Calculation of left ventricular diastolic time constant (Tau) in dogs with aortic regurgitation using continuous-wave Doppler spectra.

OBJECTIVE: To investigate a new noninvasive method for calculating left ventricular diastolic time constant (Tau) through a continuous-wave aortic regurgitation Doppler spectrum. METHODS: According to ultrasound guidance, twenty-four animal models (beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB (MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals, (t2-t1) and (t3-t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau (Tau-D) was resolved and compared with catheter-derived Tau (Tau-c). RESULTS: There is no significant difference between Tau-D and Tau-c (45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively; P > 0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship ( r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement. CONCLUSIONS: This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.

Computed Tomography-Estimated Pancreatic Steatosis is Associated with Carotid Plaque in Type 2 Diabetes Mellitus Patients: A Cross-Sectional Study from China.

OBJECTIVE: To explore potential effects of pancreatic fat content measured by computed  tomography (CT) on carotid plaque in patients with type 2 diabetes mellitus (T2DM). METHODS: T2DM patients who underwent an un-enhanced CT scan of the upper abdomen and ultrasound of the carotid artery were enrolled. The patients were divided into a non-plaque group and a plaque group (including hypoechoic plaque subgroup and non-hypoechoic plaque subgroup). The CT attenuation of pancreas and spleen were measured. Pancreas-to-spleen attenuation ratio (P/S) and the difference between pancreatic and splenic attenuation (P-S) were calculated. The cutoff values of P/S and P-S were obtained using receiver operating characteristic curves. Logistic regression models were used to evaluate association of P/S or P-S with carotid plaque or hypoechoic plaque. RESULTS: 337 patients were enrolled, including 101 cases in the non-plaque group, 146 cases in the hypoechoic plaque subgroup, and 90 cases in the non-hypoechoic plaque subgroup. P/S and P-S in hypoechoic plaque group were lower than those in non-plaque group, with a cutoff value of P/S and P-S as 0.72 and -13.33, respectively. After adjusting for risk factors, P/S and P-S correlated with carotid plaque [for low P/S: OR (95% CI): 3.15 (1.47-6.73), P = 0.0031; for low P-S: OR (95% CI): 2.84 (1.42-5.66), P = 0.0031] as well as carotid hypoechoic plaque [for low P/S: OR (95% CI): 1.82 (1.07-3.08), P = 0.0259; for low P-S: OR (95% CI): 1.82 (1.09-3.02), P = 0.021]. CONCLUSION: T2DM patients with hypoechoic carotid plaque have higher pancreatic fat content than those without. Pancreatic steatosis correlates with carotid plaque and hypoechoic plaque in T2DM patients.

Calculation of Left Ventricular Diastolic Time Constant (TAU) in Dogs with Mitral Regurgitation Using Continuous-Wave Doppler.

The left ventricular diastolic time constant (Tau) cannot be practically measured non-invasively. Thus, the aim of this study was to investigate a new method for the evaluation of Tau using continuous-wave (CW) Doppler in dogs with mitral regurgitation. Guided by ultrasound, we created 12 beagle models of mitral regurgitation and acute ischemic left ventricular diastolic dysfunction. Raw audio signals of the CW Doppler spectra were collected, and new mitral regurgitation Doppler spectra were observed after computer re-processing. The new Doppler spectra contour line was constructed using MATLAB (Version R2009), and two time intervals, t1-t2 and t1-t3, were measured on the descending branch of the mitral regurgitation Doppler spectrum and were substituted into Bai's equation group. The Doppler-derived Tau (Tau-d) was resolved and compared with the simultaneous catheter-derived Tau (Tau-c). No significant difference (p > 0.05) between Tau-d (49.33 ± 18.79 ms) and Tau-c (48.76 ± 17.60 ms) was found. A correlation analysis between Tau-d and Tau-c suggested a strong positive relationship (r = 0.85, p = 0.000). Bland-Altman plots of Tau-d and Tau-c revealed fair agreement. Compared with previous non-invasive approaches, this method is simpler and more accurate. There is a strong positive relationship and fair agreement between Tau-d and Tau-c.

The Prevalence and Association of Varicoceles on Male Patients With Benign Prostatic Hyperplasia/Lower Urinary Tract Symptoms.

OBJECTIVE: To investigate the association between the prevalence of varicocele and benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) in elder man in China. METHODS: A total of 831 BPH/LUTS outpatients who were 40 years or older were recruited. The patients' age, total prostatic volume (TPV), International Prostate Symptom Score, total prostate-specific antigen, nocturia, and body mass index were recorded. The presence and grade of varicocele were diagnosed by physical examination in combination with scrotal color Doppler. RESULTS: The total prevalence of varicocele was 53.0%. The prevalence values of varicoceles in patients were 40-49, 50-59, 60-69, 70-79 years old, and 80 or above were 43.0%, 42.4%, 54.0%, 59.5%, and 64.0%, respectively. When comparing with varicocele grade, TPV (P = .002) was found to be significantly different. Nocturia frequencies increased significantly in patients with varicocele (P < .01). There were no difference in terms of International Prostate Symptom Score, total prostate-specific antigen, and body mass index between patients with no varicocele and with grades 1, 2, and 3 varicoceles (P > .05). CONCLUSION: For elderly patients, the prevalence of varicocele shows an increasing trend with aging. Higher-grade varicoceles are associated with higher TPV and nocturia levels. Varicocele, which may be a factor that affects BPH/LUTS, cannot be overlooked.