Normal ECG Parameters

Parameter	Canine	Feline
Heart Rate (beats per minute)	Adults: 70-160 Toy Breeds: up to 180 Puppies: up to 220	160-240
Rhythm	Normal Sinus Rhythm Sinus Arrhythmia Wandering Atrial Pacemaker	Normal Sinus Rhythm Sinus Arrhythmia
Interval (seconds)
P	<0.04	<0.04
PR	0.06 to 0.13	0.05 to 0.09
QRS	<20kg: <0.05 >20 kg: <0.06 Giant breeds: <0.065	<0.04
QT	0.15 to 0.25	0.12 to 0.18
Amplitude (mV) in Lead II
P	<0.4	<0.2
R	<20kg: <2.5 >20kg: <3.0	<0.9
MEA	+40° to +100°	-5° to +160°

Electrocardiology