cardiac transplant recipients. Methods and ResultsThe left anterior descending coronary artery was studied with intracoronary ultrasound in 80 cardiac transplant recipients at the time of routine screening coronary angiography 2 weeks to 13 years after transplantation. A mean and index of intimal thickening were obtained at four coronary sites. Intimal proliferation was classified as minimal, mild, moderate, or severe according to thickness and degree of vessel circumference involved. Twenty patients were studied within 1 month of transplantation and had no angiographic evidence of coronary disease. An intimal layer was visualized by ultrasound in only 13 of these 20 presumably normal hearts. The 60 patients studied 1 year or more after transplantation all had at least minimal intimal thickening. Twenty-one patients (35%) showed minimal or mild, 17 (28%) moderate, and 21 (35%) severe thickening. Forty-two of these 60 patients had angiographically normal coronary arteries, 21 (50%) of whom had either moderate or severe thickening. All 18 patients with angiographic evidence of coronary disease had moderate or severe intimal thickening, but there was no statistically significant difference in intimal thickness or index when compared with the patients with moderate or severe proliferation and normal angiograms (thickness, 0.53±0.35 mm versus 0.64±0.30 mm, p = NS; index, 0.28±0.10 versus 0.34±0.10, p = NS). ConclusionsThe majority of patients 1 or more years after cardiac transplantation have ultrasound evidence of intimal thickening not apparent by angiography. Intracoronary ultrasound offers early detection and quantitation of transplant coronary disease and provides characterization of vessel wall morphology, which may prove to be a prognostic marker of disease.

Sensitivity and Specificity of Echocardiographic Diagnosis of Pericardial Effusion

In order to evaluate the reliability and sensitivity of echocardiograms for detecting and quantitating pericardial effusion, 41 patients had echocardiograms on the day prior to cardiac operation. A fluid trap was used to aspirate the pericardium at operation. Thirty-nine of 41 patients had echocardiograms of diagnostic quality. In 25 patients, the echocardiogram was negative for pericardial effusion, with 0-16 ml identified at operation. In 13 patients, the echocardiogram was positive for pericardial effusion, with 15-775 ml aspirated at operation. A transition of patterns of relative posterior epicardial-pericardial movement was noted as the pericardial fluid volume increased. More than 15 ml was always found when a posterior echo-free space persisted throughout the cardiac cycle between a flat pericardium relative to the epicardium. In the presence of such a posterior echo-free space, a large anterior echo-free space made a moderately large pericardial effusion likely. In the absence of this diagnostic posterior echo-free space, an anterior echo-free space had no diagnostic significance, as it was found in 11 patients with less than 16 ml of pericardial effusion. A small posterior echo-free space persisting throughout the cardiac cycle between pericardial and epicardial echoes demonstrating virtually identical movements was found in two patients without any surgical evidence for pericardial effusion, but with evidence of adhesive fibrocalcific pericardial disease. A method of estimating pericardial volume is proposed, which uses the difference between the cubed diameters at the end-diastole of the pericardium and epicardium.

Mitral valve prolapse in one hundred presumably healthy young females.

Clinical, electrocardiographic, cpoardiograpbic, and echocardiographic examinations were performed in 100 presumably healthy young females. Treadmill testing and ambulatory electrocardiographc moni.toring were performed in a selected group of these subjects. Phonocardiograms, recorded with the subjects supine at rest, after inhalation of amyl nitrite, and in the upright position, revealed a 17% incidence of nonejection clicks and/or late or mid to late systolic murmurs (PHONO-MSCLSM). Echocardiographic studies were performed in the second, third, fourth, and fifth intercostal space with emphasis on the importance of transducer angulation on the chest. Studies obtained with the transducer perpendicular to the cbest in the sagittal plane, or pointing cephalad at a Owe when both mitral leallets and left atrium are recorded, are opftimal to study the mitral valve systolic motion. With the transducer in this position, 21 subjects were found to have pansystolic or late systolic prolapse, as previously defined on the echocardiogram. The presence of these echocardiographic findings was statistically related to the presence of PHONO-MSCLSM. Other echocartdiographic patterns were identified and their relation to PHONO-MSCLSM and transducer position is discussed. Ten subjects with both echocardiographic evidence of mitral valve prolapse and PHONOMSCLSM were identified (group EP), while 18 other subjects had either echocardiographic or phonocardiographic findings suggestive of mitral valve abnormality (group EorP). Seventy-two subjects had no abnormality (group noEP). The incidence of various clinical, electrocardiographic, and echocardiographic findings in these three groups was determined. Some findings said to be common in patients with proven mitral valve prolapse were seen more frequently in group EP subjects.Echocardiographic and phonocardiographic findings suggesting mitral valve abnormalities were found more commonly than expected in a population of presumably healthy young female.

Differentiation of constrictive pericarditis and restrictive cardiomyopathy by Doppler echocardiography.

Doppler ultrasound recordings of mitral, tricuspid, aortic, and pulmonary flow velocities, and their variation with respiration, were recorded in 12 patients with a restrictive cardiomyopathy and seven patients with constrictive pericarditis. Twenty healthy adults served as controls. The patients with constrictive pericarditis showed marked changes in left ventricular isovolumic relaxation time and in early mitral and tricuspid flow velocities at the onset of inspiration and expiration. These changes disappeared after pericardiectomy and were not seen in patients with restrictive cardiomyopathy or in normal subjects. The deceleration time of early mitral and tricuspid flow velocity was shorter than normal in both groups, indicating an early cessation of ventricular filling, but only patients with restrictive cardiomyopathy showed a further shortening of the tricuspid deceleration time with inspiration. Diastolic mitral and tricuspid regurgitation was also more common in the patients with restrictive cardiomyopathy. These results suggest that patients with constrictive pericarditis and restrictive cardiomyopathy can be differentiated by comparing respiratory changes in transvalvular flow velocities. In addition, although baseline hemodynamics in the two groups were similar, characteristic changes were seen with respiration that suggest differentiation of these disease states may also be possible from hemodynamic data.

Cardiac tamponade and pericardial effusion: Respiratory variation in transvalvular flow velocities studied by Doppler echocardiography☆

Cardiac tamponade has been associated with an abnormally increased respiratory variation in transvalvular blood flow velocities. To determine whether this finding is consistently present in cardiac tamponade, seven patients were studied prospectively with Doppler echocardiography before and after pericardiocentesis and the results were compared with those found in 20 normal adults and 14 asymptomatic patients with pericardial effusion who did not have definite clinical evidence of tamponade. Doppler ultrasound evaluation included measurement of mitral, tricuspid, aortic, pulmonary and central venous flow velocities, as well as left ventricular ejection and isovolumic relaxation times during inspiration, expiration and apnea. In the patients with severe cardiac tamponade, respiratory variation in transvalvular flow velocities and left ventricular ejection and isovolumic relaxation times were markedly increased compared with values in normal subjects and those obtained after pericardiocentesis. In the 14 asymptomatic patients with pericardial effusion but without overt tamponade, 7 showed respiratory variation in flow velocity similar to that of normal subjects. The other seven patients demonstrated increased respiratory change compared with normal, but less than that in the patients with tamponade. Clinical and hemodynamic data in this latter group suggest that these patients may represent an intermediate stage of pericardial effusion with an element of hemodynamic compromise.

TRICUSPID ANNULAR MOTION

Triscupid annular motion is related to right ventricular systolic function in the same way mitral annulus motion is related to left ventricular function. Tricuspid annular excursion reflects the longitudinal motion of the right ventricle, and the systolic descent of the anulus correlates with systolic venous inflow to the right atrium. However, it has not been shown clearly how to reproducibly quantify this motion. Therefore we describe a method to measure triscuspid annular motion using two-dimensional oriented M-mode echocardiography from the apical view. We studied a group of 10 normal subjects (mean age, 28.7 years; range, 25 to 38 years) and a group of 29 patients (mean age, 57.2 years; range, 20 to 84 years) with disease of the left side of the heart but no evidence of involvement of the right side of the heart. In each subject, tricuspid and mitral annular motion were measured respectively at their lateral, septal or medial, anterior, and posterior margin points. The total tricuspid annular motion for normal subjects was, as follows: lateral, 24.9 +/- 3.5 mm; medial, 20.1 +/- 2.5 mm; anterior, 21.6 +/- 3.8 mm; and posterior, 22.3 +/- 2.3 mm. Interobserver and intraobserver variability was low, with a coefficient of variance for the different annular points ranging from 6.19% to 11.56% between observers and from 4.10% to 7.26% within observer. We conclude that it is possible to measure tricuspid annular motion with this method in a reproducible way and to use it as a diagnostic tool in evaluating function of the right side of the heart.

Reliability and reproducibility of two dimensional echocardiographic measurement of the stenotic mitral valve orifice area

Abstract A wide angle phased array sector scanner was used to find the optimal method, the reliability and the reproducibility of measuring the mitral valve area with two dimensional echocardiography in patients with rheumatic mitral stenosis. Initial experience with 18 patients revealed that tracing the early diastolic actual black-white interface of the perceived orifice was the most reliable method for drawing the mitral valve orifice area. Good interobserver correlation was obtained when two observers used either method to calculate the mitral valve area ( r = 0.93). Similarly good intrastudy reliability was obtained when any one observer applied one measurement method to different diastolic cycles within the same study ( r = 0.89). The phased array two dimensional echocardiogram properly differentiated patients with critical mitral stenosis from those with non-critical mitral stenosis, but the correlation between the echocardiographically and the hemodynamically derived mitral valve areas was less good than previously reported ( r = 0.83). Imaging a test object with varied known orifice sizes and excised stenotic mitral valves of known orifice size with a phased array and mechanical sector scanner failed to reveal superiority of either instrument. Further testing with a phased array instrument revealed that the perceived orifice was critically dependent on receiver gains settings for any transmitted power level. Receiver gain settings too low led to image dropout, indicating a falsely large orifice. Receiver gain settings too high led to image saturation, indicating a falsely narrowed orifice. Six additional patients with predominant mitral stenosis later underwent imaging with strict attention paid to individual receiver gain settings. Combining the data from these 6 patients with those from the initial 18 patients gave a better correlation between the echocardiographic and hemodynamic calculated mitral valve areas ( r = 0.92). Accurate noninvasive measurement of the mitral valve area with two dimensional echocardiography in patients with mitral stenosis appears to depend on use of the proper echocardiographic technique to localize the true commissural edge of the valve in early diastole, the correct instrument settings and the appropriate method for drawing the perceived orifice. The noninvasive measurement of the mitral valve orifice with two dimensional echocardiography in mitral stenosis provides clinically useful data that are reliable and reproducible if these factors are taken into account.