Sudden asystole during radiofrequency ablation: a case report and literature review.

Background: Radiofrequency (RF) ablation is a widely accepted and ideal therapeutic tool to cure some tachycardias. The occurrence of complications varies depending on the procedure being performed. Sudden unexpected prolonged asystole is rare for most ablation procedures and the underlying mechanisms remain unclear.

Evaluation of the surface ECG in detecting isthmus conduction block after ablation of typical atrial flutter.

Objectives: To investigate the value of changes in P wave morphology and duration detected by surface electrocardiogram (ECG) during proximal coronary sinus (PCS) and low lateral right atrial (LLRA) stimulation as a marker for complete bidirectional isthmus conduction block in the procedure of typical atrial flutter ablation.

Methods: Morphology, duration, and ratio of a positive terminal P wave were estimated in 52 typical atrial flutter patients before and after radiofrequency catheter ablation (RFCA).

Results: Atrial flutter ablation resulted in a complete bidirectional isthmus block in all 52 patients.

Mechanisms of atypical flutter wave morphology in patients with isthmus-dependent atrial flutter.

Sixty-three episodes of isthmus-dependent atrial flutter (AFL) in 55 patients were studied to characterize variations in flutter wave morphology and to investigate the mechanisms of the atypical flutter waves on surface ECG. The activation patterns of coronary sinus (CS) and their relationship with flutter wave morphology on the ECG were analyzed. In 46 episodes of counterclockwise AFL (CCW-AFL), there were four types of flutter waves on ECG.

Computing motif correlations in proteins.

Protein motifs, which are specific regions and conserved regions, are found by comparing multiple protein sequences. These conserved regions in general play an important role in protein functions and protein folds, for example, for their binding properties or enzymatic activities. The aim here is to find the existence correlations of protein motifs.