You may want to check a recent discussion on VIN (From the Trenches) about running "ECGs regularly" on healthy patients. It's not done in most instances and is not advised by veterinary cardiologists. You know why? Because most arrhythmias can be detected on a thorough physical exam. During auscultation of the heart, you detect an abnormal rhythm. You detect pulse deficits. THEN you run an ECG. Every vet should be conducting a thorough physical exam on their patients prior to anaesthesia.
Since you often cannot detect heart disease on physical exam (and ECG is not going to be of use for that in most cases) - you better do good anaesthesia monitoring that includes blood pressure. If you support the blood pressure during anaesthesia (using increased IV fluid rates with or without colloids and/or dopamine), it is less likely that the heart will go into failure afterwards. Those vets you saw that had cases of CHF after a dental - did they monitor and support blood pressure during the procedure?
As for CHF after anaesthesia, it's not surprising. There are many animals that have occult cardiomyopathy (cats) or that are not showing outward signs of heart disease. Most animals with cardiomyopathies actually do NOT have arrhythmias, so an ECG will be of no use. Many animals with heart disease do not even have a murmur. IMO, ECGs are only warranted in those animals presenting for syncope episodes (or possible syncope), or those with detectable arrhythmias (or bradycardia/certain tachycardias) on auscultation/physical exam.
But you know what, this is a veterinary discussion. Something that belongs on the types of boards that VIN has. Not a "pre-vet" forum!
You are right this does belong on another forum for in-depth discussion for professionals. I am still only a tech, but I work for a veterinary cardiologist. On the same note you are only a doctor and not a cardiologist--so our knowledge of the subject is probably on somewhat equal footing.
That being said I am not going to further debate the merits/necessities of electrocardiograms. What I will do is point out a few last things. I agree with you that not every healthy animal should have an ECG performed for the hell of it. But doing one prior to anesthesia is not just for ****s and giggles.
You even bring that point to the surface in your post, but ignore the ramifications.
here are many animals that have occult cardiomyopathy (cats) or that are not showing outward signs of heart disease
If you are not picking up any of your standard murmur/arrhythmia/pulse deficits/gallop sounds that may cause you reason to run an electrocardiogram, what are you going to do? Wait until it develops clinical signs to work it up? Refer out to a specialist for an Echocardiogram? Perform Chest rads (on 'healthy animals' - I also would like to see these as standard prior to anesthesia on older animals)?
No, your ECG is most likely going to pick up an abnormality. J
ust today I was looking at a case with a cat who had a seemingly innocuous ECG results. 15 year old (again in for an elective dental), no chest rads done, no catheter placed ended up crashing on the table and unable to recover. Initial electrocardiogram results revealed a heart rate of 250, sinus tachycardia. The doctor judged the elevated heart rate to be from stress and went ahead with the dental. Now was this a judgment call that went bad, was it an occult case, was there another cause? I know the doctor and have my personal (biased) opinion of what happened and will just say quality of care is determined by how convenient it is for this doctor to get done what they "have to do" instead of postponing their schedule.
For the record those patients who developed CHF after anesthesia, yes they were being monitored for blood pressure and were on fluids. BP dropped, fluid rate increased, and contributed to the compensation of the heart disease and the wonderful thing that is CHF.
For about $3000-$5000 (depending on model) you can buy a patient monitor to use in surgery that will do ECG/Capnography/Pulse Ox/ETC02/BP/Temp and it will print out stats and ECGs for you. That's a price for a brand new model as well, you can get units that are plenty cheaper if you want to buy used. I realize that capital equipment expenditures aren't exactly easy to do all the time and that you can't always spring for the latest and greatest. But in the end a vets business usually comes from word of mouth, and you aren't going to win over any customers if your patients keep dying off during common procedures.
In the end, the simple monitoring of a patient while they are already under anesthesia is like going skydiving before making sure you actually have a parachute attached to you.
-j
p.s. I don't know what crazy world (or crazy monitor you are using)you live on where the heart is still producing anything that looks remotely close to a normal QRS complex in a dead/dying animal.