The relationship between 25-hydroxyvitamin D levels and ambulatory arterial stiffness index in newly diagnosed and never-treated hypertensive patients.

OBJECTIVES: Vitamin D insufficiency has been shown to be associated with cardiac dysfunctions, such as cardiac hypertrophy and hypertension, in animal studies. Arterial stiffness is a prognostic marker for cardiovascular disease. Previous studies have demonstrated that 25-hydroxyvitamin D [25(OH)D] levels were negatively correlated with arterial stiffness index. The aim of this study was to investigate the relationship between 25(OH)D levels and arterial stiffness, which is evaluated using an ambulatory arterial stiffness index (AASI), in patients who have untreated and newly diagnosed essential hypertension. DESIGN: A total of 123 consecutive patients with newly diagnosed and untreated essential hypertension were included. Patients were divided into two groups according to their 25(OH)D levels. Vitamin D insufficiency was defined by 25(OH)D levels less than 20 ng/ml. All patients were referred for ambulatory blood pressure monitoring. The regression slope of diastolic and systolic blood pressure was computed for each individual on the basis of ambulatory blood pressure readings. AASI was described as one minus the respective regression slope. RESULTS: The mean AASI was significantly higher in patients with 25(OH)D levels less than 20 as compared with patients with 25(OH)D levels greater than or equal to 20 (0.50±0.20 vs. 0.34±0.17, P<0.001). In Pearson's correlation analysis, AASI had a significantly strong negative correlation with vitamin D levels (r=-0.385, P<0.001). In multivariate linear regression analysis, vitamin D levels were found to be significantly and independently associated with AASI (ß=-0.317, P=0.035). CONCLUSION: Arterial stiffness measured by AASI in newly diagnosed and untreated patients with essential hypertension were significantly related to vitamin D levels.

Myocardial tissue perfusion predicts the evolution of fragmented QRS in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: Fragmented QRS complex (fQRS) is associated with worse outcomes in several cardiovascular conditions. However, alterations in fQRS in patients with ST elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) and association of fQRS with myocardial blush grade (MBG) has not been investigated until now. In this study, we aimed to investigate the association of MBG after primary PCI with evolution of fQRS. METHODS: Our study consisted of 401 consecutive patients with STEMI who underwent primary PCI. Patients were categorized into two subgroups according to persistence or new-onset of fQRS (Group 1) and absence or resolution of fQRS (Group 2) at 48 hours after primary PCI. The evolution of fQRS on pre- and post-PCI ECG and their relation with myocardial reperfusion parameters were investigated. RESULTS: Patients in group 1 showed older age, higher rate of smoking, lower HDL-cholesterol, lower LVEF, higher angina-to-door time, higher TIMI frame count, and high rate of patients with MBG <3 compared to patients with group 2 (P < 0.05). In correlation analysis, LVEF showed positive correlation with MBG (r = 0.448, P < 0.001) and negative correlation with the number of leads with fQRS (r = -0.335, P < 0.001). In multivariate regression analysis, new-onset or persistance of fQRS after primary PCI is significantly associated with MBG <3, peak CK-MB level, pre-PCI fQRS at anterior localization and smoking. CONCLUSION: Our findings showed that despite complete ST-segment resolution in all patients, fQRS is independently associated with impaired microvascular myocardial perfusion. So, fQRS, as a simple and easily available noninvasive marker, may be useful in stratification of high-risk patients with increased extent of infarcted myocardium who underwent primary PCI.

Diagnostic accuracy of P-wave dispersion in prediction of maintenance of sinus rhythm after external cardioversion of atrial fibrillation.

OBJECTIVE: P-wave dispersion (PWD) is an electrocardiographic measurement, which reflects a disparity in an atrial conduction. In this study, we aim to demonstrate the diagnostic accuracy of PWD in predicting recurrence of atrial fibrillation (AF) in patients with sinus rhythm restoration after external cardioversion. METHODS: This prospective, observational study consists of 26 patients, who underwent external cardioversion for non-valvular persistent AF and successfully cardioverted to sinus rhythm (13 men, mean age 58.1 ± 11 years). Twelve-lead surface electrocardiogram of each patient was recorded immediately after the external cardioversion process to measure the P-wave duration. Recurrent AF was assessed for each patient during the 12-month follow-up after restoring the sinus rhythm. Patients were divided into the 2 groups with respect to the AF recurrence (recurrent AF group, (n=19), and sinus rhythm group, (n=7)) and variables that can affect AF development were compared between the two groups. Stepwise logistic regression analysis was used to identify the independent predictors of AF recurrence and ROC curve analysis was performed to determine the cut-off value of independent factors. RESULTS: The two groups have similar demographic, clinical and echocardiographic features. Patients with recurrent AF had significantly higher PWD than those who continued to have a sinus rhythm (80 ± 21 msec vs 53 ± 11 msec, p=0.001, respectively). There is a positive correlation observed between the increase in PWD and the risk of AF recurrence (r=0.643; p=0.001). In logistic regression analysis, PWD was found to be an independent predictor of AF recurrence (OR 1.192 (95% CI 1.032-1.375), p= 0.013). Receiver operating characteristic analysis revealed that the best cut-off value of PWD for maintenance of sinus rhythm was 58 msec (sensitivity: 86%, specificity: 95%, AUC=0.917, 95% CI=0.785-1.05, p=0.001). CONCLUSION: This study suggests that PWD analysis after successful external cardioversion has diagnostic accuracy to predict the recurrence of AF.