© 1974 American Heart Association, Inc.
Influences of Physical Training on the Heart of Dogs
1 Pauline and Adolph Weinberger Laboratory for Cardiopulmonary Research, Department of Internal Medicine, and the Department of Physiology, University of Texas Southwestern Medical School Dallas, Dallas, Texas 75235, Dr. Wyatt's current address is Cardiology Research, Cedars-Sinai Medical Research Institute, 4751 Fountain Avenue, Los Angeles, California 90029.
2 Pauline and Adolph Weinberger Laboratory for Cardiopulmonary Research, Department of Internal Medicine, and the Department of Physiology, University of Texas Southwestern Medical School Dallas, Dallas, Texas 75235
To investigate the effects of physical training on cardiac dimensions and function, eight dogs were exercised for 12 weeks by treadmill running 1 hour/ day, 5 days/week. Five dogs were confined in cages as controls for an 8-week period. Heart rates were monitored by telemetry during rest and exercise. Maximum QRS spatial magnitudes were calculated from records of McFee lead electrocardiograms. Left ventricular end-diastolic dimensions were determined radiographically by the bead and clip technique. No statistically significant changes occurred during the control period. Training produced statistically significant decreases in heart rate at rest (72 beats/min to 49 beats/min,P < 0.005) and at a standard work load of 6.1 mph on a level treadmill (205 beats/ min to 158 beats/min, P < 0.005) and statistically significant increases in work load (5.4 mph to 9.1 mph, P < 0.005) at a standard heart rate of 194 beats/min. Improvements were rapid during the first 4 weeks of training but gradual during the remaining 8 weeks. Training caused small but statistically significant increases in left ventricular end-diastolic wall thickness (8.7 mm to 9.3 mm, P < 0.0025), estimated left ventricular mass (83.6 g to 91.2 g, P < 0.01), and maximum (McFee) QRS spatial magnitude (4.0 mv to 4.8 mv, P < 0.05).
Key Words: standard work load • telemetry • exercise • left ventricular end-diastolic dimensions • bead and clip technique • maximum QRS spatial magnitude • heart rate in trained dogs
Accepted on August 27, 1974
This article has been cited by other articles:
 |
|
 |
|
  D. J. Duncker and R. J. Bache Regulation of Coronary Blood Flow During Exercise Physiol Rev, July 1, 2008; 88(3): 1009 - 1086. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. L. Stepien, K. W. Hinchcliff, P. D. Constable, and J. Olson Effect of endurance training on cardiac morphology in Alaskan sled dogs J Appl Physiol, October 1, 1998; 85(4): 1368 - 1375. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. J. Raskoff, S. Goldman, and K. Cohn The "Athletic Heart" Prevalence and Physiological Significance of Left Ventricular Enlargement in Distance Runners JAMA, July 12, 1976; 236(2): 158 - 162. [Abstract] [PDF]
|
|