49 A case report of cardiac contractility modulation therapy for heart failure treatment in patient with amyloidosis: is to be considered a valid therapeutic option?

Aims Cardiac amyloidosis (CA) is primarily associated with fibril deposits in many cardiac structures, causing biventricular wall thickness and stiffness. CA may result in arrhythmias and particularly in an aggressive form of heart failure (HF). Cardiac contractility modulation (CCM) showed to be a concrete therapeutic option in patients with symptomatic HF despite optimal medical therapy (OMT), with Left Ventricular Ejection Fraction (LVEF) between 25% and 45%, with narrow QRS complex (<130 ms). This case aims to further explore the effectiveness of CCM therapy in a patient affected by concomitant ischaemic cardiomyopathy and CA. Methods and results A 42-year-old man with Chronic HF secondary to both post-ischaemic due to spontaneous coronary artery dissection (SCAD) and post alcoholic dilated cardiomyopathy was hospitalized at our department in February 2020 due to worsening HF (3rd HF hospitalization in the same year). The patient was a NYHA class III, with chronic kidney failure, a narrow QRS complex (100 ms) and a LVEF of 27% with familiar history of sudden death, already implanted with ICD. The patient resulted untreatable with sacubitril/valsartan, as it elicited strong hypotension. During current hospitalization the BNP value was 942.60 pg/ml, and the Quality of Life (QoL) evaluated from Minnesota Living with Heart Failure Questionnaire (MLHFQ) score was 72 points. Moreover, the patient underwent umbilical biopsy that confirmed the presence of amyloidosis. Thus, the CCM therapy device (Optimizer® Smart, Impulse Dynamics) was implanted to try to reduce HF symptoms and hospitalizations. The therapy was programmed for 10 h per day, with delivery of CCM from both septal leads with amplitude of 6.5 V at 20.56 ms pulses duration. Figure 1A and B shows the septal position of leads and a surface ECG with the CCM therapy spike after QRS. The patient significantly improved as early as the first period after implantation. The 10-month in-office FU performed on December 2020 revealed in addition to the absence of new HF hospitalizations, a significant improvement in QoL and HF-symptoms, with a MLWHFQ score of 42, an enhancement to NHYA class II, and even a slight decrease of BNP of 767 pg/ml. The echo exam revealed no significant changes in the EF, with an improvement of global longitudinal strain and no worsening of other haemodynamic parameters. A further FU performed in June 2021 showed continuous improvement of QoL with a MLWHFQ score of 25 e no HF hospitalizations. Conclusions In this patient affected by multiple cardiomyopathies, including CA, CCM therapy proved to improve its QoL with no HF hospital admissions since the implantation. The absence of significant echocardiographic worsening is a positive aspect, considering the patient’s status, the concomitant aetiologies, and the presence of amyloidosis, given its progressive and infiltrative nature.

Preliminary study on left bundle branch area pacing in children：clinical observation of 12 cases

Objective: To explore the safety and feasibility of left bundle branch area pacing (LBBAP) in children. Methods: This study observed 12 children attempted LBBAP from 2019 to 2021 in our department prospectively. Clinical data, pacing parameters, electrocardiograms, echocardiographic measurements and complications were recorded at implant and during follow-up. Results: The 12 patients aged between 3 and 14ys and weighted from 13 to 48kg. 11 patients were diagnosed with third-degree AVB and 1 patient (case 4) suffered from cardiac dysfunction due to right ventricular apical pacing (RVAP). LBBAP was successfully achieved in all patients with narrow QRS complexes. LVEF of case 4 recovered on the 3rd day after LBBAP. The median of LVEDD Z score of the 12 patients decreased from 1.75 to1.05 3 months after implantation (p<0.05). The median of paced QRS duration was 103ms. The median of pacing threshold, R-wave amplitude and impedance were 0.85V, 15mV and 717Ω respectively and remained stable during follow-up. No complications such as loss of capture, lead dislodgement or septal perforation occurred. Conclusions: LBBAP can be performed safely in children with narrow QRS duration and stable pacing parameters. Cardiac dysfunction caused by long-term RVAP can be corrected by LBBAP quickly.

Prospective evaluation of the learning curve and electrical characteristics of left bundle branch area pacing

Background Left bundle branch area pacing (LBBAP) has recently been introduced as a physiological pacing technique with a synchronous ventricular activation. Objective To prospectively evaluate the feasibility and learning curve, as well as the electrical characteristics of LBBAP. Methods In 80 consecutive LBBAP pacemaker patients, ECG characteristics during intrinsic rhythm, RV septum pacing (RVSP) and LBBAP were evaluated. From the ECG's QRS duration and LVAT (stimulus to V6 R-wave peak time, RWPT) were measured. Also, the left bundle branch potential (LBBpot) to V6 RWPT interval was measured and compared to the LVAT. After conversion of the ECG into VCG (Kors conversion matrix), QRS area, as measurement for electrical dyssynchrony, was calculated. Results Permanent lead implantation was successful in 77/80 patients (96%) undergoing an attempt at LBBAP. LBBAP lead implantation time as well as fluoroscopy time were significantly shorter during last 25% of implantation compared to first 25% of implantations (17±5 min vs. 33±16 min and 12±7 min vs. 21±13 min, respectively, panel A and B). LBB capture was obtained in 54/80 patients (68%). In 36/45 patients (80%) with intact AV conduction and narrow QRS an LBBpot was present. The mean interval between the LBBpot and the onset of QRS was 22±6 ms. In the patients with narrow QRS (n=45), QRS duration increased significantly during both RVSP (139±24 ms) and LBBAP (123±21 ms), compared to intrinsic rhythm (95±13 ms). QRS area on the other hand, increased during both RVSP (73±20 μVs) but decreased during LBBAP (41±15 μVs), to values close to intrinsic rhythm (32±16 μVs, panel C). For all patients, QRS area was significantly lower in patients with LBB capture compared to patients without capture (43±18 μVs vs 54±21 μVs, respectively). In patients with LBB capture (n=54), LVAT was significantly shorter compared to patients without LBB capture (75±14 vs. 88±9 ms, respectively). In the patients with LBB capture, there was a significant correlation between the LBBpot – V6 RWPT and S – V6 RWPT intervals (Pearson correlation 0.739, P&lt;0.001). Conclusion LBBAP is a safe and feasible technique, with a clear learning curve that seems obtained after ± 40–60 implantations. LBB capture is obtained in two-thirds of patients. Although QRS duration remains prolonged, LBBAP largely restores ventricular electrical synchrony to values close to intrinsic (narrow QRS) rhythm. FUNDunding Acknowledgement Type of funding sources: None.