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A 48 year-old male presents with 3 months of exertional dyspnoea.

He takes candesartan 8 mg daily and atenolol 50 mg daily for hypertension. ECG is shown above (Fig 1).

What is the most likely diagnosis?

This patient was originally diagnosed with sinus tachycardia at 100 bpm.

In fact this patient has a focal atrial tachycardia originating from the right upper pulmonary vein (ECG following ablation shown in Figure 3). Atrial flutter or atrial tachycardia with 2:1 conduction (the start of the ECG) are often misdiagnosed as sinus tachycardia. There are two important signs that should make one suspicious that this is not sinus rhythm. Firstly, the presence of a long apparent PR interval would be unusual for sinus tachycardia in a young patient whereby elevated sympathetic tone would ensure more slick conduction down the AV node. Secondly, ‘funny’ appearance of T-waves should make one suspicious that there are P waves buried within them. Looking at all leads, particularly V1 (Figure 2) and mapping them out is instructive.

Stem: A 29 year-old male presents with a 2 month history of frequent palpitations. His initial ECG is shown in Figure A. Bedside TTE shows mild-moderate global LV dysfunction. What are the differential diagnoses?

Answer: This is a regular wide complex tachycardia with left bundle branch block morphology (QRS width ~ 125ms). Differential diagnoses for regular wide complex tachycardia (QRS > 120 ms) in general include VT, SVT with aberrancy (any regular SVT – inc. atrial tachycardia, AVNRT, AVRT, atrial flutter, sinus tachycardia), and pre-excited tachycardia. The typical LBBB morphology suggests that the ventricle is being activated from the region of the right bundle. Hence, specific diagnoses to consider given the morphology include SVT with LBBB aberrancy (or fixed LBBB), bundle branch reentrant VT, idiopathic moderator band VT and atriofascicular antidromic tachycardia.

Stem (continued): Adenosine was given with no effect suggesting this was less likely to be a re-entrant SVT involving the AV node (ie. AVNRT, AVRT). He was subsequently given metoprolol and amiodarone – ECGs post are shown (Figure B and C). Does this help with the diagnosis?

Answer: These ECGs rule in VT – there is clear cut AV dissociation (sinus p waves regularly marching through). In Figure C, there is some irregularity suggesting an automatic (rather than re-entrant) mechanism. VT continued despite cardioversion and amiodarone. Thus the patient has incessant VT causing a tachycardia mediated cardiomyopathy. Catheter ablation was performed with the focal VT successfully ablated at the moderator band (adjacent to the exit of the right bundle – hence the typical LBBB morphology). LV function returned to normal after 2 months.

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Prof Kazuaki Negishi, 24 May 2022

Cardio-oncology is a rapidly emerging speciality globally. Cardio-oncology is dedicated to the prevention, identification, and treatment of cardiovascular complications in cancer patients as well as in long-term survivors. This is pertinent as cancer treatments are more complex than ever and cancer survivorship is rapidly increasing. Notably, Australia has one of the best cancer survivor rates globally.

An article published in the Internal Medicine Journal, led by Professor Kazuaki Negishi, senior author and of University of Sydney and Nepean Hospital assessed the status of cardio-oncology services in Australia through an online multi-disciplinary survey. There were 118 responses analysed with 70% reporting no dedicated cardio-oncology services existed at their institution, with insufficient funding being the main reason. Most respondents were oncologists (35%), followed by cardiologist (31%), haematologist (18%) and radiation oncologists (14%). The vast majority of respondents agreed or strongly agreed (86%) cardio-oncology is an important sub-speciality. Cancer specialists estimated 15% of their patients did not receive optimal cancer care due to cardiotoxicity or a history of cardiovascular disease. Additionally, 50% of cancer specialists were neutral to very unconfident in identifying cardiotoxicity. In regard to cardio-oncology education, nearly all respondent supported increased cardio-oncology session at national society meetings (88%) and the creation of national cardio-oncology guidelines (97%).

The results of this Australian first survey demonstrate “the overwhelming support for Australian cardio-oncology guidelines and an increased presence at national society meetings suggest there is a sizable appetite for the growth of cardio-oncology services in Australia.” Hopefully, these findings can be used for an evidence base for further funding of cardio-oncology services in Australia.

In conclusion, the authors suggest “a multi-disciplinary team funding model following existing templates in oncology may be a pathway forward. Our findings indicate that there is a strong support for further cardio-oncology education, guidelines and services nationally.”

You can find the full article here: https://onlinelibrary.wiley.com/doi/10.1111/imj.15682