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Biomedical subjects

J A Rumberger

Publications and source records attributed to J A Rumberger.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cardiac production of angiotensin II and its pharmacologic inhibition: effects on the coronary circulation.

Angiotensin II (AII), produced systemically as well as locally in the heart, affects the coronary circulation, as do consequences of its pharmacologic inhibition. AII is a powerful vasoconstrictor directly acting on vascular smooth muscle cells, modulating sympathetic innervation and calcium ion influx, and releasing other vasoconstrictor factors. In addition to these immediate actions, AII has longer-term biologic actions that influence cardiac endothelial function, vascular smooth muscle cell phenotype expression, and fibroblast proliferation. Moreover, the production of AII is interrelated with the vasodilator substances bradykinin, nitric oxide, and prostaglandins E2 and I2 (prostacyclin). Circulating hormonal actions of AII include fluid retention, direct vasoconstriction, and sympathetic neuromodulation, all resulting in increased left ventricular preload and afterload. Because of these local and hormonal characteristics, AII can immediately affect the myocardial balance of metabolic demand and supply and long term can induce structural vascular and myocardial alterations. Pharmacologic inhibition of AII production likely conveys myocardial and vascular protection in situations of acute myocardial oxygen debt. In the long term, inhibition of AII may attenuate structural changes in the coronary microcirculation related to various cardiomyopathies or acute tissue injury, and direct antiatherogenic effects may also occur.

Angiotensin II↗
PubMed1998

Angiographic correlates of "spotty" coronary artery calcium detected by electron-beam computed tomography in patients with normal or near-normal coronary angiograms.

To characterize relations between coronary plaque formation, focal, "spotty" coronary calcified lesions, and luminal narrowing, coronary calcium was examined by electron-beam computed tomography in 49 patients with normal or near-normal angiograms. Based on a coronary segmental analysis and on a patient-by-patient analysis, spotty coronary calcium was associated with slight angiographic changes consistent with early atherosclerotic disease and compensatory arterial remodeling.

Adult↗
PubMed1998

Arterial calcification and not lumen stenosis is highly correlated with atherosclerotic plaque burden in humans: a histologic study of 723 coronary artery segments using nondecalcifying methodology.

OBJECTIVES: This study was designed to evaluate whether calcium deposition in the coronary arteries is related to atherosclerotic plaque burden and narrowing of the arterial lumen. BACKGROUND: Many studies have recently documented the feasibility of electron beam computed tomography to detect and quantify coronary artery calcification in patients. Although these studies suggest a general relation between calcification and severity of coronary artery disease, the value of coronary calcium in defining atherosclerotic plaque and coronary lumen narrowing is unclear. Previous pathologic comparisons have failed to detail such a relation in identical histologic sections. This finding may be due to atherosclerotic remodeling. METHODS: A total of 37 nondecalcified coronary arteries were processed, sectioned at 3-mm intervals (723 sections) and evaluated by computer planimetry and densitometry. RESULTS: A significant relation between calcium area and plaque area was found on a per-heart basis (n = 13, r = 0.87, p < 0.0001), per-artery basis (left anterior descending coronary artery [LAD]: n = 13, r = 0.89, p < 0.0001; left circumflex coronary artery [LCx]: n = 11, r = 0.7, p < 0.001; right coronary artery [RCA]: n = 13, r = 0.89, p < 0.0001) and per-segment basis (n = 723, r = 0.52, p < 0.0001). In contrast, a poor relation existed between residual histologic lumen area and calcium area for individual hearts (r = 0.48, p = NS), individual coronary arteries (LAD: r = 0.59, p = NS; LCx: r = 0.10, p = NS; RCA: r = 0.59, p = NS) and coronary segments (r = 0.07, p = NS). Longitudinal changes in external elastic lamina areas were highly correlated with changes in plaque area values (r = 0.60, p < 0.0001), whereas lumen area did not correlate with plaque size change (r = 0.01, p = NS). CONCLUSIONS: Coronary calcium quantification is an excellent method of assessing atherosclerotic plaque presence at individual artery sites. Moreover, the amount of calcium correlates with the overall magnitude of atherosclerotic plaque burden. This study suggests that the remodeling phenomenon is the likely explanation for the lack of a good predictive value between lumen narrowing and quantification of mural calcification.

Adult↗
PubMed1998

Measuring the effect of risk factors on coronary atherosclerosis: coronary calcium score versus angiographic disease severity.

OBJECTIVES: This study sought to determine whether noninvasive quantification of coronary calcium is comparable to selective coronary angiography in measuring the effect of cardiovascular risk factors on coronary atherosclerosis. BACKGROUND: Electron beam computed tomography (EBCT) allows the delineation of anatomic coronary atherosclerotic disease and may be useful for noninvasively defining the role of established and new cardiovascular risk factors in selected patient groups. METHODS: A total of 211 consecutive patients, 26 to 79 years old, referred for evaluation of suspected or recently diagnosed coronary artery disease were examined. Selective coronary angiography was used to define five angiographic disease categories: normal coronary arteries, nonobstructive disease and one-, two- or three-vessel disease. EBCT was used to calculate coronary calcium scores, and cardiovascular risk, including lipid variables and fibrinogen levels, was assessed. RESULTS: Coronary calcium score and angiographic disease severity categories were largely predicted by identical risk factors (i.e., age, male gender, total/high density lipoprotein cholesterol ratio, fibrinogen) and, to a lesser degree, hypertension. Only smoking predicted angiographic disease severity but not calcium scores. The risk factors together explained a comparable proportion of the variability in angiographic disease categories and in calcium score quintiles (33% vs. 41%, p=0.16 by bootstrap analysis). An overall risk score composed of these risk factors separated angiographic disease categories and calcium score quintiles with a similar area under the receiver operating characteristic curve ([mean+/-SE] 0.81+/-0.03 vs. 0.83+/-0.03, p=NS). CONCLUSIONS: Quantification of coronary calcium is comparable to selective coronary angiography in measuring the effect of established cardiovascular risk factors on coronary atherosclerosis. Thus, EBCT may be useful for the noninvasive evaluation of the relations between conventional or developing cardiovascular risk factors and coronary atherosclerosis.

Adult↗
PubMed1998

Intravenous electron-beam computed tomographic coronary angiography for segmental analysis of coronary artery stenoses.

OBJECTIVES: We sought to identify and localize significant coronary stenoses on a segmental basis by electron-beam computed tomography (EBCT) and intravenous administration of a contrast agent. BACKGROUND: The clinical applicability and limitations of intravenous EBCT coronary angiography have not been defined. METHODS: EBCT was performed within 24 h of selective coronary angiography (SCA) in 28 patients (19 men and 9 women, mean [+/-SD] age 60 +/- 10 years). After examination for coronary calcium, EBCT coronary angiography was performed using overlapping slices (in-plane resolution 0.34 to 0.41 mm) with a nominal slice thickness of 1 mm. Based on quantitative analysis of SCA, lumen diameter narrowing > or = 50% (i.e., significant stenoses) was evaluated in 8 (major) or 12 (including side branches) coronary artery segments, using both two-dimensional (tomographic) and three-dimensional (volume) data sets. RESULTS: Of the 330 segments assessable by SCA, 237 (72%) were visualized by EBCT. The sensitivity (+/-SE) for detection of significant stenoses was 82 +/- 6%; specificity was 88 +/- 2%; positive and negative predictive values were 57 +/- 7% and 96 +/- 2%, respectively; and overall accuracy was 87 +/- 2%. If only eight (major) coronary artery segments were considered, 194 (88%) of 221 segments were visualized, and the overall accuracy was 90 +/- 2%. Seven (18%) of 38 significantly stenotic segments were classified as having < 50% stenoses by EBCT. Six of these segments (86%), but only 9 (29%) of the 31 correctly classified stenotic segments, were severely calcified (area > 20 mm2, p = 0.02). In 23 (12%) of 199 nonstenotic segments falsely classified as having > or = 50% stenosis by EBCT, the lumen diameter was significantly smaller than that of the segments correctly classified as negative (mean [+/-SD] 1.5 +/- 0.8 vs. 2.9 +/- 1.1 mm, p < 0.001). CONCLUSIONS: Intravenous EBCT coronary angiography allows for accurate segmental evaluation of significant disease in the major coronary arteries and may be of value for ruling out significant disease. The main determinant of false negative results is substantial segmental calcification, whereas the main determinant of false positive results is small vessel size.

Adult↗
PubMed1998

Reproducibility of right and left ventricular volume measurements by electron-beam CT in patients with congestive heart failure.

UNLABELLED: The applicability and reproducibility of electron-beam computed tomography (EBCT) was tested to define left and right ventricular volumes in patients with congestive heart failure in a clinical setting. METHODS: Ten patients (mean age 64 +/- 11 years) with dilated hearts and stable congestive heart failure (functional class III-IV) were studied. After determination of the individual circulation time, two serial short axis polytomographic EBCT studies were performed within a mean interval of 14.8 +/- 10 days. Following intravenous contrast administration, biventricular end-diastolic volumes (LVEDV, RVEDV), end-systolic volumes (LVESV, RVESV), and left ventricular muscle mass (LVMM) were determined using previously developed techniques. RESULTS: Adequate contrast opacification in both ventricular cavities was obtained in all patients at baseline and at follow-up. Values were 323.4 +/- 99.3 (mean +/- SD) and 332.6 +/- 105.4 ml for LVEDV, 249.3 +/- 75.6 and 250.5 +/- 79.3 ml for LVESV, 236.8 +/- 56.2 and 251.2 +/- 72.7 ml for RVEDV, 179.8 +/- 76.4 and 188.3 +/- 64.0 ml for RVESV, and 207.7 +/- 70.6 and 204.9 +/- 81.9 g for LVMM (p = NS, respectively, paired t-test). Linear regression analysis correlating biventricular volumes and left ventricular muscle mass measurements in the serial scans yielded r-values in the range of 0.89 to 0.95 and a small SEE. The SE of the mean differences between left and right ventricular ejection fraction measurements was 1 point, respectively. CONCLUSION: EBCT studies of ventricular volumes in patients with dilated hearts and congestive heart failure are highly reproducible and offer the potential for serial assessment of these patients in whom quantitation of ventricular volumes has been shown to be of prognostic value.

Cardiac Volume↗
PubMed1998

Measurement of myocardial infarct size by electron beam computed tomography: a comparison with 99mTc sestamibi.

RATIONALE AND OBJECTIVES: The authors sought to determine, using a variety of regional left ventricular ejection fraction (EF) and wall thickening (WTh) criteria, the applicability to measure left ventricular (LV) infarct size using electron-beam CT (EBCT) in patients as compared with technetium 99m (99mTc) sestamibi scanning as reference standard. METHODS: Twelve patients (age 57 +/- 11 years) underwent 99mTc sestamibi scanning and EBCT at hospital discharge after an acute index anterior myocardial infarction. Left ventricular infarct size was defined using standard 99mTc sestamibi scanning. Regional EF and WTh were analyzed on each EBCT scan with use of a floating epicardial centroid method. In five contiguous LV tomograms, the amount of infarcted myocardium was estimated using the following EF and WTh criteria: EF < or = 35%, 30%, 25%, 20%, and WTh < or = 2 mm, 1 mm, and 0 mm. RESULTS: Infarct size measured with 99mTc sestamibi was 33.3% (+/- 18.3%) (mean +/- SD, range 6%-54%) of the LV. Using an EF < or = 35% or absolute WTh < or = 2 mm as criteria for infarcted myocardium, EBCT yielded 28% (+/- 17%) and 27% (+/- 16%), respectively (P = NS, paired Student's t test, versus 99mTc sestamibi). Although, with use of the other criteria, EBCT tended to underestimate infarct size compared with 99mTc sestamibi, a close correlation across the entire range of infarct size determinations (range, 0.72-0.82) regardless of the underlying criteria suggested an internal consistency of the data. CONCLUSIONS: Quantitative analysis of regional myocardial function by EBCT allows an estimate of anterior infarct size when compared with 99mTc sestamibi. This suggests that in addition to previously established applications after acute myocardial infarction such as examination of cardiac volumes and mass, EBCT also may provide for infarct size determination.

Adult↗
PubMed1997

Quantitative evaluation of regional myocardial perfusion using fast X-ray computed tomography.

Clinical quantitation of regional myocardial perfusion using a minimally invasive and easily applied technique could allow for ready quantitation of the functional significance of coronary disease, allow for further understanding of flow reserve in various cardiomyopathic and hemodynamic overload (pressure versus volume) conditions, and possibly provide basic information needed regarding the development and clinical significance of coronary collateral vessels and diseases of the myocardial microcirculation. Electron beam CT (EBCT) is a unique cardiac imaging modality that allows for rapid acquisition tomographic slices of the heart with excellent spatial resolution. It has been demonstrated to provide accurate measurements of cardiac anatomy, biventricular function, myocardial mass, and estimates of mural atherosclerotic plaque burden via quantification of coronary calcium. The application of classical indicator techniques for use by fast x-ray computed tomography techniques such as electron beam CT has been shown to allow quantitative analysis of regional myocardial perfusion throughout the myocardium. Initial studies using central intravenous contrast injection in experimental animals showed a close correlation of regional myocardial perfusion as quantitated by electron beam CT with measurements using radiolabeled microspheres at resting and moderately increased flow states. At high flow states, however, electron beam CT significantly underestimated absolute myocardial perfusion and thus myocardial flow reserve. Using another fast CT device, the Dynamic Spatial Reconstructor (DSR), concepts of intramyocardial vascular blood volume and its relation to myocardial flow have been established. By adapting these concepts to electron beam CT scanning and accounting for the increase in intramyocardial vascular blood volume at vasodilatation, the ability to correctly quantitate perfusion states up to approximately 400 mL.min-1. 100 g-1 using central intravenous contrast administration was demonstrated. This implies that studies can be done with intravenous injection methods for characterization of regional myocardial perfusion up to the normal flow reserve of approximately 4:1. Important physiologic and clinical abnormalities in flow reserve generally result in a ratio < 3:1. Electron beam CT offers the capability to quantitate regional myocardial perfusion in both the clinical and research setting. Of particular interest is the ability to provide quantitative regional myocardial perfusion which can be coupled to the evaluation of cardiac anatomy and function as well as mural coronary atherosclerotic calcium burden during the same scanning session. Thus, electron beam CT has the potential to become a valuable, minimally invasive clinical tool for comprehensive analysis of cardiac function and coronary status.

Cardiomyopathies↗
PubMed1997

Electron beam computed tomographic coronary calcium score cutpoints and severity of associated angiographic lumen stenosis.

OBJECTIVES: We sought to determine a range of cutpoints for coronary calcium scores measured by electron beam computed tomography (EBCT) in predicting the likely severity of associated angiographic coronary artery stenoses. BACKGROUND: EBCT can quantify coronary calcium and allow the estimation of atherosclerotic plaque burden, but use of the calcium score to define lumen narrowing is controversial. METHODS: A total of 213 patients (mean [+/- SD] age 50 +/- 9 years) underwent coronary angiography and EBCT. Maximal percent diameter stenosis in any artery was paired with total coronary calcium score. Receiver operating characteristic (ROC) curve analysis was done using definitions of "disease" for maximal stenosis from > or = 20% to 100%, and the corresponding score cutpoints were determined for 90% sensitivity, 90% specificity or "optimal" sensitivity and specificity. RESULTS: ROC curve areas ranged from a mean (+/- SE) of 0.91 +/- 0.02 for > or = 20% stenosis to 0.83 +/- 0.03 for 100% stenosis. Optimal calcium score cutpoints consisted of nonoverlapping values ranging from 15 for > or = 20% stenosis to 327 for 100% stenosis, whereas sensitivities and specificities ranged from 78% to 84%, depending on maximal stenosis severity. Calcium score cutpoints for 90% sensitivity and 90% specificity were also nonoverlapping and ranged from 3 and 27, respectively, for > or = 20% stenosis to 154 and 945, respectively, for 100% stenosis; corresponding specificities and sensitivities ranged from 40% to 78%. CONCLUSIONS: These data define the ranges for EBCT coronary calcium score cutpoints that predict the likely severity of associated maximal angiographic stenosis severity to a high sensitivity, high specificity or optimal sensitivity/specificity. These cutpoints potentially can be used in conjunction with clinical variables to predict the severity of lumen narrowing in patients undergoing assessment for coronary artery disease.

Adult↗
PubMed1997

Determination of ventricular ejection fraction: a comparison of available imaging methods. The Cardiovascular Imaging Working Group.

Knowledge of left ventricular ejection fraction has been shown to provide diagnostic and prognostic information in patients with known or suspected heart disease. In clinical practice, the ejection fraction can be determined by using one of the five currently available imaging techniques: contrast angiography, echocardiography, radionuclide techniques of blood pool and first pass imaging, electron beam computed tomography, and magnetic resonance imaging. In this review, we discuss the clinical application as well as the advantages and disadvantages of each of these methods as it relates to determination of ventricular ejection fraction.

Angiocardiography↗
PubMed1997

Right and left ventricular remodeling after orthotopic single lung transplantation for end-stage emphysema.

BACKGROUND: Orthotopic single lung transplantation (LTX) is now an established treatment modality for patients with end-stage emphysema. LTX has been shown to cause unloading of the right ventricle with improvement in right ventricular (RV) structure and function both immediately and up to weeks after surgery, mostly in patients with severe pulmonary hypertension and decreased RV function. Long-term effects of lung transplantation on both RV and left ventricular (LV) anatomy and function, however, are not well known. METHODS: Seventeen patients undergoing LTX for end-stage emphysema and preserved RV function underwent serial electron beam computed tomography RV and LV function studies before, 3 months after, 1 year after, and 2 years after transplantation. Right-sided heart catheterization was performed before transplantation and at 1 and 2 years follow-up. RESULTS: RV end systolic volume decreased significantly (-15.5%), and RV ejection fraction increased significantly (+16%) in the first 3 months after LTX. This change was paralleled by a decrease in pulmonary pressure and vascular resistance, indicating a permanent RV unloading. This improvement was maintained up to 2 years after LTX. LV end-diastolic volume (+25%), LV stroke volume (+29%), and LV muscle mass (+28%) increased significantly in the first 3 months after LTX. This remodeling was maintained during the 2-year follow-up. CONCLUSIONS: Significant changes in cardiac anatomy and function occur shortly after LTX, most likely as a consequence of adaptation to a new hemodynamic state in patients with well preserved RV function before LTX. Furthermore, these acute changes persist for at least 2 years after LTX.

Adult↗
PubMed1996

[Electron beam tomography in cost effective diagnosis of coronary heart disease].

BACKGROUND: Electron beam CT (EBCT) can acquire rapid, multiple thin-section tomograms of the beating heart in synchrony with the electrocardiogram and quantity coronary calcification without intravenous contrast. Coronary calcification is an active process exclusively associated with atherosclerotic plaque formation and regulated in a manner similar to the calcification of bone. Clinical studies have demonstrated that EBCT coronary calcification (1) follows a pattern similar to the epidemiology of coronary artery disease (CAD), (2) has a high sensitivity (90-95%) for coronary plaque and significant angiographic coronary stenoses, and (3) has the potential to assess the prognosis of patients with coronary atherosclerotic disease. Coronary calcium area or "score" correlates best with overall plaque burden within the coronary system. However, coronary calcium is of limited value in distinguishing coronary stenosis on a segment-by-segment basis. EBCT AND CAD: Due to spiraling health care costs, there is a need for cost-efficient strategies in the diagnosis and stratification of patients with known or suspected CAD. There are two major patient groups in which EBCT calcium scanning has a potential for cost-efficient application: (1) in asymptomatic, high-risk patients, identification of significant plaque burden may direct judicious use of long-term drug therapy or further investigation to those individuals most likely to benefit from an aggressive risk factor modification and medical program; (2) in patients with chest pain syndromes but no prior CAD, EBCT calcium scanning compares favorably with conventional diagnostic methods. In particular, using receiver operating characteristic analysis, the sensitivity and specificity of an EBCT calcium score of 80 in detecting obstructive CAD are both about 85%. Using a theoretical model, EBCT calcium scanning was found to be the most cost-effective approach to diagnosis in populations with a low-to-moderate likelihood of obstructive CAD when compared with treadmill exercise, stress thallium, and stress echocardiography. CONCLUSIONS: EBCT calcium scanning is not a substitute for coronary angiography, but it has clear advantages over other more traditional diagnostic methods for CAD. In particular, it can be performed conveniently and inexpensively in most patients. Additionally, the site and extent of calcification are intimately related to the atherosclerotic plaque burden. The analyses presented suggest that it may also provide a cost-effective clinical alternative in specific subsets of the population.

Adult↗
PubMed1996

Regional left ventricular wall thickness and systolic function during the first year after index anterior wall myocardial infarction: serial effects of ventricular remodeling.

There is controversy regarding changes in regional left ventricular systolic function and thickness during remodeling after infarction. To address this, electron beam computed tomography was done in 22 patients with an index anterior wall infarction at discharge, 6 weeks, 6 months and 1 year, and global ventricular chamber volumes and mass quantified. A mid-ventricular short-axis scan from each study was divided into 4, 90 degrees sectors (anterior, septal, lateral and posterior walls). Regional wall thickness, ejection fraction, and absolute and percent wall thickening were determined and compared with 10 normal adults. Global infarct size was estimated at 24.2%+/- 3.4% of the ventricle. In these subjects, the ventricular chamber enlarged steadily during the year, while global ventricular mass initially decreased during the first 6 weeks, but then increased by 1 year. Regional ejection fraction changed little during the year, apart from the lateral wall, which was less than normal. Absolute wall thickening was reduced in the anterior (infarct) and septal walls throughout the year, but was normal and unchanged in the posterior and lateral walls. Regional percent wall thickening was not different from normal individuals. The anterior wall was thinned at discharge and tended to thin further during the year. The lateral wall was thinner than normal 6 weeks after infarction, but remained unchanged thereafter. The posterior wall tended to thin for the first 6 months, but the values at any time were not above normal. There was little change in septal wall thickness throughout the year. It is concluded that, after a moderate size, uncomplicated index anterior infarction, regional systolic function remains generally unaffected by remodeling. However, regional walls tend to thin and/or remain at normal thickness. These data confirm differential regional patterns after anterior infarction for systolic function, muscle atrophy and/or minimal hypertrophy which accompany serial changes in global ventricular chamber volumes and mass.

Aged↗
PubMed1996

Electron beam computed tomography and coronary artery disease: scanning for coronary artery calcification.

OBJECTIVE: To review the association of coronary artery calcification with coronary atherosclerosis and its potential clinical application as detected on electron beam computed tomography (EBCT). DESIGN: A literature review of coronary artery calcification, coronary artery disease, and EBCT is presented, and clinical applications of EBCT are discussed. RESULTS: Recent studies have confirmed that arterial calcification is an active process intimately associated with atherosclerotic plaque evolution. Clinical investigations with use of EBCT have shown that a scan "negative" for coronary calcification is common in patients with normal or near-normal findings on coronary angiography, whereas patients with severe obstructive disease most commonly have "positive" scans--greater amounts of coronary artery calcium are associated with more severe luminal disease. Coronary artery calcium as evaluated on EBCT follows patterns that reflect the development of coronary atheromatous disease as a function of age and gender. Although histologic studies have confirmed that not all atherosclerotic segments have detectable calcification, the area of coronary artery calcification quantified on EBCT has a direct, positive relationship with the histopathologic coronary plaque area. CONCLUSION: The long-held notion of "degenerative" calcification of the coronary arteries with aging is incorrect. Although the incidence of coronary artery calcification increases with patient age, this relationship simply parallels the increased incidence of coronary atherosclerosis with advancing age. Data suggest that EBCT is a highly sensitive and specific test for coronary atherosclerosis and provide a basis for clinical applications when EBCT is viewed as a noninvasive method to estimate human coronary atherosclerotic involvement and "plaque burden."

Adult↗
PubMed1996

Ventricular remodeling after orthotopic cardiac transplantation.

OBJECTIVE: To determine quantitative changes in ventricular chamber volumes and left ventricular mass after orthotopic cardiac transplantation. MATERIAL AND METHODS: Right ventricular and left ventricular chamber volumes and left ventricular muscle mass were quantified by electron beam computed tomography in 10 patients at 1 month and 12 months after orthotopic cardiac transplantation. RESULTS: During the study period, the mean right ventricular end-diastolic volumes increased from 117 +/- 26.1 cc to 143 +/- 25.3 cc (P < 0.005), and the mean left ventricular end-diastolic volumes increased from 90 +/- 20.6 cc to 117 +/- 27.3 cc (P < 0.001). Left ventricular stroke volume increased from 63 +/- 16.5 cc at 1 month to 78 +/- 19.8 cc by 12 months (P < 0.005). These changes were associated with a concurrent reduction in global left ventricular muscle mass from 168 +/- 25.2 g to 145 +/- 16.3 g (P < 0.01). The left ventricular end-diastolic volume/mass ratio, an index of wall tension, was abnormally low at 1 month but was in the normal range by 12 months (P < 0.0005). Both left ventricular and right ventricular ejection fractions were normal at all times and not significantly changed between the 1-month and 12-month studies. CONCLUSION: Significant right and left ventricular remodeling occurs between 1 month and 12 months after orthotopic cardiac transplantation, with progressive cavity dilatation but reduction in global left ventricular muscle mass. These adjustments, especially in the left ventricle, tend to reduce the volume/mass ratio by 1 year and are compatible with normalization of ventricular wall tension between the early and late scan dates. Routine clinical measurements of ejection fraction alone mask the almost parallel increases in stroke volume and end-diastolic volume during the first 12 months after orthotopic cardiac transplantation.

Adult↗