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Notes: Background: There is a significant difference in repolarization on the surface ECG between men and women. The effect of testosterone on repolarization of myocardium may provide a basis for the physiological and pathophysiological importance of these distinctions between sexes. The purpose of this study is to compare the repolarization characteristics of surface ECG in patients with secondary hypogonadotropic hypogonadism to those of healthy men and women. Methods: The study consisted of 45 consecutive patients with the diagnosis of secondary hypogonadotropic hypogonadism (study group) and age-, weight- and height-matched normal healthy men (n = 35) and women (n = 39) (control group). 12-lead ECG recordings were obtained and electronic calipers were used for measurements of ECG repolarization variables. ECG variables were compared with those of control groups. Results: J point amplitude (0.12 ± 0.07 vs 0.05 ± 0.05 mV, respectively), T max (0.74 ± 0.28 vs 0.60 ± 0.27 mV, respectively), T wave area (81 ± 36 vs 60 ± 29 mVms, respectively) and T wave descending time (93 ± 16 vs 85 ± 15 ms, respectively) were significantly higher in healthy subjects than hypogonadal men. In comparison with those of healthy women, hypogonad males have higher J point (0.05 ± 0.05 vs 0.02 ± 0.02 mV), taller T wave (0.60 ± 0.27 vs 0.34 ± 0.13 mV), consequently less T wave area (60 ± 29 vs 34 ± 16 mVms), ascending (62 ± 18 vs 53 ± 11) and descending angle (67 ± 17 vs 55 ± 12). Corrected QT was not different among groups. Conclusions: Testosterone deprivation in hypogonadotropic hypogonadism attenuates J point, T wave peak, T wave area, and T wave descending time, but does not reach to the level of those in healthy women. Testosterone has no effect on QT interval in this group of age. Hormone replacement therapy of these patients will provide informative contribution.

Notes: Background: There are few data related to the seasonal influences on the QT dispersion. Methods: We analyzed the effects of seasons on QT dispersion in a large group of healthy young males. We studied the seasonal variability of QT dispersion in 523 healthy male subjects aged 22 ± 4 years (ranging from 20 to 26). Four seasonal 12-lead resting electrocardiograms (ECGs) recorded at double amplitude were performed at 25 mm/s at intervals of 3 months. Subsequent ECGs were recorded within 1 hour of the reference winter recording. QT dispersion was defined as the difference between the longest and the shortest mean QT intervals. Results: There was a significant seasonal variation in QT dispersion (P = 0.001), with the largest QT dispersion in winter (71 ± 18 ms) and the smallest one in spring (43 ± 19). Conclusion: There exists a significant seasonal variation in QT dispersion of healthy subjects and such variability should be taken into consideration in the evaluation process of QT dispersion.

Notes: Background: Atrial fibrillation is a frequent arrhythmia in patients undergoing hemodialysis. The consequences of hemodialysis on P wave durations and P wave dispersion have not been fully understood. The objective of this study was to study the effect of dialysis on P wave maximum (Pmax), P wave minimum (Pmin), and P wave dispersion (Pd). Methods: We studied Pmax, Pmin, and Pd in 32 patients (17 men and 15 women, mean age 54 ± 18 years) with chronic renal failure undergoing hemodialysis. The difference between maximum and minimum P wave duration was calculated and defined as P wave dispersion (Pd= Pmax− Pmin). Results: There was a significant increase in Pmax at the end of dialysis compared to the beginning (98 ± 13 ms vs. 125 ± 12 ms, P 〈 0.001). Pmin did not show any significant change (71 ± 11 ms vs. 73 ± 10 ms, P = 0.42). Pd was significantly increased at the end of dialysis (27 ± 9 ms vs. 52 ± 11 ms, P 〈 0.001). There was a negative correlation between serum potassium, magnesium, phosphate, blood urea nitrogen, and creatinin at the end of dialysis and Pmax and Pd, respectively (P 〈 0.05). A weak positive correlation was found between serum calcium, bicarbonate at the end of dialysis and Pmax and Pd (P 〈 0.05). Conclusion: Hemodialysis ends with significant increase in P wave maximum duration and P wave dispersion, which might be responsible for the increased occurrence of atrial fibrillation in these groups of patients.

Notes: Background: Thorax impedance cardiography (TIC) can provide important information about the hemodynamic state of patients. In this study, we aimed at finding out if TIC can be used in the early follow-up of acute right ventricular myocardial infarction (RVMI).Methods: The study consisted of patients with RVMI who were admitted to our coronary care unit between March 1998 and October 1999. The patients were divided into two groups: group A: patients with hemodynamically significant RVMI, and group B: patients with hemodynamically insignificant RVMI. All impedance measurements were performed with the commercially available device BoMed NCCOM3. We measured stroke volume index, cardiac index and ejection fraction by TIC. The measurements were done on the day of admittance (day O), first day and second day continuously, and on the third to fifth day during bed rest. Comparisons of TIC measurements and vital signs were made by Friedman analysis. Group A and group B were compared by Mann Whitney U test and chi square. The level of statistical significance was set at P 〈 0.05.Results: There were 26 patients in group A (mean age: 62 ± 10) and 14 patients in group B (mean age: 61 ± 12). There were no statistically significant differences between the groups in age and sex. There were statistically significant differences between group A and B with regard to stroke volume index (32 ± 5 vs 28 ± 5; P = 0.0147), total peripheral resistance (19 ± 5 vs 23 ± 5; P = 0.0084); ejection fraction (0.44 ± 0.16 vs 0.58 ± 0.08; P = 0.0131). The vital signs with statistically significant differences were systolic arterial blood pressure (110 ± 17 vs 88 ± 7, P 〈 0.0001); diastolic arterial blood pressure (72 ± 12 vs 55 ± 13; P = 0.0002) and heart rate (89 ± 12 vs 71 ± 11; P 〈 0.0001). The differences disappeared on the second day. The lack of significance continued on the fifth day. Friedman analysis revealed that all the TIC parameters except for left ventricular ejection fraction change towards the normal range. Ejection fraction did not change in group B but decreased in group A on the second day; however it was stable later.Conclusion: TIC can provide easily obtained parameters which may have a role in the treatment of hemodynamically significant RVMI. This is particularly important in coronary care centers with limited invasive capabilities. A.N.E. 2000;5(4):330–335