Title Cardiac Electrophysiology and Pacing
Type Stage Two
Code HPS138
Requirement Optional

Module objective

By the end of this module the Clinical Scientist in HSST will be able to support interventional electrophysiology (EP) and cardiac pacing procedures, including complex three-dimensional mapping procedures of structurally normal and abnormal hearts in children and adults with CHD. They will be able to interpret baseline, exercise and ambulatory ECG recordings in patients with CHD, including acquired arrhythmia syndromes. They will be able to support the cardiac surgical team in the process of epicardial surgical pacemaker implantation. They will be able to support implant of and perform follow-up assessment and optimal programming of implantable cardiac devices, including those for diagnosing and treating bradycardias, tachycardias and cardiac resynchronisation devices. They will be able to develop and run a regional follow-up service for patients with these devices, including remote follow-up via industry-provided devices.

Knowledge and understanding

By the end of this module the Clinical Scientist in HSST will critically analyse, synthesise, evaluate and apply their expert knowledge of cardiac EP and pacing, including:

Non-invasive investigation of rhythm abnormalities:

  • the range of cardiac rhythm abnormalities that present in children and adults with congenital cardiac disease, and those who present in childhood with acquired cardiac disease that affects the conduction system of the heart;
  • the genetic implications of familial arrhythmia syndromes, and know how these present in children;
  • the indications for non-invasive electrophysiological testing in children and adults with CHD;
  • the expected abnormalities of the ECG in patients with arrhythmia syndromes, including the changes in the ECGs of these patients with exercise testing and diagnostic drug testing;
  • how to interpret the 12-lead ECG, including the knowledge of normal variation and patterns of abnormality through infancy and childhood;which heart rhythm problems in patients with arrhythmia syndromes require acute medical or interventional treatment, and how to access this treatment in a timely manner;
  • arrhythmia epidemiology and prognosis (genetics, pathophysiology, risk evaluation) techniques, modalities, indications, interpretation, and the diagnostic yield of general cardiology non-invasive and imaging techniques such as:
    • exercise testing
    • echocardiography including TOE
    • cardiac MRI
    • cardiac CT imaging
    • nuclear cardiology
    • blood sampling and other laboratory analysis
    • genetic analysis
  • techniques, modalities, indications, interpretation and the diagnostic yield of non- invasive arrhythmia assessment techniques such as:
    • electrocardiography:
      • conventional 12-lead ECG
      • ECG monitoring (Holter, event monitoring, implantable event and loop monitoring)
      • signal-averaged ECG and body surface mapping
      • heart rate variability and baroreflex sensitivity
      • T-wave and micro-T-wave alternans
      • ECG-drug infusion tests (flecainide, etc.)
  • autonomic nervous system evaluation:
    • carotid sinus massage
    • tilt testing

Invasive investigation and treatment of rhythm abnormalities:

  • which heart rhythm problems in patients with arrhythmia syndromes require acute medical or interventional treatment, and how to access this treatment in a timely manner;patient and procedure-type selection for specific arrhythmia management
  • autonomic system influences on EP and arrhythmias;
  • channelopathies and other inherited syndromes:
    • long and short QT syndromes
    • Brugada syndromes
    • hypertrophic cardiomyopathies
    • right ventricular arrhythmogenic cardiomyopathies
    • neuromuscular cardiomyopathies (myotonic dystrophy)
    • catecholaminergic polymorphic ventricular tachycardia
    • ryanodine syndromes
    • congenital conduction disorders
    • other (Chagas disease, etc.)
  • clinical presentation, ECG and EP of the different types and variants of cardiac arrhythmias, including:
    • conduction disturbances
    • arrhythmic clinical syndromes
    • genetic disorders
    • autonomic system-mediated disorders (induction, cardiac activation)
    • responses to electrical stimulation and to drug administration, cardiac activation, EP diagnosis
    • sinus node and atrial impulse formation and conduction disorders – AV nodal and His-Purkinje conduction disorders
    • atrial flutter
    • junctional and AV node ectopy and tachycardias
    • accessory pathway-mediated tachycardias
    • atrial (and thoracic vein) ectopy and tachycardias
    • atrial fibrillation
    • ventricular ectopy and tachycardias
    • ventricular fibrillation
  • patient and procedure-type selection for specific arrhythmia management strategies/targets(risks and benefits).

Electrophysiology procedures:

  • the indications for invasive testing in the EP laboratory;
  • cellular EP; ion channel function and regulation, and the effects of ionic imbalance on cardiac EP;
  • cardiac anatomy relevant to the genesis and treatment of arrhythmias, including detailed anatomy of the thoracic veins, of the right and left atria and inter-atrial septum, right and left outflow tracts, aortic root, coronary artery and coronary venous systems, the AV junction (triangle of Koch, tricuspid annulus, mitral annulus) and associated accessory pathways;
  • underlying mechanisms of arrhythmias: normal automatic behaviour, abnormal
  • automatism, triggered activity, micro-reentry, macroreentry, and other mechanisms;
  • EP principles, including
    • measurement of local activation time and voltage
    • interval measurements
    • conduction velocity and tissue wavelength
    • concealed conduction
    • gap phenomenon
  • normal and abnormal electrophysiology of the different heart chambers and the major thoracic vessels;
  • EP laboratory equipment (fluoroscopy, catheters, sheaths, EP signal recording systems, navigation systems, programmed electrical stimulation systems);
  • ECG and EP signals (differential amplifier: noise, gain, clipping, filters, bipolar/unipolar, voltage/timing/morphology);
  • programmed electrical stimulation techniques (pulse width/amplitude, unipolar/bipolar, continuous/extra-stimulus stimulation, atrial/ventricular/other location stimulation, pacing algorithms);
  • complications and adverse effects of EP studies: pathophysiology, diagnosis, prevention, management;adenosine
  • catheter placement techniques, including cardiac access (transvenous, pericardial, other), guiding means (fluoroscopic and non-fluoroscopic);
  • intracardiac catheter positioning and electrophysiological pacing techniques that elucidate the arrhythmia mechanism;
  • electrogram activation patterns and their changes in response to planned electrophysiological perturbations that allow determination of arrhythmia mechanism;
  • use of stimulators, catheters, mapping systems and lesions creation technologies sufficient for their safe application in patient treatment;
  • three-dimensional mapping using a range of computerised mapping technologies, and when this would be useful to support an invasive study;
  • the potential for diagnostic use of medication during an electrophysiology study to induce arrhythmias or reveal conduction disease;
  • the usefulness of TOE in guiding the interventional trans-septal puncture during an ablation procedure if required, and will have knowledge of the equipment required to perform the scan and the anatomy involved. They would not be required to perform the scan;
  • the haemodynamic data obtained during a catheterisation procedure, including the potential effects of cardiac arrhythmia on the haemodynamics;
  • interpretation of therapy modalities in EP other than ablation, such as:
    • medical therapy
    • autonomic system manoeuvres
    • cardioversion and defibrillation
    • anti-tachycardia pacing and device therapies
  • pharmacological tests and modulation, for example:
    • adenosine
      • type I drugs for unmasking Brugada ECG
      • adrenaline for unmasking congenital long QT syndrome

Cardiac device implantation:

  • indications for cardiac device implantation, be aware of the issues involved in device implantation in children compared with adults and be able to support a clinician in implanting an appropriate device to treat the relevant rhythm issues;
  • the published international guidelines regarding patient selection for device implantation;
  • how to assess data on individual patients to determine evidence-based treatment for each individual patient;
  • management of lead problems and programming issues specifically related to leads;
  • rate-modulated pacing and sensor technology;
  • management of peri-procedural complications, e.g. cardiac tamponade, and pneumothorax.
  • the principles of defibrillation and the engineering of device and of defibrillating leads;
  • the medical treatment of tachyarrhythmias, including interaction of drugs with defibrillation threshold and arrhythmia cycle length, the pro-arrhythmic effect of antiarrhythmic drugs and their effect on left ventricular function;
  • indications, techniques, performance and response interpretation of therapy;
  • medico-legal issues concerning provision of information, and driving restrictions and end of life issues.
  • specific issues regarding lead longevity in young children with the associated growth that they will undergo following implantation;
  • the reasons for, usefulness of and limitations behind epicardial pacing in small children and postoperative patients where access to the cardiac chambers via typical transvenous routes may not be possible;
  • differences of professional expert opinion on the best method of pacemaker implantation in very young or small children (epicardial/endocardial systems);
  • the paucity of evidence on which to base decisions/guidelines due to the small and diverse population of children requiring pacemakers, leading to guidelines based on consensus expert opinion.

Device follow-up:

  • the indications for and frequency required for appropriate follow-up across the range of ages and devices;
  • the wide range of devices available to allow for optimal programming, including the need for potential programming or device changes relating to a child’s growth or developmental needs.
  • the need to optimise devices to achieve the best balance of function and longevity, given the requirement for children and young people to undergo device changes (frequently under general anaesthesia) over a much longer period than is usual in the adult-acquired heart disease pacing population;
  • potential issues with long-term pacemaker dependency and cardiac dysfunction, which may relate to lead position;
  • why careful attention should be taken to position leads optimally at implant as per current best evidence or opinion;
  • how to perform remote monitoring of devices using near patient technology rather than requiring patients to always attend hospital for review;
  • cardiac anatomy, including those patients with operated and unoperated structural congenital heart defects, and the bearing that the anatomy and/or surgery may have on the types of arrhythmia and their treatment options;
  • the appearance of images obtained during a standard angiographic assessment of cardiac structure and function;
  • the impact of general anaesthesia on the inducibility of cardiac arrhythmias and the haemodynamic changes that may occur related to sedation or general anaesthetic;
  • the use of defibrillation in resuscitation and in the techniques of basic and intermediate life support;
  • the potential effects that a diagnosis of cardiac arrhythmia may have on a child or young person and their family, and initial and ongoing emotional or psychological support that may be required as they come to terms with the diagnosis and its implications, including the effect of potential treatment options;
  • the possible risk of sudden cardiac death that some arrhythmic syndromes carry and that may have no currently available treatment options (which may be very distressing for the patients, family and the team treating them);
  • the rapid advances in EP and cardiac rhythm management and the new treatments may become available in the future;
  • potential clinical benefits of telemedicine for device follow-up;
  • the breadth of available devices and the indications for choosing to implant one over another through regular contact with industry device providers;
  • keep up to date about the development and release of new devices that would potentially benefit patients in the congenital group.


Technical and clinical skills

By the end of this module the Clinical Scientist in HSST will be expected to critically reflect on their clinical practice. They will apply in practice a range of advanced clinical and communication skills to advise and communicate effectively with patients, relevant clinicians, patients and the public, and other healthcare professionals, and will be able to:

  • determine whether standard exercise testing, cardiopulmonary exercise testing, ambulatory monitoring or tilt-table testing would be the most appropriate investigation modality;
  • interpret 12-lead ECGs in the clinical context;
  • interpret invasive and non-invasive (such as standard exercise testing, cardiopulmonary exercise testing, ambulatory monitoring or tilt-table testing and 12-lead ECGs) EP testing and produce expert reports on the results of these investigations;
  • interpret the results from a range of invasive testing, including cardiac catheterisation studies and EP procedures;
  • perform external defibrillator and planned direct current (DC) cardioversion.

Cardiac electrophysiology:

  • interpret clinical invasive cardiac EP studies;
  • interpret images relating to catheter position in relation to the conduction system of the heart;
  • use test results to plan further treatment and discuss these plans with a multidisciplinary team to ensure that the patient is treated in the most appropriate method and in a timely manner;
  • liaise during procedures with EP clinicians and communicate during the procedure to ensure appropriate treatment;
  • interpret the results of three-dimensional mapping to guide interventional treatment with ablation;
  • manage the technical equipment (EP systems, programmable stimulator, ablation systems, 3D mapping, haemodynamic monitoring systems, pacing and defibrillation systems, etc.);
  • recognise and manage the complications and the adverse effects of EP studies;
  • appreciate the limitations and the potential risks of therapies;
  • reflect on the challenges of applying research to practice in relation to the diagnosis and management of patients requiring cardiac EP procedures and suggest improvements, building on a critique of available evidence;
  • educate patients about the treatment options available to them and explain treatment strategies;
  • deliver education about arrhythmias to patients relatives and other healthcare professionals to demonstrate/diagnose/confirm any given arrhythmia mechanism and the critical components by a combination of pattern recognition and electrical interaction with the arrhythmia mechanism (e.g. extra-stimulation/entrainment).

Cardiac pacing/device therapy:

  • use the results of investigations to plan appropriate cardiac device implantation as per published international guidelines regarding patient selection;
  • assess ECGs of patients with known or suspected inherited or genetic cardiac disease and determine a treatment plan based on the outcomes of baseline ECGs and those obtained during diagnostic drug testing;
  • assist with the insertion of temporary and permanent pacing wires, techniques and skills involved;
  • use a temporary pacing box during procedures and following cardiac surgery to optimise haemodynamics;
  • programme and optimise implantable devices from a range of device companies, including pacemakers, defibrillators, loop recorders and cardiac resynchronisation devices;
  • perform overdrive pacing using temporary epicardial pacing wires in postoperative patients and implement device programming changes to stop abnormal cardiac rhythms in patients with implantable devices for treatment of cardiac tachyarrhythmias;
  • manage device malfunction and troubleshooting;
  • assess current drain and battery longevity;
  • interpret and assess electrograms, markers, intervals, Holter features and other storage and diagnosis capabilities and appropriate programming and/or medical intervention in response to new findings;
  • evaluate device diagnostic data in the clinical context and in reference to other non-invasive or invasive techniques;
  • critically reflect on the challenges of applying research to practice in relation to the diagnosis and management of patients requiring cardiac EP procedures and suggest improvements, building on a critique of available evidence;
  • communicate the results of testing with families and patients and discuss the various treatment options with them in the light of multidisciplinary discussion regarding their appropriateness.

Attitudes and behaviours

By the end of this module the Clinical Scientist in HSST will be expected to critically evaluate their own response to both normal and complex situations. They will consistently demonstrate the professional attributes and insights required of a Clinical Scientist in HSST working within the limits of professional competence, referring as appropriate to senior staff, and will:

  • recognise and minimise the anxiety of patients and their parents or families before, during and after procedures, and appreciate the psychological impact of the patient’s CHD/syndrome on the patient and their family and manage it sensitively;
  • educate patients and their parents or families about cardiac rhythm disease, treatment strategies and outcomes, including risks and benefits of interventional treatment. Tailor this education individually to the level of understanding of the child or young person, including those with learning difficulties;
  • update patients and families regarding technical advancements in device technology and how these might be relevant to the specific patient;
  • liaise with patients and their families regarding appropriate follow-up, including contact with patients after requests for review of data from near-patient remote monitoring systems. This will include the need for discussion regarding abnormal findings that could cause the patient or their family to become increasingly anxious, and the management of this situation. This may also involve breaking bad news such as the need for further interventional procedures or the deterioration of a patient’s overall condition and a potential reduced life expectancy;
  • liaise appropriately and in a timely manner with consultant EP team members when abnormal findings are demonstrated to ensure that appropriate patient review and treatment are performed if required;
  • develop a critical attitude towards techniques in invasive EP and cardiac device implantation and contribute to the selection of the best available techniques according to procedure results, clinical evidence and practice guidelines.


Code Title Action
HPS1-1-2-20 Cardiac (Congenital and Paediatric) [v1] View