Effects of biventricular pacing on right ventricular function assessed by standard echocardiography

Background and aim: The aim of this study was to evaluate the short term effect of cardiac resynchronisation therapy (CRT) on right ventricular (RV) function assessed by standard echocardiography. Methods: Data from 57 patients (54 men, 95%; three women, 5%), aged 66.4 +/- 8.7 years with heart failure (HF) was analysed. All patients were in NYHA III-IV functional classes, despite optimal pharmacological treatment according to the current guidelines, had left ventricular ejection fraction <= 35% and QRS complex = 120 ms in a standard electrocardiogram. At baseline and three months after CRT implantation the patients' histories were taken, an anthropometrical examination was made, laboratory tests including the level of NT-proBNP and electrocardiogram were performed, and echocardiographic examination was extended by tissue Doppler imaging techniques and complex RV evaluation. Results: Three months after CRT implantation in the whole study group, the average NYHA functional class had decreased from 3.11 +/- 0.28 to 2.25 +/- 0.68 (p < 0.001), and the six-minute walk test distance had increased from 298.04 +/- 107.42 m to 373.12 +/- 127.15 m (p < 0.001). CRT improved RV systolic function in the whole study group. Tricuspid annular plane systolic excursion had increased from 13.95 +/- 2.80 to 15.79 +/- 2.33 mm (p < 0.001), and so likewise had systolic excursion velocity (S'), which rose from 8.84 +/- 3.45 to 11.00 +/- 3.43 cm/s (p < 0.001). Tricuspid regurgitation grade decreased from 2.02 +/- 0.95 to 1.86 +/- 0.91 (p = 0.013). RV systolic pressure decreased from 31.07 +/- 20.43 to 27.75 +/- 17.35 mm Hg (p < 0.001). RV fractional area change rose from 31.35 +/- 10.30% to 35.40 +/- 10.51% (p < 0.001). Conclusions: This study showed that CRT improved RV systolic function evaluated with parameters assessed in standard echocardiographic examination three months after therapy initiation. The observed improvement was consistent among all applied echocardiographic parameters reflecting RV systolic function.