06/08/2026
This 3-year-old Pomeranian presented with a persistently low resting heart rate. He also has an undescended testicle requiring surgery, prostatic enlargement, and an elevated ALKP liver enzyme, so his unexpectedly low heart rate was an important concern before anesthesia.
So, we performed atropine response test.
What is atropine response test❓
📝 https://shinzovet.com.my/2026/02/14/atropine-response-test/
Why did we perform the test while he was sitting⁉️
Because he really did not want to be held in lateral recumbency. 🥲
Placing 4–5 ECG clips on such a small, 3kg restless patient was also challenging. Therefore, we used , which requires only 2 clips.
💡For a complete diagnostic ECG assessment, this setup is not ideal. However, in this particular patient, it provided a practical way to monitor his heart rate and assess how it responded to atropine.
Before atropine, his heart rate was 69 bpm.
Following atropine administration, his heart rate increased dramatically to approximately 250 bpm.
This strong chronotropic response supports the possibility that his resting bradycardia is primarily vagally mediated (extracardiac) rather than being caused solely by an inability of the heart’s pacemaker to increase its rate.
That is encouraging news for his upcoming surgery. It suggests that atropine may be effective in increasing his heart rate if clinically significant bradycardia occurs during anesthesia.
🚨However, this does not mean that anesthesia is completely risk-free. His underlying conditions and baseline bradycardia still warrant careful anesthetic planning, continuous monitoring, and readiness to manage cardiovascular changes during surgery.
Sometimes, good clinical decision-making means adapting our diagnostic approach to the patient in front of us—balancing ideal methodology with what is practical, safe, and clinically meaningful.