The follow guidelines are recommended for Cardiologists, the purpose of the heart testing schemes.
- Consistency in the grading of heart murmurs is important between cardiologists. The follow guidelines are recommended for the purpose of the heart testing schemes.
- Grade I/VI is focal and quiet, difficult to hear in anywhere but a near-silent environment
- Grade II/VI is less intense than the heart sounds
- Grade III/VI is of a similar intensity to the heart sounds
- Grade IV/VI is more intense than the adjacent heart sounds
- Grade V and VI/VI are associated with a palpable pre-cordial thrill
- Where the point of maximal intensity (PMI) of a murmur is found to be very localised, but with a lower grade of murmur also audible elsewhere, the grade of the localised murmur should be recorded.
- When murmurs vary markedly with respirations and/or sinus arrhythmia in dogs, the most frequently heard grade (modal) should be allocated, rather than the maximum (eg. often found in the first beat or a series). In cats with dynamic murmurs, the maximum intensity should be recorded.
- Where a decision between two grades is not easily made: to help to differentiate between the grades, the higher grade should be recorded where there is a marked radiation of the murmur and/or where the murmur is more than of brief duration.