High-frequency QRS analysis compared to conventional ST-segment analysis in patients with chest pain and normal ECG referred for exercise tolerance test

Background: The novel analysis of high-frequency QRS components (HFQRS-analysis) has been proposed in patients with chest pain (CP) and normal electrocardiography (ECG) referred for exercise tolerance test (ex-ECG). The aim of the study was to compare the diagnostic value of ex-ECG with ex-HFQRS-analysis. Methods: Patients with CP and normal ECG, troponin, and echocardiography were consid­ered. All patients underwent ex-ECG for conventional ST-segment-analysis and ex-HFQRS-analysis. A decrease ≥ 50% of the HFQRS signal intensity recorded in at least 2 contiguous leads was considered an index of ischemia, as ST-segment depression ≥ 2 mm or ≥ 1 mm and CP on ex-ECG. Exclusion criteria were: QRS duration ≥ 120 ms and inability to exercise. End-point: The composite of coronary stenosis ≥ 70% or acute coronary syndrome, revascu­larization, cardiovascular death at 3-month follow-up. Results: Three-hundred thirty-seven patients were enrolled (age 60 ± 15 years). The percent­age of age-adjusted maximal predicted heart rate was 89 ± 10 beat per minute and the maximal systolic blood pressure was 169 ± 23 mm Hg. Nineteen patients achieved the end-point. In multivariate analysis, both ex-ECG and ex-HFQRS were predictors of the end-point. The ex-HFQRS-analysis showed higher sensitivity (63% vs. 26%; p < 0.05), lower specificity (68% vs. 95%; p < 0.001), and comparable negative predictive value (97% vs. 96%; p = 0.502) when compared to ex-ECG-analysis. Receiver operator characteristics analysis showed the incremental diagnostic value of HFQRS (area: 0.655, 95% CI 0.60–0.71) over conventional ex-ECG (0.608, CI 0.55–0.66) and CP score (0.530, CI 0.48–0.59), however without statistical significance in pairwise comparison by C-statistic. Conclusions: In patients with CP submitted to ex-ECG, the novel ex-HFQRS-analysis shows a valuable incremental diagnostic value over ST-segment-analysis

Slow- versus traditional strength training in obese female participants: preliminary results

The aim of this study was to provide comparative data on a slow versus a traditional supervised resistance training in an obese female population. Forty obese female patients admitted to our rehabilitation hospital were assigned randomly to a slow training group (ST group; mean age: 47.44 years, mean BMI: 38.53 kg/m2) and a traditional training group (TT group; mean age: 54.34 years, mean BMI: 39.37 kg/m2). The ST protocol included five repetitions for five consecutive bouts on the leg press and extension machine. The duration of each repetition (concentric+eccentric phases) was 6 s for leg press and 5 s for leg extension. The initial load was 50% of the one repetition maximum and then gradually reduced by 20% for each bout. The TT protocol included six consecutive repetitions for five bouts on the leg press and leg extension with 80% of the one repetition maximum load. Both groups performed 10 sessions. All of the patients were assessed by a visual analogue scale for pain, a Borg scale for subjective fatigue, and an isokinetic strength test. Statistically significant strength improvements were observed in both groups. In ST group statistically significant improvements in visual analogue scale scores for knee pain were found at post, larger than that observed in TT group. Subjectively perceived fatigue on the Borg scale decreased more at post in ST group in comparison with TT group. Our preliminary data suggest that ST may represent a preferential strengthening method in obese patients as it can lead to significant strength gains with a relatively lower loading effect on the knee, and hence reduced perception of pai