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Significance of left atrial spontaneous echo contrast in rheumatic mitral valve disease as a predictor of systemic arterial embolization: A transesophageal echocardiographic study

The association between left atrial spontaneous echo contrast (SEC) and a history of systemic arterial embolization was evaluated in 359 consecutive patients with rheumatic mitral valve disease during a 3-year period. All patients underwent transesophageal echocardiographic (TEE) and cardiac catheterization studies. Of these, 207 patients had predominant mitral stenosis, 55 had significant mitral regurgitation, and the remaining 97 with xenograft mitral valve replacement developed valvular dysfunction (32 resulted in predominant mitral stenosis and 65 in significant mitral regurgitation). Left atrial SEC was detected in 108 patients (group A) and was absent in 251 (group B). Group A patients showed a higher frequency of left atrial thrombi or history of previous embolization than those in group B (59.3% vs 7.2%; p < 0.001). Group A patients also had a higher frequency of recent (< or = 1 week before TEE study) and remote (> 1 week before TEE study) embolization than did group B patients (recent: 19.4% vs 2.8% [p < 0.001]; remote: 13.0% vs 4.0% [p < 0.001]). Multivariate analysis showed that left atrial SEC (p = 0.01) was the only independent predictor of systemic arterial embolization. It is concluded that patients with left atrial SEC had a significantly higher risk for thromboembolism, and TEE is a useful modality to identify this subset of patients with rheumatic mitral valve disease.

New electrocardiographic criteria for the differentiation between counterclockwise and clockwise atrial flutter: correlation with electrophysiological study and radiofrequency catheter ablation

Objective To develop new electrocardiographic (ECG) criteria for the differentiation between counterclockwise and clockwise atrial flutters. Background Traditionally, the ECG differentiation between counterclockwise and clockwise atrial flutters is based on the flutter wave polarity in the inferior leads. However, determination of flutter wave polarity is subjective and sometimes difficult, especially in flutter waves of undulating pattern. Patients The study comprised 37 consecutive patients with drug resistant atrial flutter; 30 had counterclockwise and 17 had clockwise atrial flutter (10 had both forms of atrial flutter). The isthmus dependence was confirmed by entrainment study and catheter ablation. The ECG patterns of both types of atrial flutter were compared and the flutter wave polarity in the inferior leads was determined by four independent cardiologists. Results The flutter wave polarity in the inferior leads appeared negative in 24, positive in one, and equivocal in five of the counterclockwise atrial flutters; polarity appeared negative in one, positive in 10, and equivocal in six of the clockwise atrial flutters. However, the aVF/lead I flutter wave amplitude ratio was > 2.5 in all counterclockwise but < 2.5 in all clockwise atrial flutters. The flutter wave nadirs in the inferior leads corresponded to the upstrokes in V1 in all counterclockwise atrial flutters, but corresponded to the downstrokes in V1 in all clockwise atrial flutters. Conclusions The flutter wave polarity in the inferior leads does not correlate well with the flutter wave rotating direction. However, counterclockwise and clockwise atrial flutters can be differentiated by new ECG criteria with high accuracy.