Natriuretic Peptide Concentrations and Echocardiography Findings in Patients with Micro-atrial Fibrillation

Atrial fibrillation (AF) is a rhythm disorder characterized by very rapid and disorganized atrial-derived electrical activations with uncoordinated atrial contractions. Very short periods of AF-like activity (micro-AF) may be precursors of undetected, silent episodes of atrial fibrillation. Here, we examined the relationship between natriuretic peptide concentrations and echocardiography findings in patients with micro-AF.

The electrocardiograms (ECGs) of patients complaining of palpitations were recorded with a 24‑hour Holter monitor, and the patients were consecutively included in the study. Micro-AF was defined as sudden, irregular atrial tachycardia lasting less than 30 sec with episodes of ≥5 consecutive supraventricular depolarizations with the absolute absence of p-waves. After a G-power test, patients were consecutively included in the study: 45 patients in the micro-AF group and 45 patients in the control group. Laboratory parameters, ECG and echocardiographic findings of the two groups were compared.

N-terminal pro B-type natriuretic peptide (Pro-BNP) and serum troponin T concentrations were higher in the micro-AF group, (375.5±63.6 pg / ml vs. 63.1±56.8 pg / ml, p<0.001; 13±11.4 ng / dl vs. 4.4±2.4 ng / dl, p<0.001 respectively.) Each 1 pg / ml increase in serum Pro-BNP increased the risk of micro-AF by 1.8 %. In the ROC analysis, the cut-off value of Pro-BNP for the diagnosis of micro-AF was 63.4 pg / ml, with a sensitivity of 91.1 % and a specificity of 73.3 %. Atrial electro-mechanical delay durations were significantly higher in the micro-AF group. To predict micro-AF, the inter-annulus plane electromechanical delay time (inter-annulus plane AEMD) had a cut-off value of 18.5 sec, with a sensitivity of 93.3 % and a specificity of 91.1 %. Left intra-annulus plane electro-mechanical delay time (intra-annulus AEMD LEFT) had a cut-off value of 11.5 sec with a 95.6 % sensitivity and 75.6 % specificity. In the ECG evaluation, maximum P wave duration (Pmax) (113±10.2 ms vs. 98±10.4 ms; p<0.001), minimum P wave duration (Pmin) (73.8±5.5 ms vs.70±6.3 ms; p<0.001) and P wave dispersion (PWD) (39.1±7.9 ms vs.28±7.6 ms; p<0.001) were longer in the micro-AF group.

Micro-AF in patients may be predicted by evaluating ECG, echocardiographic, and serum natriuretic peptide data.