Treatment-Related Changes in Left Atrial Structure in Atrial Fibrillation: Findings From the CABANA Imaging Substudy

[Figure: see text].

Measurements of the left atrium and pulmonary veins for analysis of reverse structural remodeling following cardiac ablation therapy

RATIONALE AND OBJECTIVES

Geometric analysis of the left atrium and pulmonary veins is important for assessing reverse structural remodeling following cardiac ablation therapy. Most volumetric analysis techniques, however, require laborious manual tracing of image cross-sections. Pulmonary vein diameters are typically measured at the junction between the left atrium and pulmonary veins, called the pulmonary vein ostia, with manually drawn lines on volume renderings or in image slices. In this work, we describe a technique for making semi-automatic measurements of left atrial volume and pulmonary vein diameters from high resolution CT scans and demonstrate its use for analyzing reverse structural remodeling following cardiac ablation therapy.

METHODS

The left atrium and pulmonary veins are segmented from high-resolution computed tomography (CT) volumes using a 3D volumetric approach and cut planes are interactively positioned to separate the pulmonary veins from the body of the left atrium. Left atrial volume and pulmonary vein ostial diameters are then automatically computed from the segmented structures. Validation experiments are conducted to evaluate accuracy and repeatability of the measurements. Accuracy is assessed by comparing left atrial volumes computed with the proposed methodology to a manual slice-by-slice tracing approach. Repeatability is assessed by making repeated volume and diameter measurements on duplicated and randomized datasets. The proposed techniques were then utilized in a study of 21 patients from the Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation Trial (CABANA) pilot study who were scanned both before and approximately 3 months following ablation therapy.

RESULTS

In the high resolution CT scans the left atrial volume measurements show high accuracy with a mean absolute difference of 2.3±1.9 cm(3) between volumes computed with the proposed methodology and a manual slice-by-slice tracing approach. In the intra-rater repeatability study, the mean absolute difference in left atrial volume was 4.7±2.5 cm(3) and 4.4±3.4 cm(3) for the two raters. Intra-rater repeatability for pulmonary vein diameters ranged from 0.9 to 2.3 mm. The inter-rater repeatability for left atrial volume was 5.8±5.1 cm(3) and inter-rater repeatability for pulmonary vein diameter measurements ranged from 1.4 to 2.3 mm. In the patient study, significant (p<.05) decreases in left atrial volume and all four pulmonary vein diameters were observed. The absolute change in LA volume was 20.0 cm(3), 95%CI [12.6, 27.5]. The left inferior pulmonary vein diameter decreased 2.1 mm, 95%CI [0.4, 3.7], the left superior pulmonary vein diameter decreased 3.2 mm, 95%CI [1.0, 5.4], the right inferior pulmonary vein diameter decreased 1.5 mm, 95%CI [0.3, 2.7], and the right superior pulmonary vein diameter decreased 2.8 mm, 95%CI [1.4, 4.3].

CONCLUSIONS

Using the proposed techniques, we demonstrate high accuracy of left atrial volume measurements as well as high repeatability for left atrial volume and pulmonary vein diameter measurements. Following cardiac ablation therapy, a significant decrease was observed for left atrial volume as well as all four pulmonary vein diameters.

Centerline tracking for quantification of reverse structural remodeling of the pulmonary veins following cardiac ablation therapy

RATIONALE AND OBJECTIVES

Patients with atrial fibrillation undergo structural remodeling resulting in increased pulmonary vein sizes. Studies have demonstrated that these changes are reversible following successful ablation therapy. To date, analyses of pulmonary vein structure have focused on measurements at the pulmonary vein ostia, and the full extent of reverse remodeling along the length of the pulmonary veins has not yet been fully characterized.

MATERIALS AND METHODS

An automated, three-dimensional method is proposed that quantifies pulmonary vein geometry starting at the ostia and extending several centimeters into the veins. A centerline is tracked along the length of the pulmonary vein, and orthogonal planes are computed along the curve. The method was validated against manual measurements on each of the four pulmonary veins for 10 subjects. The proposed methodology was used to analyze the pulmonary veins in 21 patients undergoing cardiac ablation therapy with preoperative and postoperative computed tomographic scans.

RESULTS

Validation results demonstrated that the automated measurements closely followed the manual measurements, with an overall mean difference of 11.50 mm(2). Significant differences in cross-sectional area at the two time points were observed at all pulmonary vein ostia and extending for 2.0 cm (excluding the 0.5-cm interval) into the left inferior pulmonary vein, 3.5 cm into the left superior pulmonary vein, and 2.0 cm into the right superior pulmonary vein.

CONCLUSIONS

Quantitative analysis along the length of the pulmonary veins can be accomplished using centerline tracking and measurements from orthogonal planes along the curve. The patient study demonstrated that reverse structural remodeling following ablation therapy occurs not only at the ostia but for several centimeters extending into the pulmonary veins.

Computed tomographic coronary artery calcium assessment for evaluating chest pain in the emergency department: long-term outcome of a prospective blind study

OBJECTIVE

To determine the long-term outcome of computed tomographic (CT) quantification of coronary artery calcium (CAC) used as a triage tool for patients presenting with chest pain to an emergency department (ED).

PATIENTS AND METHODS

Patients (men aged 30-62 years and women aged 30-65 years) with chest pain and low-to-moderate probability of coronary artery disease underwent both conventional ED chest pain evaluation and CT CAC assessment prospectively. Patients' physicians were blinded to the CAC results. The results of the conventional evaluation were compared with CAC findings on CT, and the long-term outcome in patients undergoing CT CAC assessment was established. Primary end points (acute coronary syndrome, death, fatal or nonfatal non-ST-segment elevation myocardial infarction, fatal or nonfatal ST-segment elevation myocardial infarction) and secondary outcomes (coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, coronary stenting, or a combination thereof) were obtained when the patient was dismissed from the ED or hospital and then at 30 days, 1 year, and 5 years.

RESULTS

Of the 263 study patients, 133 (51%) had a CAC score of zero. This absence of CAC correlated strongly with the likelihood of noncardiac chest pain. Among 133 patients with a CAC score of zero, only 1 (<1%) had cardiac chest pain. Conversely, of the 31 patients shown to have cardiac chest pain, 30 (97%) had evidence of CAC on CT. When a CAC cutoff score of 36 was used, as suggested by receiver operating characteristic analysis, sensitivity was 90%; specificity, 85%; positive predictive value, 44%; and negative predictive value, 99%. During long-term follow-up, patients without CAC experienced no cardiac events at 30 days, 1 year, and 5 years.

CONCLUSION

Findings suggest that CT CAC assessment is a powerful adjunct in chest pain evaluation for the population at low-to-intermediate risk. Absent or minimal CAC in this population makes cardiac chest pain extremely unlikely. The absence of CAC suggests an excellent long-term (5-year) prognosis, with no primary or secondary cardiac outcomes occurring in study patients at 5-year follow-up.

Lipoma causing upper extremity deep vein thrombosis: a case report

We report a case of lipoma in the right infraclavicular and axillary area compressing subclavian vein there by presenting with upper extremity deep venous thrombosis (UEDVT) and persistent symptoms of venous congestion. Patient was also found to be a heterozygous carrier of prothrombin 20210 gene mutation. Surgical excision of lipomatous tissue performed after 6 months of anticoagulation resulted in a complete resolution of symptoms.

Abnormal electron beam computed tomography results: the value of repeating myocardial perfusion single-photon emission computed tomography in the ongoing assessment of coronary artery disease

OBJECTIVE

To determine whether asymptomatic patients with atherosclerosis, indicated by the presence of coronary artery calcium on electron beam computed tomography, are at enough risk for progression of disease to justify a repeated stress single-photon emission computed tomography (SPECT) examination after an initial normal to low-risk perfusion study.

PATIENTS AND METHODS

We retrospectively identified patients who had abnormal results on electron beam computed tomography (coronary artery calcium score > 0) and normal to low-risk results on SPECT (defined as a summed stress score of 0-3) within a 3-month period from January 1, 1995, to October 31, 2002. Of the 504 identified patients, 285 remained after exclusion criteria were applied. Of the 285 patients, 69 (mean +/- SD age, 58.2 +/- 7.6 years; 91% male) underwent at least 1 repeated myocardial perfusion SPECT imaging study within 4 years of their initial assessment as normal or at low risk without recurrence of symptoms. The value of repeated SPECT imaging was assessed by detection of a substantial change in the repeated SPECT study and by documentation of a clinical event (death, nonfatal myocardial infarction, or revascularization). Follow-up was 100% complete at a mean of 4.3 +/- 1.6 years.

RESULTS

Only 4 patients (6%) had a substantial progression in their SPECT risk category; substantial changes on the SPECT scans occurred only in patients with a coronary artery calcium score greater than 100. Three patients underwent revascularization, yielding a 5-year rate for survival free of revascularization of 94% (95% confidence interval, 88%-100%). No deaths or nonfatal myocardial infarctions were reported.

CONCLUSION

The principal findings of this study indicate that asymptomatic patients with initial normal or low-risk results from stress SPECT performed because of abnormal coronary artery calcium scores who remain asymptomatic are at low risk of death, myocardial infarction, or coronary revascularization. Three patients underwent revascularization by percutaneous coronary intervention despite the absence of symptoms. A substantial change in SPECT results (defined as progression from normal or low-risk summed stress score to intermediate- or high-risk summed stress score) affected 6% of patients and was not associated with any adverse hard events (nonfatal myocardial infarction or death).

Relationship and prognostic value of coronary artery calcification by electron beam computed tomography to stress-induced ischemia by single photon emission computed tomography

BACKGROUND

Stress single photon emission computed tomography (SPECT) is commonly performed in patients with abnormal electron beam computed tomography (EBCT) to define risk stratification, but the published prognostic data for patients undergoing both SPECT and EBCT are limited. The objective of the study was to examine the association and prognostic value between EBCT, coronary artery calcium score (CACS), and stress SPECT imaging.

METHODS

We identified 835 patients (age 54.8 +/- 10.0 years, 77% male) who underwent EBCT and stress SPECT within a 3-month period. Coronary artery calcium score was categorized as normal (0), minimal (1-10), mild (11-100), moderate (101-400), and severe (>400). Single photon emission computed tomography summed stress score (SSS) was categorized as normal, low risk, intermediate risk, and high risk per Cedar Sinai criteria. Average follow-up was 4.8 +/- 3.2 years. End points were all-cause death, death/myocardial infarction (MI), and death/MI/late revascularization.

RESULTS

The correlation of CACS to SSS was weak but statistically significant (r = +0.19, P < .001). The percentage of high-risk SSS increased with higher CACS scores; 4% of patients with normal EBCT and 18% with severe CACS had high-risk SSS. Coronary artery calcium score (chi2 = 11.4, P < .001), diabetes mellitus (chi2 = 4.6, P = .031), and chest pain class (chi2 = 8.7, P = .003) were independently associated with high-risk SPECT. The SSS (chi2 = 6.9, P = .009) and CACS (chi2 = 7.8, P = .005) were independently associated with mortality, as well as with both secondary end points of death/MI and death/MI/late revascularization. Only CACS predicted mortality in the 408 asymptomatic patients (chi2 = 5.2, P = .02), but these patients had an annual mortality of only 0.4% over the next 5 years.

CONCLUSIONS

In selected patients undergoing both EBCT and SPECT, CACS is weakly correlated with SPECT SSS, likely reflecting the different information provided by EBCT and SPECT. Coronary artery calcium score is independently associated with high-risk SPECT after adjustment for clinical variables. Coronary artery calcium score and SSS are complementary for the prediction of mortality in symptomatic patients. Only CACS predicted mortality in the asymptomatic patients, but they had a low annual mortality.

Aortic Valve Calcification

Background— Aortic valve calcification (AVC) is considered degenerative. Recent data suggested links to atherosclerosis or coronary disease (CAD).

Methods and Results— AVC and coronary artery calcifications (CAC) were prospectively assessed by Electron-Beam-Computed-Tomography in 262 population-based research participants ≥60 years. AVC was frequent (27%) with aging ( P <0.01) and in men ( P <0.05). AVC was associated with diabetes, hypertension, higher body-mass-index, and serum glucose (all P <0.05). AVC was a marker of higher prevalence ( P <0.01) and severity of CAD (CAC score: 441±802 versus 265±566, P <0.05) independently of age. After follow-up of 3.8±0.9 years, AVC score increased (94±271 versus 54±173, P <0.01, +11±32 U/year), faster with higher baseline AVC score ( P <0.01). Compared with participants remaining free of AVC, de novo acquisition of AVC was associated with higher LDL-cholesterol (141±31 versus 121±27 mg/dL, P <0.05) and faster CAC progression (+78±87 versus +28±47 U/year, P <0.05). In multivariate analysis, LDL-cholesterol independently determined AVC acquisition while higher baseline AVC scores determined faster progression of existing AVC.

Conclusion— In the population, AVC is frequent with aging and atherosclerotic risk factors. AVC is a marker of subclinical CAD. AVC is progressive, appearing de novo with progressive atherosclerosis whereas established AVC progresses independently of atherosclerotic risk factors and faster with increasing initial AVC loads.

Assessment of pulmonary thromboendarterectomy by tomographic electrocardiogram-gated equilibrium radionuclide angiocardiography compared with electron beam computed tomography

BACKGROUND

Successful thromboendarterectomy for chronic thromboembolic pulmonary hypertension promptly improves right ventricular (RV) function by decreasing RV volume and increasing ejection fraction (EF). Single photon emission computed tomography (SPECT) equilibrium radionuclide angiocardiography (ERNA) has been validated as a measure of RV and left ventricular (LV) volume and EF.

METHODS AND RESULTS

Nine patients with chronic thromboembolic pulmonary hypertension underwent electron beam computed tomography (EBCT) and SPECT ERNA cardiac studies before and after thromboendarterectomy. EBCT and SPECT ERNA measures of RV and LV volume and EF were compared. Before thromboendarterectomy, EBCT and SPECT ERNA RV and LV volumes and RV EF were similar. LV EF was within the normal range with both methods but was slightly greater (P = .004) when measured by EBCT (mean +/- SD, 0.61 +/- 0.08) compared with SPECT ERNA (0.54 +/- 0.10). Thromboendarterectomy measured by EBCT and SPECT ERNA produced marked similar and significant decreases in RV end-systolic (-72 +/- 59 mL vs -58 +/- 25 mL) and end-diastolic (-75 +/- 85 mL vs -76 +/- 32 mL) volumes and similar slight increases in RV EF (0.12 +/- 0.07 vs 0.05 +/- 0.06). Slight decreases in mean LV end-systolic (-19 +/- 23 mL vs -5 +/- 13 mL, P = .05) and end-diastolic (-32 +/- 53 mL vs -9 +/- 31 mL, P = .21) volumes occurred, with little change in mean LV EF (0.05 +/- 0.07 vs 0.00 +/- 0.10).

CONCLUSIONS

SPECT ERNA is an accurate method for measuring RV and LV volume and EF before and after thromboendarterectomy.

Comparison of Surgical Septal Myectomy and Alcohol Septal Ablation With Cardiac Magnetic Resonance Imaging in Patients With Hypertrophic Obstructive Cardiomyopathy

OBJECTIVES

This study sought to describe the acute morphologic differences that result from septal myectomy and alcohol septal ablation using cardiac magnetic resonance (CMR) imaging.

BACKGROUND

Surgical septal myectomy and alcohol septal ablation relieve left ventricular outflow tract obstruction in severely symptomatic patients with hypertrophic cardiomyopathy (HCM).

METHODS

Cine and contrast-enhanced CMR images were obtained in HCM patients before and after septal myectomy (n = 24) and alcohol septal ablation (n = 24). Location of septal reduction, extent of myocardial necrosis, and conduction system abnormalities with each technique were compared.

RESULTS

With septal myectomy, there was a discrete area of resected tissue consistently localized to anterior septum. In contrast, alcohol septal ablation resulted in a more variable effect. In most patients, alcohol septal ablation caused a transmural region of tissue necrosis, located more inferiorly in the basal septum than myectomy and usually extending into the right ventricular side of the septum at the midventricular level. However, there were 6 patients after alcohol septal ablation in whom there was sparing of the basal septum with residual gradients at follow-up. After the procedure, left bundle branch block developed in 46% of septal myectomy patients, and right bundle branch block was evident in 58% of alcohol septal ablation patients.

CONCLUSIONS

Septal myectomy and alcohol septal ablation for severely symptomatic, drug-refractory patients with obstructive HCM have different morphologic effects and location sites on left ventricular septal myocardium. Septal myectomy provides consistent resection of the obstructing portion of the anterior basal septum, whereas the effect of ethanol septal ablation is more variable. These findings may have important implications for patient selection and management as well as long-term outcome.

Relationship between coronary artery calcification detected by electron-beam computed tomography and abnormal stress echocardiography: association and prognostic implications

OBJECTIVES

The purpose of this study was to compare the results and prognostic value of electron-beam computed tomography (EBCT) and exercise echocardiography.

BACKGROUND

Although patients with elevated coronary artery calcium scores (CACS) might be referred for exercise echocardiography, the association of EBCT CACS with wall motion score index (WMSI) is not known.

METHODS

Patients without known coronary artery disease who underwent both clinically indicated EBCT and exercise echocardiography within a 3-month period were identified. Exercise WMSI was based on a 16-segment model (normal = 1; abnormal >1). The EBCT CACS was derived with the Agatston scoring system. Follow-up was obtained for the combined end point of death and myocardial infarction.

RESULTS

The study population included 556 patients (age 54 +/- 10 years; 65% male). Correlation between EBCT CACS and exercise WMSI was limited (r = 0.17, p < 0.0001) but statistically significant. The proportion of patients with abnormal exercise WMSI increased with increasing CACS severity (chi-square = 19.1, p < 0.001). However, even in those with CACS >400, 66% had normal exercise WMSI. Age, CACS, and chest pain were independently associated with abnormal exercise WMSI. Events occurred in 12 (2%) patients. Wall motion score index (risk ratio [RR] 3.7, p = 0.023) and age (RR 1.9, p = 0.019) were associated with events.

CONCLUSIONS

Electron-beam computed tomography CACS was predictive of abnormal exercise WMSI, but the majority of patients with elevated CACS had normal WMSI. Wall motion score index and age were the best predictors of events. Prospective studies are indicated to establish the relative roles of these tests in risk stratification.

Short-term hypoxic exposure at rest and during exercise reduces lung water in healthy humans

Hypoxia and hypoxic exercise increase pulmonary arterial pressure, cause pulmonary capillary recruitment, and may influence the ability of the lungs to regulate fluid. To examine the influence of hypoxia, alone and combined with exercise, on lung fluid balance, we studied 25 healthy subjects after 17-h exposure to 12.5% inspired oxygen (barometric pressure = 732 mmHg) and sequentially after exercise to exhaustion on a cycle ergometer with 12.5% inspired oxygen. We also studied subjects after a rapid saline infusion (30 ml/kg over 15 min) to demonstrate the sensitivity of our techniques to detect changes in lung water. Pulmonary capillary blood volume (Vc) and alveolar-capillary conductance (D(M)) were determined by measuring the diffusing capacity of the lungs for carbon monoxide and nitric oxide. Lung tissue volume and density were assessed using computed tomography. Lung water was estimated by subtracting measures of Vc from computed tomography lung tissue volume. Pulmonary function [forced vital capacity (FVC), forced expiratory volume after 1 s (FEV(1)), and forced expiratory flow at 50% of vital capacity (FEF(50))] was also assessed. Saline infusion caused an increase in Vc (42%), tissue volume (9%), and lung water (11%), and a decrease in D(M) (11%) and pulmonary function (FVC = -12 +/- 9%, FEV(1) = -17 +/- 10%, FEF(50) = -20 +/- 13%). Hypoxia and hypoxic exercise resulted in increases in Vc (43 +/- 19 and 51 +/- 16%), D(M) (7 +/- 4 and 19 +/- 6%), and pulmonary function (FVC = 9 +/- 6 and 4 +/- 3%, FEV(1) = 5 +/- 2 and 4 +/- 3%, FEF(50) = 4 +/- 2 and 12 +/- 5%) and decreases in lung density and lung water (-84 +/- 24 and -103 +/- 20 ml vs. baseline). These data suggest that 17 h of hypoxic exposure at rest or with exercise resulted in a decrease in lung water in healthy humans.

Computed Tomographic Angiography of the Coronary Arteries: Techniques and Applications

Computed tomographic coronary angiography (CT-CA) is a direct but minimally invasive method of visualizing coronary arteries. Multidetector-row computed tomography (MDCT) is currently the CT modality most commonly used for coronary artery imaging. MDCT has been successfully used to detect stenoses in coronary arteries and coronary artery bypass grafts and to assess congenital coronary anomalies. Patients should not undergo CT-CA with MDCT if they have an irregular heart rhythm, a heart rate greater than 70 beats/min, and contraindications to pharmacologic agents for heart rate control, or if they have severe coronary artery disease or are likely to require revascularization.

Operator-interactive method for simultaneous measurement of left and right ventricular volumes and ejection fraction by tomographic electrocardiography-gated blood pool radionuclide ventriculography

BACKGROUND

A method that uses single photon emission computed tomography (SPECT) equilibrium radionuclide angiocardiography (ERNA) to measure right ventricular (RV) and left ventricular (LV) volumes (in milliliters) and ejection fraction (EF) is described.

METHODS AND RESULTS

We recorded 35 paired SPECT ERNA and electron beam computed tomography (EBCT) cardiac studies in 27 patients; for comparison with EBCT, a method for measurement of RV and LV volumes and EF with SPECT ERNA was developed in 18 paired studies and was validated and assessed for reproducibility in 17. Validation indicated that SPECT ERNA and EBCT were similar for measurement of RV volume (end-systolic and end-diastolic volumes in a combined analysis) and EF (180+/-74 mL vs 182+/-80 mL and 0.44+/-0.11 vs 0.43+/-0.11, respectively) and for measurement of LV volume and EF (88+/-36 mL vs 84+/-43 mL and 0.53+/-0.081 vs 0.59+/-0.07, respectively). The SPECT ERNA method was quite reproducible.

CONCLUSIONS

RV and LV volumes and EF can be measured readily via SPECT ERNA.

Clinical presentation, investigation, and management of pulmonary vein stenosis complicating ablation for atrial fibrillation

BACKGROUND

Although segmental or circumferential ablation is effective in eliminating pulmonary vein (PV)-mediated atrial fibrillation (AF), this procedure may be complicated by the occurrence of PV stenosis.

METHODS AND RESULTS

To establish the clinical presentation, diagnostic manifestations, and interventional management of PV stenosis, 23 patients with stenosis of 34 veins complicating ablation of AF were evaluated. Each patient became symptomatic 103+/-100 days after undergoing ablation. In 8 veins, the ablation producing the PV stenosis was a repeated procedure for continued AF. Nineteen patients presented with dyspnea on exertion, 7 with dyspnea at rest, 9 with cough, and 6 with chest pain. On multirow spiral computed tomography examination, the narrowest lumen of the affected PVs measured 3+/-2 mm compared with 13+/-3 mm at baseline (P< or =0.001). The relative perfusion of affected lung segments on isotope scans was reduced to 4+/-3% of total perfusion compared with 22+/-10% in unaffected segments. At percutaneous intervention, these veins showed 80+/-13% stenosis, with a mean gradient of 12+/-5 mm Hg. This was significantly reduced to a residual stenosis of 9+/-8% (P< or =0.001) and a residual gradient of 3+/-4 mm Hg (P< or =0.001). Twenty veins were treated with balloon dilatation alone, whereas 14 veins were stented with standard 10-mm-diameter bare-metal stents. Although the symptomatic response was nearly immediate and impressive, 14 patients developed in-stent or in-segment restenosis, requiring repeated interventions in 13.

CONCLUSIONS

Percutaneous intervention produces rapid and dramatic symptom relief in patients with highly symptomatic PV stenosis after radiofrequency ablation for AF. Nevertheless, alternative treatment methods will be required to decrease recurrent in-stent or in-segment restenosis.

Atypical presentation of eosinophilic endomyocardial disease

Idiopathic hypereosinophllic syndrome is classically defined as prolonged, unexplained peripheral eosinophilia in a patient presenting with evidence of end-organ damage. The heart is frequently Involved, resulting In eosinophilic endomyocardial disease and eventually restrictive cardlomyopathy. The mortality rate is high because of progressive heart failure or ventricular arrhythmias. We describe a patient who presented with a left ventricular apical thrombus without notable peripheral eosinophilia. Findings from clinical evaluation and extensive diagnostic testing, including right ventricular biopsy, were Inconclusive. Resection of the thrombus and subjacent endomyocardium revealed eosinophilic Infiltration of the endomyocardium, which led to the diagnosis of eosinophilic endomyocardial disease. Clinicians should be aware of the variable presentation of patients with eosinophil-associated endomyocardial disease so that affected patients may benefit from early diagnosis and treatment.

Progression of Subclinical Coronary Atherosclerosis

Background— Obesity is associated with coronary artery calcification (CAC), a marker of the presence and extent of subclinical coronary atherosclerosis. Obesity adds incremental information in identifying those at higher risk of coronary heart disease to traditional risk factor assessment. The present study examined associations between obesity measures and progression of CAC in those at higher (≥10%) and lower (<10%) 10-year coronary heart disease risk according to the Framingham risk equation.

Methods and Results— In this study, 443 asymptomatic white individuals >30 years of age (243 men) had baseline and follow-up CAC measurements an average of 8.9 years apart. Multivariable linear regression models were fit to determine associations of obesity measures at baseline with progression of CAC defined as log e of the difference between follow-up and baseline CAC area plus 1 divided by time (in years) between examinations, adjusting for baseline CAC quantity, age, sex, baseline hypertension status, and baseline cholesterol level. Among 329 participants (74.3%) in the lower-risk group, waist circumference ( P =0.024), waist-to-hip ratio ( P <0.001), body mass index ( P =0.036), and being overweight compared with being underweight or of normal weight ( P =0.008) were each significantly positively associated with progression of CAC. Among those at higher coronary heart disease risk, no baseline obesity measures were associated with CAC progression.

Conclusions— Various measures of obesity were associated with increased progression of CAC in those at lower risk of coronary heart disease. Future studies examining the effectiveness of weight reduction strategies in reducing CAC progression among those with an otherwise favorable risk factor profile may be warranted.

CT evaluation of left atrial pulmonary venous anatomy

Multidetector CT (MDCT) visualization of the left atrial pulmonary venous anatomy is becoming increasingly requested prior to radiofrequencey catheter ablation (RFCA) procedures for refractory cardiac arrhythmias. MDCT imaging can define left atrial anatomy including atrial size and venous attachments as well identify complications such as stenoses, dissections or perforations. Proper understanding enables the cardiac imager to be knowledgeable so as to obtain the specific information needed for the interventional cardiologist. This paper reviews the left atrial venous anatomy, the clinical aspects of refractory atrial fibrillation, MDCT imaging protocols, procedural aspects of the ablation, and complications should they arise.

Evaluation and Clinical Implications of Aortic Valve Calcification Measured by Electron-Beam Computed Tomography

BACKGROUND

Electron-beam computed tomography (EBCT) is used to measure coronary calcification but not for aortic valve calcification (AVC). Its accuracy, association with aortic stenosis (AS) severity, and diagnostic and prognostic value with respect to AVC are unknown.

METHODS AND RESULTS

In 30 explanted aortic valves, the AVC score by EBCT (1125+/-1294 Agatston units [AU]) showed a strong linear correlation (r=0.96, P<0.0001) with valvular calcium weight (653+/-748 mg) by pathology that allowed estimation of calcium weight as AVC score/1.7, with a small standard error of the estimate (53 mg). In 100 consecutive clinical patients, we measured AVC by EBCT and AS severity by echocardiographic aortic valve area (AVA). The AVC score was 1316+/-1749 AU (range 0 to 7226 AU). Intraobserver and interobserver variabilities were excellent (4+/-4% and 4+/-10%, respectively). AVC and AVA were strongly associated (r=0.79, P<0.0001) but had a curvilinear relationship that suggested that AVC and AVA provide complementary information. AVC score > or =1100 AU provided 93% sensitivity and 82% specificity for diagnosis of severe AS (AVA <1 cm2), with a receiver operator characteristic curve area of 0.89. AVC assessment by echocardiography was often more severe than by EBCT (P<0.0001). During follow-up, 22 patients either died, developed heart failure, or required surgery. With adjustment for age, sex, symptoms, ejection fraction, and AVA, the AVC score was independently predictive of event-free survival (risk ratio 1.06 per 100-AU increment [1.02 to 1.10], P<0.001), even after adjustment for echocardiographic calcifications.

CONCLUSIONS

AVC is accurately and reproducibly measured by EBCT and shows a strong association and diagnostic value for severe AS. The curvilinear relationship between AVC and AVA suggests these measures are complementary, and indeed, AVC provides independent outcome information. Thus, AVC is an important measurement in the evaluation of patients with AS.

Comparison of acute and chronic antioxidant interventions in experimental renovascular disease

Reactive oxygen species (ROS) can modulate renal hemodynamics and function both directly, by leading to vasoconstriction, and indirectly, by inducing renal inflammation and tissue growth. The involvement of oxidative stress in the pathogenesis of renovascular disease (RVD) is increasingly recognized, but the relative contribution of long-term tissue injury to renal dysfunction remains unclear. We hypothesized that functional and structural alterations elicited by oxidative stress in RVD would be more effectively modulated by chronic than by acute antioxidant intervention. Renal hemodynamics and function were quantified in vivo in pigs using electron-beam computed tomography at baseline and after vasoactive challenge (ACh and sodium nitroprusside); after 12 wk of RVD (simulated by concurrent hypercholesterolemia and renal artery stenosis, n = 7); RVD acutely infused with the SOD-mimetic tempol (RVD+tempol, n = 7); RVD chronically supplemented with antioxidant vitamins C (1 g) and E (100 IU/kg; RVD+vitamins, n = 7); or control (normal, n = 7). Renal tissue was studied ex vivo using immunoblotting and immunohistochemistry. Basal renal blood flow (RBF) and glomerular filtration rate were similarly decreased in all RVD groups. ACh-stimulated RBF remained unchanged in RVD, increased in RVD+tempol, but further increased (similarly to normal) in RVD+vitamins ( P < 0.05 vs. RVD). Furthermore, RVD+vitamins also showed a decreased presence of superoxide anion, decreased NAD(P)H-oxidase and nitrotyrosine expression, increased endothelial nitric oxide synthase expression, and attenuated renal fibrosis. Chronic antioxidant intervention in early RVD improved renal hemodynamic responses more effectively than acute intervention, likely due to increased nitric oxide bioavailability and decreased structural injury. These suggest that chronic tissue changes play an important role in renal compromise mediated by oxidative stress in RVD.

Statistical assessment of regional time-density measurement of myocardial perfusion

RATIONALE AND OBJECTIVES

The measurement of time-density relationships of the myocardium in studies of magnetic resonance perfusion images is a clinical technique used in assessing myocardial perfusion. This article presents a new technique, allowing regional time-density measurement and display of myocardial perfusion with improved accuracy compared with traditional manual trace techniques. Moreover, a method using statistical methods to discriminate relative decreased perfusion regions that differ significantly from the normally perfused myocardial tissue is introduced.

MATERIALS AND METHODS

Human datasets were obtained using a 1.5 T Signa Echospeed system (GE Medical Systems, Milwaukee, WI). The perfusion sequence was a 2D cardiac-gated fast gradient echo sequence with echo train readout, generating an in-plane pixel size of 1.46 mm2. Seven 10-mm-thick contiguous short axis tomographic slice images were obtained during a prolonged single breathhold. Data was collected at 30 time phases per slice image level during passage of 20 cc gadolinium contrast injected at a rate of 4-5 cc/sec into an antecubital vein.

RESULTS

Dilution properties can be determined and displayed as color-encoded regions superimposed on the myocardial slice according to the area of interest. Time-density curves throughout the perfusion study can be generated. Moreover, displays of normal and decreased perfusion areas can be used as statistically enhanced diagnosis guides.

CONCLUSION

This measurement, display, and diagnosis technique adds diagnostically important information to previous measurement and visualization techniques, providing enhanced detection and quantitative evaluation of regional deficits in myocardial contractility and perfusion, providing improved reliability and reproducibility of clinical diagnoses from MR-perfusion data.

Long-term antioxidant intervention improves myocardial microvascular function in experimental hypertension

Hypertension increases oxidative stress, which can impair myocardial microvascular function and integrity. However, it is yet unclear whether long-term antioxidant intervention in early hypertension would preserve myocardial perfusion and vascular permeability responses to challenge. Pigs were studied after 12 weeks of renovascular hypertension without (n=8) or with daily supplementation of antioxidants (100 IU/kg vitamin E and 1 g vitamin C, n=6), and compared with normal controls (n=7). Myocardial perfusion and microvascular permeability were measured in vivo by electron beam computed tomography before and after 2 cardiac challenges (intravenous adenosine and dobutamine). Basal left ventricular muscle mass was also obtained. Mean arterial pressure was significantly increased in both groups of hypertensive animals (without and with antioxidants, 123+/-9 and 126+/-4 mm Hg, respectively, versus normal, 101+/-4 mm Hg; both P<0.05), but muscle mass was not different among the groups. The impaired myocardial perfusion response to adenosine observed in hypertensives (normal, +51+/-14%; P<0.05 versus baseline; hypertension, +14+/-15%; P=0.3 versus baseline) was preserved in hypertensive pigs that received antioxidants (+44+/-15%; P=0.01 compared with baseline). Long-term antioxidant intervention also preserved subendocardial microvascular permeability responses in hypertension. On the other hand, antioxidant intervention had little effect on the hypertension-induced myocardial vascular dysfunction observed in response to dobutamine. This study demonstrates that the impaired myocardial perfusion and permeability responses to increased cardiac demand in early hypertension are significantly improved by long-term antioxidant intervention. These results support the involvement of oxidative stress in myocardial vascular dysfunction in hypertension and suggest a role for antioxidant strategies to preserve the myocardial microvasculature.

Clinical safety of magnetic resonanceimaging early after coronary artery stent placement

OBJECTIVES

Our aim was to examine the rate of adverse cardiac events in patients undergoing magnetic resonance imaging (MRI) <8 weeks after coronary stent placement.

BACKGROUND

The risk of coronary stent thrombosis from dislodgement due to MRI early after stent placement is not well defined. Manufacturers recommend postponing MRI studies until eight weeks after coronary stent placement.

METHODS

We analyzed the Mayo Clinic Rochester Percutaneous Coronary Intervention Database and examined records of 111 patients who underwent MRI <8 weeks after coronary stent placement treated with aspirin and a thienopyridine. Occurrence of death, myocardial infarction (MI), and repeat revascularization within 30 days of MRI were recorded.

RESULTS

Magnetic resonance imaging (1.5 tesla) was performed within a median of 18 days (range, 0 to 54 days) after coronary stent placement. Four noncardiac deaths occurred, and three patients had repeat revascularization procedures. Stent thrombosis did not occur (95% confidence interval, 0% to 3.3%).

CONCLUSIONS

Magnetic resonance imaging <8 weeks after coronary stent placement appears to be safe, and the risk of cardiac death or MI due to stent thrombosis is low. Postponing MRI does not appear to be necessary.

Constrictive pericarditis in 26 patients with histologically normal pericardial thickness

BACKGROUND

Traditionally, increased pericardial thickness has been considered an essential diagnostic feature of constrictive pericarditis. Although constriction with a normal-thickness pericardium has been demonstrated clinically by noninvasive imaging, the details of clinicopathological correlates have not been described.

METHODS AND RESULTS

A total of 143 patients with proven constriction underwent pericardiectomy at Mayo Clinic between 1993 and 1999. Their baseline characteristics, operative data, and pathological specimens were reviewed retrospectively. The pericardium was of normal thickness (< or =2 mm) in 26 patients (18%; group 1) and was thickened (>2 mm) in 117 (82%; group 2). The most common causes of constriction in group 1 included previous cardiac surgery, chest irradiation, previous infarction, and idiopathic disease. There was little difference in symptoms and findings on physical examination between the 2 groups. Microscopically, no patient had an entirely normal pericardium. Histopathological abnormalities in group 1 were mild and focal, including fibrosis, inflammation, calcification, fibrin deposition, and focal noncaseating granulomas. Pericardiectomy was equally effective in relieving symptoms regardless of the presence or absence of increased thickness.

CONCLUSIONS

Pericardial thickness was not increased in 18% of patients with surgically proven constrictive pericarditis, although the histopathological appearance was focally abnormal in all cases. When clinical, echocardiographic, or invasive hemodynamic features indicate constriction in patients with heart failure, pericardiectomy should not be denied on the basis of normal thickness as demonstrated by noninvasive imaging.

Renal artery stent placement: complications at a single tertiary care center

PURPOSE

To describe complications after renal artery stent placement in patients with atherosclerotic renal artery stenosis (RAS) at a single tertiary care center and analyze the risk factors for these complications.

MATERIALS AND METHODS

Medical records and angiograms of 171 patients who underwent a total of 179 consecutive percutaneous transluminal renal artery stent placement (PTRS) procedures for atherosclerotic RAS were retrospectively reviewed. Data on patient comorbidities, procedure indication, lesion location, serum creatinine level, and procedure-related complications were analyzed. The Wilcoxon rank-sum test was used to assess the association of continuous risk factors with complications, and the chi(2) test was used to assess the association of categoric risk factors with outcomes.

RESULTS

The technical success rate for PTRS was 98%. Major complications included renal infarction in five patients (2.8%), permanently increased serum creatinine level in 10 patients (5.6%) that required hemodialysis in five (2.8%), blood transfusion in four patients (2.2%), surgical intervention for procedure-related complications in two patients (1.1%), and deep vein thrombosis in one patient (0.6%). Overall, major complications occurred in 15 procedures (8.4%). Death within 30 days after PTRS occurred in two patients (1.1%), but neither death was definitively caused by the procedure. No risk factors were found to be significantly (P <.05) associated with major complications. Patients with renal artery site or renal function complications tended to be older (P =.01) and have higher creatinine levels (P =.06).

CONCLUSIONS

Renal artery stent placement allows treatment of advanced atheromatous RAS in patients with significant medical and surgical comorbidities. Complications are frequent but few have long-term significance.

Incidental renal artery stenosis among a prospective cohort of hypertensive patients undergoing coronary angiography

OBJECTIVE

To determine the feasibility, safety, and clinical yield of angiographic screening among hypertensive patients undergoing coronary angiography.

PATIENTS AND METHODS

This study was a prospective cohort analysis of hypertensive patients who underwent cardiac catheterization at a tertiary care referral center from July 1998 to March 1999. Abdominal aortography was performed to screen for renal artery stenosis, the percentage of which was measured.

RESULTS

The mean +/- SD age of the 297 study patients was 64.9+/-10.2 years; 58.6% were male, and 98.0% were white. Mean +/- SD systolic/diastolic blood pressure was 142.8+/-22.5/79.6+/-11.4 mm Hg. Aortography required a mean incremental dose of 62+/-9 mL of nonionic contrast agent. No complications were attributable to aortography. Of 680 renal arteries, 611 (90%) were visualized adequately. Also, 53% of patients had normal renal arteries, 28% had stenoses less than 50%, and 19.2% had stenoses of 50% or more. Renal artery stenosis was bilateral in 3.7% of patients and high grade (>70% stenosis) in 7%. Patients with renal artery stenosis were more likely to have had a previous coronary intervention. In multivariate analysis, systolic blood pressure (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.03-138; P=.02), history of stroke or transient ischemic attack (OR, 2.7; 95% CI, 1.27-5.78; P=.01), and cancer (OR, 2.0; 95% CI, 1.02-3.82; P=.04) independently correlated with renal artery stenosis of 50% or more.

CONCLUSION

The prevalence of incidental renal artery stenosis among hypertensive patients undergoing coronary catheterization is significant. Therefore, screening abdominal aortography should be considered in these patients to better define their risk of cardiovascular complications.

Contrast echocardiography improves the accuracy and reproducibility of left ventricular remodeling measurements: a prospective, randomly assigned, blinded study

OBJECTIVES

We sought to assess the impact of contrast injection and harmonic imaging, on the measure by echocardiography of left ventricular (LV) remodeling.

BACKGROUND

Left ventricular remodeling is a precursor of LV dysfunction, but the impact of contrast injection and harmonic imaging on the accuracy or reproducibility of echocardiography is unclear.

METHODS

We prospectively collected LV images by using simultaneous methods. Then, LV volumes were measured off-line, in blinded manner and in random order. The accuracy of echocardiography was determined in comparison to electron beam computed tomography (EBCT) in 26 patients. The reproducibility of echocardiography was assessed by three blinded observers with different training levels in 32 patients.

RESULTS

End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), as measured by EBCT (195 +/- 55, 58 +/- 24 and 137 +/- 35 ml and 71 +/- 5%, respectively) and echocardiography with harmonic imaging and contrast injection (194 +/- 51, 55 +/- 20 and 140 +/- 35 ml and 72 +/- 4%, respectively), showed no differences (all p > 0.15) and excellent correlations (all r > 0.87). In contrast, echocardiography using harmonic imaging without contrast injection underestimated the EBCT results (all p < 0.01). Reproducibility was superior with rather than without contrast injection for intraobserver and interobserver variabilities (all p < 0.001). Values measured by different observers were different without contrast injection, but were similar with contrast injection (all p > 0.18). Consequently, intrinsic patient differences represented a larger and almost exclusive proportion of global variability with contrast injection for EDV (94 vs. 79%), ESV (93 vs. 82%), SV (87 vs. 53%) and EF (84 vs. 41%), as compared with harmonic imaging without contrast injection (all p < 0.005).

CONCLUSIONS

For assessment of LV remodeling, echocardiography with harmonic imaging and contrast injection improved the accuracy and reproducibility, as compared with imaging without contrast injection. With contrast injection, variability was almost exclusively due to intrinsic patient differences. Therefore, when evaluation of LV remodeling is deemed important, assessment after contrast injection should be the preferred echocardiographic approach.

Rapid three-dimensional echocardiography : clinically feasible alternative for precise and accurate measurement of left ventricular volumes

BACKGROUND

Clinical applicability of conventional ultrasonographic systems using mechanical adapters for 3D echocardiographic imaging has been limited by long acquisition and processing times. We developed a rapid (6-s) acquisition technique that collects apical tomograms using a continuously internally rotating transthoracic transducer. This study was performed to examine the clinical feasibility of rapid-acquisition 3D echocardiography to estimate left ventricular end-diastolic and end-systolic volumes using electron-beam computed tomography as the reference standard. Methods and Results-We collected a series of 6 to 11 apical echocardiographic tomograms, depending on heart rate, in 11 patients. There was good correlation, low variability, and low bias between rapid 3D echocardiography and electron-beam computed tomography for measuring left ventricular end-diastolic volume (r=0.96; standard error of the estimate, 21.34 mL; bias, -4.93 mL) and left ventricular end-systolic volume (r=0.96; standard error of the estimate, 14.78 mL; bias, -6.97 mL).

CONCLUSIONS

The rapid-acquisition 3D echocardiography extends the use of a multiplane, internally rotating handheld transducer so that it becomes a precise and clinically feasible tool for assessing left ventricular volumes and function. A rapid-image acquisition time of 6 s would allow repeated image collection during the course of a clinical echocardiographic examination. Additional work must address rapid and automated data processing.

Rib artifacts in electron beam tomography: incidence and severity without and with the cone beam reconstruction algorithm

Electron beam tomography (EBT) may be compromised by rib artifacts. Two hundred forty-seven abdominal studies were performed without (Group A, n = 222) or with (Group B, n = 25) the cone beam algorithm. One hundred eighty-six (83.8%) and nine (36%) studies of Groups A and B, respectively, displayed some level of artifact. In Groups A and B, major, minor, and no artifacts were found in 115 (51.5%) and 0 (0%), 71 (32.3%) and 9 (36%), and 36 (16.2%) and 16 (64%) patients, respectively (p < 0.01). The cone beam algorithm improves EBT studies of the abdomen.

High-spatial-resolution contrast-enhanced MR angiography of the renal arteries: a prospective comparison with digital subtraction angiography

PURPOSE

To evaluate a high-spatial-resolution three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiographic technique for detecting proximal and distal renal arterial stenosis.

MATERIALS AND METHODS

Twenty-five patients underwent high-spatial-resolution small-field-of-view (FOV) 3D contrast-enhanced MR angiography of the renal arteries, which was followed several minutes later by more standard, large-FOV 3D contrast-enhanced MR angiography that included the distal aorta and iliac arteries. For both acquisitions, MR fluoroscopic triggering and an elliptic centric view order were used. Two readers evaluated the MR angiograms for grade and hemodynamic significance of renal arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of digital subtraction angiograms.

RESULTS

The high-spatial-resolution small-FOV technique provided high sensitivity (97%) and specificity (92%) for the detection of renal arterial stenosis, including all four distal stenoses encountered. The portrayal of the segmental renal arteries was adequate for diagnosis in 19 (76%) of 25 patients. In 12% of the patients, impaired depiction of the segmental arteries was linked to motion.

CONCLUSION

The combined high-spatial-resolution small-FOV and large-FOV MR angiographic examination provides improved spatial resolution in the region of the renal arteries while maintaining coverage of the abdominal aorta and iliac arteries.

Imaging of the pericardium

Computed tomography (CT) and magnetic resonance imaging (MRI) are modalities well suited for imaging of the pericardium and pericardial disease. Both offer excellent resolution with a wide field of view. Both have advantages and disadvantages when compared with each other and with echocardiography. Establishing the diagnosis of constrictive pericarditis is a common indication for CT or MRI of the pericardium. Pericarditis, neoplasms, effusions, and congenital anomalies are additional conditions involving the pericardium that can be diagnosed with CT and MRI.

Polyarteritis nodosa: spectrum of angiographic findings

The purpose of this study was to review the positive angiographic findings in patients with polyarteritis nodosa (PAN). The authors reviewed the angiograms of 56 consecutive patients (25 women and 31 men; age range, 18-81 years; mean age, 55 years) with PAN and arterial abnormalities consistent with necrotizing vasculitis. Aneurysms were present in 27 patients and segments of ectasia were present in seven patients, for a total of 34 (61%) of 56 patients with aneurysmal lesions. The remaining 22 (39%) patients had arterial lesions that were occlusive: luminal irregularity, stenosis, or occlusion. All but one of the patients with an aneurysm also had occlusive lesions. Therefore, 55 (98%) of the 56 patients were found to have occlusive lesions. Skeletal muscle arteries were affected in 18 patients, nine in the extremities. The most frequent finding in patients with PAN was occlusive arterial lesions. Although the presence of aneurysms increases specificity for the diagnosis of PAN, many patients have only occlusive lesions. Involvement of skeletal muscle arteries was common.

Localized aortic dissection: unusual features by transesophageal echocardiography

Transesophageal echocardiography relies on the presence of an undulating intimal flap for the diagnosis of aortic dissection. Furthermore, to distinguish true dissection from echo artifacts, the flap has to be identified in more than one view, and it must have a motion independent of the aortic wall. We describe the transesophageal echocardiography appearance of a localized aortic dissection with atypical features for an intimal flap. Awareness of this unusual echocardiographic appearance of an intimal flap will avoid misdiagnosis of the potentially serious acute aortic dissection.

CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation

Benign primary cardiac neoplasms are rare but may cause significant morbidity and mortality. However, they are usually treatable and can often be diagnosed with echocardiography, computed tomography (CT), or magnetic resonance (MR) imaging. Myxomas typically arise from the interatrial septum from a narrow base of attachment. Fibroelastomas are easily detected at echocardiography as small, mobile masses attached to valves by a short pedicle. Cardiac fibromas manifest as a large, noncontractile, solid mass in a ventricular wall at echocardiography and as a homogeneous mass with soft-tissue attenuation at CT. They are usually homogeneous and hypointense on T2-weighted MR images and isointense relative to muscle on T1-weighted images. Paragangliomas usually appear as large, echogenic left atrial masses at echocardiography and as circumscribed, heterogeneous masses with low attenuation at CT. These tumors are usually markedly hyperintense on T2-weighted MR images and iso- or hypointense relative to myocardium on T1-weighted images. Cardiac lipomas manifest at CT as homogeneous, low-attenuation masses in a cardiac chamber or in the pericardial space and demonstrate homogeneous increased signal intensity that decreases with fat-saturated sequences at T1-weighted MR imaging. Cardiac lymphangiomas manifest as cystic masses at echocardiography and typically demonstrate increased signal intensity at T1- and T2-weighted MR imaging. Familiarity with these imaging features and with the relative effectiveness of these modalities is essential for prompt diagnosis and effective treatment.

Calcified left ventricular mass: unusual clinical, echocardiographic, and computed tomographic findings of primary cardiac osteosarcoma

Primary cardiac osteosarcomas are rare and usually originate in the left atrium. In contrast, osteosarcomas metastatic to the heart most commonly involve the right cardiac chambers. This case report describes an unusual primary cardiac osteosarcoma, initially observed as a slowly growing, densely calcified mass of the left ventricle with subsequent secondary pulmonary metastasis. Although cardiac tumors may be asymptomatic, this patient had recurrent bouts of ventricular tachyarrhythmia. We describe the clinical, echocardiographic, and radiological observations spanning 6 years and the gross and microscopic features at autopsy.

Three-dimensional contrast-enhanced MR angiography with real-time fluoroscopic triggering: design specifications and technical reliability in 330 patient studies

Technical reliability was determined for triggering three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiography with MR fluoroscopy. Technical requirements for high reliability were also identified. Reliability was evaluated in 330 consecutive patient studies of the neck, thorax, abdomen, and pelvis. Contrast material arrival was detected fluoroscopically in 325 of the 330 studies (98.5%), and the 3D sequence was successfully triggered in 321 of 330 studies (97.3%). Fluoroscopic triggering of centrically encoded 3D MR angiographic acquisitions is a highly reliable means of obtaining 3D MR angiograms with high spatial resolution.

Calcific constrictive pericarditis: is it still with us?

BACKGROUND

The presence of pericardial calcification on a plain radiograph strongly suggests constrictive pericarditis in patients with heart failure. However, calcific constrictive pericarditis is considered rare in the United States since tuberculosis incidence has decreased, and doubt has therefore been raised about the importance of this radiologic finding in modern cardiovascular practice.

OBJECTIVE

To determine the clinical and prognostic significance of pericardial calcification on radiography in patients with constrictive pericarditis.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

A consecutive series of 135 patients (mean age +/- SD, 56 +/- 16 years) who from 1985 through 1995 had constrictive pericarditis confirmed surgically (n = 133) or by autopsy (n = 2). Patients were divided into two groups: those with pericardial calcification on chest radiography (group I) and those without (group II).

MEASUREMENTS

Clinical and diagnostic findings were compared in both groups, and outcome was compared in 132 patients who had pericardiectomy.

RESULTS

Pericardial calcification was seen in 36 patients (27%). The cause of constrictive pericardial disease was indeterminate in 67% of patients in group I and in 21% of patients in group II (P < 0.001). Patients in group I had had symptoms for a longer period and were more likely to have pericardial knock, larger atrial size, and atrial arrhythmia. Significantly more perioperative deaths were seen in group I, but incidence of late survival and incidence of noncalcific disease were similar in both groups.

CONCLUSIONS

Pericardial calcification is a common finding in patients with constrictive pericarditis. It is often associated with idiopathic disease and other markers of disease chronicity and is an independent predictor of increased perioperative mortality rates.

CT and MR imaging of primary cardiac malignancies

Primary cardiac malignancies are rare tumors that are difficult to diagnose clinically. Different primary cardiac malignancies may have different clinical, morphologic, and radiologic features and intracardiac locations. Angiosarcoma is the most common primary cardiac malignancy. It tends to occur in the right atrium and involve the pericardium. Because of its tendency to hemorrhage, angiosarcoma often demonstrates areas of increased signal intensity with T1-weighted sequences. Undifferentiated sarcomas typically occur in the left atrium and have variable epidemiologic and radiologic features. Rhabdomyosarcoma is the most common primary cardiac malignancy in children and is more likely than other primary cardiac sarcomas to involve the valves. Primary cardiac osteogenic sarcoma almost always occurs in the left atrium and frequently demonstrates calcification. Certain features (eg, broad base of attachment, origin at a site other than the atrial septum) help differentiate this tumor from left atrial myxoma. Leiomyosarcoma favors the left atrium and tends to invade the pulmonary veins and mitral valve. Fibrosarcoma also tends to occur in the left atrium and is often necrotic. Liposarcoma is very rare and usually manifests as a large, infiltrating mass. Foci of macroscopic fat are occasionally seen. Primary cardiac lymphoma occurs more commonly in immunocompromised patients, frequently involves the pericardium, and, unlike other primary cardiac malignancies, may respond to chemotherapy. The advent of cross-sectional imaging has allowed earlier detection of primary cardiac malignancies as well as more accurate diagnosis and characterization.