THE RELATİONSHİP BETWEEN BLOOD GAS PARAMETERS OBTAİNED FROM THE CORONARY SİNUS DURİNG THE PROCEDURE AND CRT RESPONSE İN PATİENTS WİTH HEART FAİLURE WHO UNDERWENT CRT IMPLANTATİON

Heart failure (HF) is one of the clinical syndromes with the highest morbidity and mortality rates among cardiovascular diseases. Despite pharmacological treatments, symptoms persist in a significant proportion of patients, and mortality cannot be prevented. Therefore, device-based therapies, particularly cardiac resynchronisation therapy (CRT), have gained an important place in the treatment algorithm.CRT aims to correct mechanical dyssynchrony by enabling simultaneous contraction of the left and right ventricles. It also aims to reduce sudden cardiac death rates with its defibrillator feature. Current guidelines emphasise that CRT provides significant benefits in terms of symptomatic improvement and long-term survival when appropriate patient selection is made. However, not all patients who meet the criteria have benefited equally from CRT. It is difficult to predict in advance which heart failure patients will benefit from CRT.The aim of the study is to analyse blood gas parameters obtained from the coronary sinus during the procedure in cases of symptomatic heart failure with low ejection fraction despite optimal medical treatment and in patients with indications for CRT according to current guidelines. This analysis aims to contribute to the prior identification of patients who may benefit.