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Clinical case studies

Ectopy in Groups

Group beating always provide fascinating ECGs! This week, we take a look at several different combinations of ectopy sequences including ventricular and atrial trigemilets, ventricular bigemilets and more.

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Clinical case studies

Fact or Artefact

Dr Harry Mond explores another form of ECG interference often referred to as 'subtle artefact' which can mimic cardiac arrhythmias and sometimes lead to serious misdiagnoses and inappropriate treatments.

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Clinical case studies

ECG Artefact

An ECG artefact is an inscription on an ECG tracing that doesn't originate from a cardiac source. Dr Harry Mond teaches us how to recognise artefact on an ECG and what causes the different types of interference to prevent ECG misdiagnosis.

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Clinical case studies

Pacing Therapies for Tachyarrhythmias

Dr Harry Mond visits the early history and recent technological advances in pacing therapies for the treatment of tachyarrhythmias.

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Clinical case studies

Pacing and Coronary Artery Disease

Continuing our pacing series, Dr Harry Mond explores pacing and coronary artery disease, alongside the valuable ECG clues for its detection which should not be ignored.

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Clinical case studies

Ventricular Pacing Minimisation Algorithms

Right ventricular pacing may, over time, result in left ventricular dysfunction. This week Dr Harry Mond explores the range of minimisation algorithms developed for its management, while reviewing the law of AV conduction.

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Clinical case studies

Pacemaker Mediated Tachycardia

Dr Harry Mond visits Pacemaker Mediated Tachycardia and explores the two types of programmable algorithms, 'prevention detection' and 'intervention' for its successful treatment.

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Clinical case studies

Single Chamber Ventricular Pacing

Not all ECG recordings are straightforward, as illustrated by this "bizarre" ECG. In this latest edition in our clinical case studies series, our Medical Director Dr Harry Mond explains how he assessed an ECG he was asked to look at, and how eliminated incorrect solutions...

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Clinical case studies

Rate Adaptive Pacing

Dr Harry Mond explores rate adaptive pacing where he highlights minute ventilation and closed loop stimulation (CLS) reminding us of the importance of pattern recognition in the prevention of repeating ECGs.

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Clinical case studies

Conduction System Pacing

Further to our pacing series, Dr Harry Mond analyses one of the most difficult cases he has seen in a bid to teach us about Conduction System Pacing and how 'His' bundle pacing can be recognised.

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Clinical case studies

Pacemaker-Ventricular Block

Dr Harry Mond compares the well defined and easily identifiable ECG appearances of pacemaker-ventricular block and pacemaker-atrial block and how it allows us to interpret even the most bizarre pacing ECGs.

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Clinical case studies

Biventricular Pacing

This week, Dr Harry Mond explores biventricular pacing, often referred to as simultaneous depolarisation of the right and left ventricles and how it's an indication for permanent cardiac pacing.

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Clinical case studies

Where Am I Pacing From?

Where am I pacing from? Dr Harry Mond discusses the four identifying ECG features in determining the pacing site in the atrium or ventricle that are often misunderstood. A reminder that it's not always just the timing, but also the positioning!

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Clinical case studies

Dual Chamber Pacing

Further to our Cardiac Pacing series, Medical Director Dr Harry Mond revisits the three letter code to teach us about Dual Chamber Pacing.

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Clinical case studies

Fundamentals of Cardiac Pacing

In the first of a series on the electrocardiography of cardiac pacing, Assoc Prof Mond explores the fundamentals and everything you need to know about the stimulus artefact.

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Clinical case studies

The AV delay

This week we take a closer look at the AV delay by exploring the differences between the paced and sensed AV delay while focusing on the importance of the law of AV conduction.

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Clinical case studies

Single Chamber Atrial Pacing

Not all ECG recordings are straightforward, as illustrated by this "bizarre" ECG. In this latest edition in our clinical case studies series, our Medical Director Dr Harry Mond explains how he assessed an ECG he was asked to look at, and how eliminated incorrect solutions...

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Clinical case studies

Ventricular interpolation and all that jazz

This week Dr Harry Mond revisits the well-known and researched ventricular interpolation with a review of the footprints and exceptions to the rule in a bid to teach something new.

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Clinical case studies

rSr’ in V1

Disagreement over the use of the terms “incomplete” or “partial” right bundle branch block (RBBB) had us take a deeper look at what is established in literature as an rSr’ pattern in V1/V2 with a QRS of 100 -120 ms, and when to call normal,...

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Clinical case studies

ECG artefact. What does it mean?

Handed this ECG, we were asked if it was an example of a rate adaptive pacing, which uses changes in transthoracic impedance to increase the pacemaker rate in response to physiologic demand. Assoc Prof H Mond explains how to find the correct diagnosis.

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Clinical case studies

How would you interpret this ECG

This Holter tracings showed a number of 2.8 second nocturnal pauses. A bundle branch block is also present. So the question was asked: Is this high degree AV block and does the patient need a pacemaker?

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Clinical case studies

The ventricular ectopic compensatory pause

This week Dr Harry Mond reviews the ventricular ectopic compensatory pause with a focus on full and partial pauses while teaching us a lesson on timing.

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Clinical case studies

Notches and nipples in the T wave!

This is one that is sure to spark conversation as a topic we know little about. Assoc Prof Harry Mond suggests some may even disagree with his view, and invites you not to hesitate to make some noise!

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Clinical case studies

A kaleidoscope of colour

After recently discussing the two most common variations of reversed arm and leg leads, we now explore combinations of Right Arm-Right Leg Reversed, including the double twists, & all the tell-tale footprints.

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Clinical case studies

Can ECGs cause headaches?

Can ECGs cause headaches? Well this one might! Leading on from our last ECG topic, this week we further explore twisted leads but involving all limbs with “leg leads on arms” & “arm leads on legs” & the major defining footprints.

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Clinical case studies

Dextrocardia and reversed limb leads

Last week some of you suggested dextrocardia in response to our case of reversed arm leads. This week shows that with dextrocardia the chest leads are very different and how to avoid misdiagnosis

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Clinical case studies

Report ECGs with your eyes open!

This week, Assoc Prof Mond discusses abnormalities commonly missed by physicians when reporting on ECGs, with a focus on reversed arm leads and how to avoid serious misdiagnosis.

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Clinical case studies

What did I see this week?

Something rarely seen in Holter monitoring, the ventricular pentageminy with ventricular ectopics every 5th beat, and other curious rhythms!

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Clinical case studies

Boring bundle branch block

Last week we proved not all bundle branch blocks are boring. Now we delve even deeper into mistaken rhythms, common misdiagnosis and those rarely talked about, including the crochetage sign

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Clinical case studies

Bundle branch block

This week Assoc Prof Mond discusses the not so boring bundle branch block while exploring some puzzling occurrences including alternating bundle branch block and bidirectional rhythm. The clue is in the rhythm strip.

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Clinical case studies

Is this ventricular exit block?

Often asked to review cardiac pacing ECGs, this one was presented as intermittent failure of ventricular capture. Revisiting atrial pacing and the tell-tale clues, we’re able to make the correct diagnosis.

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Clinical case studies

Exotic ventricular ectopy part two

In the final part of this 2-part series, we explore even more exotic ectopy, including ventricular couplets, interpolation, unipolar bigemilets, trigemilets and more.

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Clinical case studies

Exotic ventricular ectopy part one

A look at exotic ventricular ectopy this week, with 8 different examples, their footprints and the veritable kaleidoscope of findings that may result.

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Clinical case studies

Unusual ventricular ectopy

A controversial one this week: AFib with ventricular bigeminy. Or is it? Exploring trigeminy, ventricular parasystole, pseudo-ventricular parasystole and other possibilities, this one is sure to divide opinion.

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Clinical case studies

Exotic atrial ectopy part two

In the final part of this 2-part series, Assoc Prof H Mond further explores the different forms of atrial ectopy including the atrial couplet, triplet, run & non-conducted types.

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Clinical case studies

Exotic atrial ectopy part one

In part one of a two part series, Assoc Prof H Mond explores exotic atrial ectopy in all its forms, including the anatomy and characteristics of 12 different examples.

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Clinical case studies

Twisted Leads for Twisted Minds

Assoc Prof Mond shares this case to delve into unusual and classical patterns of twisted leads in 12-lead ECG, including the double twist, and shares the tell-tale footprints of all.

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Clinical case studies

Unusual AV Wenckebach

Assoc Prof Harry Mond identifies a plethora of insights that come with studying Wenckebach sequences. This week, a definitely not boring look into atrioventricular (AV) and non-AV types, and how it’s all in the timing!

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Clinical case studies

Managed ventricular pacing

A ‘bizarre’ case of dual chamber pacing with an 80ms AV delay, called us for a second opinion! With examples of a) Atrial pacing at 50 bpm and prolonged AV delay b) Wenckebach AV block; & Ventricular paced beat after 2 secs, we deep dive...

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Clinical case studies

Is this artefact?

This week MD Assoc Prof H Mond examines the similarities between the characteristics of artefact vs non-atrioventricular Wenckebach blocks and the importance of recognising footprints for correct diagnosis.

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Clinical case studies

Rate dependent bundle branch block

Exploring another ventricular aberration this week, we look at rate dependent bundle branch block, its defining characteristics, a number of important differential diagnoses and how to avoid serious misdiagnosis.

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Clinical case studies

Sino-atrial Wenckebach

With a pause about twice the cycle length of the R to R intervals and no P, QRS or T waves, this case tackles one of the most difficult explanations in ECG interpretation and demands a revisit to the fundamentals or “footprints” of Wenckebach AV...

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Clinical case studies

The bizarre atrioventricular (AV) delay

In this first of his Fun With ECG series, our MD Assoc Prof Harry Mond looks at this bizarre atrioventricular (AV) delay. Look closely at the ECG. The AV delay timings don’t make sense. The AV delay for atrial sensing/ventricular pacing (As Vp) is always...

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Clinical case studies

Interpreting the Holter monitor rate histogram

In this rare case, we see two very unusual and critical factors that together lead to atrial oversensing and “apparent” violation of the lower rate limit; a very narrow zone of open atrial sensing and far-field R wave sensing. While the first time MD Assoc...

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Clinical case studies

Non-physiologic atrial pacing

First thoughts on this Holter tracing was artefact, but the native rhythm showed a regular pattern of irregularity! Taking a close look at overnight tracings when the rhythm would be slow and the “artefact” less likely, revealed what was really going on. In this case...

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Clinical case studies

Vagal hypertonia in 44-year male

The Holter monitor tracings of a 44-year old male caused a lot of excitement at CardioScan this week. With 12 bradycardia episodes overnight, it was initially considered Wenckebach AV block. While clinically, rather than visually, correct, it nevertheless, did not fulfil the footprints of Wenckebach...

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Clinical case studies

Mode switching: Fast and slow pacing

Seen for the first time, the pattern in this 24hr histogram gives instantly recognisable clues about what is happening, even without looking at the tracings. Normally, we see a diurnal pattern of rate changes during the day with lower rates at night, but rarely a...

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Clinical case studies

Is this rate adaptive pacing?

Handed this ECG, our Medical Director Assoc Prof Harry Mond was asked if it was an example of a rate adaptive pacing, which uses changes in transthoracic impedance to increase the pacemaker rate in response to physiologic demand. It was not a paced rhythm, however,...

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Clinical case studies

What’s in a name?

Sinus arrhythmia is unusual in a 63-yr-old but we were asked to amend a ‘normal’ result to reflect this diagnosis. With classical examples of the pattern in under 30s and showing how NOT to confuse it with atrial ectopy, Assoc Prod Harry Mond shows how...

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Clinical case studies

Nocturnal pauses and bundle branch block –...

Showing a number of 2.8 second nocturnal pauses and bundle branch block, this latest case begs the question: is this high degree AV block and does the patient need a pacemaker? Using 11 difference traces, Assoc Prof Harry Mond delves into the topic of Wenckebach...

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Clinical case studies

Confused with complete heart block

This ECG was reported as complete heart block, and at first glance it sure looks like it. But a closer examination revealed the ventricular response was irregular. In this latest case study Assoc Prof Harry Mond explains two P wave patterns that reveal the rhythm...

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Clinical case studies

Is this dual chamber pacing?

Reported as dual chamber pacing, this case study needed closer examination. With obvious atrial pacing, the question of ventricular pacing remained. Assoc Prof Harry Mond details the characteristics that reveal the correct diagnosis, and why this should not be confused with pacemaker malfunction.

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Clinical case studies

Not what it seems – Pseudo WPW

The presentation of pseudo Wolff-Parkinson-White Syndrome recently had an international customer return a report with a note pointing out that we had missed the diagnosis of intermittent pre-excitation - the Wolff-Parkinson-White Syndrome. But as Assoc Prof Harry Mond explains in this latest cardiac case study,...

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Clinical case studies

Is this ventricular tachycardia?

Atrial flutter or supraventricular tachycardia with block can often give the appearance of a bidirectional tachycardia, which can be caused by many other things. In this latest case study, our Medical Director Assoc Prof Harry Mond explains how to identify the characteristics of a tachycardia...

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Clinical case studies

It’s all in the timing

Overnight Wenckebach AV block is a common finding in young people and is usually found in the presence of sinus bradycardia/sinus slowing. In this latest edition in our clinical case studies series, we look at how to identify atypical Wenckebach AV block, and how it’s...

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Clinical case studies

A bizarre ECG

Not all ECG recordings are straightforward, as illustrated by this "bizarre" ECG. In this latest edition in our clinical case studies series, our Medical Director Dr Harry Mond explains how he assessed an ECG he was asked to look at, and how eliminated incorrect solutions...

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Clinical case studies

Is this Wenckebach?

Reversed Wenckebach occurs when there is sequential shortening of the PR interval, and can require a permanent pacemaker in certain instances. In this latest case study, we take a look at examples of reversed Wenckebach, and how to recognise the rare ECG finding.

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Clinical case studies

A bradycardia with pacing

All pacemaker companies have programmable algorithms to prevent ventricular pacing, but this can cause issues with Holter monitor test results. Our Medical Director, Dr Harry Mond, explains how pacemakers can confuse Holter monitor tracings, and how to correctly identify these algorithms on ECG patterns.

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Clinical case studies

The Wandering Atrial Pacemaker

As a rare find Wandering Atrial Pacemaker can be mistaken for marked sinus arrhythmia with unifocal atrial ectopics. Here, we look at the tell-tale characteristics that set them apart in another interesting case study by Medical Director Dr Harry Mond.

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Medical Papers

Underutilisation of Ambulatory ECG Monitoring After Stroke...

Atrial fibrillation (AF) is the leading cardiac cause of stroke. and its identification after a stroke or transient ischemic attack (TIA) is important for guiding secondary prevention management. However, paroxysmal AF frequently goes undetected and untreated if sufficient ECG monitoring is not performed. This study...

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Clinical case studies

Isorhythmic AV dissociation with idioventricular rhythm

A recent ECG was reported as sinus rhythm with intermittent bundle branch block – but this diagnosis was incorrect. CardioScan’s Medical Director Dr Harry Mond discusses the identifying factors in the ECG, and how he reached his diagnosis of an idioventricular rhythm with isorhythmic AV...

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Medical Papers

The Electrocardiographic Footprints of Atrial Ectopy

The term ectopic means ‘‘out of place” or ‘‘abnormal position” and, in relation to the heart, refers to an early heartbeat, whose origin is from a focus other than the sinus node. They increase in frequency with age and are generally innocent, unless there is...

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Medical Papers

The Electrocardiographic Footprints of Ventricular Ectopy

The term ectopic means “out of place” or “abnormal position” and, in relation to the heart, refers to an early or premature heartbeat, whose origin is from a focus other than the sinus node. Ventricular ectopics originate from an irritable focus within the ventricles and...

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Clinical case studies

The atrial compensatory pause

Compensatory pauses often follow atrial ectopics, but they can cause some confusion. In his latest case study, our Medical Director Dr Harry Mond clarifies the different types of compensatory pauses that can occur, as well as the typical characteristics of each compensatory pause as they...

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Medical Papers

One vs three channels – Ambulatory ECG...

As the technology surrounding Holter monitors continues to evolve, more options becomes available – including Holters with multi-channels, versus one channel patch Holter monitors. Our Medical Director, Dr Harry Mond, looks at the differences between one channel and multi-channel Holter monitors, and which is better...

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Medical Papers

Arrhythmic indications for ambulatory ECG monitoring

A cardiac arrhythmia is a rhythm disturbance of the heart which may require investigation using ambulatory electrocardiographic (ECG) monitoring. This may be a 24 hour or greater (Holter) or medium term (events and telemetry) recording which can be up to two weeks. Longer term recording...

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Medical Papers

Non-arrhythmic indications for ambulatory Holter ECG monitoring

There are a number of computerised packages that can measure Holter ECG recordings over a 24 or shorter period. They require high quality tracings and despite being available in a Holter monitor report, none have been found to be useful in routine medical management. Access...

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Clinical case studies

The ectopic with a broad QRS

A recent Holter monitor report caused spirited debate amongst the team about whether it showed an atrial ectopic conducted with aberration, or a ventricular ectopic. CardioScan's Medical Director, Assoc Prof Harry Mond, analyses the ECG and explains who came to the correct conclusion, as well...

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Clinical case studies

The Upside Down ECG

This week, Assoc Prof Harry Mond looks at the upside down ECG, and the puzzling trace that resulted. Each week, as our Director of Medicine he shares the real findings of unusual traces discovered at CardioScan, and what they reveal.

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Clinical case studies

Wenckebach without a pause!

The surprising trace that made even the most experienced cardiologist take pause. In this case of a 'rebel without a pause', Medical Director Dr Harry Mond examines Wenckeback sequences and the confusion with complete heart block that can sometimes occur.

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Medical Papers

The Footprints of Electrocardiographic Interference: Fact or...

Corporeal and particularly extra-corporeal interference is a very common problem encountered with both resting electrocardiograph (ECG) tracings and ambulatory recordings. When subtle, the artefact can mimic cardiac arrhythmias, leading to incorrect interpretation of the tracings. There is also a complicated interference group, usually due to...

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Medical Papers

2017 ISHNE-HRS expert consensus statement on ambulatory...

Ambulatory ECG (AECG) telemetry is typically used to evaluate symptoms such as syncope, dizziness, chest pain, palpitations, or shortness of breath, which may correlate with intermittent cardiac arrhythmias. Additionally, AECG is used to evaluate patient response to initiation, revision, or discontinuation of arrhythmic drug therapy...

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Medical Papers

The spectrum of Ambulatory ECG monitoring

The resting 12-lead electrocardiogram is a surface record of the electrical activity of the heart plotted against time with the actual standardised recording of the non-invasive test being an electrocardiograph (ECG). The test has served as the gold standard for arrhythmia recognition. The resting 12-lead...

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Clinical case studies

The Artefact and Atrial Fibrillation: An Unholy...

Working out whether an ECG is showing sinus rhythm with underlying artefact or atrial fibrillation is something that comes up regularly, and is the most common mistake made in ECG reporting. Dr Harry Mond explains how by digging a little deeper, differentiating between sinus rhythm...

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Clinical case studies

Rarely reported case of non-conducted focal atrial...

Cardiac technicians and those that report regularly on Holters may be familiar with cases like this, but the irregularities revealed in this patient are rarely reported on. Dr Harry Mond once again shares insights into another interesting trace, and what’s really going on.

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Medical Papers

Usefulness of Ambulatory 7-Day ECG Monitoring for...

Atrial fibrillation and flutter (AF) account for ~ 10% of all strokes and 50% of cardioembolic strokes. Stroke associated with AF carries a poor prognosis as more than 50% of the survivors remain with a severe deficit, and recurrence may be as high as 12%...

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Clinical case studies

Complete heart block with no AV dissociation

Some cardiologists are reluctant to identify something as complete heart block when there’s no AV dissociation, but that shouldn’t be the case. Dr Harry Mond explains why you shouldn’t be afraid to call something a complete heart block when it appears that way, what clues...

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