Effect of drugs on myocardial contractility in the intact dog and in experimental myocardial infarction

Puri, Pritpal S.; Bing, Richard J.

doi:10.1016/0002-9149(68)90307-x

Cited by 41 publications

(9 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies have shown that a rapid loss of contractile activity in the ischemic myocardium (20,26) follows coronary artery occlusion. This is followed by a passive distention of the ischemic myocardium during systole.…”

Section: Discussionmentioning

confidence: 99%

“…This method has been employed in the present investigation to distinguish the ischemic from the nonischemic portions of the myocardium. It is based on the observations reported previously (20), which indicate that in the ischemic myocardium, the pattern of fiber shortening during systole is replaced by paradoxical fiber lengthening. Straingauge bearing prongs of the assembly were directly inserted from die epicardial surface of the myocardium, and the area of ischemia was mapped out (Fig.…”

Section: Determination Of Left Ventricular Functionsmentioning

confidence: 99%

See 1 more Smart Citation

Early Changes in Energy Metabolism in the Myocardium Following Acute Coronary Artery Occlusion in Anesthetized Dogs

Braasch

Gudbjarnason

Puri

et al. 1968

Circulation Research

Self Cite

232

View full text Add to dashboard Cite

The tissue content of energy-rich phosphates and glycolytic metabolites and the activity of myocardial enzymes were examined in the dog after producing myocardial infarction by ligating branches of the anterior descending and circumflex coronary arteries. The pattern of systolic fiber movement shown by a strain-gauge assembly differentiated ischemic from nonischemic portions of myocardium. In ischemic muscle, 30 minutes after onset of ischemia, creatine phosphate content fell from 8.0 to 1.4 / z moles/g, ATP content fell from 5.8 to 1.5 fxmo]es/g, lactate content rose tenfold, and a-glycerophosphate content rose fivefold. The content of energy-rich phosphates and glycolytic metabolites did not change much in nonischemic muscle. The activities of myocardial enzymes were assayed in extracts of tissue samples from ischemic and nonischemic muscle 5 to 120 minutes after coronary artery occlusion. The activities of aldolase, lactic dehydrogenase (LDH), glyceraldehydephosphate dehydrogenase, a-glycerophosphate dehydrogenase, malatedehydrogenase (MDH).and 6-phosphogluconate dehydrogenase did not change significantly in ischemic muscle during 2 hours of observation. In nonischemic muscle, phosphofr uctokinase activity increased 75% 5 minutes after coronary occlusion, followed by an increase in activity of isocitrate dehydrogenase, creatinephosphokinase, MDH, and LDH. The enzymatic changes in nonischemic muscle suggest metabolic changes in nonischemic muscle accompanying compensatory hyperfunction and increased energy requirements of surviving muscle. ADDITIONAL KEY WORDSmyocardial ischemia enzyme profile glycolysis energy-rich phosphates myocardial fiber shortening paradoxical systolic fiber lengthening • Previous communications from this laboratory have described the biochemical changes in heart muscle that occur from 5 hours to 10 weeks following coronary oc-

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Determination Of Left Ventricular Functionsmentioning

confidence: 99%

Early Changes in Energy Metabolism in the Myocardium Following Acute Coronary Artery Occlusion in Anesthetized Dogs

Braasch

Gudbjarnason

Puri

et al. 1968

Circulation Research

Self Cite

232

View full text Add to dashboard Cite

show abstract

“…Iso-proterenol (2,7,(10)(11)(12), l-norepinephrine (3,5,6,8,(12)(13)(14), alpha adrenergic blocking agents (11,12,15), intra-aortic phase-shift balloon pumping (16)(17)(18)(19), and other techniques have been recommended for coronary shock but evidence of their efficacy has been limited to measurements of cardiac output and peripheral vascular resistance.…”

mentioning

confidence: 99%

Hemodynamics, coronary blood flow, and myocardial metabolism in coronary shock; response to l-norepinephrine and isoproterenol

Mueller¹,

Ayres²,

Gregory³

et al. 1970

J. Clin. Invest.

113

View full text Add to dashboard Cite

show abstract

“…Fifteen mongrel dogs that weighed [19][20][21][22][23][24][25][26][27][28][29][30][31][32] vard infusion pump at a rate of 0.6 ml/min. Based on a flow of approximately 25 ml/min, this infusion rate would raise serum potassium concentration and presumably the extracellular potassium concentration in the myocardium perfused by the LAD to approximately 30 mEq/ 1, which would make this region electrically inexcitable.…”

Section: Methods Experimental Preparationmentioning

confidence: 99%

Contractile reserve and left ventricular function in regional myocardial ischemia in the dog.

Yoran¹,

Sonnenblick²,

Kirk³

1982

Circulation

View full text Add to dashboard Cite

SUMMARY Contractile activity remaining in a region made ischemic by acute occlusion of the left anterior descending coronary artery (LAD) was assessed in dogs relative to its role in maintaining left ventricular (LV) function. Compensatory increases in contractility of normal myocardium were eliminated by treating all dogs with reserpine (3 mg/kg) to deplete their catecholamine stores. LV function was determined by measuring stroke volume while increasing the LV filling pressure with a shunt from the aorta to left atrium. Heart rate and mean aortic pressure were kept constant. LV function was studied after occlusion of the LAD alone and after the selective infusion of potassium chloride (1 mEq/ml) into the LAD to raise the regiotal extracellular potassium concentration to 30 mEq/mi. The reduction in LV function induced by LAD ligation was less than the reduction caused by abolishing contraction in the entire zone supplied by the LAD with infusion of potassium. The WHEN a coronary artery is occluded abruptly, loss of segmental shortening in the region of myocardium fed by this artery is generally observed. However, some collateral coronary blood flow remains and residual contractile function may remain in the region. The role of such contractile activity remaining in a region made ischemic by occlusion of a coronary artery on the overall function of the left ventricle has not been defined. Further, the relation between the size of the ischemic area and the extent of reduction in overall left ventricular (LV) function has not been precisely determined. When regional myocardial ischemia is induced, LV function is affected by the lateral dimensions of the ischemic region, the distribution of contractile activity transmurally in this region as determined by the remaining collateral coronary blood flow, the compliance of the ischemic zone, and compensatory increases in contractility in nonischemic zones of myocardium resulting from augmented sympathetic tone. This may explain the marked variation in the reported observations on this subject. '-9 We studied the effects of regional myocardial ischemia and total cardioplegia. The effects of involving varying amounts of the ventricle on overall LV function were also examined. stores.'0 This was done to abolish the compensatory increase in contractility that may occur in the nonischemic myocardium after coronary artery ligation.Dogs were anesthetized with sodium pentobarbital (30 mg/kg i.v.). Additional pentobarbital was administered as required to maintain anesthesia. After intubation with a cuffed endotracheal tube, dogs were ventilated with an intermittent positive pressure respiratory with 100% oxygen. A thoracotomy was performed in the fifth intercostal space and the heart was exposed by incising the pericardium. The left anterior descending coronary artery (LAD) was isolated and ligated 3-20 mm from its origin to vary the size of the ischemic region.After ligation of the LAD, a cannula was inserted distal to the occlusion and perfusion was continued through a pol...

show abstract

Effect of drugs on myocardial contractility in the intact dog and in experimental myocardial infarction

Cited by 41 publications

References 39 publications

Early Changes in Energy Metabolism in the Myocardium Following Acute Coronary Artery Occlusion in Anesthetized Dogs

Early Changes in Energy Metabolism in the Myocardium Following Acute Coronary Artery Occlusion in Anesthetized Dogs

Hemodynamics, coronary blood flow, and myocardial metabolism in coronary shock; response to l-norepinephrine and isoproterenol

Contractile reserve and left ventricular function in regional myocardial ischemia in the dog.

Contact Info

Product

Resources

About