CONGRESS ABSTRACT

CLINICAL CASE PRESENTATION A 62-year-old female smoker went to the emergency room for ankle swelling. ECG showed sinus tachycardia, left bundle branch block (LBBB) and non-sustained ventricular tachycardias. Blood test revealed a mild elevation of high sensitivity cardiac troponin I (31 ng/L) and a remarkable elevation of amino-terminal pro-B-type natriuretic peptide (17100 pg/mL). After intensive cardiac care unit admission, obstructive coronary artery disease was excluded by coronary angiogram. Transthoracic echocardiogram (TTE) showed a severely dilated and dysfunctional left ventricle (LV) and a severe mitral regurgitation (MR); signs of LV dissynchrony, namely septal flash and apical rocking were visually detected. Speckle-tracking technology displayed a reduced regional longitudinal strain of the apical segments of the interventricular septum and the anterior wall of LV (which resulted to be an area of late gadolinium enhancement on cardiovascular magnetic resonance) and a delayed contraction of the LV anterolateral wall. 3 weeks after medical treatment for heart failure with reduced ejection fraction (HFrEF) was started, an implantable cardiac resynchronization therapy (CRT) – defibrillator was implanted; the LV lead was located in an anterolateral coronary vein. After 6 weeks, a 45% reduction in telesystolic volume, a 8% absolute increase in LV ejection fraction, an increase of cardiac output and LV global longitudinal strain, a decrease of signs of dissynchrony and MR, an improvement of LV diastolic function and left atrial (LA) function, quantified by LA reservoir strain and a normalization of dimensions and systolic function of the right ventricle were observed on TTE. DISCUSSION CRT is usually considered in patients on optimal medical treatment for HFrEF. However, up‐titration of medical treatment to guideline‐recommended doses may not possible sometimes and its efficacy can be limited in patients with LBBB1 who may benefit from CRT earlier than guidelines currently recommend2. Speckle-tracking technology, displaying the site of latest left ventricular activation, may guide LV lead implantation2. REFERENCES 1 Sze E et al; Impaired Recovery of Left Ventricular Function in Patients With Cardiomyopathy and Left Bundle Branch Block; J Am Coll Cardiol. 2018 Jan 23;71(3):306-317 2 Glikson M et al; 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy; Eur. Heart J. 2021 Sept 14; 42 (35):3427–3520