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.

A novel application of CT angiography to detect extracoronary vascular abnormalities in patients with spontaneous coronary artery dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is associated with extracoronary vascular abnormalities, which depending on type and location may warrant treatment or provide additional diagnostic or prognostic information about this uncommon entity. Fibromuscular dysplasia (FMD), aneurysms, and dissections have been detected in multiple vascular territories by magnetic resonance angiography, CT angiography (CTA), and catheter angiography. The optimal modality to detect extracoronary vascular abnormalities is unknown. We highlight the technique and feasibility of a novel CTA protocol to detect extracoronary vascular abnormalities in these patients, incorporating patient safety and convenience. METHODS: The complete CTA protocol consisting of a single CTA of the neck, chest, abdomen, and pelvis was performed on 39 SCAD outpatients. All examinations were performed with 200 mL of low-osmolar contrast agent and used radiation dose modulation techniques. Average volume CT dose index was 9 mGy for the chest, abdomen, and pelvis portions and 21 mGy for the neck portion. Studies were independently reviewed by 2 senior vascular radiologists. RESULTS: Two patients had nondiagnostic CTA neck evaluation because of technical acquisition errors. Extracoronary vascular abnormalities were detected in 27 of 39 patients (69%). Catheter angiography detected brachial artery FMD in 1 patient, a vascular bed not included in the SCAD CTA protocol. Extracoronary vascular abnormalities were common, including FMD, aneurysms, dissection, and aortic tortuosity, and were seen in the iliac (36%), carotid and/or vertebral (31%), splanchnic (10%), and renal (26%) arteries and in the thoracic and/or abdominal aorta (10%). CONCLUSIONS: The frequency of extracoronary vascular abnormalities and extent of territories identified the CTA protocol in our cohort are high. A tailored CTA may be the optimal imaging technique for detecting extracoronary vascular abnormalities in patients with suspected underlying vasculopathy. Although the clinical significance of extracoronary vascular abnormalities remains unclear, detection of these abnormalities has identified patients in whom cerebral imaging and serial monitoring have been recommended.

Multimodality imaging of a giant aortic valve papillary fibroelastoma.

Papillary fibroelastomas (PFEs) are benign cardiac tumors arising from endocardium. They are commonly found on valvular surfaces and average 1.0-1.5 cm in size. Though often asymptomatic, PFEs can lead to potentially severe complications, primarily due to their embolic potential. Surgical resection is recommended for all symptomatic or large PFEs. We report the case of a patient presenting with cardiovascular symptoms who was found to have a very large aortic valve PFE, as diagnosed by histopathologic examination following surgical resection. Multimodality cardiovascular imaging demonstrates the classic morphologic findings, including a pedunculated appearance and oscillating "frond-like" surface projections.

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.

MR imaging findings in 76 consecutive surgically proven cases of pericardial disease with CT and pathologic correlation.

To describe findings of patients with surgically confirmed pericardial disease on state of the art MR sequences. Retrospective review was performed for patients who underwent pericardiectomy and preoperative MR over a 5 year period ending in 2009. Patients' records were reviewed to confirm the diagnosis of chronic recurrent pericarditis, constrictive pericarditis, or pericardial tumor. MR imaging findings of pericardial thickness, IVC diameter, presence or absence of pericardial or pleural effusion, pericardial edema, pericardial enhancement, and septal "bounce" were recorded. Patients with constriction had a larger IVC diameter (3.1 ± 0.4 cm) than patients with recurrent pain and no constriction (2.0 ± 0.4 cm). Mean pericardial thickness for the 16 patients with chronic recurrent pericarditis but no evidence of constriction was 4.8 ± 2.9 mm. Mean pericardial thickness for patients with constriction was 9.2 ± 7.0 cm with calcification, and 4.6 ± 2.1 cm without calcification. 94% of patients with chronic recurrent pericarditis had gadolinium enhancement of the pericardium, while 76% of patients with constriction had pericardial enhancement. Septal "bounce" was present in 19% of chronic recurrent pericarditis cases and 86% of constriction cases. 5 patients had a pericardial neoplasm, 1 of which was not identified preoperatively. State of the art MR techniques can identify significant and distinct findings in patients with chronic recurrent pericarditis, constrictive pericarditis, and pericardial tumors.

Computed tomography of cardiac pseudotumors and neoplasms.

Important features of cardiac masses can be clearly delineated on cardiac computed tomography (CT) imaging. This modality is useful in identifying the presence of a mass, its relationship with cardiac and extracardiac structures, and the features that distinguish one type of mass from another. A multimodality approach to the evaluation of cardiac tumors is advocated, with the use of echocardiography, CT imaging and magnetic resonance imaging as appropriately indicated. In this article, various cardiac masses are described, including pseudotumors and true cardiac neoplasms, and the CT imaging findings that may be useful in distinguishing these rare entities are presented.

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.

MR imaging of cardiac masses.

Cardiac MR imaging is the preferred method for assessment of cardiac masses. A comprehensive cardiac MR imaging examination for a cardiac mass consists of static morphologic images using fast spin-echo sequences, including single-shot techniques, with T1 and T2 weighting and fat suppression pulses as well as dynamic imaging with cine steady-state free precession techniques. Further tissue characterization is provided with perfusion and delayed enhancement imaging. Specific cardiac tumoral characterization is possible in many cases. When specific tumor characterization is not possible, MR imaging often can demonstrate aggressive versus nonaggressive features that help in differentiating malignant from benign tumors.

Apical ballooning syndrome or aborted acute myocardial infarction? Insights from cardiovascular magnetic resonance imaging.

INTRODUCTION: Apical Ballooning Syndrome (ABS) is a novel acute cardiac syndrome that mimics acute myocardial infarction (AMI). This study evaluates the diagnostic utility of cardiac magnetic resonance imaging (CMR) in patients with suspected ABS. METHODS AND MATERIALS: Contrast-enhanced CMR was performed in 13 consecutive patients with suspected ABS on the basis of their initial clinical presentation and cardiac catheterization results. RESULTS: Ten patients (all female, mean age 71 +/- 8 years) had an eventual diagnosis of ABS. CMR demonstrated left ventricle regional wall motion abnormalities (RWMA) involving the apex and mid-ventricle. Six also had right ventricular apical akinesis. There was no myocardial delayed enhancement (MDE) in these patients. The remaining three patients had initial features suggestive of ABS but were eventually determined to have AMI. Left ventriculography showed typical apical ballooning that was not explained by coronary angiography results. Two had MDE and persistent RWMA consistent with anterior AMI. One had RWMA on CMR consistent with a single vascular territory, and subsequent intravascular ultrasound showed obstructive plaque in the left anterior descending (LAD) artery. The final diagnosis in these patients was AMI with clot lysis prior to coronary angiography. CONCLUSION: While ABS mimics AMI, AMI with spontaneous clot lysis may also mimic ABS, and at least in some patients, be mistaken for ABS. ABS is characterized by the absence of MDE and complete myocardial viability on CMR. The diagnosis of ABS can be excluded if CMR demonstrates MDE consistent with myocardial necrosis in a pattern and distribution consistent with AMI.

ECG-gated cardiac CT angiography using 64-MDCT for detection of patent foramen ovale.

OBJECTIVE: The purpose of our study was to show the feasibility of ECG-gated, 64-MDCT cardiac angiography for the detection of patent foramen ovale (PFO). MATERIALS AND METHODS: Chart review was performed on 214 consecutive patients referred for clinically indicated 64-MDCT angiography. The study cohort consisted of 20 patients who had previously undergone transesophageal echocardiography (TEE). Blinded consensus review of each CT angiography was performed by two experienced cardiac radiologists and results were compared with TEE, which served as a reference standard. CT criteria for the diagnosis of PFO were distinct left atrial "flap" in the expected location of the septum primum, continuous column of contrast material connecting this flap to the right atrium, and a "jet" of contrast material from the column into the right atrium. RESULTS: Of the 20 patients who underwent both TEE and cardiac CT angiography, six (30%) were found to have a PFO by TEE. Using the presence of a left atrial flap as the only diagnostic criterion, all six cases of PFO were detected using CT (sensitivity = 100%). Of the 14 patients with no PFO seen on TEE, 12 of these were correctly identified using CT (specificity = 86%). Using all three criteria together, the sensitivity decreased to 66% and the specificity increased to 100%. CONCLUSION: ECG-gated cardiac CT angiography performed with a 64-MDCT scanner can be used to reliably detect PFO.

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.