Cardiovascular adaptations to exercise training after uncomplicated acute myocardial infarction.
OBJECTIVE
This study examined the cardiovascular adaptations of an exercise training program and evaluated the role of peripheral vasodilator capacity in contributing to these adaptations after myocardial infarction.


METHODS
A total of 44 consecutive patients with uncomplicated myocardial infarction underwent 3 wks of exercise training. Controls (n = 12) with comparable myocardial infarction were selected from our database and were restricted to a program with minimal activity. All patients performed cardiopulmonary exercise testing with hemodynamic measurements. Forearm and calf reactive hyperemic flow were measured by venous occlusive plethysmography as indices of peripheral vasodilator capacity.


RESULTS
Despite no change in arteriovenous oxygen difference at peak exercise after training, training resulted in significant increases in oxygen consumption, cardiac output, and stroke volume and a significant decrease in systemic vascular resistance at peak exercise (overall, P < 0.05). Calf reactive hyperemic flow increased significantly after training (P < 0.001), but forearm reactive hyperemic flow did not. Furthermore, increase in calf reactive hyperemic flow after training had a positive correlation with increases in peak cardiac output, stroke volume, and oxygen consumption after training and an inverse correlation with peak systemic vascular resistance.


CONCLUSIONS
Exercise training improved exercise tolerance by improving hemodynamic responses to exercise after myocardial infarction. This improved exercise performance was linked to a training-induced increase in calf vasodilator capacity.
Motohiro
Masayuki
M
Second Department of Internal Medicine, Kansai Medical University, Moriguchi City, Osaka, Japan.
Yuasa
Fumio
F
Hattori
Toshihiko
T
Sumimoto
Tsutomu
T
Takeuchi
Masaharu
M
Kaida
Mutsuhito
M
Jikuhara
Toshimitsu
T
Hikosaka
Makoto
M
Sugiura
Tetsuro
T
Iwasaka
Toshiji
T
D000222:Adaptation, Physiological / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology; D005080:Exercise Test; D005081:Exercise Therapy; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005542:Forearm / Q000098:blood supply; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000534:rehabilitation*; D010101:Oxygen Consumption / Q000502:physiology; D010991:Plethysmography; D012039:Regional Blood Flow; D014655:Vascular Resistance / Q000502:physiology