Practical and systematic approach using the steerable catheter and stylet-driven lead to deliver safe and effective left bundle branch area pacing.

INTRODUCTION: Current delivery tools were not designed for left bundle branch area pacing (LBBAP). Challenges using these tools include lack of reach into the right ventricle and poor support for the lead to penetrate the interventricular septum. Concerns using stylet-driven leads (SDL) for LBBAP have been previously highlighted. Knowledge and the technical know-how of using SDL for LBBAP need to be evaluated in a fair and consistent manner. A stepwise approach is devised for use of Agilis HisProTM steerable catheter with Tendril STS Model 2088TC lead for LBBAP and evaluated for safety and reproducibility. METHODS: Consecutive patients undergoing LBBAP using the stepwise approach with Agilis HisProTM steerable catheter were analyzed. The safety, efficacy and reproducibility of the technique were evaluated. The lead parameters were analyzed in the immediate (1 day) and short-term period (3-6 months) post implantation. RESULTS: LBBAP was attempted in 41 patients using the stepwise approach of which 37 (90.7%) were successful. The lead parameters were stable in the immediate and short-term post implantation in all our patients. There was no significant difference between the group of patients with multiple repositioning of the lead compared to those successful at the 1st attempt. There were no acute or short-term lead and procedural complications. CONCLUSION: A stepwise and systematic approach using the Agilis HisProTM steerable catheter and proper handling of the Tendril STS Model 2088TC stylet-driven lead is an important part of the armamentarium to deliver LBBAP in a practical, effective and reproducible manner.

Physiological pacing: just a lot of buzz or the next paradigm shift in bradycardia pacing?

ABSTRACT: Cardiac pacing has been an established therapy for bradyarrhythmia due to sinus or atrioventricular nodal disease since the 1950s. However, contemporary studies have shown that conventional right ventricular pacing (RVP) causes electromechanical dyssynchrony, which can lead to atrial fibrillation, heart failure and even death. Recently, the push for a more physiological cardiac pacing has seen a revival in the utilisation and development of conduction system pacing (CSP). There has been a shift towards adopting His bundle pacing (HBP) or left bundle branch area pacing (LBBaP) in bradycardia patients worldwide and in Singapore. This review serves to outline the electrophysiological concepts behind CSP and illustrate the different paced electrocardiogram characteristics of HBP, LBBaP and RVP to aid understanding of this revolutionary pacing approach among medical practitioners in Singapore.

Contemporary wearable and handheld technology for the diagnosis of cardiac arrhythmias in Singapore.

Twelve-lead electrocardiography (ECG) remains the gold standard for the diagnosis of cardiac arrhythmias. It provides a snapshot of the cardiac electrical activity while the leads are attached to the patient. As medical training is required to use the ECG machine, its use remains restricted to the clinic and hospital settings. These aspects limit the usefulness of 12-lead ECG in the diagnosis of cardiac arrhythmias, especially in individuals with short-lasting and infrequent paroxysmal symptoms. The introduction of ECG recording features in wearable and handheld smart devices has changed the paradigm of cardiac arrhythmia diagnosis, empowering patients to record their ECG as and when symptoms occur. This review describes contemporary ambulatory heart rhythm monitors commonly available in Singapore and their expanding role in the diagnosis of cardiac rhythm abnormalities.

A case report: use of cerebral oximetry in the early detection of cerebral hypoperfusion in a post-cardiac arrest patient during targeted temperature management.

BACKGROUND: We present a patient who received cerebral oximetry monitoring during targeted temperature management (TTM) post-cardiac arrest and discuss its potential in the early detection of cerebral hypoperfusion and implications on haemodynamics and ventilatory management. CASE SUMMARY: A 60-year-old Chinese male was admitted for acute pulmonary oedema with Type 2 respiratory failure. He failed an initial trial of non-invasive ventilation and was planned for intubation and mechanical ventilation. However, the patient suffered a pulseless electrical activity cardiac arrest peri-intubation. He was started on our institution's protocolized post-cardiac arrest care bundle, which included cerebral regional oxygen saturation (rSO2) monitoring and TTM. Initial arterial blood gas (ABG) post-return of spontaneous circulation showed severe respiratory acidosis, and the patient was sedated, paralyzed, and ventilator settings optimized. Repeat ABG showed resolution of respiratory acidosis. However, a drop in rSO2 to 35% was subsequently noted. Ventilator settings were quickly adjusted, and dobutamine was started to improve global and cerebral perfusion. These measures improved cerebral rSO2 to more than 50%. Patient was cooled for 24 h and gradually rewarmed. He was later extubated with a cerebral performance category of 1 and is now on outpatient follow-up. DISCUSSION: During post-cardiac arrest care, there are many factors which can contribute to a decrease in cerebral blood flow. Therapeutic hypothermia and ventilation strategies, including the use of neuromuscular blocking agents, can both reduce pCO2 which is a major regulator of cerebrovascular tone. Accidental hypocapnia can lead to adverse cerebral vasoconstriction and hypoperfusion. Without cerebral oximetry, cerebral ischaemia may not be detected early and can potentially result in secondary brain injury.

Tachy- and bradyarrhythmia as an initial presentation of human immunodeficiency virus-related primary cardiac lymphoma: a case report.

BACKGROUND: Primary cardiac lymphoma is defined as extranodal lymphoma involving the heart or pericardium. Common presentations of human immunodeficiency virus (HIV)-associated cardiac lymphoma include heart failure, cardiac tamponade, and rhythm abnormalities. Arrhythmia is an uncommon presentation and treatment in young HIV patients is particularly challenging. We present a unique case of primary cardiac lymphoma in an HIV patient presenting with both symptomatic tachy- and bradyarrhythmias. CASE SUMMARY: A 27-year-old man presented with intermittent palpitations and chest pain for 2 weeks. He has a significant past history of advanced HIV. He was noted to have complete heart block on cardiac monitoring. Imaging showed a large mass in the right atrioventricular (AV) groove extending into the myocardium, associated with a moderate pericardial effusion. During his stay, he developed symptomatic tachy-brady arrhythmias, with intermittent junctional tachycardia, supraventricular tachycardia, and complete AV block. After a multidisciplinary team discussion, endomyocardial biopsy was performed under fluoroscopy and transthoracic echocardiography guidance. Histology from the interventricular septum was consistent with Epstein-Barr virus positive B-cell lymphoma. The patient was subsequently transferred to a tertiary hospital with cardiothoracic surgical support to initiate chemotherapy. DISCUSSION: To our knowledge, our patient is the first reported case of HIV-related primary cardiac lymphoma presenting with palpitations secondary to paroxysmal supraventricular tachycardia with concomitant AV block. This case illustrates the utility of multi-modality imaging in the investigation of a cardiac mass and the importance of having a high index of suspicion for pathology, such as cardiac lymphoma in HIV patients complaining of apparently minor cardiac complaints.