HEMODYNAMIC RESPONSE TO EXERCISE AFTER BETA-ADRENERGIC AND PARASYMPATHETIC BLOCKADE

1967 ◽  
Vol 45 (5) ◽  
pp. 813-819 ◽  
Author(s):  
Gordon R. Cumming ◽  
W. Carr
Keyword(s):  
Heart Rate ◽  
Cardiac Index ◽  
Left Ventricular ◽  
Cardiac Response ◽  
Exercise Heart Rate ◽  
Stroke Index ◽  
Beta Adrenergic ◽  
The Mean ◽  
Response To Exercise ◽  
Control Exercise

Cardiac responses to supine bicycle exercise were studied in six normal subjects after the intravenous administration of 5 mg of propranolol and again after the additive effect of 0.03 mg/kg of atropine. Mean resting heart rate was decreased 15 beats/min by propranolol and then increased by 38 beats/min after atropine. Mean exercise heart rate was 157 for control exercise, 119 after propranolol and 143 after propranolol + atropine. The resting cardiac index was reduced 21% by propranolol and restored to control values after atropine. The mean control exercise cardiac index was 7.2 l/min per m2; this was reduced to 5.8 after propranolol and increased to 6.2 after atropine. The mean stroke index was not altered by control exercise, increased 3 ml/beat per m2 with exercise after propranolol and increased 6 ml/beat per m2 with exercise after propranolol + atropine. Resting pulmonary artery, aortic and left-ventricular end-diastolic pressures were not altered by propranolol or by propranolol + atropine. The mean control exercise left-ventricular end-diastolic pressure was 9 mm Hg, increased to 19 mm Hg after propranolol and fell to 12 mm Hg after propranolol + atropine. The mean exercise aortic systolic pressure was 10 mm Hg below the value for control exercise after propranolol and 8 mm Hg below control after propranolol + atropine. Atropine lessens the inhibition of the cardiac response to exercise with beta adrenergic inhibition, possibly by increasing the heart rate.

Aortic blood flow in dogs during treadmill exercise

1959 ◽  
Vol 14 (5) ◽  
pp. 809-812 ◽  
Author(s):  
Dean L. Franklin ◽  
Richard M. Ellis ◽  
R. F. Rushmer
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Treadmill Exercise ◽  
Essential Feature ◽  
Left Ventricular ◽  
Cardiac Response ◽  
Aortic Blood Flow ◽  
Direct Measurements ◽  
Flow Through ◽  
Response To Exercise

Instantaneous blood flow through the thoracic aorta was monitored continuously during spontaneous activity in intact dogs by means of a new, pulsed, ultrasonic flowmeter. Integrated flow per stroke, accumulated flow per unit time and heart rate were simultaneously derived by means of electronic computers. During treadmill exercise at 3 mph on a 5% grade, the heart rate increased by two- or threefold, but the aortic flow per stroke was only slightly increased. This observation was confirmed by direct measurements, of left ventricular diameter. An increase in stroke volume is not an essential feature of the cardiac response to exercise in these experiments. Submitted on December 15, 1958

Hemodynamic response to graded exercise after chronic beta-adrenergic blockade

1977 ◽  
Vol 42 (2) ◽  
pp. 133-138 ◽  
Author(s):  
T. Reybrouck ◽  
A. Amery ◽  
L. Billiet
Keyword(s):  
Cardiac Index ◽  
Maximal Exercise ◽  
Hemodynamic Response ◽  
Exercise Heart Rate ◽  
Adrenergic Blockade ◽  
Stroke Index ◽  
Working Capacity ◽  
Beta Adrenergic ◽  
Artery Pressure ◽  
Graded Exercise

The effect of sustained beta-adrenergic blockade (BB) on the hemodynamic response to graded exercise has been studied in 31 patients with high blood pressure. Hemodynamic investigations were conducted during a control period and were repeated after 1 mo of BB. Similar readjustments were observed at rest and during submaximal and maximal exercise. No significant change occurred in maximal physical working capacity during beta blockade. This resulted from hemodynamic readjustments. Maximal exercise heart rate was reduced by 34%, and this was compensated for by a 31% enhancement in stroke index. Consequently cardiac index decreased by only 14%. In the Fick equation the decrease in cardiac index was further compensated by an increase of the total arteriovenous O2 difference of 8%, thereby maintaining O2 delivery to the tissues. At maximal exercise mean brachial artery pressure dropped 14.5%, while mean pulmonary artery pressure increased by 20%. It is concluded that the compensatory action of the stroke volume, resulting from the interaction of an increased preload and a decreased impedance, played a major role in the hemodynamic readjustments following chronic BB to maintain maximal working capacity.

Cardiovascular Functions Under Chloralose-Urethane and 21-Hydroxypregnane-3,20 Dione Sodium Succinate (Viadril)

1957 ◽  
Vol 190 (2) ◽  
pp. 317-319 ◽  
Author(s):  
Esther M. Greisheimer ◽  
Dorothy W. Ellis ◽  
George H. Stewart ◽  
Lydia Makarenko ◽  
M. J. Oppenheimer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Index ◽  
Sodium Succinate ◽  
Peripheral Resistance ◽  
Mean Blood Pressure ◽  
Stroke Index ◽  
Mean Values ◽  
The Mean ◽  
Cardiovascular Functions

Fifty-five determinations of cardiovascular functions were made on eight dogs under chloralose-urethane anesthesia and forty-one on six dogs under 21-hydroxypregnane-3,20 dione sodium succinate (Viadril). No preanesthetic medication was used. Cardiac output was determined by the dye dilution technique, using the cuvette oximeter. Blood pressure was determined by strain gauge. The mean values found under chloralose-urethane were: cardiac index 4.08, mean blood pressure 146 mm Hg, peripheral resistance 5709 dynes/sec/cm–5, heart rate 149 beats/min. and stroke index 27 cc. The mean values found under 21-hydroxypregnane-3, 20 dione sodium succinate were: cardiac index 5.15, mean blood pressure 104 mm Hg, peripheral resistance 3997 dynes/sec/cm–5, heart rate 172 beats/min. and stroke index 29 cc. When successive determinations were made within a short period of time, the cardiac index and stroke index increased, peripheral resistance decreased and blood pressure and heart rate remained fairly steady.

Determinants of duration of left ventricular ejection in normal young men

1964 ◽  
Vol 19 (2) ◽  
pp. 279-283 ◽  
Author(s):  
William B. Jones ◽  
Glenn L. Foster
Keyword(s):  
Heart Rate ◽  
Factor Analysis ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Ventricular Ejection ◽  
Left Ventricular Ejection ◽  
Exercise Heart Rate ◽  
Stroke Index ◽  
Ejection Time ◽  
Ventricular Ejection Time

The factors governing the duration of ejection were studied by statistical techniques at rest and during exercise in man. Data consist of 207 points in 20 subjects. Linear stepwise regression analysis results in the following formula for the prediction of the duration of ejection from the heart rate, stroke index, and the aortic diastolic pressure: duration of ejection = .36646 - .00108 (rate) - .00036 (diastolic pressure) + .00076 (stroke index). The correlation coefficient is 0.90 on comparison with the measured duration of ejection. The error of estimate is .0155 sec. The validity of the three variables was confirmed by factor analysis. Heart rate was found to be the major determinant of the duration of ejection. Stroke index and pressure have a relatively minor but statistically significant effect. ventricular ejection time prediction and calculation; factor analysis of ventricular ejection; cardiac output during exercise; heart rate, stroke index, and ventricular ejection; aortic diastolic pressure and ventricular ejection Submitted on July 18, 1963

Vasodilator Therapy in Children: Acute and Chronic Effects in Children with Left Ventricular Dysfunction or Mitral Regurgitation

PEDIATRICS ◽  
1984 ◽  
Vol 73 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Robert H. Beekman ◽  
Albert P. Rocchini ◽  
Macdonald Dick ◽  
Dennis C. Crowley ◽  
Amnon Rosenthal
Keyword(s):  
Heart Failure ◽  
Cardiac Index ◽  
Mitral Regurgitation ◽  
Clinical Improvement ◽  
Ventricular Dysfunction ◽  
Left Ventricular ◽  
Stroke Index ◽  
Vasodilator Therapy ◽  
Chronic Effects ◽  
Acute And Chronic Effects

To determine the acute and chronic effects of vasodilator therapy in children, vasodilator therapy was evaluated in 13 children (aged 0.2 to 14.5 years) with severe left ventricular dysfunction or mitral regurgitation. In seven children, nitroprusside increased cardiac index by an average of 33% (P < .01) and increased stroke index by 29% (P < .01). In eight children, hydralazine caused a 31% increase in cardiac index (P < .01) and a 27% increase in stroke index (P < .02). Ten children received chronic oral vasodilator therapy and were followed for 5.7 ± 1.4 (SEM) months. Early clinical improvement was observed in every child. Symptoms of heart failure diminished in all, and five children became entirely asymptomatic. A significant (P < .05) improvement was noted in growth velocity, respiratory rate, heart size, and incidence of gallop rhythm after 1 month of therapy. The duration of the beneficial response to vasodilator therapy varied considerably, however, and significant improvement for the group was not found after 1 month. Four children had sustained clinical improvement for 6 months or longer, but the others experienced recurrent heart failure within 1 to 4 months.

scholarly journals Echocardiographic evaluation of cardiac resynchronization therapy

2006 ◽  
Vol 134 (11-12) ◽  
pp. 488-491 ◽  
Author(s):  
Milan Petrovic ◽  
Goran Milasinovic ◽  
Bosiljka Vujisic-Tesic ◽  
Vera Jelic ◽  
Zarko Calovic ◽  
...  
Keyword(s):  
Cardiac Resynchronization Therapy ◽  
Left Ventricular ◽  
Cardiac Resynchronization ◽  
Diastolic Filling ◽  
Lv Function ◽  
Mitral Insufficiency ◽  
Stroke Index ◽  
Resynchronization Therapy ◽  
Filling Time ◽  
The Mean

Introduction: Cardiac resynchronization therapy (CRT) is relatively new tool in treatment of chronic heart failure (HF), especially in dilated cardiomyopathy (DCM) with the left bundle branch block (LBBB). Objective: The Objective of our study was to assess the success of CRT in treatment of severe HF and the role of echocardiography in the evaluation of Results of such therapy. Method: The group consisted of 19 patients, 13 males and 6 females, mean age 58.0?8.22 years (47-65 years) with CRT applied for DCM, severe HF (NYHA III-IV), LBBB and ejection fraction (EF) <35%. The mean follow up was 17 months (6.5-30). Standard color Doppler echocardiography examination was performed in all patients before and after CRT. The parameters of systolic and diastolic left ventricular function, mitral insufficiency and the right ventricular pressure were evaluated. Results: Following the CRT, statistically significant improvement of the end-systolic LV dimension, cardiac output, cardiac index, myocardial performance index (p<0.01) and stroke index (p<0.05) was recorded. The mean value of EFLV was increased by 10% and LV fractional shortening improved by 6% in 10/16 (62%) patients. CRT resulted in decreased MR (p<0.01), prolonged LV diastolic filling time (p<0.02) and reduced RV pressure (p<0.05). Interventricular mechanical delay was shortened by 28% (18 msec) Conclusion: CRT has an important role in improvement of LV function and correction of ventricular asynchrony. The echocardiography is a useful tool for evaluation of HF treatment with CRT.

Constancy of stroke volume in ventricular responses to exertion

1959 ◽  
Vol 196 (4) ◽  
pp. 745-750 ◽  
Author(s):  
Robert F. Rushmer
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Response ◽  
Indirect Measurements ◽  
Increase Stroke Volume ◽  
Normal Man ◽  
The Right ◽  
Response To Exercise ◽  
Indicator Dilution Techniques

Diastolic and systolic dimensions of the left ventricle and the free wall of the right ventricle in intact dogs are affected little by spontaneous exercise. The concept that stroke volume and heart rate in normal man increase by about the same relative amounts was derived from estimations of cardiac output, particularly in athletes, based upon indirect measurements using foreign gases or CO2. Data for man obtained with the modern cardiac catheterization or indicator dilution techniques confirm the impression derived from intact dogs that increased stroke volume is neither an essential nor a characteristic feature of the normal cardiac response to exercise. Stroke volume undoubtedly increases whenever cardiac output is increased with little change in heart rate (e.g. in athletes or in patients with chronic volume loads on the heart). Tachycardia produced experimentally with an artificial pacemaker in a resting dog causes a marked reduction in diastolic and systolic dimensions and in the stroke change of dimensions. The factors generally postulated to increase stroke volume during normal exercise may prevent the reduction in stroke volume accompanying tachycardia.

Heart rate control in diabetic rabbits: blunted response to isoproterenol

1988 ◽  
Vol 255 (5) ◽  
pp. E636-E641 ◽  
Author(s):  
B. E. Zola ◽  
B. Miller ◽  
G. L. Stiles ◽  
P. S. Rao ◽  
E. H. Sonnenblick ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Response ◽  
Atropine Sulfate ◽  
Left Ventricular ◽  
Heart Weight ◽  
Base Line ◽  
Baroreceptor Reflexes ◽  
Diabetic Rabbits ◽  
Alloxan Monohydrate ◽  
Response To Exercise

To study the effects of chronic diabetes on heart rate and adrenergic responsiveness we compared unanesthetized diabetic rabbits, 10-13 mo after alloxan monohydrate injection, to age-matched controls. There were no significant differences found between groups for body or heart weight. Both resting and intrinsic heart rate (the latter obtained after atropine sulfate and propranolol HCl) were similar. In addition, serum and left ventricular epinephrine and norepinephrine concentrations as well as left ventricular beta-receptor density and affinity were unchanged in diabetic animals. Heart rate responses to isoproterenol were blunted in diabetics at the three highest doses. Base-line mean blood pressure was modestly lower in diabetic rabbits, and parallel declines in pressure for both groups were observed in response to isoproterenol. The diminished heart rate response to isoproterenol in diabetic rabbits may be due to diminished myocardial sensitivity to catecholamines, possibly combined with altered baroreceptor reflexes. These experiments may provide an explanation for the blunted heart rate response to exercise described in human diabetics.

Comparative β-Adrenoreceptor-Blocking Effects and Pharmacokinetics of Propranolol and Pindolol in Hypertensive Africans

1979 ◽  
Vol 57 (s5) ◽  
pp. 393s-396s ◽  
Author(s):  
L. A. Salako ◽  
A. O. Falase ◽  
A. Fadeke Aderounmu
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Diastolic Pressure ◽  
Exercise Heart Rate ◽  
Double Blind ◽  
Blocking Effects ◽  
The Mean ◽  
Exercise Induced ◽  
African Patients

1. The β-adrenoreceptor-blocking effects of pindolol were compared with those of propranolol and a placebo in a double-blind cross-over trial involving nine hypertensive African patients. 2. Heart rate, systolic blood pressure and diastolic blood pressure were measured at rest and immediately after exercise before and at intervals up to 6 h after oral administration of the drugs. In addition, plasma pindolol and propranolol concentrations were determined at the same intervals. 3. Pindolol diminished systolic blood pressure at rest and after exercise and antagonized exercise-induced tachycardia, but had no effect on resting heart rate. Propranolol diminished systolic blood pressure predominantly after exercise and reduced both resting and exercise heart rate. Both drugs had no effect on diastolic pressure. 4. The mean plasma concentration reached a peak at 2 h for each drug and this coincided with the interval at which maximal β-adrenoreceptor-blocking effect was observed.

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