Small Intestinal Bacterial Overgrowth Syndrome as a Risk Factor for Ventricular Tachycardia in Chronic Heart Failure with Left Ventricular Systolic Dysfunction

Abstract

Aim. To identify the relationship between rhythm disturbances, including ventricular tachycardia (VT), and the small intestinal bowel bacterial overgrowth syndrome in chronic heart failure (CHF) with left ventricular systolic dysfunction. Materials and methods. The study included 60 patients with CHF with systolic dysfunction of the left ventricle (left ventricular ejection fraction less than 50 %). Conventional biochemical and hematological tests , ECG and echocardiography were performed. The level of the N-terminal fragment of the brain natriuretic peptide (NT-proBNP) and nonspecific inflammatory markers (C-reactive protein (CRP), fibrinogen, leukocytes, lymphocytes, neutrophil to lymphocyte ratio) were studied. Lactulose hydrogen breath test was fulfiled to detect the small intestinal bowel bacterial overgrowth syndrome (SIBOS). In the presence of complaints of palpitation and interruptions in the heart work or other indications, Holter ECG monitoring was performed. The control group consisted of 20 patients comparable to the main group by sex, age and major diseases in the absence of CHF and SIBOS.Results. The prevalence of SIBOS among patients with CHF significantly exceeded its prevalence in the group of patients without CHF (SIBOS was detected in 25 of 60 patients with CHF (42 %) and in 2 of 22 patients without CHF (9 %); p = 0.0034). The small bowel bacterial overgrowth syndrome with CHF did not have a significant impact on the functional class and the indicators of clinical and biochemical analysis of blood as well as on echocardiographic data and the number of supraventricular and ventricular extrasystoles. However, in patients with SIBOS, higher CRP values were observed (median and interquartile range: 3.6 (2.5; 4.1) vs 2.15 (0.4; 5.1); p = 0.041). In addition, among patients with CHF and a positive SIBOS test, ventricular tachycardia was significantly more common (in 45 % of patients with SIBOS and in 10.71 % of patients without SIBOS; p = 0.01555). The presence of SIBOS increased the risk of VT in patients with CHF (OR = 6.818, 95 % CI: 1.542 - 30.153; P = 0.011)). The development of VT in patients with SIBOS was associated rather with systemic inflammation than with the severity of CHF characterized by high NTproBNP numbers, while in the absence of SIBOS the opposite trend was noted.Conclusion. The development of VT in patients with SIBOS is associated rather with systemic inflammation rather than with the severity of CHF. SIBOS can be considered as an additional risk factor in the development of systemic inflammation and ventricular tachycardia in patients with CHF.