What is the veterinary cardiac auscultation?
The veterinary cardiac auscultation is based on detection and analysis of heart sounds generated by the beating heart and the resultant flow of blood through it the sounds reflect the turbulence created when the heart valves snap shut.
Cardiac auscultation is an imprecise diagnosis technic which is affected by many external factors: auscultation conditions aren´t always ideals, constants or regulars. Thorax, skin and hair characteristics are factors very variable too.
Other factors have influence too, like the equipment used for the auscultation (stethoscopes) that have significant differences between models and brands.
Finally, not everyone discern the same sounds, with the same ability our auditory perception isn´t constant. Our auditory acuity change as time passes and we stopped to sense sounds that we discern as normal before.
Is the professional’s auditory acuity changing throughout life?
“Throughout life is inevitable that auditory acuity change. The same veterinary won´t be able to heard with the same sensitivity when he´s studying in the university, when he´s working 10 years or when he´s having 25 of clinic experience”.
It is practically impossible be objective in the process and auscultation discoveries in a particular patient. Teaching is complicated too for this variability, individual differences and the fact that the record of real sounds is difficult with a standard stethoscope; and the usual methods to record the sounds modify the characteristics of the heart sounds.
In addition, human beings are “visuals” animals much more than auditors and, actually in most of the cases, we have an analytic and descriptive auditory ability smaller than visual.
Is possible to improve the cardiac auscultation capacity?
Training (and natural conditions of some people) can improve our limitations. It´s the same way that we can train our taste sense to identify a wine or train our sense of smell to distinguish between perfumes. It´s possible train our hearing to detect and identify usual or strange sounds from a patience heart.
How the auscultation sounds are transmitted?
Sounds are transmitted by means of thoracic cage´s liquids and solids and this generate changes in the transmitted sounds perception: pneumonia or pulmonary emphysema change the pulmonary tissue´s capacity. Pleural effusion isolates the thoracic cavity and blocks the sounds data capture from the outside (the same effect happen when there are a pericardial effusion but, in this case, respiratory sounds aren’t affected so much).
Obesity, a lot and thick hair, neoplasm, scars or haematomas in thoracic cavity modify the sound perception that we have from the patience.
Dr. Enrique Ynaranja. Dogs and cats´s clinic auscultation guide.