Enhanced detection of left atrial spontaneous echo contrast by transthoracic harmonic imaging in mitral stenosis

Left atrial spontaneous echo contrast: relationship with clinical and echocardiographic parameters

Spontaneous echo contrast (SEC) indicates blood stasis in cardiac chambers and major vessels, and is a known precursor of thrombus formation. Transesophageal echocardiography plays a pivotal role in detecting and grading SEC in the left atrial (LA) cavity. Assessing LA SEC can identify patients at increased risk for thromboembolic events. LA SEC also develops in patients who have sinus rhythm, especially in those with heart failure. Detection of LA SEC is not uncommon in subjects who have multiple cardiovascular comorbidities, although mechanisms behind this association are not fully understood. In patients with atrial fibrillation, the role of mitral regurgitation in counteracting LA SEC and subsequent thromboembolism is controversial. Moreover, alterations of blood coagulability and elevated levels of certain biological markers in the blood contribute to occurrence of LA SEC. This review describes the pathogenesis and assessment of SEC, in addition to the relationship between LA SEC and clinical, biological and echocardiographic parameters.

Prognostic significance of spontaneous echocardiographic contrast detected by transthoracic and transesophageal echocardiography in the era of harmonic imaging

INTRODUCTION

Echocardiographic diagnosis of spontaneous intracardiac contrast is the reflection of interactions between erythrocytes and plasma proteins. Underlying conditions are associated with low blood flow velocities in the heart. We sought to determine whether spontaneous echo contrast (SEC) detected in the era of widespread use of harmonic imaging still reflects poor prognosis and risk of thromboembolism.

MATERIAL AND METHODS

We retrospectively analyzed the database of a tertiary cardiology centre echocardiographic laboratory and identified 60 patients with SEC, but without solid intracardiac structures, and subsequently selected 60 sex- and age-matched controls without SEC. Data regarding baseline characteristics, treatment and clinical course during follow-up (median: 33.5 months; 95% CI: 24.79-40) were gained based on hospital and out-patient clinic documentation and telephone interviews. The clinical end-points included: all-cause death, cardiovascular death, stroke or transient ischemic attack (TIA), pulmonary embolism, peripheral embolism and composite thromboembolic end-point.

RESULTS

We observed that in the whole study group (p = 0.0016) and in the subgroup evaluated by TTE (p = 0.005) SEC predicted higher mortality. In the group assessed by TEE, SEC correlated with higher probability of stroke or TIA (p = 0.04). By multivariate analysis, in all patients SEC was a predictor of cardiovascular death (OR = 7.63; p = 0.008) and its localization in the left atrium independently predisposed to thromboembolism (OR = 10.15; p = 0.012). Furthermore, left ventricular SEC detected by TTE also emerged as an independent determinant of higher mortality (OR = 5.26; p = 0.015).

CONCLUSIONS

Despite a lower threshold of detection using harmonic imaging SEC is still a risk factor of poor prognosis, especially when observed on transthoracic examination.

The cardiac manifestations of antiphospholipid syndrome and their echocardiographic recognition

Antiphospholipid syndrome is an autoimmune disorder characterized by the presence of antiphospholipid antibodies, hypercoagulability, vascular thrombosis, and recurrent fetal loss. Cardiac involvement occurs frequently. Leaflet thickening and vegetations are detected quite often echocardiographically, but hemodynamically significant stenotic and/or regurgitant valvular disease is uncommon. Antiphospholipid syndrome can also cause left and right ventricular systolic and diastolic dysfunction as well as pulmonary hypertension. Other findings include spontaneous echo contrast and in situ mural thrombosis. In this review, the author discusses the major cardiac manifestations of antiphospholipid syndrome and highlights the role of echocardiography in their detection.

Improved detection of left ventricular thrombi and spontaneous echocontrast by tissue harmonic imaging in patients with myocardial infarction

BACKGROUND

Tissue harmonic imaging (THI) reduces near-field and side-lobe artifacts. This could improve recognition of cardiac masses, including thrombi and spontaneous echocontrast (SEC), a known thromboembolic risk factor.

OBJECTIVES

We tested the hypothesis that THI improves detection of left ventricular (LV) thrombi and SEC compared with transthoracic fundamental imaging in patients with recent myocardial infarction.

METHODS

In all, 118 consecutive patients with recent myocardial infarction were studied at predischarge. The echocardiographic examination was performed in both fundamental imaging and THI modality and evaluated by 3 skilled and 3 nonexperienced observers for recognition of LV thrombosis and SEC.

RESULTS

THI increased LV thrombi diagnosis by 25% by skilled observers and by 50% by nonexperienced readers, reducing the number of false-positive diagnoses by 67%. Also, compared with fundamental imaging, THI improved recognition of LV SEC by both experienced and nonexperienced observers by 56% and 62%, respectively.

CONCLUSIONS

The improved recognition of LV thrombosis and SEC by THI in patients with myocardial infarction is clinically relevant allowing appropriate treatment and prognostic stratification. Therefore, routine use of THI should be recommended when studying such patients in clinical practice.