Heart failure patients are predisposed to develop arrhythmias. Supraventricular arrhythmias can exacerbate the heart failure symptoms by decreasing the effective cardiac output and their control require pharmacological, electrical, or catheter-based intervention. In the setting of atrial flutter or atrial fibrillation, anticoagulation becomes paramount to prevent systemic or cerebral embolism. Patients with heart failure are also prone to develop ventricular arrhythmias that can present a challenge to the managing clinician. The management strategy depends on the type of arrhythmia, the underlying structural heart disease, the severity of heart failure, and the range from optimization of heart failure therapy to catheter ablation. Patients with heart failure, irrespective of ejection fraction are at high risk for developing sudden cardiac death, however risk stratification is a clinical challenge and requires a multiparametric evaluation for identification of patients who should undergo implantation of a cardioverter defibrillator. Finally, patients with heart failure can also develop symptomatic bradycardia, caused by sinus node dysfunction or atrio-ventricular block. The treatment of bradycardia in these patients with pacing is usually straightforward but needs some specific issue.

Heart failure (HF) is a complex clinical syndrome in which structural/functional myocardial abnormalities result in symptoms and signs of hypoperfusion and/or pulmonary or systemic congestion at rest or during exercise. More than 80% of deaths in patients with HF recognize a cardiovascular cause, with most being either sudden cardiac death (SCD) or death caused by progressive pump failure. Risk stratification of SCD in patients with HF and preserved (HFpEF) or reduced ejection fraction (HFrEF) represents a clinical challenge. This review will give an update of current strategies for SCD risk stratification in both HFrEF and HFpEF.

Aims The aim of our study was to evaluate the effect of cardiac resyncronization therapy on QT dispersion (QTd), JT dispersion (JTd), and transmural dispersion of repolarization (TDR), markers of heterogeneity of ventricular repolarization in a study population with severe heart failure. Methods and results Fifty patients (43 male, 7 female, age 60.2±3.1 years) suffering from congestive heart failure (n=39 NYHA class III; n=11 NYHA class IV) as a result of coronary artery disease (n=19) or of dilated cardiomyopathy (n=31), with sinus rhythm (SR), QRS duration >120 ms (mean QRS duration=156±21 ms), an ejection fraction 55 mm, presence of atrioventricular asynchrony, intra- and inter-ventricular asynchrony, underwent permanent biventricular pacemaker implantation. A 12-lead standard electrocardiogram was performed at baseline, during right-, left-, and biventricular pacing (BiVP) and QTd, JTd, and TDR were assessed. BiVP significantly reduced QTd (73.93±19.4 ms during BiVP vs. 91±6.7 ms in SR, P=0.004), JTd (73.18±17.16 ms during BiVP vs. 100.72±39.04 at baseline, P=0.003), TDR (93.16±15.60 vs. 101.55±19.08 at baseline, P<0.004), compared with SR. Right ventricular endocardial pacing and left ventricular epicardial pacing both increased QTd (RVendoP 94±51 ms, P<0.03; LVepiP 116±71 ms, P<0.02), and TDR (RVendoP 108.13±19.94 ms, P<0.002; LVepiP 114.71±26.1, P<0.05). There was no effect on JTd during right and left ventricular stimulation. Conclusions BiVP causes a statistically significant reduction of ventricular heterogeneity of repolarization and has an electrophysiological anti-arrhythmic influence on the arrhythmogenic substrate of dilated cardiomyopathy.

Background. Cardiac contractility modulation (CCM) is a novel device-based therapy for patients with heart failure with reduced and mild reduced ejection fraction (HFrEF/HFmrEF). CCM increases cardiac performance and produces reverse left ventricular remodeling, with improved symptoms, functional capacity, quality of life, and reduced HF-related hospitalizations. However, to date, little evidence is available on the effects of CCM on right ventricle (RV) function. Therefore, we analyzed the effects of CCM on RV systolic function and RV–pulmonary artery (PA) coupling. Methods. Twenty-one (65 ± 12.5 years) patients with NYHA class III, ejection fraction < 40% and QRS < 120 ms were assessed at baseline. During follow up, two patients had died, and so nineteen patients were evaluated six months after CCM therapy. Using echocardiography, tricuspid annular systolic excursion (TAPSE), myocardial systolic excursion velocity (RVs), and RV free-wall strain was measured. PA systolic pressure (PASP) was estimated from tricuspid regurgitation, adding the right atrial pressure estimation. The RV-PA coupling was calculated as TAPSE/PASP ratio. Results. After six months, patients who underwent CCM therapy showed a reduction in RV diameters and improved RV systolic function, as evidenced by the increase in both TAPSE (16.6 ± 4.2 mm vs. 18.5 ± 3.6 mm; p < 0.05), RVs (10.1 ± 1.8 cm/s vs. 11.3 ± 11.4 cm/s; p < 0.05), and RV strain (−13.7 ± 1.8% vs. −15.6 ± 2.3%; p < 0.05). CCM also determined a reduction in PASP (34.2 ± 9.8 mmHg vs. 28 ± 6.2 mmHg; p < 0.05) and an increase in the TAPSE/PASP ratio (0.52 ± 0.14 mm/mmHg vs. 0.66 ± 0.23 mm/mmHg; p < 0.05). Conclusions. At six months, CCM increases RV reverse remodeling and performance, reducing RV size and improving RV systolic function, PASP, and RV-PA coupling.

Background: Virtually all patients with heart failure with reduced ejection fraction have a reduction of myocardial mechano-energetic efficiency (MEE). Cardiac contractility modulation (CCM) is a novel therapy for the treatment of patients with HFrEF, in whom it improves the quality of life and functional capacity, reduces hospitalizations, and induces biventricular reverse remodeling. However, the effects of CCM on MEE and global longitudinal strain (GLS) are still unknown; therefore, this study aims to evaluate whether CCM therapy can improve the MEE of patients with HFrEF. Methods: We enrolled 25 patients with HFrEF who received an Optimizer Smart implant (the device that develops CCM therapy) between January 2018 and January 2021. Clinical and echocardiographic evaluations were performed in all patients 24 h before and six months after CCM therapy. Results: At six months, follow-up patients who underwent CCM therapy showed an increase of left ventricular ejection fraction (30.8 ± 7.1 vs. 36.1 ± 6.9%; p = 0.032) as well a rise of GLS 10.3 ± 2.7 vs. −12.9 ± 4.2; p = 0.018), of MEE (32.2 ± 10.1 vs. 38.6 ± 7.6 mL/s; p = 0.013) and of MEE index (18.4 ± 6.3 vs. 24.3 ± 6.7 mL/s/g; p = 0.022). Conclusions: CCM therapy increased left ventricular performance, improving left ventricular ejection fraction, GLS, as well as MEE and MEEi.