Systolic functional response of normal older and younger adult left ventricles to beta-blockade during exercise.
There is controversy over the effects of beta-blockade on the left ventricular systolic response of the heart of the elderly to stress. In this study we compared the effects of acute beta-blockade in normal older and younger adult left ventricles during exercise. The study population consisted of 17 healthy elderly people, 67 +/- 3 years old, while 18 young normal subjects, 31 +/- 4 years old, served as controls. A symptom-limited exercise treadmill test was performed before and 15 minutes after intravenous administration of 0.12 mg propranolol/kg. M-mode echocardiographic studies were performed before and immediately after each test. Intravenous propranolol at rest decreased heart rate by 14 +/- 7 beats/min in the elderly and by 7.5 +/- 8 beats/min in the young (p = 0.02), decreased the double product by 2500 +/- 1200 mmHg/min and 1830 +/- 970 mmHg/min (p = 0.05), respectively; changed the left ventricular end-systolic dimension by +0.21 +/- 0.36 cm and +0.03 +/- 0.24 cm (p = 0.09), respectively; and changed the end-diastolic dimension by +0.22 +/- 0.46 cm in the elderly and by -0.02 +/- 0.32 cm in the young (p = 0.08). The change in fractional shortening was -1.22 +/- 4.17% in the elderly and -0.78 +/- 4.05% in the young (p > 0.05), and the decrease in the systolic blood pressure/end-systolic dimension ratio was 5.9 +/- 7 mmHg/cm and 4.3 +/- 3.8 mmHg/cm, respectively (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Kyriakides
Z S
ZS
Onassis Cardiac Surgery Center, Athens, Greece.
Papaioannou
G
G
Paraskevaidis
I A
IA
Kolettis
T M
TM
Kremastinos
D T
DT
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D004452:Echocardiography / Q000187:drug effects; D004562:Electrocardiography / Q000187:drug effects; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects*
D011433:Propranolol