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R L Popp

Publications and source records attributed to R L Popp.

At least 19 recordsLinked to original sources
PubMed1996

Coronary artery intimal thickening in the transplanted heart. An in vivo intracoronary untrasound study of immunologic and metabolic risk factors.

This study examined the hypothesis that immunologic factors are the major correlates of coronary artery intimal thickening and luminal stenosis. The study population included 116 adult heart transplant recipients with a mean age of 44.7 +/- 12.0 years (89 men and 27 women) undergoing annual coronary angiography and intracoronary ultrasound 3.4 +/- 2.7 (range, 1.0-14.6) years after transplantation. Mean intimal thickness was obtained from several distinct sites along the left anterior descending and/or left circumflex coronary artery by intracoronary ultrasound. Coronary artery stenosis defined by angiography was classified as mild (< 30% luminal stenosis), moderate (> or = 30-70% luminal stenosis), or severe (> 70% luminal stenosis or diffuse pruning of distal vessels). Prevalence of any transplant coronary artery disease (TxCAD) was 85% by intracoronary ultrasound and 15% by angiography. By multiple regression analysis, only average fasting plasma triglyceride level (P < 0.006) and average weight (P < 0.007) were significantly correlated with severity of intimal thickening (R = 0.54, P < 0.0001). Donor age (P < 0.006) and average fasting plasma triglyceride level (P < 0.009) were significantly correlated with stenosis by angiography. Correlation of multiple immunologic and metabolic factors with intimal thickness by univariate analysis suggests a multifactorial etiology for TxCAD. Among the multiple univariate correlates of TxCAD, higher fasting plasma triglyceride levels and body weight are the only independent correlates of TxCAD. The absence of acute rejection as an independent predictor of intimal thickening suggests that mechanisms beyond those mediating typical cellular rejection should be targeted for advancing our understanding of Tx-CAD.

Adult↗
PubMed1996

Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma.

OBJECTIVES: The purpose of this study was to evaluate the diagnostic accuracy of biplane and multiplane transesophageal echocardiography in patients with suspected aortic dissection, including intramural hematoma. BACKGROUND: Transesophageal echocardiography is a useful technique for rapid bedside evaluation of patients with suspected acute aortic dissection. The sensitivity of transesophageal echocardiography is high, but the diagnostic accuracy of biplane and multiplane transesophageal echocardiography for dissection and intramural hematoma is less well defined. METHODS: We studied 112 consecutive patients at a major referral center who had undergone biplane or multiplane transesophageal echocardiography to identify aortic dissection. The presence, absence and type of aortic dissection (type A or B, typical dissection or intramural hematoma) were confirmed by operation or autopsy in 60 patients and by other imaging techniques in all. The accuracy of transesophageal echocardiography for ancillary findings of aortic dissection (intimal flap, fenestration and thrombosis) was assessed in the 60 patients with available surgical data. RESULTS: Of the 112 patients, aortic dissection was present in 49 (44%); 10 of these had intramural hematoma (5 with and 5 without involvement of the ascending aorta). Of the remaining 63 patients without dissection, 33 (29%) had aortic aneurysm and 30 (27%) had neither dissection nor aneurysm. The overall sensitivity and specificity of transesophageal echocardiography for the presence of dissection were 98% and 95%, respectively. The specificity for type A and type B dissection was 97% and 99%, respectively. The sensitivity and specificity for intramural hematoma was 90% and 99%, respectively. The accuracy of transesophageal echocardiography for diagnosis of acute significant aortic regurgitation and pericardial tamponade was 100%. CONCLUSIONS: Biplane and multiplane transesophageal echocardiography are highly accurate for prospective identification of the presence and site of aortic dissection, its ancillary findings and major complications in a large series of patients with varied aortic pathology. Intramural hematoma carries a high complication rate and should be treated identically with aortic dissection.

Acute Disease↗
PubMed1995

Influence of preexistent donor coronary artery disease on the progression of transplant vasculopathy. An intravascular ultrasound study.

BACKGROUND: Transplant vasculopathy (TxCAD) limits longterm survival of allograft recipients. The possibility that preexistent donor coronary disease (PEDD) might accelerate this process is of concern. The serial progression of sites with and without PEDD as assessed by intravascular ultrasonic imaging is explored in this study. METHODS AND RESULTS: Thirty patients with baseline intravascular imaging within 3 weeks of cardiac transplantation who had at least one annual follow-up study were included in this study. Vessel luminal area (LA), total area (TA), intimal index (II = TA - LA/TA), mean intimal thickness (MIT), and Stanford classification were expressed for each image site and for each patient at each study. Progression of sites and of patients with and without PEDD on the baseline study was compared. Patients with PEDD (n = 9) still had significantly more intimal disease than those without PEDD (n = 21) at the first follow-up study (MIT = 0.35 +/- 0.13 versus 0.13 +/- 0.11 mm; II = 0.29 +/- 0.11 versus 0.11 +/- 0.1; class = 3.7 +/- 0.5 versus 2.2 +/- 0.94; P < .001 for all comparisons). However, the increase in intimal thickness during the 1- year interval was not significantly different between the two groups. In 4 patients in whom both types of sites were present, no difference in progression was found. Data were similar for patients and sites studied over > 1 year. CONCLUSIONS: PEDD does not accelerate the progression of TxCAD within the first few years after cardiac transplantation. The pathophysiology of TxCAD is most likely immune mediated and does not seem to be accelerated by native coronary artery disease.

Adult↗
PubMed1995

Incidence and severity of transplant coronary artery disease early and up to 15 years after transplantation as detected by intravascular ultrasound.

OBJECTIVES: The purpose of this study was to quantify the severity of transplant coronary artery disease and to assess lesion characteristics early and up to 15 years after heart transplantation by using intracoronary ultrasound. BACKGROUND: Intravascular ultrasound has the ability to measure the components of the arterial wall and has been shown to be a sensitive method for detection of transplant coronary artery disease. METHODS: A total of 304 intracoronary ultrasound studies were performed in 174 heart transplant recipients at baseline and up to 15 (mean 3.3 +/- 0.2) years after transplantation. Mean intimal thickness and an intimal index were calculated, and lesion characteristics (eccentricity, calcification) were assessed for all coronary sites imaged (mean 3.0 +/- 0.1 sites/study). The Stanford classification was used to grade lesion severity. RESULTS: Compared with findings in patients studied at baseline (< 2 months after transplantation, n = 50), mean intimal thickness (0.09 +/- 0.02 vs. 0.16 +/- 0.02 mm, p < 0.01), intimal index (0.07 +/- 0.01 vs. 0.14 +/- 0.02, p < 0.01) and mean severity class (1.5 +/- 0.2 vs. 2.3 +/- 0.2, p < 0.01) were significantly higher at year 1 (n = 52) after transplantation. Thereafter, all three variables further increased over time and reached highest values between years 5 and 15. Calcification of lesions was detected in 2% to 12% of studies up to 5 years after transplantation, with a significant increase to 24% at years 6 to 10 (p < 0.05). CONCLUSIONS: Severity of transplant coronary artery disease appeared to progress with time after transplantation in this cross-sectional study. This characteristic was most prominent during the 1st 2 years after transplantation, whereas calcification of plaques occurred to a significant extent only later in the process. These data may serve as a reference for comparison of intravascular ultrasound findings in other studies of patients with transplant coronary artery disease.

Adult↗
PubMed1994

Filling patterns in left ventricular hypertrophy: a combined acoustic quantification and Doppler study.

OBJECTIVES: The purpose of this study was to evaluate the potential of acoustic quantification compared with Doppler echocardiography for assessment of left ventricular diastolic dysfunction. BACKGROUND: Diastolic dysfunction usually accompanies left ventricular hypertrophy. Although Doppler echocardiography is widely used, it has known limitations in the diagnosis of diastolic abnormalities. The ventricular area-change waveform obtained with acoustic quantification technology may provide an alternative to assess diastolic dysfunction. METHODS: Potential acoustic quantification variables (peak rate of area change and mean slope of area change rate during rapid filling, amount of relative area change during rapid filling and atrial contraction) were obtained and compared with widely used Doppler indexes of ventricular filling (isovolumetric relaxation time, pressure half-time, peak early diastolic velocity/peak late diastolic velocity ratio, rapid filling, atrial contribution to filling) in 16 healthy volunteers and 30 patients with left ventricular hypertrophy. RESULTS: Criteria for abnormal relaxation were present in 68% of patients by acoustic quantification and in 64% of patients by Doppler echocardiography. However, abnormal relaxation was identified in 80% of patients by one or both methods. Acoustic quantification indicated abnormal relaxation in the presence of completely normalized Doppler patterns and in patients with mitral regurgitation or abnormal rhythm with unreliable Doppler patterns. CONCLUSIONS: Acoustic quantification potentially presents a new way to assess diastolic dysfunction. This technique may be regarded as complementary to Doppler echocardiography. The combined use of the methods may improve the diagnosis of left ventricular relaxation abnormalities.

Acoustics↗
PubMed1994

Feasibility of serial intracoronary ultrasound imaging for assessment of progression of intimal proliferation in cardiac transplant recipients.

BACKGROUND: Serial quantitative coronary angiography is used to assess progression of coronary disease; however, pathology studies have demonstrated angiographic insensitivity for determining atheroma. Intracoronary ultrasound (ICUS) can define and measure the components of the arterial wall and offers the potential for precise quantitative assessment of disease progression on serial examinations. The present study was done to test the feasibility of serially assessing intimal proliferation at the same coronary site with ICUS imaging in cardiac transplant recipients. METHODS AND RESULTS: ICUS imaging was done with a 30-MHz, 5F or 4.3F ultrasound imaging catheter at the time of angiography in 70 cardiac allografts (3.8 sites per patient) initially and 1 year later. Mean intimal thickness (IT), luminal area (LA), and total area (TA) of lumen plus intima and an index of intimal thickness (II = TA - LA/TA) were measured at each site. Additionally, vessels were graded using a scale incorporating criteria of intimal thickness and circumferential involvement. Side-by-side comparisons of paired angiograms were performed both to verify the similarity of ICUS imaging site and to detect new angiographic abnormalities. At least one site could be assessed serially by ICUS in 100% of patients, but only 189 of the original 263 coronary sites (72%) (2.7 sites per patient) could be matched satisfactorily on the second study. Thirty-nine patients (56%) had mild IT and 31 patients (44%) had moderate or severe IT on the initial study. Both groups showed the same IT progression the following year (delta = 0.05 +/- 0.13 versus 0.07 +/- 0.15 mm; P = NS). Twenty-seven of the 70 patients (39%) showed progression by ICUS. The 23 patients with ICUS progression and angiographically normal vessels had the same progression in intimal thickening as the 4 patients with ICUS progression but showing angiographic disease (delta = 0.17 +/- 0.13 versus 0.22 +/- 0.10 mm; P = NS). CONCLUSIONS: Replication of the intracoronary imaging site by judgment of two observers at an initial study and at a second study 1 year later was possible in at least one vessel site in 100% of the 70 patients and in 72% (189 of 263) of the original imaging sites (2.7 sites per patient). Serial ICUS demonstrates progression of intimal thickening at specific sites in only some cardiac transplant patients. Progression of intimal proliferation can occur in individuals in the presence or absence of initially increased intimal thickening or of angiographic disease at the time of the initial studies. Angiography is insensitive for recognizing early intimal thickening of the coronary vessels.

Adolescent↗
PubMed1993

The relevance to clinical practice of the certifying examination in internal medicine.

OBJECTIVE: To determine the relevance of the initial certifying examination to the practice of internal medicine and the suitability of items used in initial certification for recertification. DESIGN: Using a matrix-sampling approach, items from the 1991 Certifying Examination were assigned to two sets of judges: directors of the American Board of Internal Medicine (ABIM) and practicing general internists. Each judge rated the relevance of items on a five-point scale. PARTICIPANTS: 54 current or former directors of the ABIM and 72 practicing general internists; practitioners were nominated by directors and their ratings were included if they spent > 80% of their time in direct patient care. RESULTS: The directors' mean rating of all 576 items was 3.98 (SD = 0.62); the practitioners' mean rating was 4.11 (SD = 0.82). The directors assigned to 27 items ratings of less than 3 and the practitioners assigned to 42 items ratings of less than 3; seven of these items received low ratings from both groups. There were differences in the two groups' ratings of the relevance of various medical content categories, but the mean rating of core items was higher than that of noncore items and the mean rating of items testing clinical judgment was higher than that of items testing knowledge or synthesis. CONCLUSIONS: These findings suggest that the initial certifying examination is relevant to clinical practice and that many of the examination items are suitable for use in recertification. Differences in perception appear to exist between practitioners and directors, and the use of practitioner ratings is likely to be a routine part of judging the suitability of items for Board examinations in the future.

Certification↗
PubMed1993

Comparison of acoustic quantification and Doppler echocardiography in assessment of left ventricular diastolic variables.

OBJECTIVE: To assess the haemodynamic correlations of the waveforms of left ventricular area change obtained by automated boundary detection with newly developed acoustic quantification technology. DESIGN: The timing of events in the cardiac cycle was identified on the wave-form automated boundary detection and was correlated with the corresponding timing derived from pulsed wave Doppler flow velocity traces of the mitral valve and left ventricular outflow tract. The amounts of area change during the rapid filling phase and during atrial contraction were correlated with the time-velocity integrals of early and late diastolic ventricular filling obtained from Doppler tracings of the mitral inflow. SETTING: A university medical school echocardiography laboratory. SUBJECTS: 16 healthy volunteers and 19 patients referred for echocardiographic studies. RESULTS: A significant correlation was found between the methods for measurement of the time from the R wave to mitral valve opening (r = 0.72, p < 0.01), isovolumic relaxation time (r = 0.62, p < 0.01), and ejection time (r = 0.54, p < 0.01). The change of total area that occurred during rapid filling and atrial filling phases measured from the acoustic waveform correlated with the time-velocity integrals of the early and late diastolic mitral valve inflow velocity derived from Doppler echocardiography (r = 0.60 and r = 0.80, respectively). CONCLUSION: The waveform of left ventricular area obtained by the automated boundary detection technique identifies the phases of the cardiac cycle and correlates with Doppler values of left ventricular diastolic function. Therefore, this new method of automated boundary detection has potential uses in the assessment of left ventricular diastolic function.

Acoustics↗
PubMed1993

Immediate and one-year safety of intracoronary ultrasonic imaging. Evaluation with serial quantitative angiography.

BACKGROUND: Intracoronary ultrasound (ICUS) has the ability to quantitatively evaluate vessel wall morphology and is well suited for serial studies of coronary artery disease regression and progression. However, the potential risk for catheter-induced endothelial damage and accelerated atherosclerosis in instrumented vessels is a concern. The acute effects as well as the 1-year safety of ICUS regarding its impact on the atherosclerotic process were assessed. METHODS AND RESULTS: The acute studies include 240 intracoronary studies performed in 170 cardiac transplant recipients. Patients were systematically heparinized. Only vessels > or = 2 mm in diameter were visualized. Coronary arteries of 38 patients were measured by quantitative coronary angiography in matched angiograms at an interval of 1 year after the initial ICUS examination was performed to assess long-term effects. The angiographic measurements in the previously instrumented and noninstrumented vessels were compared. Forty-nine vessels that had been imaged (IM) in these 38 patients with a 5F ICUS catheter were compared with 61 vessels not previously imaged (NIM) in the same patients. Absolute and percentage change in angiographically measured mean vessel diameters in the ICUS imaged and nonimaged segments were compared. Despite pretreatment with nitroglycerin, 20 patients (8.3%) had angiographically evident coronary spasm. In all cases, this was reversed by giving nitroglycerin. One year after the original imaging study, no difference was noted between imaged and nonimaged vessels in change in absolute vessel diameter (IM, -0.11 +/- 0.28 mm vs NIM, -0.07 +/- 0.22 mm; P = .49) or in percentage change in diameter (IM, -5 +/- 11% vs NIM, -3 +/- 7%; P = .32). CONCLUSIONS: Intracoronary ultrasound in cardiac transplant recipients was associated with no clinical morbidity and a low incidence of vessel spasm in large and medium-size coronary arteries. It does not accelerate progression of angiographically quantifiable coronary artery disease. This study suggests that ICUS can be safely used even in coronary arteries not undergoing interventions.

Cardiac Catheterization↗