Catecholamines and local rebound in left ventricular contractile force after release of coronary artery occlusion

1971 ◽  
Vol 5 (1) ◽  
pp. 81-85 ◽  
Author(s):  
W. H. Newman ◽  
P. P. Mathur ◽  
R. P. Walton
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Contractile Force ◽  
Left Ventricular

Segmental ventricular adjustments to brief periods of ischemia in the dog

1981 ◽  
Vol 59 (3) ◽  
pp. 287-292
Author(s):  
Z. J. Bosnjak ◽  
J. L. Seacard ◽  
E. J. Zuperku ◽  
R. L. Coon ◽  
H. M. Singh ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Ventricular Function ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Contractile Force ◽  
Left Ventricular ◽  
Myocardial Segment ◽  
Anesthetized Dogs ◽  
Calcium Permeability ◽  
Occluded Segment

The changes in left ventricular segmental contractile force induced by brief periods of ischemia (15 – 90 s) and subsequent reperfusions were analyzed in anesthetized dogs. Segmental coronary artery occlusion (left anterior descending or left circumflex) produced a decrease in segmental ventricular function in the occluded area and an increase in contractile force in the myocardial segment away from the occluded area. With reperfusion, a transient overshoot in contractile force above preischemic control levels was observed in the occluded segment. This overshoot was shown not to be dependent on adrenergic mechanisms but appears to indicate changes in calcium permeability.

Effect of exercise on coronary pressure-flow relationship in hypertrophied left ventricle

1995 ◽  
Vol 269 (1) ◽  
pp. H271-H281 ◽  
Author(s):  
D. J. Duncker ◽  
J. Zhang ◽  
T. J. Pavek ◽  
M. J. Crampton ◽  
R. J. Bache
Keyword(s):  
Coronary Artery ◽  
Myocardial Perfusion ◽  
Diastolic Pressure ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Left Ventricular ◽  
Back Pressure ◽  
Pressure Flow ◽  
Pronounced Increase ◽  
Coronary Pressure

Left ventricular (LV) hypertrophy (LVH) secondary to chronic pressure overload is associated with increased susceptibility to myocardial hypoperfusion and ischemia during exercise. The present study was performed to determine whether exercise causes alterations in minimum coronary resistance or effective back pressure [coronary pressure at zero flow (Pzf)] that limit maximum myocardial perfusion in the hypertrophied heart. Ascending aortic banding in 7 dogs increased the LV weight-to-body weight ratio to 7.7 +/- 0.3 g/kg compared with 4.6 +/- 0.2 g/kg in 11 normal dogs (P < 0.01). Maximum coronary vasodilation was produced by intracoronary infusion of adenosine. Under resting conditions, the slope of the pressure-flow relationship (conductance) was significantly lower in the LVH animals than in the normal dogs (7.2 +/- 0.8 vs. 11.9 +/- 0.8 x 10(-2) ml.min-1.g-1.mmHg-1; P < 0.01); the slope correlated with the degree of hypertrophy r = 0.74; P < 0.001). The Pzf measured during total coronary artery occlusion (Pzf,measured) was significantly elevated in LVH compared with normal dogs (25.6 +/- 2.2 vs. 13.0 +/- 1.2 mmHg; P < 0.01); Pzf,measured was positively correlated (r = 0.78, P < 0.0005) with LV end-diastolic pressure measured during total coronary artery occlusion (9.0 +/- 1.1 mmHg in normal dogs and 22.2 +/- 3.2 mmHg in LVH dogs; P < 0.01). Graded treadmill exercise to maximum heart rates of 210 +/- 9 and 201 +/- 8 beats/min in normal and LVH animals, respectively, caused similar decreases in the slope of the pressure-flow relationship in LVH (from 7.7 +/- 0.9 to 6.1 +/- 0.8 x 10(-2) ml.min-1.g-1.mmHg-1; P < 0.01) and normal dogs (from 11.9 +/- 0.8 to 10.0 +/- 0.7 x 10(-2) ml.min-1.g-1.mmHg-1; P < 0.01). However, exercise-induced increases in Pzf,measured were significantly greater in the LVH animals (from 25.6 +/- 2.2 to 40.8 +/- 2.1 mmHg; P < 0.01) than in normal animals (from 13.0 +/- 1.2 to 24 +/- 2.1 mmHg; P < 0.01) (P < 0.01 LVH vs. normal). The greater increase in Pzf paralleled a more pronounced increase in LV end-diastolic pressure in the LVH dogs from 22.2 +/- 3.2 to 39.1 +/- 2.7 mmHg) than in normal dogs from 9.0 +/- 1.1 to 14.2 +/- 2.0 mmHg). The results suggest that exaggerated increases in filling pressure during exercise in the hypertrophied left ventricles contributed to impairment of myocardial perfusion during exercise by augmenting the back pressure, which opposes coronary flow.(ABSTRACT TRUNCATED AT 400 WORDS)

Long-Term Effects of Growth Hormone on Infarct Size and Left Ventricular Function in Sheep With Coronary Artery Occlusion

2010 ◽  
Vol 55 (3) ◽  
pp. 255-261
Author(s):  
Fernanda D Olea ◽  
Andrea De Lorenzi ◽  
Claudia Cortés ◽  
Patricia Cabeza Meckert ◽  
Oscar Cendoya ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Coronary Artery ◽  
Left Ventricular Function ◽  
Infarct Size ◽  
Ventricular Function ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Left Ventricular ◽  
Long Term Effects

scholarly journals Simvastatin alleviates myocardial contractile dysfunction and lethal ischemic injury in rat heart independent of cholesterol-lowering effects

2009 ◽  
pp. 449-454 ◽  
Author(s):  
A Adameová ◽  
A Harčárová ◽  
J Matejíková ◽  
D Pancza ◽  
M Kuželová ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Plasma Cholesterol ◽  
Day Treatment ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Left Ventricular ◽  
Contractile Dysfunction ◽  
Risk Area ◽  
Cholesterol Lowering ◽  
Simvastatin Therapy

Statins, the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are most frequently used drugs in the prevention of coronary artery disease due to their cholesterollowering activity. However, it is not exactly known whether these effects of statins or those independent of cholesterol decrease account for the protection against myocardial ischemiareperfusion (I/R) injury. In this study, we investigated the effect of 5-day treatment with simvastatin (10 mg/kg) in Langendorffperfused hearts of healthy control (C) and diabetichypercholesterolemic (D-H; streptozotocin + high fat-cholesterol diet, 5 days) rats subjected to 30-min global ischemia followed by 40-min reperfusion for the examination of postischemic contractile dysfunction and reperfusion-induced ventricular arrhythmias or to 30-min (left anterior descending) coronary artery occlusion and 2-h reperfusion for the infarct size determination (IS; tetrazolium staining). Postischemic recovery of left ventricular developed pressure (LVDP) in animals with D-H was improved by simvastatin therapy (62.7±18.2 % of preischemic values vs. 30.3±5.7 % in the untreated D-H; P<0.05), similar to the values in the simvastatin-treated C group, which were 2.5-fold higher than those in the untreated C group. No ventricular fibrillation occurred in the simvastatin-treated C and D-H animals during reperfusion. Likewise, simvastatin shortened the duration of ventricular tachycardia (10.2±8.1 s and 57.8±29.3 s in C and D-H vs. 143.6±28.6 s and 159.3±44.3 s in untreated C and D-H, respectively, both P<0.05). The decreased arrhythmogenesis in the simvastatin-treated groups correlated with the limitation of IS (in % of risk area) by 66 % and 62 % in C and D-H groups, respectively. However, simvastatin treatment decreased plasma cholesterol levels neither in the D-H animals nor in C. The results indicate that other effects of statins (independent of cholesterol lowering) are involved in the improvement of contractile recovery and attenuation of lethal I/R injury in both, healthy and diseased individuals.

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