Doppler echocardiography is an imaging technique that allows a dynamic examination of the heart, in real time. This examination is useful to investigate the anatomic structures of the heart but also to assess its function. The Doppler modes help to study the blood flow (direction, speed) and to detect possible abnormal refluxes (valvular insufficiencies, interventricular communication, for example).
When is a Doppler echocardiography indicated?
An echocardiography is recommended when a cardiac arrhythmia and/or a murmur are auscultated, or whenever a cardiac disorder is suspected. It can be recommended to complete a pre-purchase examination.
How is an echocardiography Doppler exam performed?
The echography is a totally non-invasive examination, which can be performed in the box, to the nervous horse. A little zone behind the forelimb is humidified and an aqueous gel is applied to facilitate the transmission of ultrasounds.
ELECTROCARDIOGRAM OR ECG
The ECG or electrocardiogram is a recording of the electric activity of the heart muscle. It is useful to assess cardiac rhythm and heart rate. The horse's ECG can be recorded either at rest or during an effort. They can also be used to record cardiac activity over 24 hours (Holter).
What are the indications of an ECG?
An ECG is recommended in the following circumstances:
• Detection of a cardiac arrhythmia at rest,
• Fainting or collapse,
• Underlying disease that might predispose to arrhythmia (ex: aortic insufficiency, metabolic disorders…).
In case of unexplained poor performances, the ECG can underline possible arrhythmias that are undetectable when the horse is at rest.
How is an ECG performed?
Self-adhesive removable electrodes are placed on the thorax and /or the neck. They are connected to the recording unit by cables, usually placed under the saddle or harness. The ECG tracings are systematically recorded. The signals can also displayed live through telemetric transmission.