hi all,

Could somebody please explain the heart testing results for echo doppler.

iS IT UP TO AND INCLUDING 1.7 NORMAL, OR IS IT 1.7 AND OVER EQIUVOCAL AND THEN OVER 2.0 ADNOMAL.
WHAT IS A NORMAL AUSC GRADE AND WHAT IS IT PLEASE ???

anyone?

Taken from BASIC INFORMATION ON AORTIC STENOSIS IN BOXERS AND PROPOSED INTERIM MEASURES FOR ITS CONTROL.
(From Boxer '92, pp 10 - 16 (1993) )  DR. BRUCE M CATTANACH

4.1 STETHOSCOPIC EXAMINATION

4.1.1 Stethoscopic examination can be used as a method of screening for aortic stenosis. Specialist cardiologists are able to grade the sounds (heart murmurs) and this is now standardly done on a scale of I (minor) to VI (major). General veterinary practitioners may only detect louder murmurs.

4.1.2 As already indicated (3.3), murmurs attributable to stenosis of the pulmonic valve cannot be usually distinguished from those due to aortic stenosis; further testing is necessary to identify which valve is affected.

4.1.3 More importantly, purportedly innocent 'flow' murmurs can be confused with established stenosis murmurs. 'Flow' murmurs are commonly found in young puppies (-3 months) but usually disappear by 6 months of age. Their relationship, if any, to stenosis in adults is not known. However, 'flow' murmurs may also be heard in adult dogs when they are usually of mild degree (grade I). Typically, they are variable such that they may be heard on some occasions but not on others. While the significance of these adult 'flow' murmurs is not yet understood, 'flow' murmurs in Newfoundlands are associated with mild degree of fibrous tissue in the aorta, and it has been observed that 'flow' murmurs are rarely found in breeds that have low incidences of aortic stenosis.

4.1.4 The general conclusions are therefore that dogs which are free of heart murmurs (HM-free) are unlikely to have aortic (or pulmonic) stenosis; and those with minor murmurs which cannot be consistently heard ('flow' murmurs) are also unlikely to have any physical form of valvular stenosis.

4.1.5 Stethoscopic examination can also detect cardiomyopathy and myocarditis. Other systems, together with post-mortem examination findings can confirm diagnosis of these conditions.

4.3 DOPPLER ECHOCARDIOGRAPHY

4.3.1 This procedure is usually carried out concurrently with ultrasound scanning when equipment is available and is the most effective method of detecting and quantitating aortic (and pulmonic) stenosis. It does this by directly measuring the velocity of blood flow through the valves.

4.3.2 The accepted upper limit of normal blood velocity through the aortic valve is 1.5 metre/second; velocities ranging up to 2.0 metre/second are taken to correspond with 'flow' murmurs; but yet higher velocities are attributed to aortic stenosis. Maximal velocities are 6-7 metres/ second. With the highest velocities, life expectancy is usually short; with intermediate velocities, clinical signs may be seen in some dogs but not others. Doppler echocardiography serves as the key test for functional aortic stenosis.

K

Do the scores remain the same across all breeds or does the scoring vary as to what is accepted?

I think the principles apply across all breeds although various breed club health committies may have their own guideance (?). The GSP does not have an offical heart scheme and dogs are (usually) tested on the boxer protocol, flow murmurs & athletic heart will often give rise to 1/6 scores on ausculation in GSP's. To establish if the dog has a flow murmur /athletic heart or very mild AS, doppler is required and I would consider normal blood valocities to be in range detailed in quote work.

K   

Just reading this with great interest although it's very in depth for me.

I was just about to post if anybody could tell me quite what my vet means when he told me yesterday that my 2yr old Sheltie has a 'musical murmur' but please explain in very lay terms ;-)

Ok  will have a go ......  all heart murmurs are caused by a degree disruption to the "normal" flow of blood through the heart. Cardiologists (specialists in heart function) will listen to the heart grade the level of noise they hear on a scale of one to six :
Grade 1: A quiet murmur that can be heard only after careful auscultation over a localised area.
Grade 2: A quiet murmur that is heard immediately once the stethoscope is placed over its localised PMI.
Grade 3: A moderately loud murmur.
Grade 4: A loud murmur heard over a widespread area, with no thrill palpable.
Grade 5: A loud murmur with an associated precordial thrill.
Grade 6: A murmur sufficiently loud that it can be heard with the stethoscope raised just off the chest surface.

In general terms, loud murmurs are more likely to be significant than quiet murmurs. However, some murmurs are not associated with a large volume of abnormal flow but are very loud. This most often occurs when a structure is made to vibrate rapidly in the jet of abnormal blood flow. Often these murmurs are musical in nature.

From just listening to the heart an experienced cardiologist may be able to give the likely reason of the murmur based on the degree of noise and from the position on the chest wall where the noise can be heard (radiation) . The radiation of murmurs can be a helpful guide to their origin and is a rough guide to the severity of the condition. Functional murmurs are usually localised to a limited area. Murmurs associated with pathological processes can be localised or widespread. In general terms, the more widespread they are, the more significant the degree of valvular incompetence.

The only way of getting a definitive diagnosis for cause of the murmur is by doppler ultrasound where the heart is visualised and pressure of blood flowing through the various structures are measured.

K