Page 20 - Rapid Review of ECG Interpretation in Small Animal Practice, 2nd Edition

Principles of Electrocardiography

• The left precordial leads should be equidistant electrode (microphone end of smartphone)
along IC6 with V4 at the costochondral
placed craniodorsally, while the positive
VetBooks.ir junction, and V2 just to the left of the sternum electrode (listening end of smartphone is
L
(Fig. 1.6).
placed caudoventrally and the phone is angled
• While the use of alcohol or coupling gel is at approximately a 45° angle (Fig. 1.6). This
needed, if excessive amounts are utilized, if the position simulates lead III. Gentle pressure is
alcohol from one lead comes in contact with applied to insure the electrodes achieve optimal
another lead, it creates a “lead smear” whereby contact with the skin contact. The device
the QRS morphology from all the leads will position can be readjusted in order to acquire
look the same. the largest amplitude ECG.

Acquisition of a smartphone-based ECG: Besides the standard 6- or 12-lead ECG, there are
several other uses of ECG recording technology that
• Smartphone-based devices that record the rely on only a few leads. Continuous monitoring
ECG from veterinary patients are available under anesthesia or in the Intensive Care Unit
(Veterinary AliveECG™) from Apple and (ICU) using an integrated physiorecording system
Android app stores. A specially designed for blood pressure, oxygen saturation, and so on,
phone cover or small electrode-containing typically record only one lead. The ambulatory or
strip of plastic is placed on the animal’s chest. Holter ECG is an important technology for long-
The electrodes relay the surface potential to term monitoring of patients allowing detection and
the smartphone, which then displays an ECG quantification of intermittent arrhythmias. Holters
tracing on the phone’s screen. record a two or three lead ECG digitally for up to 7
• The phone or electrode strip is positioned over days. The data can then be stored and analyzed on-
the point of maximal intensity of the cardiac line with personal computer-based programs.
beat on the left thorax with the negative

7