Causes of Failures and Complications in Stimulation of the Conduction System Pacing

Conductive system stimulation relies on the direct stimulation of His-Purkinje’s specialized cardiac conduction system for physiological activation of the ventricles, as opposed to asynchronous activation induced by conventional myocardial stimulation. Since the first report of permanent His bundle stimulation in 2000, the stylet-based technique has undergone significant advances in technology. Single-center observational studies have now been supported by large multicenter, international registries, meta-analysis and the first randomised controlled trials. New evidence has elucidated mechanisms of HBP and illustrated the nature and magnitude of its potential benefits for preventing pacing-induced cardiomyopathy and correcting bundle branch block. Left bundle branch pacing (LBBP) is a newer technique in which the lead is fixed deep into the left side of the intraventricular septum to allow capture of the left bundle, distal to the His bundle. LBBP holds promise as a method for physiological pacing that overcomes some of the fixation, threshold and sensing challenges of HBP.

Physiological pacing to improve cardiac resynchronization therapy non-responder and a tryst with calcified septum—a case report

Background As per the literature, patients with intraventricular conduction delay (IVCD) do not respond well to cardiac resynchronization therapy (CRT) alone. They need advanced technological approach and out of the box thinking for a good response. Case Ours is a case of ischemic cardiomyopathy with wide QRS-IVCD, a non-responder to CRT. While planning for replacement of the device for early replacement indicator (ERI), we decided to do His-optimized CRT/left bundle optimized CRT (HOT-CRT/LOT-CRT) for the patient. Conclusion The challenges we faced with the present available hardware paved a way for insisting on the limitation of the available lumenless lead to penetrate calcified the septum and importance of the pre-procedure evaluation of intraventricular septum (IVS) for calcification by more than just echocardiography.

Echocardiography and Newer Imaging Techniques in Diagnosis and Long-Term Follow-Up of Primary Heart Tumors in Children

Background: Primary heart tumors (PHTs) in the pediatric population are very rare and do not manifest any characteristic symptoms. Methods: A retrospective analysis of 61 cases was undertaken. Data from three centers for the years 2003–2018 were gathered. The tumors’ clinical course, location, number, hemodynamic, treatment, and follow-up were evaluated. Echocardiography was complemented with magnetic resonance imaging, computer tomography, and histopathological examination. Results: Out of 61 PHT diagnoses, 56 (91.8%) were circumstantial including all 16 (26.2%) prenatal tumors. The reasons for cardiological consultations were arrhythmia, syncopes, lowered physical performance, and murmurs. Only five patients (8.2%) were suspected of tumors based on previous symptoms of sclerosis tuberosa. Rhabdomyoma was the most frequently found PHT (60.7%). The tumors were predominantly located in the ventricles (49.1%) and intraventricular septum (14.9%) and tended to be single (70.5%). About 37.7% of patients suffered from coexistent multi-organ problems, two (3.28%) from congenital heart defects and one (1.64%) from Carney’s syndrome. Tumor resection was performed on 26 (42.7%) patients, of which 16 (61.5%) underwent total and 10 (38.5%) partial tumor resection. During the follow-up (mean 4.3 years), 54 patients (88.5%) have improved or were stable, while seven (11.5%) died. Conclusions: Primary pediatric heart tumors are diagnosed completely circumstantially, and the most common is rhabdomyoma, although arrhythmia may suggest fibroma. Diagnosis of a heart tumor in children is not synonymous with fatal prognosis, and most of them require only constant observation. Life-saving operation allows improvement, while the prognosis for malignant tumors in children is definitely unfavorable.

P5700Comparison of efficacy and safety of ventricular lesions formation by unipolar and bipolar radiofrequency ablation on an animal model

Aims Despite all this technical progress, VT recurrence after unipolar ablation remains relatively high (12–47%). Bipolar ablation has been proposed as an appealing solution, which may overcome boundaries associated with unipolar ablation settings. Therefore, we have proposed an animal study to compare bipolar (BPA) vs sequential unipolar ablation (UPA) using a contact-force sensing technology on both catheters. Methods 20 large white female pigs (6 months-old, 60–70kg) underwent multiple RF ablations (30W, 60s, 30ml/min irrigation) on ventricular myocardium, from epicardial and endocardial sides. After the procedure, the animal underwent euthanasia, cardioplegia and organ excision. The hearts were fixed and underwent high-resolution cardiac MRI. Each lesion was characterized primarily in terms of volume, depth, width and transmurality. Results We evaluated 35 lesions across the intraventricular septum. No difference in volume, linear dimensions and impedance drop was observed in this area, between the two ablation settings. However, for the generation of unipolar lesions, twice the ablation time was needed. Transmurality of the lesions shows a trend in favor of BPA. We then analyzed 73 lesions from the endocardial side and 34 from the epicardial one of the ventricular free walls. Lesion transmurality was found remarkably improved in BPA (p=0.030, OR 23.73 [4.71,11.96]). Ventricular BPA lesions were significantly deeper on the epicardial side (p<0.0001) Conclusion BPA is more likely to create transmural lesions in the ventricle, when compared to UPA. Half the time is needed for the creation of comparably deep and large lesions. BPA is specifically more effective in creating epicardial lesions.

Two foreign bodies embedded in the intraventricular septum: A case report

<p>A 23-year old male was presented at the outpatient clinic of our department reporting that he had been subjected to insertion of foreign bodies in his chest. Physical examination was unremarkable. Imaging studies revealed the presence of two bodies in the subcutaneous tissue of the anterior chest wall and two needle-shaped intramyocardial bodies that were impacted in the intraventricular septum. Due to late appearance, the position, and because of the absence of symptoms, it was decided that the patient should be managed conservatively. Today, five years after the incident, the patient remains asymptomatic and he is followed-up regularly.</p>