Faculty Bibliography

Introduction: Patients receiving radiofrequency ablation (RFA) for the treatment of atrial fibrillation frequently undergo pre-procedural cardiac CT for evaluation of the left atrium and pulmonary veins. Left atrial outpouchings (LAO), including diverticula and accessory appendages, can be mistaken for an ostium of a pulmonary vein, which are important to identify as there is a potential risk of complications during RFA. The prevalence of these outpouchings has been described to be as high as 27 percent in the population of patients undergoing routine cardiac CT.1 The purpose of this study is to describe the prevalence, morphology, and size of LAO in patients undergoing RFA for treatment of atrial fibrillation. Methods: Fifty consecutive patients referred for RFA were identified from our registry of patients undergoing gated cardiac CT. Data was independently analyzed by two blinded readers for LAO. Images were evaluated using multiplanar reformatted and 3D reconstruction. The presence of LAO was defined as any abnormality that had a discernable ostium stemming from the left atrial wall. The number and size of LAO were recorded. Comparison of prevalence was evaluated using the Fisher's exact test. Results: There were a total of 29 LAO found in 24 of the 50 patients for a calculated prevalence of 48% (95% CI: 33.6 to 62.6). The prevalence in our population was significantly higher than reported in the general cohort of patients undergoing routine cardiac CT (p=0.003). The average size (length, width, and depth) of the LAO were 0.54 +/- 0.28 by 0.39 +/- 0.20 by 0.56 +/- 0.26 cm. Conclusions: Patients undergoing RFA for atrial fibrillation have a high prevalence of L

Introduction: Patients receiving radiofrequency ablation (RFA) for treatment of atrial fibrillation typically undergo pre-procedural cardiac computed tomography angiography (CCTA) to delineate pulmonary venous anatomy and transesophageal echocardiogram (TEE) to exclude left atrial and/or left atrial appendage thrombus (LAT). The addition of a late phase acquisition is theorized to aid CCTA identification and discrimination of LAT from slow left atrial appendage filling. The purpose of this study is to evaluate the diagnostic accuracy of dual-phase, ECG-gated dual-source CCTA (64-slice Definition, Siemens) compared to TEE for identification of thrombus and to assess the added value of a late phase CCTA acquisition. Methods: Fifty-three consecutive patients (37 men; mean age 63) had both dual-phase CCTA and TEE prior to RFA. Mean time between CCTA and TEE was 9 days (range 1-22). Mean early phase and late phase scan acquisition delay times were 29 sec and 30 sec, respectively. Presence of LAT was independently graded on both early phase and combined early and late phase (CP) CCTA acquisitions using a 5-point Likert scale by 2 readers blinded to the TEE results. Diagnostic accuracy for LAT was assessed for early phase and CP CCTA acquisitions using TEE results as truth. Results: CCTA identified LAT in 2 out of 3 patients with thrombi on TEE (67%). Relative to TEE, early phase and CP CCTA acquisitions demonstrated: 47% and 67% sensitivity, 84% and 100% specificity, 54% and 100% PPV, 80% and 98% NPV, respectively. Overall diagnostic accuracy was significantly improved for CP compared to early phase acquisition (98% and 77%, respectively, p<0.001). Conclusions: CCTA has excellent specificity (100%) but only modest sensitivity (66.7%) for identification of LAT in patients undergoing RFA. Addition of a late phase CCTA acquisition significantly improves overall diagnostic accuracy

Diabetic patients with coronary artery disease (CAD) are more likely to develop heart failure (HF) than nondiabetic patients, but the mechanism responsible is unclear. Evidence suggests that infarct size and accompanying remodeling may not explain this difference. We used cardiac magnetic resonance (CMR) imaging to compare degree of left ventricular (LV) myocardial scar and remodeling in diabetic and nondiabetic patients with CAD. We evaluated 85 patients (39 diabetic, 46 nondiabetic) who underwent coronary angiography showing obstructive CAD and CMR imaging within 6 months of each other. Myocardial scar was measured by late gadolinium enhancement on CMR imaging and was graded according to spatial and transmural extents on a semiquantitative scale. More diabetic than nondiabetic patients had HF (69% vs 43%, p <0.03); however, groups did not differ in total scar burden (0.94 +/- 0.60 vs 1.17 +/- 0.74, p = NS), spatial extent of scar, or extent of transmural scar. Diabetes remained an independent predictor of HF after adjustment for CAD and other variables. LV ejection fraction (36 +/- 12% vs 37 +/- 14%, p = NS) and end-diastolic volume (215 +/- 56 vs 217 +/- 76 ml, p = NS) were similar for diabetic and nondiabetic patients, respectively. In conclusion, although diabetic patients with CAD had a higher prevalence of HF than nondiabetic patients, there was no difference in myocardial scar, LV volume, or LV ejection fraction. These findings support the theory that mechanisms other than extent of myocardial injury and negative remodeling play a significant role in the development of HF in diabetic patients with CAD

OBJECTIVE: Published cardiac CT angiography (CTA) reference measurements for the cardiac chambers, aorta, and pulmonary artery (PA) are incomplete and compromised by study population, coronary artery disease (CAD), or its risk factors. The purpose of our study was to establish sex-specific normalized ranges of cardiac chamber size, wall thickness, ejection fraction (EF), and aorta and PA diameter on cardiac CTA in a population without CAD or its risk factors. MATERIALS AND METHODS: Seventy-six patients (38 men and 38 women) without known diabetes; hypertension; smoking history; or evidence of structural heart, vascular, or coronary artery diseases underwent 64-MDCTA. Obtained left atrial (LA) size, left ventricular (LV) volumes, LV wall thickness, thoracic aorta, and PA diameter measurements were normalized to body surface area (BSA). RESULTS: There were statistically significant differences noted between men and women for all measured left-sided heart and great vessel measurements. After normalization to BSA, only chamber dimensions and ascending aorta and left PA sizes remained significantly different. Selected normalized measurements for men versus women, respectively, include LA area, 10.6 +/- 2.1 versus 12.3 +/- 2.1 cm(2)/m(2); LV end-diastolic size, 72.4 +/- 15.1 versus 60.9 +/- 13.3 mL/m(2); EF, 67% +/- 7% versus 72% +/- 8%; aortic sinus, 1.6 +/- 0.2 versus 1.7 +/- 0.2 cm/m(2); ascending aorta, 1.4 +/- 0.2 versus 1.6 +/- 0.2 cm/m(2); descending aorta, 1.1 +/- 0.1 versus 1.2 +/- 0.1 cm/m2; main PA, 1.3 +/- 0.1 versus 1.4 +/- 0.1 cm/m(2); right PA, 1.1 +/- 0.1 versus 1.1 +/- 0.2 cm/m(2); and left PA, 1.0 +/- 0.1 versus 1.1 +/- 0.1 cm/m(2). CONCLUSION: Cardiac CTA measurements of the left cardiac chambers, thoracic aorta, and pulmonary arteries were established for a population without CAD or its risk factors

A 60-year-old man presented with symptoms from an intracardiac mass. His medical history included retroperitoneal fibrosis (Ormond disease). Magnetic resonance imaging revealed an obstructing bilobular mass in the right atrium, located at the caval junction and extending intramurally into the atria, septum, and right ventricle. En bloc resection of the right atrium, interatrial septum, dome of the left atrium, vena cava, anterior tricuspid annulus, right coronary artery, and partial right ventriculectomy was completed with right ventricular repair, tricuspid valve replacement, and left and right atrial replacement with bovine pericardium. This lesion was a myofibroblastic tumor with the same histologic features as his retroperitoneal fibrosis

BACKGROUND: Functional mitral regurgitation (FMR) is associated with leaflet displacement and tethering. Little is known about regional coaptation zones, including variations in coaptation length (CL) and contributions of anterior and posterior leaflets. Regional coaptation zones were analyzed in patients with normal mitral valves and with FMR. METHODS: Cardiac surgery patients underwent a three-dimensional transesophageal echocardiography. Four-dimensional volumetric datasets were acquired with Doppler interrogation. Offline analysis was performed. Orthogonal views were extracted in diastole and systole. Leaflet dimensions and coaptation distance and depth were examined for posterior and apical displacement of the coaptation zones. RESULTS: Twenty patients were analyzed (10 normal and 10 with 2 to 4+ FMR). Anterior leaflet CL was greater than posterior leaflet CL: 2.2+/-0.6 mm versus 0.9+/-0.3 mm in region 1, 3.2+/-0.7 mm versus 1.2+/-0.6 mm in region 2, and 1.8+/-0.4 mm versus 0.6+/-0.3 mm in region 3 (p<0.001). The FMR was associated with shorter leaflet CLs, with a mean anterior CL of 1.7+/-0.4 mm versus 3.1+/-0.4 mm (p=0.04), and a mean posterior CL of 0.7+/-0.3 mm versus 1.1+/-0.3 mm (p=0.03). The biggest difference in CLs was in A2-P2. Coaptation distance and depth were higher in the FMR group: 21.7+/-1.0 mm versus 17.9+/-1.0 mm (p=0.01), and 8.6+/-0.7 mm versus 5.0+/-0.7 mm (p<0.01). CONCLUSIONS: Mitral valve leaflet CL is asymmetric in normal valves, with anterior dominance. Functional mitral regurgitation is associated with a relocated coaptation zone, regional changes, and diminished coaptation. These data suggest an 'anterior leaflet reserve.' Posterior movement of the coaptation line compensates for annular dilation and presumed left ventricular enlargement in order to maintain competency until inadequate anterior leaflet CL occurs

Cardiac computed tomographic angiography (CTA) using multidetector computed tomographic scanners has proven to be a reliable technique to image the coronary vessels. CTA also provides excellent visualization of the mitral and aortic valves, and yields useful information regarding valve anatomy and function. Accordingly, an assessment of the valves should be performed whenever possible during CTA interpretation. In this paper, we highlight the imaging features of common functional and structural left-sided valvular disorders that can be seen on CTA examinations

Background: Electrocardiographic (ECG) criteria for left ventricular (LV) hypertrophy have been shown to have modest predictive values when compared to LV hypertrophy measured by cardiac magnetic resonance (CMR). Prior studies have excluded patients with cardiomyopathies and have not evaluated regional wall thickness in addition to overall LV mass and wall thickness. Thus it remains unknown how well ECG criteria will predict both regional wall thickness and overall LV mass/wall thickness compared to CMR in this population. Objective: To determine if common criteria for LV hypertrophy on ECG are predictive of regional wall thickness and overall LV mass as determined by CMR in patients with cardiomyopathy. Methods: A total of 41 consecutive patients (34 male) greater than 40 years old who underwent CMR for evaluation of cardiomyopathy (both ischemic and non-ischemic) were evaluated. Recent ECG's (mean of 8 days from CMR) were blindly evaluated and patients with a QRS > 120 were excluded from analysis. LV mass and regional wall thickness (anterior, septal, inferior, lateral) were measured at end-diastole on CMR. ECG voltage was examined by two commonly used determinants of LV hypertrophy: 1) Sokolow (SV1+RV5 or V6) and 2) Cornell (SV3 +RaVL) criteria. Pearson r correlations were used to examine the relationship between the CMR and ECG parameters. Results: Mean LV mass was 154 +/- 55 grams, and LV mass index was 76 +/- 31 grams/meters². Sokolow ECG voltage showed good to high correlations with overall LV mass and regional wall thickness, with no significant differences between LV regions (Table 1). Cornell ECG voltage correlated less strongly with CMR parameters, and also showed no significant regional differences. Conclusion: Sokolow ECG voltage criteria for LV hypertrophy demonstrates good to high correlations with LV mass and (Table presented) regional LV wall thickness in patients with cardiomyopathy. Cornell criteria performed worse in this population. No significant differences existed between LV regional wall thickness for either criteria

Quantitative assessment of regional cardiac function can improve the accuracy of detecting wall motion abnormalities due to heart disease. While recently developed fast cine displacement-encoded with stimulated echoes (DENSE) MRI is a promising modality for the quantification of regional myocardial function, it has not been validated for clinical applications. The purpose of this study, therefore, was to validate the accuracy of fast cine DENSE MRI with numerical simulation and in vivo experiments. A numerical phantom was generated to model physiologically relevant deformation of the heart, and the accuracy of fast cine DENSE was evaluated against the numerical reference. For in vivo validation, 12 controls and 13 heart-disease patients were imaged using both fast cine DENSE and myocardial tagged MRI. Numerical simulation demonstrated that the echo-combination DENSE reconstruction method is relatively insensitive to clinically relevant resonance frequency offsets. The strain measurements by fast cine DENSE and the numerical reference were strongly correlated and in excellent agreement (mean difference = 0.00; 95% limits of agreement were 0.01 and -0.02). The strain measurements by fast cine DENSE and myocardial tagged MRI were strongly correlated (correlation coefficient = 0.92) and in good agreement (mean difference = 0.01; 95% limits of agreement were 0.07 and -0.04)