Early effects of simvastatin versus atorvastatin on oxidative stress and proinflammatory cytokines in hyperlipidemic subjects.

The authors investigated the time-dependent action of atorvastatin and simvastatin on oxidative stress and cytokine levels immediately after the start of treatment. These factors play a role in endothelial dysfunction. Hyperlipidemic patients (n = 132) were assigned to treatment with 40 mg atorvastatin, 40 mg simvastatin, or placebo. Blood samples were taken before, 2 hours, 24 hours, 7 days, and 3 weeks after the administration of the statin or placebo to evaluate serum concentrations of total peroxides (TP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and soluble intercellular vascular adhesion molecule 1 (sICAM 1). In the atorvastatin group the TP changes were significantly different at 2 hours and 24 hours (p = 0.005), whereas in the simvastatin group there was a gradual, more or less linear decline in TP until 7 days (p = 0.006) and then a plateau. Simvastatin exhibited a faster statistically significant decrease over time in IL-6 and sICAM 1 levels (at 7 days, p = 0.014 and p = 0.001, respectively). TNF-alpha demonstrated a faster linear trend in the simvastatin group, but the significant effect appeared late (p = 0.006). Both simvastatin and atorvastatin exerted early beneficial effects on oxidative stress, proinflammatory cytokines, and endothelial activation in hyperlipidemic subjects. These effects became significant 2 hours following the initiation of therapy.

Autonomic nervous system changes in vasovagal syncope: is there any difference between young and older patients?

Spectral analysis of heart rate variability was used to compare the changes in autonomic function during tilting in young and older patients with vasovagal syncope. Twenty-four young (age 28 +/- 8 years) and 31 older (56 +/- 5 years) patients with unexplained syncope and a positive tilt test and 25 controls (age 48 +/- 12 years) were included in the study. Frequency-domain measurements of the low (LF) (0.06-0.15 Hz) and high (HF) (0.15-0.40 Hz) frequency bands and the ratio of LF to HF were computed from Holter recordings for 4-minute intervals before and immediately after tilting and just before the end in all groups. Syncopal patients showed a different pattern of response to tilting from controls in all spectral indexes. Young and older patients showed the same pattern of changes in all measurements, even though certain differences were observed. The LF after tilting reduced more in the older (-20 +/- 7% vs -14 +/- 5%, P < 0.001), while HF reduced more in young patients (-17 +/- 8% vs -8 +/- 3%, P < 0.001). Young patients showed mainly a cardioinhibitory type (71%) of response whereas a vasodepressor type response predominated (68%) in the older patients. The autonomic nervous system appears to play an important role in the pathophysiological mechanism of vasovagal syncope. This role is similar in young and in older patients and this should be taken into account in the therapeutic approach to the condition. Specific differences between age groups may be related to the type of vasovagal syncope.

Severe bradyarrhythmias in patients with sleep apnoea: the effect of continuous positive airway pressure treatment: a long-term evaluation using an insertable loop recorder.

AIM: In this new era of insertable loop recorders, we studied obstructive sleep apnoea-hypopnoea syndrome (OSAHS) patients in order to evaluate their arrhythmias and the beneficial effect of Continuous Positive Airway Pressure treatment (CPAP), over a long-term period. METHODS AND RESULTS: We enrolled 23 patients (16 men, 50 +/- 11 years) with moderate and severe OSAHS. In all patients, an insertable loop recorder capable of monitoring the heart rhythm for 16 months was implanted. Cardiac pauses >3 s and bradycardic episodes <40 bpm during a 2-month period before, and for 14 months after, the CPAP application, were noted. In each period, the patients underwent two 24-h Holter recordings. Before treatment, 11 patients (47%) revealed severe cardiac rhythm disturbances, mostly nocturnal. Holter recordings showed disturbances in only 3 (13%) patients (P=0.039), those in whom the insertable loop device had recorded frequent episodes. Eight weeks after the initiation of treatment, the total number of the recorded episodes tended to decrease while, during the last 6 months of the follow-up, no episodes were recorded. CONCLUSION: Approximately half of OSAHS patients evidence severe cardiac rhythm disturbances, which are significantly reduced by CPAP. Holter recordings seem unable to precisely describe the incidence of severe brady-arrhythmias and the effect of treatment.