Ambulatory electrocardiography in dogs

Abstract

Twenty-four hour ambulatory electrocardiographic recording using a Medilog tape recorder was attempted in 16 healthy pet dogs weighing between 18.4 and 34 kg, while they were living in familiar surroundings. Full 24-hour records were obtained from 10 of them and recordings of more than 10 hours duration from two others; and the findings in these recordings were similar. Maximum heart rates ranged between 110 and 300 beats/minute and the minimum rates ranged between 17 and 46 beats/minute. Intermittent ventricular premature complexes were recorded from these apparently healthy dogs and all but one dog demonstrated a sinus pause, longer than two seconds; the longest pause was 5.7 seconds. The pauses were associated with marked sinus arrhythmia and occurred in both brachycephalic and non-brachycephalic breeds.

Holter electrocardiography in dogs showing doxorubicin-induced dilated cardiomyopathy

“…However, a physiologic effect may be related since this arrhythmia was especially observed when the animals were asleep, when an elevation of the vagal tone can occur, leading to an increase in parasympathetic action to the heart (Tilley, 1992). These data are similar to the findings described by Hall et al (1991), who observed a frequent occurrence of sinus arrest ranging from 2.0 to 5.7 seconds in healthy dogs.…”

“…It is the most sensible non-invasive test that allows demonstrating transitory arrhythmias not detected by standard electrocardiography (Hall et al, 1991;Miller and Calvert, 1992;Goodwin, 1998;Mucha, 2001). …”

Holter Monitoring of Small Breed Dogs with Advanced Myxomatous Mitral Valve Disease with and without a History of Syncope

“…Arrhythmia variables included: minimum HR,mean HR,maximum HR,bradycardia (>4 successive sinus complexes at a HR <45 complexes per minute [bpm]),“dropped beats” (the term represents sinus arrhythmia and is defined as a NN interval >180% longer than the previous NN interval), sinus pauses (NN intervals >2.0 seconds),40 “premature normals” (the term represents sinus arrhythmia and is defined as a premature sinus complex [NN interval 50% shorter than the previous]),41 atrial premature complexes (APC) (a premature normal‐appearing QRS complex conducted by a P wave with abnormal morphology),42 supraventricular tachycardia (SVT) (>3 APCs at a HR >150 bpm, where the first complex is premature while the following should have NN intervals shorter than or equal to the previous NN interval),42, 43 sinus tachycardia (>3 sinus complexes at a HR >150 bpm, where the first complex was premature, while the following have NN intervals shorter than or equal to the previous NN interval),ventricular premature complex (VPC) (a premature wide and bizarre looking QRS complex, not associated with a P wave, but accompanying a large T wave of opposite polarity),42 ventricular escape complex (wide QRS complexes of different orientation occurring after a sinus pause and not associated with a P wave),42 fusion complex (normal P wave followed by an intermediate shaped QRS complex),44 second‐degree AV block (a P wave not conducting a QRS complex) 42 …”

“…“dropped beats” (the term represents sinus arrhythmia and is defined as a NN interval >180% longer than the previous NN interval), sinus pauses (NN intervals >2.0 seconds),40 …”

“…More than 5 VPCs at a HR >150 bpm was defined as VT 40, 44. APCs and VPCs were included in the statistical analyses as percentage of the total QRS complexes in 24 hours.…”