Simvastatin improves endothelial function in patients with rheumatoid arthritis.

tachycardias. In re-entrant VT, the ability of ATP to terminate the arrhythmia depends on the presence of an excitable gap (6) and on the capability of the impulses to penetrate this gap. The main limiting factor for penetrating the excitable gap is the distance to the circuit; therefore, a long burst or a short-pacing CL is needed to reach the FVT circuits. The first burst that we selected was shorter and faster than those previously reported; nevertheless, the efficacy and acceleration rate were similar, suggesting that the shorter CL might compensate for a lower number of beats in the initial ATP train (1). This observation may be important to decrease the delay before the rescue HES is delivered if needed. The number of FVTs is lower than in previous studies; however, the proportion of patients with FVT is similar. The high proportion of patients treated with beta-blockers and the inclusion of nonischemic patients may explain this difference. The use of ATP also appears to reduce the incidence of syncope/near-syncope associated with an episode of FVT, presumably as a result of a reduction in the VT duration. Interestingly, beta-blockers increased the efficacy of ATP, indicating a possible influence of autonomic tone in the maintenance of the VT (7,8). This study suggests that a single, short ATP burst is efficient and safe for the treatment of FVT, reducing the HES incidence and arrhythmia-related symptoms. Nevertheless, the small number of episodes and patients limits the power of these conclusions and, therefore, a larger prospective study is required to validate these data.