RESUMO
BACKGROUND: Cardiovascular disease (CVD) is the most common cause of death in patients with renal diseases. Cardiac arrhythmia and sudden cardiac death are particularly important, and the burden is higher in patients on hemodialysis. The aim of this study is to compare specific ECG changes as markers of arrhythmias in patients with CKD and patients with end-stage renal disease (ESRD); all without clinically manifest heart disease, with normal control subjects. RESULTS: Seventy-five ESRD patients on regular hemodialysis, 75 patients with stage 3-5 CKD and 40 healthy control subjects were included. All candidates were subjected to thorough clinical evaluation and laboratory tests including serum creatinine, glomerular filtration rate calculation, serum potassium, magnesium, calcium, phosphorus, iron, parathyroid hormone, and total iron binding capacity (TIBC). Resting twelve-lead ECG was done to calculate P wave dispersion (P-WD), corrected QT interval, QTc dispersion, Tpeak-Tend interval (Tp-e), and Tp-e/QT. Patients with ESRD had a significantly higher QTc dispersion (p < 0.001) and P-WD (p = 0.001) when compared to the other 2 groups. In the ESRD group, males had a significantly higher P-WD (p = 0.045), insignificantly higher QTc dispersion (p = 0.445), and insignificantly lower Tp-e/QT ratio (p = 0.252) as compared to females. Multivariate linear regression analysis for ESRD patients showed that serum creatinine (ß = 0.279, p = 0.012) and transferrin saturation (ß = - 0.333, p = 0.003) were independent predictors of increased QTc dispersion while ejection fraction (ß = 0.320, p = 0.002), hypertension (ß = - 0.319, p = 0.002), hemoglobin level (ß = - 0.345, p = 0.001), male gender (ß = - 0.274, p = 0.009) and TIBC (ß = - 0.220, p = 0.030) were independent predictors of increased P wave dispersion. In the CKD group, TIBC (ß = - 0.285, p = 0.013) was an independent predictor of QTc dispersion while serum calcium (ß = 0.320, p = 0.002) and male gender (ß = - 0.274, p = 0.009) were independent predictors of Tp-e/QT ratio. CONCLUSIONS: Patients with stage 3-5 CKD and those with ESRD on regular hemodialysis exhibit significant ECG changes that are considered substrates for ventricular as well as supraventricular arrhythmias. Those changes were more evident in patients on hemodialysis.
RESUMO
Background: Measurement of diaphragmatic motion by ultrasound is being utilized in different aspects of clinical practice. Defining reference values of the diaphragmatic excursion is important to identify those with diaphragmatic motion abnormalities. This study aimed to define the normal range of diaphragmatic motion (reference values) by Mmode ultrasound for the normal population. Methods: Healthy volunteers were included in this study. Those with comorbidities, skeletal deformity, acute or chronic respiratory illness were excluded. Diaphragmatic ultrasound in the supine position was performed using a lowfrequency probe. The B-mode was applied for diaphragmatic identification, and the M-mode was employed for the recording of the amplitude of diaphragm contraction during quiet breathing, deep breathing and sniffing. Results: The study included 757 healthy subjects [478 men (63.14%) and 279 women (36.86%)] with normal spirometry and negative history of previous or current respiratory illness. Their mean age and BMI were 45.17 ±14.84 years and 29.36±19.68 (kg/m2). The mean right hemidiaphragmatic excursion was 2.32±0.54, 5.54±1.26 and 2.90±0.63 for quiet breathing, deep breathing and sniffing, respectively, while the left hemidiaphragmatic excursion was 2.35±0.54, 5.30±1.21 and 2.97±0.56 cm for quiet breathing, deep breathing and sniffing, respectively. There was a statistically significant difference between right and left diaphragmatic excursion among all studied subjects. The ratio of right to left diaphragmatic excursion during quiet breathing was (1.009±0.19); maximum 181% and minimum 28%. Only 19 cases showed a right to left ratio of less than 50% (5 men and 14 women). The diaphragmatic excursion was higher in males than females. There was a significant difference in diaphragmatic excursion among age groups. Age, sex and BMI significantly affected the diaphragmatic motion. Conclusions: Diaphragmatic excursion values presented in this study can be used as reference values to detect diaphragmatic dysfunction in clinical practice. Diaphragmatic motion is affected by several factors including age, sex and body mass index.
