Acute myocardial infarction revealed by recurrent ventricular tachyarrhythmias detected by remote monitoring

Remote monitoring (RM) of cardiac implantable electronic devices (CIED) represented a major improvement in clinical practice and has been used with multiple indications. Many parameters monitored on a daily basis by current CIED can indeed assist in clinical practice (eg, decompensated heart failure) by providing the patient with optimal timing for anticipated outpatient visit or urgent medical care. Recognition of acute myocardial infarction (AMI) is not usually considered among the capabilities of RM. We present the case of an AMI occurring without any ischaemic symptoms but associated with recurrent ventricular tachyarrhythmias effectively treated by multiple interventions of the implantable cardioverter defibrillator and promptly detected by RM personnel, who recommended the patient to quickly access to the emergency department where diagnosis and revascularization of an otherwise untreated myocardial infarction was performed.

Smartwatch detection of new-onset monomorphic ventricular tachycardia in pregnancy

Smartwatches provide health tracking in various ways and there has been a recent rise in reporting cardiac arrhythmias. While original studies focused on atrial fibrillation, fewer reports have been made on other arrhythmias especially in pregnancy. We report a pregnant patient who presented at 34 weeks' gestation with palpitations. An ECG recorded through her Apple Watch showed ventricular tachycardia. Hospital ECG confirmed monomorphic ventricular tachycardia likely caused by increased sympathetic tone from the gravid state. She was admitted to the cardiac intensive care unit for close monitoring with intravenous anti-arrhythmic agents; however, the rhythm persisted. She underwent a caesarean delivery and the arrhythmia resolved post partum. She later underwent a catheter ablation, after which she discontinued all anti-arrhythmic medications with no recurrence. This case highlights the importance of requesting relevant digital health information, if available, from patients in our modern era. Controlled clinical studies are needed to validate such practices.

Right ventricular lead perforation with iatrogenic injury to an intercostal artery causing haemothorax after pacemaker implant

A woman in her 80s experienced a life-threatening complication of pacemaker implant consisting of subacute right ventricular lead perforation causing iatrogenic injury to an intercostal artery, resulting in a large haemothorax. A CT scan confirmed active bleeding from the fourth intercostal artery. The patient underwent cardiothoracic surgery via a median sternotomy approach, during which the source of the bleeding was sealed, a new epicardial lead was positioned, and the original lead was extracted. This case emphasises the potentially severe consequences of pacemaker lead perforation and secondary injury to adjacent structures. It underscores the importance of early recognition and timely intervention, preferably in a tertiary specialist unit equipped for cardiothoracic surgery and confirms the value of pacemaker interrogation and CT scans for diagnosis.

Complete atrioventricular block-an uncommon clinical presentation in an adult patient with proven dengue fever

Dengue is a viral disease that clinically presents with fever, thrombocytopenia-related haemorrhagic complications and shock in its severest form. This female patient in her 40s primarily presented to the emergency department of the cardiac centre as syncopal attacks with a complete atrioventricular block. Temporary cardiac pacing as an emergency procedure helped to maintain cardiac rhythm and haemodynamics. A history of recent onset fever helped us to suspect and confirmed by serology for dengue pathology. Normal sinus rhythm was restored after 2 days, and we removed the temporary pacing. Cardiac arrhythmia did not recur in 6 months of follow-up. The aetiology for dengue-related cardiac arrhythmia is still not established. In the recovery phase from fever, complete heart block may show up as a primary presentation in the emergency. Its timely diagnosis and temporary pacing may allow spontaneous recovery. The inclusion of electrocardiography in dengue patient guidelines should help clinicians to dictate its treatment.

Masquerading bundle branch block: an often missed electrophysiological event

Masquerading bundle branch block is an easily overlooked pattern on the ECG that indicates severe disease of the atrioventricular nodal conduction pathway. It is often caused by coronary artery disease, infiltrative diseases of the heart and idiopathic degeneration of the atrioventricular nodal conduction pathways. The diagnosis is easily missed as it needs a detailed interpretation of the ECG in addition to the clinical presentation of the patient. The presence of this specific bundle branch block pattern on the ECG indicates severe degeneration of the conduction system requiring intervention. Given its rarity, this clinical entity risks misdiagnosis and inappropriate management. This case highlights two diagnostic challenges for clinicians: the rarely described masquerading bundle branch block and the art of clinically differentiating between epilepsy and convulsive syncope.

Great mimicker: definite isolated cardiac sarcoidosis masquerading as hypertrophic cardiomyopathy

A healthy man in his 50s was hospitalised after presenting with chest pain and dyspnoea. An echocardiogram revealed asymmetrical septal hypertrophy, leading to a diagnosis of hypertrophic cardiomyopathy. Due to progressive conduction abnormalities during his hospitalisation, further evaluation was performed. Cardiac MRI revealed dense late gadolinium enhancement of the septum in the area of hypertrophy. Additionally, fluorodeoxyglucose-positron emission tomography demonstrated increased uptake within the same region, suggestive of active inflammation. Subsequent endomyocardial biopsy showed non-caseating granulomatous inflammation, consistent with cardiac sarcoidosis. Treatment with prednisone and methotrexate was initiated, and an implantable cardioverter-defibrillator was placed following thorough risk stratification. This case highlights the importance of multimodality imaging and the pursuit of a tissue diagnosis in the evaluation of cardiomyopathy.

Survival in a young child with out-of-hospital cardiac arrest: diagnostic dilemma and when to deviate from standard resuscitation guidelines

A boy in early childhood presented in cardiac arrest. Care was provided out of hospital and in the emergency department as per standard paediatric resuscitation guidelines. Despite initial return of spontaneous circulation following cardiopulmonary resuscitation, two defibrillation shocks and epinephrine via intraosseous access, he had recurrent episodes of pulseless ventricular tachycardia and ventricular fibrillation. In total, 40 defibrillation shocks were administered, and he subsequently stabilised on combined treatment with intravenous esmolol, amiodarone and milrinone. He was transferred to the paediatric intensive care unit and had an automated implantable cardioverter-defibrillator inserted prior to discharge. Genetic testing has confirmed a diagnosis of catecholaminergic polymorphic ventricular tachycardia and it is hypothesised that the childhood excitement at a popular time of year, combined with caffeinated drinks, instigated his initial cardiac arrest which was propagated with iatrogenic epinephrine. He has remained stable since, with no neurological sequelae thus far from a significantly prolonged downtime.

Electrocardiographic spiked-helmet sign in critical non-cardiac illness

The spiked-helmet sign (SHS) is an electrocardiographic finding characterised by a distinctive pattern associated with critical illness, resolving once the clinical condition improves. While the underlying mechanism remains uncertain, different mechanisms have been proposed to account for these findings including changes in intrathoracic or intra-abdominal pressures, transient compression of the coronary arteries, repolarisation abnormalities and electromechanical artefacts. We describe the development of the SHS in a patient with underlying left bundle branch pacing following the development of respiratory failure due to haemoptysis and review proposed mechanisms for its pathophysiology.

Lamin A/C cardiomyopathy presenting as high-grade atrioventricular (AV) block, atrial fibrillation, heart failure and ventricular tachycardia in a single-family cluster

Mutations in the lamin A/C (LMNA) gene have been associated with both cardiac and skeletal muscle abnormalities. Cardiac manifestations in LMNA cardiomyopathy have a variable age of onset and range from mild to life-threatening. We describe a case series illustrating manifestations of LMNA mutation in a single family with an extensive history of cardiac disease, including sudden cardiac death, and the implications for diagnosis and management. This discussion highlights potential presentations of LMNA mutations and the importance of genetic testing in patients with a family history of conduction abnormalities.

Third-degree atrioventricular block associated with severe acute hyponatraemia

Severe acute hyponatraemia, defined as a sodium concentration of less than 120 mEq/L, typically manifests with neurological manifestations, resulting in obtundation, coma, seizures, respiratory arrest and death. It very rarely is arrhythmogenic, with a literature review revealing seven cases of hyponatraemia-associated atrioventricular (AV) block of various degrees, of which only three were described as having third-degree AV block. The higher-degree AV blocks typically occurred at sodium levels closer to 115 mEq/L. We present a case of severe acute hypo-osmolar hyponatraemia-induced third-degree AV block in a patient without any other risk factors or aetiologies who initially presented with subdural haematoma and developed refractory bradycardia during his admission. The patient's third-degree AV block completely resolved after correction of his sodium. This case highlights the importance of working up the cause of new-onset third-degree AV block and the consideration of rarer electrolyte derangements such as hyponatraemia as a potential cause.

Refractory coronary vasospasm and recurrent cardiac arrest

We present a case of recurrent vasospasm as an uncommon cause of ventricular fibrillation in a young female patient who was found to have a genetic mutation of unknown significance in the desmoplakin (DSP) gene and ultimately required an implantable cardiac defibrillator and percutaneous coronary intervention. Refractory vasospasm as a cause of chest pain and cardiac arrest may be under-recognised. In this manuscript, we highlight the natural history of refractory vasospasm, treatment considerations including medical therapy, implantable cardiac defibrillator and percutaneous coronary intervention. Lastly, we explore the potential correlation between the DSP mutation and her clinical presentation and the growing importance of genetic testing in unexplained cardiac arrest.

NKX2-5 genetic mutation in a young woman with an atrial septal defect presenting with complete heart block: ICD or bradycardia pacemaker?

A woman in her 40s was admitted following syncope. The 12-lead ECG showed atrial fibrillation with slow ventricular response and suspected complete atrioventricular (AV) block. Cardiac monitoring demonstrated non-sustained monomorphic ventricular tachycardia (VT). Her medical history included surgical repair of an atrial septal defect (ASD) aged 4 years. The patient's mother died suddenly in her early 50s and also had an ASD. Given the patient's syncope, background of familial sudden cardiac death (SCD), suspicion of complete AV block and non-sustained VT, she received an implantable cardiac defibrillator (ICD). She underwent genetic testing, revealing a heterozygous NKX2-5 genetic mutation. The signature phenotype in NKX2-5 mutations is ASD with AV conduction disturbance and an increased risk of SCD secondary to ventricular arrhythmias or severe bradycardia. SCD has been described in NKX2-5 mutation carriers despite functioning permanent pacemakers (PPMs). Therefore, we propose implantation of a preventive ICD, as opposed to a PPM.

Painful left bundle branch block syndrome successfully treated by His-bundle pacing

Painful left bundle branch block (LBBB) syndrome is a rare cause of episodic chest pain associated with transient LBBB in the absence of flow-limiting coronary artery disease and myocardial ischaemia on functional testing. The aetiology of this phenomenon is not clear, but in many reported cases, these transient episodes of LBBB are rate related. The mechanism of chest pain is not well understood. Still, it is postulated that sudden loss of the ventricular contraction synchrony, which happens in LBBB, will induce a different perception of heartbeat in the brain with possible translation to the chest pain. Various treatment modalities were attempted in the past, including exercise training, medical therapy with beta-blockers and calcium channel blockers or device therapy with right ventricle pacing, biventricular pacing and lately, His-bundle pacing. This case report presents a woman with intermittent episodes of typical angina with periodic LBBB changes on her ECG. Telemetry monitoring and treadmill exercise tests show a 100% association between angina episodes and LBBB changes on ECG. Her transthoracic echocardiogram shows normal left ventricle structure and function, and her coronary angiogram shows no flow-limiting coronary artery disease. She has been successfully treated by His-bundle pacing, and her symptoms entirely resolved on her serial follow-up.

Recurrent pneumonia post atrial fibrillation ablation: do not forget to look for pulmonary vein stenosis

A man in his 50s presented with persistent chest pain, haemoptysis, cough and dyspnoea 5 months after undergoing catheter ablation for atrial fibrillation (AF). Several chest CT scans suggested pneumonia. Despite adequate treatment for recurrent pneumonia, symptoms persisted. While reviewing the initial chest CT, a partial venous infarction of the left lower lobe associated with severe left inferior pulmonary vein stenosis (PVS) was diagnosed. Stenting of the left inferior pulmonary vein with a vascular bare metal stent was performed, guided by fluoroscopy and transoesophageal echocardiography. Dual antiplatelet therapy (aspirin/clopidogrel) was introduced for 3 months, followed by long-term aspirin monotherapy. The treatment resulted in relief of his symptoms and the resolution of pulmonary opacities on chest CT. Despite low frequency, AF ablation remains the most common cause of acquired PVS. As highlighted in this case, symptoms are not specific and include recurrent pulmonary infection with delayed management.

Anaesthetic management of a patient with complex, cyanotic congenitally corrected transposition of great arteries for electrophysiological study and thermoablation

Congenitally corrected transposition of great arteries (ccTGA) is a rare congenital heart disease, and little literature is available that describes its anaesthetic management. We present the perioperative management of a patient with complex, cyanotic ccTGA who underwent electrophysiological study with catheter ablation under general anaesthesia. Good understanding of the patient's complex cardiac anatomy and physiology and multidisciplinary communication are vital to facilitate the successful care of the patient.

Sjogren syndrome presenting as atrioventricular block in an adult

A woman in her late teens with a history of Juvenile idiopathic arthritis (JIA) and ongoing sicca symptoms presented with syncope. Upon admission, she was found to be bradycardic with a second-degree atrioventricular (AV) block. After infectious, structural and metabolic aetiologies had been ruled out, she was worked up for rheumatologic causes.Our patient had elevated titres of anti-Sjogren syndrome (SS) antibodies anti-Ro antibodies and was diagnosed with AV block secondary to SS. She was treated with a permanent pacemaker. Patient was followed up in clinic where she denied further syncopal episodes and was started on secretagogues for sicca symptoms.

Revisiting propafenone toxicity

Propafenone is a Vaughan Williams class 1c antiarrhythmic medication widely used for treatment of arrhythmias. Although the long-term safety of propafenone use has not been established, it is commonly used for treatment of atrial fibrillation in patients with no structural heart disease. Propafenone is well known as pill-in-the-pocket treatment for its effect in terminating paroxysmal episodes of atrial fibrillation. Herein, we discuss an unusual adverse reaction to propafenone in a patient who presented with symptomatic bradycardia and hypotension. The aim of this article is to increase physician awareness for propafenone toxicity and its management, with a focused literature review on propafenone pharmacotherapy.

Cystic tumour of the atrioventricular node: treatment dilemma

An asymptomatic 18-year-old black woman was found to have an incidental finding of third-degree atrioventricular (AV) block on a routine ECG. 2-Dimensional transthoracic echocardiography showed a heterogeneous mass in the region of the peri-membranous septum in the AV node area. A cardiac MRI showed a well-defined cystic mass arising from the right side of the interatrial septal wall. An MRI compatible permanent pacemaker was implanted with plans to monitor the tumour with non-invasive imaging. Cystic tumour of the AV node is a rare primary cardiac tumour. It is known as the smallest and most common primary cardiac tumour that can cause sudden death. All previous six cases of living patients with cystic tumour of the AV node reported in the literature were females and symptomatic. We present a rare case of a patient with cystic tumour of the AV node, and we highlight the treatment dilemmas for this condition.

Cystic tumour of the atrioventricular node: treatment dilemma

An asymptomatic 18-year-old black woman was found to have an incidental finding of third-degree atrioventricular (AV) block on a routine ECG. 2-Dimensional transthoracic echocardiography showed a heterogeneous mass in the region of the peri-membranous septum in the AV node area. A cardiac MRI showed a well-defined cystic mass arising from the right side of the interatrial septal wall. An MRI compatible permanent pacemaker was implanted with plans to monitor the tumour with non-invasive imaging. Cystic tumour of the AV node is a rare primary cardiac tumour. It is known as the smallest and most common primary cardiac tumour that can cause sudden death. All previous six cases of living patients with cystic tumour of the AV node reported in the literature were females and symptomatic. We present a rare case of a patient with cystic tumour of the AV node, and we highlight the treatment dilemmas for this condition.