Metabolic syndrome and its association with left ventricular dysfunction in patients with left bundle branch block.

BACKGROUND: The present study and for the first time hypothesizes that the patients with left bundle branch block (LBBB) suffer considerably from metabolic syndrome (MetS) and this metabolic phenomenon can be associated with cardiac dysfunction status such as ventricular dilation and reduced left ventricular ejection fraction (LVEF) in these patients. METHODS: A retrospective study was conducted on 220 consecutive patients with diagnosed LBBB. MetS status was diagnosed using the Adult Treatment Panel III of the National Cholesterol Education Program criteria. Systolic function state was assessed using two-dimensional echocardiography. RESULTS: The overall prevalence of MetS among studied LBBB patients was 16.8%. Regarding left ventricular functional status in the two groups, the mean LVEF in the groups with and without MetS was 37.03 ± 9.09% and 43.43 ± 15.62% with a significant difference (p = 0.017). However, left ventricular dilation was similarly detected in both groups with and without MetS (21.6% versus 30.6%, p = 0.273). Multivariable linear regression model showed subjects with MetS had lower LVEF in the presence of confounders (Beta = 6.915, p = 0.039). CONCLUSION: A notable number of LBBB patients suffered from MetS and this metabolic phenomenon is significantly associated with lowering left ventricular function in LBBB patients.

Main clinical determinants of the presence of coronary artery disease in patients with left bundle branch block.

BACKGROUND: Considering clinical parameters as main predictors for coronary artery dis-ease (CAD)in patients with left bundle branch block (LBBB) can be very helpful to explain high likelihood of ischemic events in LBBB conditions. In the present study, we attempted to identify major clinical determinants to predict CAD occurrence in patients with LBBB. METHODS: A retrospective chart review of 229 consecutive patients with the diagnosis of complete LBBB pattern on electrocardiograms was conducted. The final diagnosis of LBBB was based on the Criteria Committee of the New York Heart Association. The participants were also classified based on coronary angiography evidences into two groups including CAD patients (n =99) and non-CAD patients (n =130). RESULTS: Among 99 patients with CAD, 27 (27.3%) had single vessel disease, 30 (30.3%) had two-vessel disease and 42 (42.4%) had three-vessel disease. Also, only two of them had left main lesions. The number of diseased coronary vessels was significantly higher in men than in women so that three vessels disease in men was revealed in 28% and in women was observed in 10.9% (p = 0.002). Using a multivariable logistic regression analysis, male gender (2.445, 95% CI: 1.372-4.367, p = 0.002), advanced age (1.063, 95% CI: 1.032-1.095, p < 0.001), and cigarette smoking (4.112, 95% CI: 1.145-8.635, p = 0.012) were main predictors of CAD in LBBB patients. CONCLUSION: A notable number of patients with LBBB suffered concomitantly from CAD that the presence and severity of this ischemic event could be predicted by male gender, advanced age, and history of smoking in these patients.

Clinical determinants of left ventricular ejection fraction deterioration in patients suffered from complete left bundle branch block.

BACKGROUND: Recently, the deleterious effects of left bundle branch block (LBBB) on left ventricular systolic function have been taken into consideration. OBJECTIVES: The present study aimed to identify underlying factors that predict left ventricular ejection fraction (LVEF) deterioration in patients suffered from complete LBBB. PATIENTS AND METHODS: In a retrospective case-control study, the data of 220 consecutive patients diagnosed with LBBB on their electrocardiograms were assessed. They were referred to Isfahan Heart Center in Isfahan Province, Iran in 2013. LVEF deterioration was defined as a decrease in LVEF at least 10% between the baseline and follow-up echocardiography study. Thus, achieving the LVEF values ≤ 40% in patients with an initial EF of > 50% was considered LVEF deterioration. RESULTS: Among 220 patients, 40% of LBBB patients suffered LVEF deterioration within 3 months of initial assessment. The group with LVEF deterioration had higher male to female ratio, had higher NYHA score, and suffered more from systolic hypertension than another group. Those with coronary artery disease (CAD) had also significantly lower LVEF than non-CAD ones. Adverse associations were revealed between systolic blood pressure and LVEF measurement (r = -0.193, P = 0.006) as well as between NYHA score and LVEF (r = -0.215, P = 0.002). A multivariable logistic regression model showed that among baseline variables, male gender (OR = 3.218, P < 0.001), history of systolic hypertension (OR = 2.012, P = 0.029), higher NYHA score (OR = 1.623, P = 0.005), and the presence of coronary artery disease (OR = 2.475, P = 0.028) could effectively predict LVEF deterioration in patients with LBBB. CONCLUSIONS: Male gender, history of hypertension, high NYHA score, and the presence of CAD predict LVEF deterioration in patients with LBBB.