Estimation of the QTc interval in the presence of right bundle branch block: A comparative study using validated formulae for left bundle branch block.

BACKGROUND: Adequate measurement of the QT interval is of clinical importance in order to identify patients at higher risk for ventricular arrhythmias. Previous studies have described different methods to estimate baseline QT in patients with left bundle branch block (LBBB). However, the evidence regarding the assessment of the QT in patients with right bundle branch block (RBBB) is scarce. AIM: To analyze the feasibility and reliability of the different formulae described for LBBB in the estimation of the baseline QT in the presence of RBBB. METHODS: We performed an observational study including patients who underwent electrophysiology study and/or ablation. Two types of RBBB were considered: 1) pacing-induced and 2) transient true RBBB. QRS, JT and QT intervals were measured during baseline and RBBB. Estimated QTc was calculated using LBBB formulae: Bogossian, Rautaharju, Tabatabaei, Tang-Rabkin, Yankelson, Wang. Linear correlation and intraclass correlation coefficients (ICC) were used to assess the reliability of these formulae for the estimation of baseline QTc. RESULTS: We finally included a total of 100 patients. Correlations between baseline and estimated QTc were strong (R > 0.7) for all the formulae except for Tabatabaei. Yankelson and Wang showed the highest reliability (ICC = 0.775 and 0.727, respectively). Yankelson appeared to be the most accurate formula, with a mean estimated QTc closest to baseline values. CONCLUSION: Previously described formulae for LBBB exhibited marked differences regarding reliability in the estimation of the QTc interval in the presence of RBBB. According to our results, Yankelson showed the most consistent and accurate agreement in this setting.

The Role of Anxiety in Patients With Persistent Atrial Fibrillation Undergoing Elective Cardioversion: An Observational Study.

OBJECTIVE: Anxiety is often present among patients with atrial fibrillation (AF). This condition has been associated with greater symptom severity and worse quality of life in these patients. However, the influence of anxiety on the risk of AF recurrence is not well known. We aimed to define the level of anxiety in patients with persistent AF undergoing elective cardioversion (EC) and determine whether there is an association between anxiety and the risk of early AF recurrence after EC. METHODS: Anxiety was measured before EC using the State-Trait Anxiety Inventory. Early AF recurrence was assessed with a control electrocardiogram at 30-day follow-up. RESULTS: We included 107 patients undergoing effective EC. Early AF recurrence was diagnosed in 40 patients (37.4%). Compared with those who remained in sinus rhythm, individuals with early AF recurrence had significantly higher levels of trait anxiety (23.1 [10.4] versus 17.9 [9.5]; p = .013) and larger left atrial volume index (45.8 [12.3] versus 37.9 [13.3] ml/m; p = .004). Both variables remained independently associated with early AF recurrence after multivariate analysis. A predictive model including trait anxiety score >20 and left atrial volume index >41 ml/m showed acceptable accuracy for the diagnosis of early AF recurrence (area under the curve = 0.733; 95% confidence interval = 0.634-0.832; p < .001). CONCLUSIONS: Our study shows that trait anxiety is an independent risk factor for early AF recurrence after EC. Further studies are warranted to assess the beneficial role of anxiety-reducing strategies on the outcomes of patients with AF.

Differences in mother-to-infant bonding according to type of C-section: Elective versus unplanned.

Aim To compare the mother-to-infant bond of mothers who gave birth by elective C-section versus urgent C-section in the first 48-72h of life and 10-12weeks after delivery. METHODS: This is a cohort prospective study of women giving birth by C-section. 48-72h after delivery, sociodemographic variables were collected, Mother-to-Infant Bonding Scale and newborn's response to separation test were performed. 10-12weeks after delivery Mother-to-Infant Bonding Scale and questions about baby's feeding were completed. RESULTS: A total of 116 dyads were recruited, 58 in each group. No significant differences between the two C-sections in bonding, newborn response to separation or type of feeding were observed at any time points. However, those dyads presenting with an abnormal bond at time 1 had more frequently an abnormal bond at time 2 (50% versus 8.1%, p=0.000). CONCLUSIONS: No differences in mother-to-infant bond were found according to type of C-section.