Many thanks to Dr Katrina Starmer for sharing this interesting case.
AF (initials changed for privacy), drove himself to a Far North Queensland Emergency Department with a 3 hour history of chest discomfort, palpitations and diaphoresis that started suddenly while lifting heavy objects in the hot sun. He had no past medical history but had one previous episode of palpitations 4 months ago which was not investigated. He was on no medications and denied alcohol, smoking or recreational drug use.
On arrival in ED he was noted to be markedly distressed, clutching his chest, with diaphoresis and nausea. He had a heart rate of approximately 260bpm but was normotensive at 120 systolic. He was afebrile, had a normal BSL and was saturating >95% on room air.
His first ECG showed the following rhythm:
- Describe the rhythm and give a provisional diagnosis
- What would your management of this patient be?
- Broad complex, irregular tachycardia at approximately 260bpm with slurred upstroke (delta wave) noted in V3 and V4, possible AF with accessory pathway.
- It was decided that due to the patient’s distress (despite being haemodynamically stable) as well as the possibility of Wolf Parkinson White eccentric conduction, that DC cardioversion would be the safest approach. AV nodal blockers such as Adenosine, b-blockers and calcium channel blockers were avoided due to the risk of unregulated conduction through the accessory pathway, resulting in ventricular fibrillation.
The patient was consented for procedural sedation and synchronised DC cardioversion. He was cannulated, pre oxygenated, given 100mg of IV propofol and had defibrillation pads placed in the AP position. Two shocks were delivered – the first at 200j was not successful at cardioverting his tachycardia. A second shock at 360j reverted the rhythm to sinus.
His second ECG shows the moment of DC cardioversion and another one 30 minutes after:
Describe his resultant ECG?
Sinus rhythm with short PR and slurred upstroke (delta wave) in V3/V4 suggestive of underlying WPW.
Diagnosis: AF with WPW.
The patient was admitted to coronary care and had an angiogram which showed a small non-culprit lesion to the LAD. This did not require stenting. He was transferred to an electrophysiology referral centre where he underwent electrophysiology studies for consideration of ablation of his accessory pathway.
Take home points:
1. AF with an accessory pathway is rare but it’s out there.. consider it as a differential in the presentation of irregular broad complex tachycardia
2. For broad complex tachycardia, if the patient is unstable or if there is any doubt.. give synchronised DC cardioversion.