Syed, Imran S.

Introduction Multi-detector computed tomography (MDCT) is commonly used to identify pulmonary vein and left atrial anatomy prior to catheter ablation for atrial fibrillation (CAAF). Additionally, transesophageal echocardiography (TEE) is utilized to exclude left atrial/left atrial appendage thrombus (ICT). Whether MDCT alone can be used to exclude thrombus obviating the need for TEE is unknown. Methods All Pts referred for CAAF at Mayo Clinic between March 2004 and October 2006 were included. Clinical data (including CHADS score), 64 slice MDCT (non-ECG gated), TEE and intra-cardiac echocardiograph (ICE) were all performed and recorded. Image data was reviewed independently and blinded. The left atrial appendage (LAA) was defined as fully opacified or underfilled. An underfilled LAA was further interrogated using a region of interest over the filling defect and mean attenuation in Hounsfield Units (HU) were recorded. Results In total 400 Pts (mean age 56 ± 10 yrs; 76% male; EF 56 ± 10 % ) were included. 362 had no ICT by TEE nor filling defect by MDCT. 38 patients had an underfilled LAA in whom ICT was confirmed by TEE in 7. Sensitivity and specificity of MDCT for ICT was 100% and 92% respectively with a NPV of 100%. In 19 Pts with underfilled LAA’s, a mean LAA emptying velocity was found to be significantly reduced at 26 cm/s (6 – 61 cm/s). Those with a thrombus had a mean attenuation value below 70 HU. CHADS2 score was higher (2.0 versus 1.0) in Pts with LAA filling defect versus those without LAA filling defect. All Pts with confirmed thrombus were taking Warfarin. ICT was not seen in any Pts aged <52 yrs with CHADS score ≤1. Conclusions Sensitivity and specificity of MDCT for detection of LAA thrombus is high. LAA filling defects on MDCT correlate with low emptying velocities by TEE and low attenuation value in HU. These data would suggest that in the absence of MDCT filling defect, no further imaging is required. TEE should be utilized prior to CAAF to investigate MDCT filling defects. Multidetector Computed Tomography for the Detection of LAA Thrombus

Background: Radiation therapy (RT) to the chest may induce various combined cardiac problems such as constrictive pericarditis (CP), restrictive myocardial disease, and coronary artery disease. Therefore, it was hypothesized that the MRI and transthoracic echocardiographic (TTE) findings in patients with CP may differ according to the history of RT. Methods: A total of 68 patients with CP who performed both TTE and MRI study at Mayo Clinic from 2002 to 2008 were reviewed and divided into two groups according to the history of RT; RT group (group I, n=13, 53.6±9.8 years, 8 males) versus no RT group (group II, n=55, 59.0±14.8, 45 males). Results: The results of TTE study were summarized in table . Early diastolic velocity of septal mitral annulus (E′) and deceleration time (DT) of mitral inflow was significantly lower, and the ratio of early diastolic mitral inflow velocity (E) to E′ is significantly higher in group I than in group II. Left atrial volume index (LAVI) was significantly lower and LA area and left ventricular end-diastolic dimension (LVEDD) was significantly smaller in group I than in group II. Delayed enhancement of pericardium was the only significant finding in MRI and significantly prevalent in group I than in group II (100.0% in group I vs 63.6% in group II, p=0.012). The other MRI findings including pericardial thickness, left ventricular and right ventricular ejection fraction, and the presence of pericardial and pleural effusion were not different between the groups. Conclusion: In CP patients with the history of RT compared to patients without history of RT, E′ and DT was significantly lower, LAVI and LVEDD were smaller, pericardial DE in MRI was invariably found. The lower E′ velocity and decreased chamber size and volumes may be explained by RT induced coexisting myocardial disease. TTE findings of the patients

Background— Constrictive pericarditis (CP) is a disabling disease, and usually requires pericardiectomy to relieve heart failure. Reversible CP has been described, but there is no known method to predict the reversibility. Pericardial inflammation may be a marker for reversibility. As a pilot study, we assessed whether cardiac magnetic resonance imaging pericardial late gadolinium enhancement (LGE) and inflammatory biomarkers could predict the reversibility of CP after antiinflammatory therapy. Method and Results— Twenty-nine CP patients received antiinflammatory medications after cardiac magnetic resonance imaging. Fourteen patients had resolution of CP, whereas 15 patients had persistent CP after 13 months of follow-up. Baseline LGE pericardial thickness was greater in the group with reversible CP than in the persistent CP group (4±1 versus 2±1 mm, P =0.001). Qualitative intensity of pericardial LGE was moderate or severe in 93% of the group with reversible CP and in 33% of the persistent CP group ( P =0.002). Cardiac magnetic resonance imaging LGE pericardial thickness ≥3 mm had 86% sensitivity and 80% specificity to predict CP reversibility. The group with reversible CP also had higher baseline C-reactive protein and erythrocyte sedimentation rate than the persistent CP group (59±52 versus 12±14 mg/L, P =0.04 and 49±25 versus 15±16 mm/h, P =0.04, respectively). Antiinflammatory therapy was associated with a reduction in C-reactive protein, erythrocyte sedimentation rate, and pericardial LGE in the group with reversible CP but not in the persistent CP group. Conclusions— Reversible CP was associated with pericardial and systemic inflammation. Antiinflammatory therapy was associated with a reduction in pericardial and systemic inflammation and LGE pericardial thickness, with resolution of CP physiology and symptoms. Further studies in a larger number of patients are needed.

Background— Primary amyloidosis has a poor prognosis as a result of frequent cardiac involvement. We recently reported a high prevalence of intracardiac thrombus in cardiac amyloid patients at autopsy. However, neither the prevalence nor the effect of anticoagulation on intracardiac thrombus has been evaluated antemortem. Methods and Results— We studied all transthoracic and transesophageal echocardiograms of cardiac amyloid patients at the Mayo Clinic. The prevalence of intracardiac thrombosis, clinical and transthoracic/transesophageal echocardiographic risks for intracardiac thrombosis, and effect of anticoagulation were investigated. We identified 156 patients with cardiac amyloidosis who underwent transesophageal echocardiograms. Amyloidosis was the primary type (AL) in 80; other types occurred in 76 patients, including 56 with the wild transthyretin type, 17 with the mutant transthyretin type, and 3 with the secondary type. Fifth-eight intracardiac thrombi were identified in 42 patients (27%). AL amyloid had more frequent intracardiac thrombus than the other types (35% versus 18%; P =0.02), although the AL patients were younger and had less atrial fibrillation. Multivariate analysis showed that atrial fibrillation, poor left ventricular diastolic function, and lower left atrial appendage emptying velocity were independently associated with increased risk for intracardiac thrombosis, whereas anticoagulation was associated with a significantly decreased risk (odds ratio, 0.09; 95% CI, 0.01 to 0.51; P <0.006). Conclusions— Intracardiac thrombosis occurs frequently in cardiac amyloid patients, especially in the AL type and in those with atrial fibrillation. Risk for thrombosis increased if left ventricular diastolic dysfunction and atrial mechanical dysfunction were present. Anticoagulation therapy appears protective. Timely screening in high-risk patients may allow early detection of intracardiac thrombus. Anticoagulation should be carefully considered.