Spectral analysis of heart rate variability in dogs with mild mitral regurgitation

Yoko Fujii Department of Surgery I, Azabu University, School of Veterinary Medicine, Fuchinobe, Sagamihara-shi, Kanagawa-ken, 229-8501, Japan.

Search for other papers by Yoko Fujii in
Current site
Google Scholar
PubMed
Close
 DVM, MS
and
Yoshito Wakao Department of Surgery I, Azabu University, School of Veterinary Medicine, Fuchinobe, Sagamihara-shi, Kanagawa-ken, 229-8501, Japan.

Search for other papers by Yoshito Wakao in
Current site
Google Scholar
PubMed
Close
 DVM, PhD

Click on author name to view affiliation information

Abstract

Objective—To assess autonomic function in dogs with mild mitral regurgitation (MR) that did not have clinical signs of the condition.

Animals—6 healthy adult Beagles.

Procedure—Mild MR was experimentally induced. A 24-hour ambulatory ECG was recorded before and after induction of MR. Heart rate variability was analyzed in frequency domains by use of the ambulatory ECG. Low-frequency (LF) and high-frequency (HF) power were calculated by integrating over their frequency intervals, and the ratio of LF to HF was also calculated. Measurements of frequency domains were analyzed for 4 time periods (midnight to 6 AM, 6 AM to noon, noon to 6 PM, and 6 PM to midnight).

Results—Dogs with experimentally induced MR were classified as International Small Animal Cardiac Health Council class Ia. The HF power of dogs with MR was significantly decreased between 6 AM and noon. The ratio of LF to HF in dogs with MR was significantly increased for the periods between midnight and 6 AM, 6 AM and noon, and noon and 6 PM.

Conclusions and Clinical Relevance—Compensatory response through autonomic modulation was observed in dogs with mild MR that did not have abnormalities, except for cardiac murmur, during clinical examination. This result suggests that treatment during the early stages of mild MR may be beneficial. Additional studies are necessary to determine whether such treatment will delay the onset of congestive heart failure and prolong survival in dogs affected with mild MR. (Am J Vet Res 2003; 64:145–148)

Abstract

Objective—To assess autonomic function in dogs with mild mitral regurgitation (MR) that did not have clinical signs of the condition.

Animals—6 healthy adult Beagles.

Procedure—Mild MR was experimentally induced. A 24-hour ambulatory ECG was recorded before and after induction of MR. Heart rate variability was analyzed in frequency domains by use of the ambulatory ECG. Low-frequency (LF) and high-frequency (HF) power were calculated by integrating over their frequency intervals, and the ratio of LF to HF was also calculated. Measurements of frequency domains were analyzed for 4 time periods (midnight to 6 AM, 6 AM to noon, noon to 6 PM, and 6 PM to midnight).

Results—Dogs with experimentally induced MR were classified as International Small Animal Cardiac Health Council class Ia. The HF power of dogs with MR was significantly decreased between 6 AM and noon. The ratio of LF to HF in dogs with MR was significantly increased for the periods between midnight and 6 AM, 6 AM and noon, and noon and 6 PM.

Conclusions and Clinical Relevance—Compensatory response through autonomic modulation was observed in dogs with mild MR that did not have abnormalities, except for cardiac murmur, during clinical examination. This result suggests that treatment during the early stages of mild MR may be beneficial. Additional studies are necessary to determine whether such treatment will delay the onset of congestive heart failure and prolong survival in dogs affected with mild MR. (Am J Vet Res 2003; 64:145–148)

All Time Past Year Past 30 Days
Abstract Views 41 0 0
Full Text Views 196 106 10
PDF Downloads 86 56 1
Advertisement