Left atrial size and function are related to pulmonary hypertension in coronary artery disease

Background: Left atrial (LA) size reflects diastolic burden and is a prognostic parameter of common cardiovascular death. However, the association between LA size and function and pulmonary hypertension (PH) in coronary artery disease (CAD) has not been well investigated. We hypothesized that LA size and function are associated with PH in CAD. Methods: One hundred seven patients with CAD were studied. LA size was determined in three different methods; namely, LA volume index (LAV), LA area index, and LA dimension. LAV total emptying fraction was also determined. Pulsed Doppler E, A, E/A, DT, tissue Doppler E′, A′, and E/E′ were measured. Pulmonary artery systolic pressure (PASP) was estimated. Results: All LA size parameters are significantly associated with PH. LAV emptying fraction, age, E, E/A, E/E′, and A′ were also associated with PH significantly. CAD patients with PH showed larger LA size, higher E, E/A, and E/E′ and lower LAV emptying fraction, A and A′ than CAD patients without PH. Multivariate regression analysis revealed that maximum LAV, E, E/A ratio, and age were independent predictors of PH. Maximum LAV > 35.6 mL/m² predicted PASP > 40 mmHg with a sensitivity of 83.9% and specificity of 62.2%. Conclusion: LAV is associated with PH in CAD patients. (Echocardiography 2012;29:535‐540)     

Usefulness of compensatory hyperkinesis in the noninfarcted left ventricular wall in separating single from multivessel coronary artery disease in patients with initial ST-elevation acute myocardial infarction

We assessed the contractility of the contralateral wall on 2-dimensional echocardiography in 50 patients with an initial ST-elevation acute myocardial infarction who underwent coronary angiography. Compensatory hyperkinesis, which we defined as a fractional thickening of >/=60% in the contralateral wall, was a strong predictor of single-vessel coronary artery disease, with a positive predictive value of 85%.     

Prevalence of left atrial appendage pseudothrombus filling defects in patients with atrial fibrillation undergoing coronary computed tomography angiography

Background

Previous reports have shown that computed tomography (CT) is a useful, noninvasive test for detecting atrial thrombi. However, blood stasis in the left atrial appendage (LAA) of patients with atrial fibrillation (AF) may be a common cause for false-positive results.

Objectives

We retrospectively evaluated the prevalence of filling defects that may simulate thrombus in the LAA of patients with AF during routine coronary CT angiography (CTA).

Methods

The LAA of 7 patients with AF was studied for the presence of filling defects and compared with 250 healthy persons. LAA volume in the patients with AF was measured at 10 different cardiac phases and compared with 30 healthy patients.

Results

Of the 7 patients with AF studied with CTA, 5 were positive for LAA filling defects. Follow-up imaging studies, including transesophageal echocardiogram, contrast-enhanced magnetic resonance angiography, or delayed-CT, were negative for LAA thrombus. Of 250 patients without AF, CTA showed no evidence of LAA filling defects. Patients with AF had significantly larger LAA volumes at all cardiac phases measured compared with patients without AF (15.2 ± 6.93 mL compared with 6.85 ± 3.01 mL at atrial contraction [P = 0.0187], 17.4 ± 7.76 mL compared with 9.46 ± 3.43 mL at ventricular systole [P = 0.0351], and 14.5 ± 5.87 mL compared with 8.48 ± 3.10 mL at mid-diastole [P = 0.0341]). Compared with the healthy persons, the patients with AF showed reduced percentages of change in LAA volume when the atrial contraction phase was compared with other phases: 44.0% ± 25.6% compared with 16.5% ± 12.2% compared with ventricular systole (P = 0.0004) and 29.5% ± 23.7% compared with −1.63% ± 8.84% at mid-diastole (P < 0.0001).

Conclusions

Pseudothrombus filling defects are common in the LAA of patients with AF undergoing coronary CTA and should not be mistaken for real thrombus.     

Cardiac CT Prior to Left Atrial Appendage Closure Device Implantation and Percutaneous Mitral Valve Interventions

Recent advances in percutaneous techniques have allowed them to emerge as an attractive alternative to surgery in select patients. Left atrial appendage closure has emerged as a novel therapeutic option in patients an nonvalvular atrial fibrillation who cannot take anticoagulation therapy. Furthermore, percutaneous mitral valve procedures have shown promising results in high risk patients. These percutaneous procedures require multimodality imaging for preprocedural planning and during the procedure. Computed tomography has emerged as an attractive imaging modality prior to percutaneous procedures given its ability to perform comprehensive assessment of cardiac and extracardiac structures. This review assesses the role of computed tomography as it pertains to left atrial appendage occlusion and mitral valve transcatheter procedures.     

Detection of phrenic nerves and their relation to cardiac anatomy using 64-slice multidetector computed tomography

The improved temporal and spatial resolution allowed by multidetector computed tomography (MDCT) has facilitated the noninvasive assessment of cardiac anatomy before transcatheter electrophysiologic procedures. Clarification of spatial relations of phrenic nerves and key cardiac structures is important to decrease potential complications. The purpose of this study was to reconstruct the course of the right and left phrenic pericardiophrenic bundles and their relations to cardiac structures using 64-slice MDCT. One hundred six consecutive subjects (age 61 +/- 13 years; 39% women) who underwent self-referred coronary computed tomographic angiography using 64-slice MDCT underwent retrospective assessment of the phrenic nerves contained within the pericardiophrenic bundles. The course of the nerves was outlined in relation to the left atrial appendage, coronary sinus, and cardiac veins. The ability to individually detect the left and right phrenic nerves, as well as the frequency of direct contact between the left phrenic nerve and cardiac veins, was recorded. The left phrenic nerve was identified in 78 of 106 patients (74%). It crossed the left atrial appendage (n = 72, 91%), great cardiac vein (n = 63, 80%), posterior vein of the left ventricle (n = 39, 49%), posterior interventricular vein (n = 8, 10%), and anterior interventricular vein (n = 7, 9%). Mean Hounsfield units (HUs) of the left phrenic nerve was 81 +/- 25. The right phrenic nerve was identified in 50 of 106 patients (47%). Mean HUs of the right phrenic nerve were 94 +/- 26. In conclusion, cardiac imaging using 64-slice MDCT enabled adequate detection of the left and right phrenic nerves in relation to cardiac anatomy. In the setting of electrophysiologic interventions, MDCT before a procedure may elucidate anatomic relationships and help minimize inadvertent complications.