Non-invasive atrial fibrillation organization follow-up under successive attempts of electrical cardioversion

The development of non-invasive tools able to provide valuable information about the effectiveness of a shock in external electrical cardioversion (ECV) is clinically relevant to enhance these protocols in the treatment of atrial fibrillation (AF). The present contribution analyzes the ability of a non-linear regularity index, such as sample entropy (SampEn), to follow-up non-invasively AF organization under successive attempts of ECV and to predict the effectiveness of every single shock. To this respect, the atrial activity (AA) preceding each delivered shock was extracted by using a QRST cancellation method. Next, the main atrial wave (MAW), which can be considered as the fundamental waveform associated to the AA, was obtained by applying a selective filtering centered on the dominant atrial frequency (DAF). Finally, the MAW organization was estimated with SampEn and two thresholds (Th1 = 0.1223 and Th2 = 0.0832) were established to predict the ECV outcome. Results indicated that, prior to the first attempt, all the patients who needed only one shock to restore NSR were below Th1. In addition, most of them were above Th2 in case of AF relapsing during the first month. Regarding several shocks, all the patients who maintained NSR more than one month were below Th2 after the first shock. Moreover, all the patients who relapsed to AF during the first month were between Th1 and Th2 and, finally, all the patients with ineffective ECV were above Th1. After each unsuccessful shock, a SampEn relative decrease was observed for the patients who finally reverted to NSR, but the largest variation took place after the first attempt, thus indicating that this shock plays the most important role in the procedure. Indeed, by considering jointly the patients who needed only one shock and the patients who needed several shocks, 91.67% (22 out of 24) of ECVs resulting in NSR, 93.55% (29 out of 31) of ECVs relapsing to AF during the first month and 100% (10 out of 10) of ECVs in which NSR was not restored were correctly classified. As conclusion, the MAW organization analysis via SampEn can provide useful information that could improve the effectiveness of conventional external ECV protocols used in AF treatment.     

Correlation between total cardiovascular risk and bone density in postmenopausal women

The aim of the paper was to examine the correlation between the total risk of cardiovascular events, determined by the SCORE (Systematic Coronary Risk Evaluation) system, and bone density in postmenopausal women. Examinees and method: The research involved 300 postmenopausal women. On the basis of bone density measurements, the participants were divided into three groups: group I — 84 examinees had osteoporosis, group II — 115 examinees had osteopenia, and group III — 101 examinees had normal bone mineral density (BMD). Results: Participants with high SCORE risk were statistically significantly older compared to low-risk women (60±3 vs. 55±5; p<0.001). They had significantly lower BMD and T scores (?1.09±0.94 vs. ?2.86±0.63; p<0.001). Elevation of the SCORE risk by 1% caused a BMD decrease of 0.033 g/cm²(0.029 to 0.036 gr/cm²). Multivariate logistic regression analysis showed that the following factors caused a significant increase in the risk of decreasing BMD: every year of life by 20%, menopause duration by 26%, increase in systolic blood pressure (BP) by 1 mm Hg by 7%, increase in SCORE risk by 1% by 5.31 times, physical inactivity by 5.96 times, and osteoporosis in the family history by 3.91 times. Conclusion: Postmenopausal women who are at high risk for cardiovascular diseases have a lower BMD than those who are not at high risk for cardiovascular diseases.