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 by using a series of ECG tracings, as well as explaining how he reached the correct conclusion when asked whether an ECG was showing a ventricular tachycardia.

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.

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 dissociation.

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 affected by timing.

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 into the relationship between atrial and ventricular 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 straight line, unless there is complete heart block (slow) or a regular continual rapid tachyarrhythmia (fast). This, however, is both fast and slow, so what is the diagnosis? We take a closer look to uncover the result.

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 and Non-conducted Atrial Ectopics, reminding us of the differences between termination and extension, and that atrial and ventricular ectopics terminate a Wenckebach sequence differently!

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 MD Assoc Prof Harry Mond looks at non-physiologic atrial pacing together with major objections to single lead rate adaptive atrial pacing and why this case is CANNOT be AAI pacing with a ventricular minimisation pacing algorithm.

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 to the symptoms being presented.