This is the conclusion to 81 year old female CC: Chest Pain.
Due to a significant language barrier, we were unable to obtain a useful medical history. Yet this case highlights the importance of a good scene assessment to gain additional information of clinical importance.
First, let's examine the patient's 12-Lead ECG.
We have a bradycardic, wide complex rhythm with no visible P-waves. It is also unremarkable for ischemia or infarction. Given the rate, we have a few possibilities:
- Junctional rhythm with RBBB
- Idioventricular rhythm
In the field, the distinction between these two possibilities is entirely academic. Our treatment modality relies instead on our patient's presentation.
As our patient is asymptomatic, of interest in this case is one of our patient's medications.
Digoxin is commonly prescribed for atrial fibrillation and atrial flutter. It works by increasing the refractory period of the AV node, effectivily slowing AV nodal conduction and the ventricular rate. It follows naturally that digitalis toxicity commonly includes bradyarrhythmias and AV nodal blocks.
A second look at the 12-Lead ECG shows fibrillatory waves in V1 and V2, consistent with underlying atrial fibrillation. Likely our patient is suffering from digitalis toxicity with atrial fibrillation, a 3rd degree AV block, and an idioventricular escape rhythm. Other high risk differentials include myocardial infarction and hyperkalemia.
The paramedics on this call began with a working diagnosis of digitalis toxicity, performing serial 12-Leads enroute to identify ischemic changes. They started an IV, applied combo-pads to the patient, and closely monitored the patient until they arrived at the receiving facility.
At the receiving facility, blood labs were drawn and the patient's digoxin levels returned at 3.0 ng/mL, which is above the normal therapuetic range of 0.8-2.0 ng/mL. The patient's troponin levels remained below 0.4 ng/mL.
The patient was diagnosed with acute digitalis toxicity and admitted for observation. The patient was scheduled for a pacemaker implantation and lost to follow-up by the EMS agency.