- Approximately 8-10 year old mn DSH obtained by rescue group 2 weeks ago
- Preanesthetic exam revealed a grade 3/6 cardiac murmur
- Routine castration performed with no complications
- Echo shows mild turbulence in the Ao and the following measurements: IVSd=6.8, LVPWd=7.0, LVIDd=14.3, IVSs=10.9, LVPWs=9.9, LVIDs=6.1, FS=57%, LA=9.7, LA;Ao=1.1, HR=186.
- Blood flow velocities across the atriventricular, aortic, and pulmonic valves are all normal (1-1.5m/s). There is no SAM. No MVI is seen, either.
- Approximately 8-10 year old mn DSH obtained by rescue group 2 weeks ago
- Preanesthetic exam revealed a grade 3/6 cardiac murmur
- Routine castration performed with no complications
- Echo shows mild turbulence in the Ao and the following measurements: IVSd=6.8, LVPWd=7.0, LVIDd=14.3, IVSs=10.9, LVPWs=9.9, LVIDs=6.1, FS=57%, LA=9.7, LA;Ao=1.1, HR=186.
- Blood flow velocities across the atriventricular, aortic, and pulmonic valves are all normal (1-1.5m/s). There is no SAM. No MVI is seen, either.
- My primary differentials for the thickened left ventricular septal and free walls at diastole include decreased preload, systemmic hypertension, and HCM. T4 and blood pressure measurements are pending.
- If T4 and BP are normal, would you start meds for early HCM? My temptation is to do no meds since they do not seem warranted. I also want to keep his care simple and not jeapordize his potential for future adoption.
- Recheck in 1 year or sooner?
Comments
To me the IVS and VFW are
To me the IVS and VFW are hypertrophied. If this cat is not hypertensive and T4 is normal I would be concerned about cardiomyopathy. I am surprised that we don’t see more turbulence on CFI. In the first video I get the impression that there is thickening of the IVS that extends into the ventricular outflow tract.
Right sided images are not seen here but don’t forget about dynamic right vetnricular outflow obstruction.
? if you should treat or not- controversial.
We will see what otheres have to say. Hopefully EL and Peter will give their opinion.
The images posted are from
The images posted are from right parasternal long axis views. Are you referring to left parasternal views? I have those, as well. What do you mean by dynamic right ventricular outflow obstruction? CF and PW Doppler on the pulmonic artery were normal.
Sorry- I meant the right side
Sorry- I meant the right side of the heart.
From June Boon Veterinary
From June Boon Veterinary Echocardiography second edition:
Dynamic Right Vetnricular Outflow Obstruction:
DRVO is occasionally seen in people and has been reported in cats. The cause of the obstruction is not well defined and may simply be secondary to excessive hypertrophy of the right ventricular wall or septum into the right ventricular outflow tract or cavity. Color flow Doppler documents the presence of turbulent flow within the right ventricular outflow tract and spectral Doppler displays a llate peaking flow velocity. This is a dynamic and variable obstruction to flow and is termed dynamic right ventricular outflow obstruction (DRVO). Frame by frame analysis can show septal and right ventricular free wall apposition at the point where high velocity flow originates. The gradients associated with this RV outflow obstruction are low with velocities ranging from 1.7 ro 4 m/sec in cats and man. This is sometimes the only detectable abnormality in some cats with murmurs, and clinical signs related to cardiac disease are not present. The absence of other cardiac disease is more common in older cats than in young cats with DRVO. Reported association in the cat include HCM, Chronic renal failure with and without hypertension, hyperthyroidism, anemia, neoplasia and inflammationary processes. Hyperdynamic function especially when associated with some of the listed conditions or with increased sympathetic stimulation are hypothesized as underlying causes of DRVO.
Note: references left out.
“Dynamic right ventricular outflow obstruction may be the cause of some murmurs in cats”
I am including an image from VIN that shows where you place the CFI and Pulse Wave or continuous Flow Doppler to measure DRVO. I suspect if you are measuring pulmonary outflow it would probably be normal and you would still have DRVO. I am not saying your cat has DRVO – but it should be a consideration.
Hi!
Basically, you’re
Hi!
Basically, you’re completely right. There is left ventricular concentric hypertrophy visible, particularly the basal septum is hyperechoic. I would of course consider the differentials that you mentioned. If no other cause can be found, primary cardiomyopathy is likely.
Re turbulence: I would recommend to change your color Doppler settings: There are lots of artifacts, the PRF setting is too high, and the Doppler appears slow. What you can do is decrease the PRF (Nyquist limit to 0.9- 1m/s), decrease the line density, increase the persisitence. Summarizing, I’m unsure if there is a real turbulence within the LVOT. Dynamic obstruction of the right ventricular outflow tract (DRVOTO), which is a benign finding in cats and not always associated with disease, should also be considered, as has already been mentioned. If you place your PW sample gate within the RVOT and you see a dagger shaped profile at a higher speed, DRVOTO is present.
Re therapy: There are no studies supporting the hypothesis that any treatment at this stage slows down the progression of the disease. I would probably not give any treatment but just start re-echo the patient in 5-6 months. If the left atrium increases in size (right 4-chamber-view >18 mm in systole) I would start a little Lasix and ACEI. If it increases to >21 mm, I would give Clopidogrel.
Best regards!
Peter
Peter,
Is Clopidogrel
Peter,
Is Clopidogrel available in the United States?
Sorry Peter- I did not know
Sorry Peter- I did not know that was the same as Plavix.
Thanks Peter and Randy. I
Thanks Peter and Randy. I will make those adjustments to my presets. And I will start looking for DRVO.
Ok disclaimer experienced
Ok disclaimer experienced based partially political opinion speaking here:) Its important to realize that LV hypertrophy does not mean clinical disease and as mentioned is more often in older cats caused by effector organ issues: psudohypertrophy from volume contraction from pancreatitis, renal disease, cancer, ADR and so forth and of course HT4 and hypertension. The heart gets sympathetically beat on it goes Arnold Schwartzi on you (sorry Peter I know you austrians have an issue with Arnold:) ) The key here is the la/ao is normal about 1.2 June Boon (eyeballing it on your video), HR normal, no dynamic or significant fixed obstruction… so in these cases its prudent politically to downplay the LV numbers and let the cat be a cat. Owners hear “pathology” and they want to throw meds or pile it into the “old cat disease” category and start looking for a new cat:( Hopefully not but human nature is what it is. Numbers are numbers so looking at the cat, HR, volumes, boig cat vs small cat.. if all normal I just put the probe down and say “yeh he’s a bit thick in the ventricle but not causing an issue”,,, run a T4 and bp and look for causes of volume contraction and pseudohypertrophy (I’ve backed into a ton of abdominal disease this way over the years fyi after getting called in to do an echo on a new murmur from volume shift) and then just forget you looked at the heart and maybe look again in 6 months…
As a mobile sonographer over the years I believe to have solidified my relationships with tons of clients more on objectively downplaying mildly excessive numbers based on small sample groups and without breed specifics objectively as well as getting that key diagnosis. Both the downlplay as well as the rock star dx are equally improtant because we scan boring case more times than something interesting and still have to show our worth as practitioners/specialists t the client or the pet owner in all cases. Sorry for the tangent but the numbers thing stimulated a thought process:)
Thanks Eric. Fortunately,
Thanks Eric. Fortunately, this is a rescue group that will do anything and everything for their cats. I want to find balance between being truthful about what I see but not overcalling it so that they feel compelled to keep him and not adopt him out. This has been a great discussion for me because I need to read more about DRVO. I don’t recall learning about this before, and if I did, I forgot about it. For others who are reading this thread, I just found a nice free article online from JVIM by Rishniw and Thomas describing DRVO obstruction in cats. I will try to attache the link: http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2002.tb02385.x/abstract