‘Supernormal’ left ventricular filling in athletic dogs
Early diastolic flow through the mitral valve, represented by the E wave on Doppler echocardiography, is driven by the pressure gradient between the full left atrium and the relaxing left ventricle. In most canine and feline patients, the commonest cause of accelerated transmitral flow is pathologically-increased left atrial pressure….due to either mitral insufficiency or compromised LV filling.
However, just occasionally, one comes across a young fit and healthy patient (usually for investigation of a murmur rather than any manifestation of cardiac failure) in which transmitral E wave velocity is markedly rapid.
Transmitral PW Doppler in a 1 y.o. Border Terrier investigated for apparent syncope. From a left apical view peak arly diastolic flow exceeds 1.3m/s. The upper limit of reference range for canine transmitral E wave is commonly reported at approximately 1.0m/s
I’ve not come across the term in veterinary cardiology but in the human field this is described as ‘supernormal’ filling and is attributed to vigorous diastolic recoil of the LV in fit individuals.
e.g. https://www.123sonography.com/book/338
and
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC101148/
The patient in question had an otherwise unremarkable echocardiogram with no evidence of left atrial dilation (i.e. no evidence of increased LA pressure).
