Cardiovascular Drugs and Therapy 1992;6:475-479 © Kluwer Academic Publishers, Boston. Printed in U.S.A.
Intravenous Atenolol in Elderly Patients in the Early Phase of Acute Myocardial Infarction Z e n o n S. Kyriakides, 1 Dimitrios Kremastinos, 1 George Karavolias, ~ Costas Papadopoulos, 1 T h o m a s Apostolou, 1 J o h n Paraskevaidis, ~ a n d Pavlos Toutouzas 2 IDepartment of Cardiology, Athens General Hospital; 2Department of Cardiology, Athens University Medical School, Hippokration Hospital, Athens, Greece
Summary. The aim of this study was to assess the hemodynamic response to intravenous atenolol in elderly patients with acute myocardial infarction. We studied 14 elderly men, aged 64-85 years, and 14 younger men, aged 29-48 years, in the early postfibrinolytic phase of acute myocardial infarction. All the patients were in Killip class I. A triple-lumen Swan-Ganz thermodilution catheter was introduced into the right h e a r t chambers. The patients received 5 mg intravenous atenolol over 5 minutes. All hemodynamic parameters were measured before and 10 minutes after atenolol. The hemodynamic characteristics and the location and extent of acute myocardial infarction were the same in both groups before atenolol. The hemodynamic changes after atenolol administration were the same in the two groups, but the stroke volume and cardiac indexes decreased to a greater extent in the elderly (p = .01 and p = .0001, respectively). These results indicate t h a t intravenous atenolol in the early postfibrinoiytic phase of acute myocardial infarction is safe in Killip class I elderly patients, a l t h o u g h the cardiac and stroke volume indexes decrease, and the increase in the total systemic resistance is more in older than in younger patients.
Cardiovasc Drug Ther 1992;6:475-479 Key Words. beta-adrenergic antagonists, elderly patients, acute myocardial infarction, cardiac performance
performance was diminished after a pharmacologically induced increase in afterload [6]. One important factor that should be considered is the known increase in circulating norepinephrine concentrations with advancing age [7]. Increased norepinephrine levels in the elderly could undoubtedly compete with atenolol for occupany of beta receptors in the heart. During acute myocardial infarction, it has been shown that catecholamine stimulation is increased [8], so the heart is under sustained catecholamine stimulation. Multicenter trials suggest that intravenous administration of a beta blocker to selected patients early during the evolution of myocardial infarction is safe but has not been shown to be beneficial. Intravenous plus oral beta blocker is beneficial [9,10]. However, many physicians believe that beta blockers have major untoward effects in elderly patients and refrain from administering them. This study was designed to assess the hemodynamic response and the clinical tolerance of intravenous atenolol administration in the postfibrinolytic phase of acute myocardial infarction in elderly patients.
Patients and Methods Decreased beta-adrenoreceptor concentrations accompany old age [1] and beta receptors have been found less responsive to propranolol with increasing age [2]. Dillon et al. [3] found an age-related decrease in cyclic AMP production in response to isoproterenol, which suggested that beta adrenoreceptors in the elderly might be less responsive to agonists. However, the inotropic response to dobutamine and other synthetic inotropic drugs is reduced in normal elderly people and in patients with congestive heart failure
The study was carried out on patients with proved myocardial infarction with ST elevation who were within 12 hours of the onset of symptoms before the administration of atenolol, not already on beta blockers or verapamil, and had no clear contraindications to beta blockers (heart rate persistently
Intravenous Atenolol in Elderly Patients in the Early Phase of Acute Myocardial Infarction Z e n o n S. Kyriakides, 1 Dimitrios Kremastinos, 1 George Karavolias, ~ Costas Papadopoulos, 1 T h o m a s Apostolou, 1 J o h n Paraskevaidis, ~ a n d Pavlos Toutouzas 2 IDepartment of Cardiology, Athens General Hospital; 2Department of Cardiology, Athens University Medical School, Hippokration Hospital, Athens, Greece
Summary. The aim of this study was to assess the hemodynamic response to intravenous atenolol in elderly patients with acute myocardial infarction. We studied 14 elderly men, aged 64-85 years, and 14 younger men, aged 29-48 years, in the early postfibrinolytic phase of acute myocardial infarction. All the patients were in Killip class I. A triple-lumen Swan-Ganz thermodilution catheter was introduced into the right h e a r t chambers. The patients received 5 mg intravenous atenolol over 5 minutes. All hemodynamic parameters were measured before and 10 minutes after atenolol. The hemodynamic characteristics and the location and extent of acute myocardial infarction were the same in both groups before atenolol. The hemodynamic changes after atenolol administration were the same in the two groups, but the stroke volume and cardiac indexes decreased to a greater extent in the elderly (p = .01 and p = .0001, respectively). These results indicate t h a t intravenous atenolol in the early postfibrinoiytic phase of acute myocardial infarction is safe in Killip class I elderly patients, a l t h o u g h the cardiac and stroke volume indexes decrease, and the increase in the total systemic resistance is more in older than in younger patients.
Cardiovasc Drug Ther 1992;6:475-479 Key Words. beta-adrenergic antagonists, elderly patients, acute myocardial infarction, cardiac performance
performance was diminished after a pharmacologically induced increase in afterload [6]. One important factor that should be considered is the known increase in circulating norepinephrine concentrations with advancing age [7]. Increased norepinephrine levels in the elderly could undoubtedly compete with atenolol for occupany of beta receptors in the heart. During acute myocardial infarction, it has been shown that catecholamine stimulation is increased [8], so the heart is under sustained catecholamine stimulation. Multicenter trials suggest that intravenous administration of a beta blocker to selected patients early during the evolution of myocardial infarction is safe but has not been shown to be beneficial. Intravenous plus oral beta blocker is beneficial [9,10]. However, many physicians believe that beta blockers have major untoward effects in elderly patients and refrain from administering them. This study was designed to assess the hemodynamic response and the clinical tolerance of intravenous atenolol administration in the postfibrinolytic phase of acute myocardial infarction in elderly patients.
Patients and Methods Decreased beta-adrenoreceptor concentrations accompany old age [1] and beta receptors have been found less responsive to propranolol with increasing age [2]. Dillon et al. [3] found an age-related decrease in cyclic AMP production in response to isoproterenol, which suggested that beta adrenoreceptors in the elderly might be less responsive to agonists. However, the inotropic response to dobutamine and other synthetic inotropic drugs is reduced in normal elderly people and in patients with congestive heart failure
The study was carried out on patients with proved myocardial infarction with ST elevation who were within 12 hours of the onset of symptoms before the administration of atenolol, not already on beta blockers or verapamil, and had no clear contraindications to beta blockers (heart rate persistently
