Ruvin S. Gabriel

Role of the CHADS2Score in the Evaluation of Thromboembolic Risk in Patients With Atrial Fibrillation Undergoing Transesophageal Echocardiography Before Pulmonary Vein Isolation

OBJECTIVESnThe goals of this study were to determine: 1) if low-risk patients assessed by a CHADS(2) score, a clinical scoring system quantifying a risk of stroke in patients with atrial fibrillation (AF), require a routine screening transesophageal echocardiogram (TEE) before pulmonary vein isolation (PVI); and 2) the relationship of a CHADS(2) score with left atrial (LA)/left atrial appendage (LAA) spontaneous echo contrast, sludge, and thrombus.nnnBACKGROUNDnThere is no clear consensus of whether a screening TEE before catheter ablation of AF should be performed in every patient.nnnMETHODSnInitial TEEs for pre-PVI of 1,058 AF patients (age 57 +/- 11 years, 80% men) were reviewed and compared with a CHADS(2) score.nnnRESULTSnCHADS(2) scores of 0, 1, 2, 3, 4, 5, and 6 were present in 47%, 33%, 14%, 5%, 1%, 0.3%, and 0% of patients, respectively. The prevalence of LA/LAA thrombus, sludge, and spontaneous echo contrast were present in 0.6%, 1.5%, and 35%. The prevalence of LA/LAA thrombus/sludge increased with ascending CHADS(2) score (scores 0 [0%], 1 [2%], 2 [5%], 3 [9%], and 4 to 6 [11%], p < 0.01). No patient with a CHADS(2) score of 0 had LA/LAA sludge/thrombus. In a multivariate model, history of congestive heart failure and left ventricular ejection fraction <35% were significantly associated with sludge/thrombus.nnnCONCLUSIONSnThe prevalence of LA/LAA sludge/thrombus in patients with AF undergoing a pre-PVI screening TEE is very low (<2%) and increases significantly with higher CHADS(2) scores. This suggests that a screening TEE before PVI should be performed in patients with a CHADS(2) score of >or=1, and in patients with a CHADS(2) score of 0 when the AF is persistent and therapeutic anticoagulation has not been maintained for 4 weeks before the procedure.

The Safety of Definity and Optison for Ultrasound Image Enhancement: A Retrospective Analysis of 78,383 Administered Contrast Doses

BACKGROUNDnThe purpose of this retrospective analysis was to define the incidence of severe adverse events after exposure to ultrasound contrast agents.nnnMETHODSnData between January 1, 2001, and September 30, 2007, were collected using invited responses to an on-line web-based questionnaire from 1 general and 12 cardiac ultrasound laboratories. During a period of 4.5 +/- 2.4 years, a total of 66,164 doses of Definity (Lantheus Medical Imaging, North Billerica, MA) and 12,219 doses of Optison (GE Healthcare, Buckinghamshire, UK) were administered, reflecting contrast use in 5% of transthoracic and 28% of stress echocardiographic procedures. More than 10,000 doses were given to critically ill patients in intensive care unit settings or to patients with acute chest pain of suspected cardiac origin. The median age of patients who received an ultrasound contrast agent was 60 years, 49% were male, and the mean body mass index was 32 +/- 1.4 g/m(-2).nnnRESULTSnSevere reactions that were considered probably related to an ultrasound contrast agent developed in 8 patients (0.01%), all of whom were outpatients, and 4 (0.006%) of these were consistent with anaphylactoid reactions. There were no deaths reported. All patients recovered with treatment. No serious events were seen in inpatients.nnnCONCLUSIONnThis multicenter, retrospective analysis includes the largest number of doses of ultrasound contrast agents ever published and a large number of patients evaluated in a wide variety of settings, including the critically ill. It shows that these agents have a good safety profile in both cardiac and abdominal ultrasound applications. The incidence of severe adverse reactions to ultrasound contrast agents is no greater, and may be lower, than that reported for contrast agents commonly used in other cardiac imaging tests.

The Role of Multimodality Imaging in the Management of Pericardial Disease

Received November 12, 2009; accepted March 19, 2010. nnPericardial pathology is commonly encountered in clinical practice and may present either as an isolated process or in association with other systemic disorders. Recognizing pericardial pathology can be relatively straightforward, particularly if the clinical manifestation is typical (eg, the patient with acute pericarditis and an audible friction rub reporting retrosternal pain, exacerbated by inspiration or in the supine position) or when an associated disease process gives a direct clue to the diagnosis (eg, the finding of a complex pericardial effusion in a patient with a known malignancy). In these situations, the diagnostic pathway can be limited to a relatively small sequence of tests to basically confirm the initial clinical suspicion.1nnHowever, pericardial disease can also result in nonspecific symptoms and equivocal physical findings. When the initial tests of choice turn out to be nondiagnostic or the course of the disease is prolonged, pericardial disease may cause considerable diagnostic dilemmas. Furthermore, established diagnostic techniques may not visualize the full extent of the pericardial disease process. In such difficult clinical situations, an integrated multimodality imaging approach may provide incremental value. Unfortunately, current guidelines do not address the role of a multimodality approach in the difficult to manage pericardial patient.1 This review will therefore discuss the potential role of different imaging modalities in the diagnosis and management of pericardial disorders, with a specific focus on what constitutes a rational multimodality imaging approach.nnThe 3 imaging modalities most commonly used for evaluation of pericardial disease are echocardiography, cardiac computed tomography (CT), and cardiac MRI (CMR). The main indications and limitation for each test are summarized in Table 1. Echocardiography remains the initial imaging method of choice for the majority of patients with pericardial disease, but in many clinical scenarios, a transthoracic echocardiogram (TTE) …

Comparison of severity of aortic regurgitation by cardiovascular magnetic resonance versus transthoracic echocardiography.

Transthoracic echocardiography is the current standard for assessing aortic regurgitation (AR). AR severity can also be evaluated by flow measurement in the ascending aorta using cardiac magnetic resonance (CMR); however, the optimal site for flow measurement and the regurgitant fraction (RF) severity grading criteria that best compares with the transthoracic echocardiographic assessment of AR are not clear. The present study aimed to determine the optimal site and RF grading criteria for AR severity using phase-contrast flow measurements and CMR. A prospective observational study was performed of 107 consecutive patients who were undergoing CMR of the thoracic aorta. Using CMR, the AR severity and aortic dimensions were measured at 3 levels in the aorta (the sinotubular junction, mid-ascending aorta, and distal ascending aorta). The results were compared to the transthoracic echocardiographic grade of AR severity using multiple qualitative and quantitative criteria (grade 0, none; I+, mild; II+, mild to moderate; III+, moderate to severe; and IV+, severe). The mean RF values were significantly greater at the sinotubular junction than at the distal ascending aorta (13 ± 13.3% vs 9.4 ± 12.6%, respectively; p <0.001). The RF values that best defined AR severity using phase-contrast CMR were as follows: grade 0 to I+, <8%; grade II+, 8% to 19%; grade III+, 20 to 29%; and grade IV+, 30%) at the sinotubular or mid-ascending aorta. In conclusion, the quantitative RF values of AR severity using phase-contrast flow are best assessed in the proximal ascending aorta and differ from recognized quantitative echocardiographic criteria.

Safety of Ultrasound Contrast Agents in Stress Echocardiography

Definity and Optison are perflutren-based ultrasound contrast agents used in echocardiography. United States Food and Drug Administration warnings regarding serious cardiopulmonary reactions and death after Definity administration highlighted the limited safety data in patients who undergo contrast stress echocardiography. From 1998 and 2007, 2,022 patients underwent dobutamine stress echocardiography and 2,764 underwent exercise stress echocardiography with contrast at the Cleveland Clinic. The echocardiographic database, patient records, and the Social Security Death Index were reviewed for the timing and cause of death, severe adverse events, arrhythmias, and symptoms. Complication rates for contrast dobutamine stress echocardiography and exercise stress echocardiography were compared with those in a control group of 5,012 patients matched for test year and type who did not receive contrast. Ninety-five percent of studies were performed in outpatients. There were no differences in the rates of severe adverse events (0.19% vs 0.17%, p = 0.7), death within 24 hours (0% vs 0.04%, p = 0.1), cardiac arrest (0.04% vs 0.04%, p = 0.96), and sustained ventricular tachycardia (0.2% vs 0.1%, p = 0.32) between patients receiving and not receiving intravenous contrast, respectively. In conclusion, severe adverse reactions to intravenous contrast agents during stress echocardiography are uncommon. Contrast use does not add to the baseline risk for severe adverse events in patients who undergo stress echocardiography.

Cardiac MR Assessment of Aortic Regurgitation: Holodiastolic Flow Reversal in the Descending Aorta Helps Stratify Severity

PURPOSEnTo assess the utility of holodiastolic flow reversal (HDR) in the descending aorta on velocity-encoded cardiac magnetic resonance (MR) images in the stratification of aortic regurgitation (AR) severity.nnnMATERIALS AND METHODSnThis study was approved by the institutional review board, with waiver of informed consent. A total of 80 patients (overall mean age, 49 years ± 18 [standard deviation]; 22 women and 58 men) with clinical indication for cardiac MR imaging of the aorta were analyzed retrospectively. Velocity-encoded MR imaging was used to quantify AR and assess for HDR at the level of the middescending aorta. These indexes were compared with a qualitative integrated echocardiographic evaluation of AR severity. Sensitivity and specificity for HDR in the prediction of substantial AR were determined, and logistic regression analysis (with associated odds ratios and C statistics) was performed, with HDR and regurgitant fraction as independent predictors. An additional 42 patients (overall mean age, 48 years ± 21; 12 female and 30 male) were then prospectively evaluated in similar fashion to evaluate a decision model derived from analysis of the first group.nnnRESULTSnHDR predicted severe AR (echo grade, 4) with high sensitivity (100%) and specificity (93%). HDR was highly specific (100%) but had lower sensitivity (61%) for moderate to severe AR (echo grade, 3-4). Integration of HDR and direct AR quantification into a combined stratification model based on analysis of the primary group showed good predictive results in the validation group, with a C statistic of 0.94 for moderate to severe AR and 0.93 for severe AR.nnnCONCLUSIONnHDR in the middescending thoracic aorta observed at cardiac MR is indicative of severe AR and can be used in conjunction with quantified regurgitant values obtained from velocity-encoded MR imaging to stratify AR severity.

Role of Transesophageal Echocardiography Compared to Computed Tomography in Evaluation of Pulmonary Vein Ablation for Atrial Fibrillation (ROTEA Study)

BACKGROUNDnComputed tomography (CT) is the gold standard for assessing pulmonary vein (PV) anatomy and stenosis after ablation for atrial fibrillation (AF), but radiation exposure can be a concern. Transesophageal echocardiography (TEE) provides anatomic and functional assessment of the PVs, although no study hasxa0prospectively compared findings on TEE with those on CT.nnnMETHODSnThe Role of Transesophageal Echocardiography Compared to Computed Tomography in Evaluation of Pulmonary Vein Ablation for Atrial Fibrillation (ROTEA) study was a prospective, single-blinded observational study of patients with paroxysmal or persistent AF undergoing ablation. TEE and CT were performed immediately before and 3 months after AF ablation. The study included 43 patients (84% men; mean age, 56 ± 11 years).nnnRESULTSnIn the preprocedural study, TEE identified 98% of PVs with adequate Doppler measurements obtained. After ablation, no moderate or severe PV stenosis was detected on CT, and a 30% to 50% reduction in luminal diameter was seen in 5% of studied veins. Functional PV stenosis by pulsed-wave Doppler was seen in two veins on TEE. PV diameters decreased after ablation by 0.20 ± 0.03 and 0.22 ± 0.03 cm as measured by CT and TEE, respectively (P < .001). However, TEE underestimated PV ostial dimensions compared with CT, especially for the inferior PVs. Severe spontaneous echo contrast and low left atrial appendage emptyingxa0velocities, were identified in 10% of patients in sinus rhythm after ablation.nnnCONCLUSIONSnIn the ROTEA study, TEE was feasible in assessing PVs before and after ablation, providing bothxa0anatomic and functional information that complemented CT. PV ostial dimensions after ablation can be monitored using either modality, although TEE underestimates PV dimensions, especially for the inferior veins.

Managing catheter ablation for atrial fibrillation: the role of echocardiography

Atrial fibrillation (AF) is a common arrhythmia associated with the serious clinical consequences of systemic thrombo-embolism and heart failure. Catheter ablation for AF is an evolving treatment option for patients with drug-refractory paroxysmal and persistent AF. The ablation procedure relies on precise knowledge of the left atrium, left atrial appendage, and pulmonary venous anatomy and function. Echocardiography is an integral component of multiple imaging modalities which contribute to its success. Both transoesophageal echocardiography and transthoracic echocardiography provide essential anatomical and functional information to guide all aspects of management. This article reviews the role of echocardigraphy in AF ablation, from appropriate patient selection and pre-procedural screening, to evaluating complications and determining the need for long-term anticoagulation.

Estimation of myocardial strain from non-rigid registration and highly accelerated cine CMR

Sparsely sampled cardiac cine accelerated acquisitions show promise for faster evaluation of left-ventricular function. Myocardial strain estimation using image feature tracking methods is also becoming widespread. However, it is not known whether highly accelerated acquisitions also provide reliable feature tracking strain estimates. Twenty patients and twenty healthy volunteers were imaged with conventional 14-beat/slice cine acquisition (STD), 4× accelerated 4-beat/slice acquisition with iterative reconstruction (R4), and a 9.2× accelerated 2-beat/slice real-time acquisition with sparse sampling and iterative reconstruction (R9.2). Radial and circumferential strains were calculated using non-rigid registration in the mid-ventricle short-axis slice and inter-observer errors were evaluated. Consistency was assessed using intra-class correlation coefficients (ICC) and bias with Bland–Altman analysis. Peak circumferential strain magnitude was highly consistent between STD and R4 and R9.2 (ICCu2009=u20090.876 and 0.884, respectively). Average bias was −1.7u2009±u20092.0u2009%, pu2009<u20090.001, for R4 and −2.7u2009±u20091.9u2009%, pu2009<u20090.001 for R9.2. Peak radial strain was also highly consistent (ICCu2009=u20090.829 and 0.785, respectively), with average bias −11.2u2009±u200918.4u2009%, pu2009<u20090.001, for R4 and −15.0u2009±u200921.2u2009%, pu2009<u20090.001 for R9.2. STD circumferential strain could be predicted by linear regression from R9.2 with an R2 of 0.82 and a root mean squared error of 1.8u2009%. Similarly, radial strain could be predicted with an R2 of 0.67 and a root mean squared error of 21.3u2009%. Inter-observer errors were not significantly different between methods, except for peak circumferential strain R9.2 (1.1u2009±u20091.9u2009%) versus STD (0.3u2009±u20091.0u2009%), pu2009=u20090.011. Although small systematic differences were observed in strain, these were highly consistent with standard acquisitions, suggesting that accelerated myocardial strain is feasible and reliable in patients who require short acquisition durations.

Multimodality Imaging Assessment of Anatomic and Functional Pulmonary Vein Stenosis

A 68-year-old man with a history of permanent atrial fibrillation and symptoms of fatigue and palpitations underwent pulmonary vein ablation under intracardiac echocardiography and NAVX system 3D mapping guidance. He noticed improvement in his symptoms after the procedure and remained in sinus rhythm on follow-up arrhythmia monitoring. However, symptoms of shortness of breath and a nonproductive cough developed over 2 to 3 months. A computed tomography scan confirmed a significant stenosis of the left superior pulmonary vein. Multimodality imaging techniques were …