Purpose: The purposes of this study were to compare the magnitude and phase between the RR interval and QT interval variability in the frequency domain. METHODS: Twenty four, 12-13 year old healthy males were randomly selected. At resting state and for 5 minutes, ECGs were obtained, and they were digitized to 1000Hz. After measurement of RR interval, QT interval variability was measured using template matching strategy. After normalization of the RR and QT interval time series, power spectral and cross spectral analysis were performed. From each of the time series, low- (0.04-0.15 hertz) and high- (0.15-0.4 hertz) frequency power were measured. From the phase spectrum, the phases and time lags between the two time series at each of the two frequency range were calculated. RESULTS: The average of RR interval and QT interval was 616.0+/-71.0, 364.0+/-47.0 msec, respectively. Their normalized low- and high- frequency power was 4.4+/-7.9 NU(normalized unit), 0.1+/-0.1 NU(p<0.005), and 11.0+/-30.0 NU, 0.3+/-0.3(NU, p<0.005), respectively. The phase differences and resulting time lags between the two interval were -0.5+/-0.4 pi radian(-0.9 seconds) and -0.2+/-0.3 pi radian(-0.4 seconds) in the low- and high-frequency range, respectively. CONCLUSION: During resting state, when compared to RR interval, QT interval oscillates in significantly lower amplitude in both low- and high- frequency ranges. However, the oscillations precede those of the RR interval 0.9 seconds and 0.4 seconds, respectively.
Electrocardiography ; Humans ; Male

PURPOSE: The object of this study is to determine whether QT interval variability in patients with postoperative tetralogy of Fallot increases. METHODS: We enrolled 41 patients who had total correction of tetralogy of Fallot, and 31 healthy controls. They were 6-12 years old. Patients were divided into 2 groups : arrhythmia-positive patients(n=10) who had ventricular premature contractions more than 30/hour or who had couplets, and arrhythmia-negative patients(n=31). We selected the 10-minute arrhythmia-free portion of 24-hour ambulatory ECG recorded during sleep(1-3AM). We selected the 2nd beat of recordings for a template, then found the QT interval for each beat. The method was that T-wave shape best matches template T-wave under the time-stretch model. The mean heart rate and variance and mean QT interval and variance were computed and then a QT variability index(QTVI)-which represents the log ratio between QT interval variability and heart rate variability-was derived. RESULTS: Postoperative tetralogy of Fallot patients with/without ventricular arrhythmia showed significantly increased QTVI compared with the control(-0.481+/-0.310/-0.661+/-0.376 vs -1.200+/-0.380, P<0.0001). There was a trend that QTVI in patients with ventricular arrhythmia increased more than in patients without ventricular arrhythmia, but there were no statistical significances. CONCLUSION: QT interval variability increased in repaired tetralogy of Fallot patients with/without ventricular arrhythmia compared with the control. And this finding indicates that inhomogeneity of temporal ventricular repolarization exists in repaired tetralogy of Fallot patients.
Arrhythmias, Cardiac ; Electrocardiography ; Heart Rate ; Humans ; Tetralogy of Fallot*

PURPOSE: The purposes of this study were to determine short- and long-term fractal correlation behavior of heart rates during daily activity in patients with neurocardiogenic syncope. METHODS: Twenty five patients with histories of neurocardiogenic syncope episodes were included. Their analogue 24h ambulatory Holter electrocardiograms were analyzed. The tape was digitized and the digitized electrocardiograms were partioned into sections of one hour. Then their RR intervals were measured and 20,000 points of RRI were used. To quantify the fractal correlation behavior, we employed the detrended fluctuation analysis, and short-term(n16, alpha2) fractal scaling exponents were calculated. RESULTS: When compared to control, 24-hour average values of alpha1 and all alpha1 values at quarters of each day were significantly higher in patients with syncope. On the contrary, their 24-hour average value of alpha2 and all alpha2 values at quarters of each day were lower in patients with syncope. However, statistical significances were found in 24-hour average value of alpha2 and in alpha2 value at MN-6AM. CONCLUSION: In the syncope patients with neurocardiogenic syncope, short-term fractal scaling exponents of RR interval was significantly high throughout the day. Therefore, their RR intervals were smoother in the short term scale and had a tendency to continue in the same direction of increase or decrease, which may contribute to persistent decrease in heart rate during a syncopal attack.
Child* ; Electrocardiography ; Fractals* ; Heart Rate* ; Heart* ; Humans ; Syncope ; Syncope, Vasovagal*

PURPOSE: The purpose of this study is to evaluate the effect of diabetes mellitus (DM) and preoperative glycemic control on prognosis in Korean patients with upper tract urothelial carcinoma (UTUC) who underwent radical nephroureterectomy (RNU). MATERIALS AND METHODS: A total of 566 patients who underwent RNU at six institutions between 2004 and 2014 were reviewed retrospectively. Kaplan-Meier and Cox regression analyses were performed to assess the association between DM, preoperative glycemic control, and recurrence-free, cancer-specific, and overall survival. RESULTS: The median follow-up period was 33.8 months (interquartile range, 41.4 months). A total of 135 patients (23.8%) had DM and 67 patients (11.8%) had poor preoperative glycemic control. Patients with poor preoperative glycemic control had significantly shorter median recurrence-free, cancer-specific, and overall survival than patients with good preoperative glycemic control and non-diabetics (all, p=0.001). In multivariable Cox regression analysis, DM with poor preoperative glycemic control showed association with worse recurrence-free survival (hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.31 to 3.90; p=0.003), cancer-specific survival (HR, 2.96; 95% CI, 1.80 to 4.87; p=0.001), and overall survival (HR, 2.13; 95% CI, 1.40 to 3.22; p=0.001). CONCLUSION: Diabetic UTUC patients with poor preoperative glycemic control had significantly worse oncologic outcomes than diabetic UTUC patients with good preoperative glycemic control and non-diabetics. Further investigation is needed to elucidate the exact mechanism underlying the impact of glycemic control on UTUC treatment outcome.
Carcinoma, Transitional Cell ; Diabetes Mellitus ; Follow-Up Studies ; Humans ; Prognosis* ; Retrospective Studies ; Treatment Outcome

PURPOSE: Chlormadinone acetate (CMA) therapy for benign prostatic hyperplasia (BPH) may lower the serum prostate specific antigen (PSA) level. However, little is known about the effect of CMA on the total or free serum PSA levels of PSA. Such information would be important since PSA testing is useful for prostate cancer screening. Thus, we prospectively studied the effect of CMA therapy on the total and free serum PSA levels. MATERIALS AND METHODS: The patients with lower urinary tract symptoms (LUTS) and BPH who were aged over 50 years were treated with 50mg CMA for 6 months. Men with a PSA level greater than 10ng/ml were excluded to reduce the likelihood of including cases of occult prostate cancer. Those with suspicious findings on the digital rectal examination and serum PSA testing were biopsied to rule out prostate cancer. alpha- blocking agents were permitted to treat the men with LUTS. Serum levels of the total and free PSA were measured at the study baseline and after approximately 3 and 6 months. The prostate volume (PV) was assessed by transrectal ultrasonography. RESULTS: The analysis included 170 patients with a mean age of 67.9 years, a baseline PV of 47.3ml and a baseline total PSA of 4.1ng/ml. The total PSA levels declined from 4.1ng/ml at baseline to 2.0ng/ml after 6 months of treatment (50.7% decrease, p<0.01). The mean percent free PSA (21% to 22% at baseline) was not significantly altered by CMA treatment. The PSA levels and PV at baseline did not affect the rate of decline of PSA. CONCLUSIONS: The total PSA serum levels decreased by an average of 50% during CMA therapy, but the percent free PSA did not change significantly. This information is potentially useful in the interpretation of the PSA data that's used for early detection of prostate cancer in the men receiving CMA.
Chlormadinone Acetate* ; Digital Rectal Examination ; Humans ; Lower Urinary Tract Symptoms ; Male ; Mass Screening ; Prospective Studies ; Prostate* ; Prostate-Specific Antigen* ; Prostatic Hyperplasia* ; Prostatic Neoplasms ; Ultrasonography