– 12 year old FS Jack Russel terrier with grade 4/6 systolic heart murmur in need of anesthesia for dental procedure and mass removal; no clinical signs of heart disease; chest rads not yet performed wt 6.8kg
– there is evidence of volume overload (eccentric hypertrophy) and moderate LAE on echo
– 12 year old FS Jack Russel terrier with grade 4/6 systolic heart murmur in need of anesthesia for dental procedure and mass removal; no clinical signs of heart disease; chest rads not yet performed wt 6.8kg
– there is evidence of volume overload (eccentric hypertrophy) and moderate LAE on echo
– LVIDs is normal and fractional shortening only mildly elevated at 45-48%
– moderate MR with club-shaped prolapsing mitral valaves and trace TR (TR max vel 2.5m/s)
– Ao Max Vel and Pul Max Vel wnl
I find these B2 CVD cases tricky when assessing risk for anesthesia as there is a wide spectrum of changes that occur in the B2 stage of heart disease. I am usually pretty confident in calling stage B1’s safe to go ahead with anesthesia. What are your thoughts for risk in this case and would you start an ace-inhibitor at this stage?
Comments
Jacquie this will be a long
Jacquie this will be a long post because you hit the case presentation that has no consensus to begin with and then add anesthesia which is another layer.
First thing: any hypertension? The Lv contracts stiffly from a subjective standpoint and I see this with hypertension cases but its my own personal observation.
If hypertensive then its “legal” to use an ACEi on this case even if no consensus in the cardio world for its use… back door to an ACEi.
For me I would use one anyway on my own dog but for a clients dog I would give the options and say we could from one school of thought but don’t have to use an acei from another school of thought. Maybe proteinuria is present and you can justify an ACEi that way… a second back door:)
I personally would tx an ACEi for 7-10 days and see what happens. Nothing likely dramatic would occur but if I get a couple of more %FS points and a subjectively happier heart then I feel better about it.
I know Peter is very conservative on ACEi usage but I’m still of the thought that the older we get the more we need an ACEi and an aspirin:) But ACEi are cheaper in the states as well.
Torbutrol premed, propofol induction, isoflo maintenance, maintenance fluid support and frequent BP measurments and avoid excessive tachycardia or hypothermia during the procedure. get in get done get out and don’t give the patient time to give you problems.
That’s what I have always done but doesn’t mean its right but I would monitor with the echo during the procedure periodically to ensure the heart is not getting shocky and hypocontractile.
As usual EL is right on.
You
As usual EL is right on.
You can back door hypertension. If MI velocity is accurately measured and no signs of Aortic stenosis (which you said there was not)- then peripheral pressure can be determined. Use the modified Bernoulli equation. In any MI case you would expect and hope for Eccentric Hypertrophy with increased FS. Anything less would be of some concern. Remember that myocardial decompensation occurs late in the course of disease (in small dogs). The signs of CHF are more related to the vomume overload.
I recently attended a seminar given by Dr Christopher Stauthammar- cardiologist University of Minnesota. One of his lectures was titled Cardiac Disease and Anesthesia. I will share with you the section on Mitral Valve Disease.
“The predominate concern in patients with mitral valve disease is minimizing vasoconstriction. In small breeds contractility is generally well preserved, however marked deterioration of ventricular contractility is common in large breeds of dogs. Vasoconstriction increases the afterload to the left ventricle with a susequent increase in mitral regurgitation and potential development of pulmonary edema and arrhythmias. Vasodilation and increasing contractility will directly reduce mitral regurgitation. Low dose acepromazine may be used to decrease mitral regurgitation. Include opioids for reduction of inhalant drug concentrations with the choice of opioid determined by the level of expected pain. Etomidate, propofol or ketamine/diazepam are all suitable induction drugs. Isoflurane or sevoflurane are appropriate for maintenace, and vasodilatory effects of the inhalants will further reduce the mitral regugitation.”
” Most patients will require fluid support for maintenace of blood pressure. Ideally, a sodium restricted crystalloid fluid (0.45% NaCl/2.5% dextrose) should be used in the face of heart disease. The rate of fluid therapy however, is far more important than the fluid type. The standard anesthetic fluid rate of 10 ml/kg/hr would likely result in fluid overload in patients with moderate disease. A general rate of 3-5 ml/kg/hr for patients with mild to moderate disease and 2-3 ml/kg/hr for patients with severe disease is recommended. Left atrial size is useful in determining fluid rate. Fluid rate is of lesser concern for those patients with trictly right sided heart disease. Extreme caution should be exercised with colloid administration”
If you are interested in a copy of this seminar please e mail me at randyhermandvm@comcast.net.
I hope this helps confirm what EL has noted. I am sure Peter has his opinions (well respected) too.
I pasted your measurements
I pasted your measurements into my spreadsheet: all values in mm /95%
IVSd: 4.1 (6.6-8.1)
LVDd: 38.6 (22.7-24.7)
PWd: 7.1 (5.2-6.5)
IVSs: 11 (9.9-11.5)
LVDs: 21.3 (13.2-15)
PWs: 11.9 (8.7-10.3)
FS: 45% (30-46)
LA: 2.96 (14.3-16.7)
AO: 1.31 (14.3-16.3)
IVSd/LVIDd 0.11 (0.22-0.34)
LVIDd/ LVPWd 5.4 ( >3 < 5)
I see a substantial volume overload with a normal fractional shortening- which gives me some concern about myocardial decompensation.
The LA/AO June Boon method- should be less than 1.1- So I see substantial increased LA pressure. I am also not sure why the IVS is measuring so much smaller than the the VFW.
Randy I think I got an MR
Randy I think I got an MR flow around 5 m/s – may be slightly under estimated but indirectly indicates that this patient is not likely hypertensive but will recommend a BP check to be safe. The LAE looks less worse on 2-D. I will e-mail you to get the copy of the seminar you mentioned (thanks!)
So I guess the bottom line in this case that this patient is at increased risk under anesthesia but with careful technique is likely to do OK. I have personally anesthetized patients with worse parameters than this and they did great but I did have a good chat with owners prior to doing it.
This is not my own case though (mobile scan) so I am a bit more cautious with recommendations as I will not be in charge of the anesthesia myself.
Thanks Eric and Randy
Great stuff Randy
Great stuff Randy