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R L Popp

Publications and source records attributed to R L Popp.

At least 235 records · Page 13Linked to original sources

Distribution and morphologic features of coronary artery disease in cardiac allografts: an intracoronary ultrasound study.

The longitudinal distribution and circumferential pattern of coronary intimal proliferation were studied with intravascular ultrasonography in 135 patients after heart transplantation. Eighty-seven (64%) of 135 patients had significant intimal thickening, with most lesions (63%) concentric and free of fibrosis or calcification. Both diffuse and nonuniform longitudinal patterns of intimal thickening were found.

Adult↗

Pitfalls in creation of left atrial pressure-area relationships with automated border detection.

Creation of pressure-area relationships (loops) with automated border detection (ABD) involves correction for the variable inherent delay in the ABD signal relative to the pressure recording. This article summarizes (1) the results of in vitro experiments performed to define the range of, and factors that might influence, the ABD delay; (2) the difficulties encountered in evaluating a thin-walled structure like the left atrium in the dog model; and (3) the solutions to some of the difficulties found. The in vitro experiments showed that the ABD delay relative to high-fidelity pressure recordings ranges from 20 to 34 msec and 35 to 57 msec at echocardiographic frame rates of 60/sec and 33/sec, respectively. The delay was not influenced significantly by the type of transducer used, distance from the target area, or size of the target area. The delay in the ABD signal, relative to the echocardiographic image, ranges from nil to less than one frame duration, whereas it is delayed one to two frame durations relative to the electrocardiogram processed by the imaging system. In the dog model, inclusion of even small areas outside the left atrium rendered curves with apparent physiologic contour but inappropriately long delays of 90 to 130 msec. To exclude areas outside the left atrial cavity, time-gain compensation and lateral gain compensation were used much more extensively than during left ventricular ABD recording. By changing the type of sonomicrometers used in our experiments, we were able to record simultaneously ABD and ultrasonic crystal data. However, both spontaneous contrast originating from a right-sided heart bypass pump and electronic noise from the eletrocautery severely interferred with ABD recording.

Animals↗

Flow velocity acceleration in the left ventricle: a useful Doppler echocardiographic sign of hemodynamically significant mitral regurgitation.

Doppler echocardiography is a sensitive method to detect mitral regurgitation in patients with both native and prosthetic valves. However, estimates of the amount of mitral regurgitation remain semiquantitative, and even severe mitral regurgitation may be underestimated in the presence of markedly eccentric regurgitant jets or acoustic shadowing of the left atrium by mitral or aortic prostheses. This report describes the Doppler findings in 10 patients with severe native valve mitral regurgitation (angiographic grade III or IV) and in 15 patients with severe bioprosthetic mitral regurgitation that required valve replacement. An increase in peak mitral flow velocity above normal values was seen in eight of 10 patients with severe native valve mitral regurgitation (greater than or equal to 130 cm per second) and 11 of 15 patients with severe prosthetic valve mitral regurgitation (greater than or equal to 210 cm per second). One of 10 patients with a native valve and four of 15 patients with a bioprosthetic valve appeared to have only a localized left atrial systolic flow disturbance, incorrectly suggesting that the mitral regurgitation was mild. However, in all patients with severe mitral regurgitation, a low velocity (less than 100 cm per second) flow signal could be recorded in the left ventricle that was directed toward the mitral valve in systole. This flow signal showed a gradual increase in velocity as the sample volume was moved toward the mitral valve, with an abrupt further increase on entry into the left atrium. This signal was continuous with antegrade mitral flow and had the same orientation as mitral regurgitation recorded by continuous wave technique from the apex. A similar flow signal was not recorded in the left ventricle of any individual in a control group of 30 patients who had no mitral regurgitation or who had angiographic grade I or II mitral regurgitation. These findings suggest that acceleration of left ventricle flow toward the mitral valve in systole is only recorded when there is hemodynamically significant mitral regurgitation that is approximately equal to angiographic grade III or IV. Recognition of this Doppler finding may help in the estimation of mitral regurgitation severity, especially in difficult diagnostic situations.

Aged↗

Variability of Doppler echocardiographic indexes of left ventricular filling in transplant recipients and in normal subjects.

This study examines the reproducibility and variability of pulsed wave Doppler versus continuous wave Doppler ultrasound indexes of left ventricular filling in cardiac allograft recipients and in normal subjects. The following indexes were studied: isovolumic relaxation time, pressure half-time, peak early mitral flow velocity, and peak mitral flow velocity after atrial systole. Intraobserver and interobserver variability were assessed by regression analysis. Individual components of variance (subject, reader, beat, day, and tracing) were estimated in a subset of five patients and five normal subjects, and estimated total variance defined for each group. Temporal (day-to-day) variability for 95% confidence was estimated for these patients and for normal subjects. Temporal variability in the group from which the subsets were drawn was measured from absolute and percent change in values on two occasions. Estimated and observed 95% confidence limits were compared. Intersubject variability was the largest component of variance in both transplant recipients and in normal subjects. For all indexes in transplant recipients (in the absence of rejection) and normal subjects, observed absolute mean differences (+/- 2 standard deviations) between values from recordings taken on two different days were larger than the 95% confidence limits estimated from the components of variance analysis. The observed 95% limits for transplant recipients versus normal subjects were as follows: isovolumic relaxation time, 20 msec versus 6 msec; pressure half-time, 16 msec versus 9 msec; peak early mitral flow velocity, 32 cm per second versus 17 cm per second; and peak mitral flow velocity after atrial systole, 28 cm per second versus 10 cm per second.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Improvement in left ventricular diastolic filling by septal myectomy in hypertrophic cardiomyopathy.

Abnormalities in left ventricular diastolic function or filling are considered to be responsible for some of the symptoms in patients with hypertrophic cardiomyopathy. To clarify whether the abnormalities in left ventricular diastolic filling are improved by septal myectomy, 13 patients with hypertrophic cardiomyopathy and intracavitary pressure gradient were studied preoperatively and postoperatively by use of pulsed Doppler echocardiography. Peak early diastolic filling velocity (E), the ratio of peak early diastolic filling to peak atrial filling velocities (E/A ratio), and deceleration time were measured from the transmitral flow velocity pattern before and after septal myectomy. Although E and E/A ratio did not change after septal myectomy, deceleration time significantly shortened from 314 +/- 72 to 271 +/- 53 milliseconds (n = 10; p less than 0.05). Further, if seven patients with significant changes in heart rate (greater than 30%) or in the Doppler-determined severity of mitral regurgitation (more than one degree) were excluded (because these parameters may effect E and E/A ratio), there were also significant changes in E (81 +/- 21 versus 98 +/- 25 cm/sec, p less than 0.05) and in E/A ratio (0.84 +/- 0.17 versus 1.14 +/- 0.33, p less than 0.05). Because left ventricular systolic function has been demonstrated to remain constant or to decrease by most measures after septal myectomy, relief of some symptoms may be largely the result of the improvement in diastolic filling suggested by these criteria.

Adult↗

Left ventricular diastolic dysfunction in end-stage dilated cardiomyopathy: simultaneous Doppler echocardiography and hemodynamic evaluation.

Left ventricular diastolic dysfunction is an integral component of end-stage dilated cardiomyopathy. To better characterize this disorder we studied 15 patients undergoing catheterization during cardiac transplant screening evaluation. Pulsed-wave Doppler echocardiographic recordings of mitral inflow were obtained with simultaneous high-fidelity left ventricular and phase-corrected pulmonary capillary wedge pressures. Doppler-derived isovolumic relaxation times were within normal limits, despite a prolonged coefficient of relaxation (tau), and correlated with pulmonary capillary wedge--left ventricular crossover pressure. Peak velocity of early diastolic filling was similar to that reported in normal subjects and did not correlate with crossover pressure or tau. Early diastolic acceleration and deceleration times were shortened compared with reported normal values. Acceleration time correlated with mean negative dP/dt from mitral valve opening to left ventricular minimum pressure and with crossover pressure, and deceleration time correlated with mean dP/dt from left ventricular minimum pressure to the peak of the rapid filling wave. Late diastolic filling at atrial contraction was absent in 12 patients, all of whom had a significant early diastolic rapid filling wave and an elevated end-diastolic pressure. Despite an increase in pulmonary capillary wedge pressure during atrial contraction, the failing ventricles were unable to generate detectable forward transmitral flow. Poor cardiac pump function was shown by low left ventricular stroke volume, which correlated with the diastolic flow velocity integral. Thus, in end-stage cardiomyopathy, the transmitral flow velocity pattern is characterized by normal peak early filling velocity, low normal isovolumic relaxation time, shortened acceleration and deceleration times of early diastolic flow, decreased early flow velocity integral, and absent or decreased filling during atrial contraction. This pattern reflects interaction between elevated transmitral driving pressure and the compromised relaxation and compliance of a left ventricle functioning on an elevated pressure-volume curve.

Adult↗

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.

Adult↗

Features of mildly dilated congestive cardiomyopathy compared with idiopathic restrictive cardiomyopathy and typical dilated cardiomyopathy.

Congestive cardiomyopathy was recognized in eight patients with only mildly dilated ventricles (an echocardiographic ventricular diastolic dimension index of less than 10% to 15% above the normal range) but with other features typical of end-stage congestive cardiomyopathy. Such patients with mildly dilated cardiomyopathy (MDCM) represented 5% of heart transplant recipients with cardiomyopathy, who were analyzed by us. The clinical, echocardiographic, and hemodynamic data, as well as the gross and microscopic pathologic findings of the hearts in this group were compared with similar data in five patients with idiopathic restrictive cardiomyopathy (IRCM) and 10 patients with typical dilated cardiomyopathy (DCM). Compared with IRCM and DCM, patients with MDCM had a higher incidence of familial cardiomyopathy (p less than 0.009). The echocardiographic features of patients with MDCM and DCM were virtually identical, showing globular hearts with predominant left ventricular dilation and diffuse poor left ventricular contraction. Patients with IRCM had marked atrial dilation but less abnormality of left ventricular size and contraction parameters. On the basis of echocardiographic data, patients with IRCM and MDCM could be well segregated. Cardiac index and light microscopic examinations were similar in the three groups. However, electron microscopy showed a lack of myofibrillar loss in patients with IRCM, little or no myofibrillar loss in those with MDCM, and almost total myofibrillar loss in those with DCM. Patients with MDCM have a high prevalence of familial cardiomyopathy. Absolute heart size and electron microscopic features of the MDCM group were intermediate between IRCM and DCM, but other clinical, echocardiographic and hemodynamic findings were similar to typical DCM.

Adolescent↗

Echocardiographic contrast increases the yield for right ventricular pressure measurement by Doppler echocardiography.

Doppler ultrasound has become accepted as a measurement of right ventricular systolic pressure in patients who have a quantifiable signal from tricuspid regurgitation. This study evaluated the use of intravenous injection of saline solution for echo contrast to increase the percentage of quantifiable tricuspid regurgitant signals in patients who have any detectable tricuspid regurgitation at baseline. Patients underwent a standard Doppler evaluation, followed by a contrast study with the injection of 4 to 6 ml of agitated saline solution into a brachial vein. Baseline and contrast tricuspid regurgitant signals were assessed for quality, quantifiability, and reproducibility of the derived pressures by three observers on two occasions. The average absolute pairwise deviation among the three observers was low: 1.6 mm Hg (standard deviation, 1.4 mm Hg). The intraobserver mean discrepancy was low: 0.03 mm Hg (standard deviation, 2.33 mm Hg). Patients who did not have tricuspid regurgitation (n = 10) failed to develop such regurgitation during contrast injection. Only eight of 40 patients (20%) who had trace or mild tricuspid regurgitation had quantifiable baseline signals, but 34 patients (85%) had quantifiable signals with contrast injection. All patients who had mild to moderate, moderate, or severe tricuspid regurgitation (n = 10) had quantifiable signals before contrast injection. Of all patients who had any tricuspid regurgitation, 88% had quantifiable signals with contrast injection. Echo contrast was shown to improve the yield of quantifiable signals in patients who had trace and mild tricuspid.

Adult↗

Assessment of left ventricular wall motion abnormalities with the use of color kinesis: a valuable visual and training aid.

Accurate interpretation of left ventricular segmental wall motion by echocardiography is an important yet difficult skill to learn. Color-coded left ventricular wall motion (color kinesis) is a tool that potentially could aid in the interpretation and provide semiquantification. We studied the usefulness of color kinesis in 42 patients with a history of congestive cardiomyopathy who underwent two-dimensional echocardiograms and a color kinesis study. The expert's reading of the two-dimensional wall motion served as a reference for comparison of color kinesis studies interpreted by the expert and a cardiovascular trainee. Correlation between two-dimensional echocardiography and the expert's and trainee's color coded wall motion scores were r = 0.83 and r = 0.67, respectively. Reproducibility between reviewers and between operators was also assessed. Interobserver variability for color-coded wall motion showed a correlation of r = 0.78. Correlation between operators was also good; r = 0.84. Color kinesis is reliable and appears promising as an adjunct in the assessment of wall motion abnormalities by echocardiography. It is both a valuable visual aid, as well as a training aid for the cardiovascular trainee.

Adult↗