TxA2 inhibition and ischemia-induced loss of myocardial function and reactive hyperemia

1990 ◽  
Vol 258 (5) ◽  
pp. H1402-H1408 ◽  
Author(s):  
J. L. Mehta ◽  
W. W. Nichols ◽  
R. Schofield ◽  
W. H. Donnelly ◽  
V. K. Chandna
Keyword(s):  
Coronary Artery ◽  
Coronary Occlusion ◽  
Myocardial Function ◽  
Reactive Hyperemia ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Leukocyte Infiltration ◽  
Coronary Reperfusion ◽  
Reperfusion Arrhythmias ◽  
Premature Ventricular Contractions

To determine the contribution of thromboxane (Tx) A2 release in reperfusion injury, 17 dogs were subjected to total coronary occlusion for 1 h and reperfusion for 1 h. Eleven dogs were treated with saline, and six were treated with selective TxA2 synthetase inhibitor U63,557A (5 mg/kg iv) 30 min before coronary artery occlusion. In all saline-treated dogs, peak reactive hyperemia after 10-s total coronary artery occlusion was diminished (P less than 0.01) after reperfusion. Myocardial segmental shortening was also reduced (9.8 +/- 1.9 to -6.7 +/- 2.0%, P less than 0.01) in the reperfused region. Reperfusion was associated with 737 +/- 343 premature ventricular contractions (PVCs) per hour. Histology revealed extensive myocardial infiltration and capillary plugging by leukocytes in the reperfused region. Myeloperoxidase, an index of leukocyte infiltration, was also increased (P less than 0.02) in the reperfused region. In the U63,557A-treated animals, serum and plasma TxB2 levels were markedly (P less than 0.02) reduced. Decrease in myocardial shortening fraction was less in U63,557A- than in saline-treated animals (P less than 0.05). The frequency of reperfusion PVCs was also significantly reduced (10 +/- 5 PVCs/h, P less than 0.02 compared with saline-treated dogs). However, peak reactive hyperemia was reduced similar to that in saline-treated dogs. Myocardial infiltration and capillary plugging by leukocytes in the reperfused regions was also similar in the U63,557A- and saline-treated dogs. These results indicate that treatment with U63,557A decreases reperfusion arrhythmias and preserves myocardial function. However, coronary reperfusion-induced deterioration in reactive hyperemia is not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of regional ventricular postextrasystolic potentiation after coronary occlusion in dogs

1977 ◽  
Vol 233 (3) ◽  
pp. H392-H348
Author(s):  
B. Crozatier ◽  
D. Franklin ◽  
P. Theroux ◽  
H. Tomoike ◽  
S. Sasayama ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Occlusion ◽  
Myocardial Function ◽  
Premature Ventricular Contraction ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Ventricular Contraction ◽  
Regional Myocardial Function ◽  
Irreversible Damage ◽  
Postextrasystolic Potentiation

Postextrasystolic potentiation following coronary artery occlusion was studied serially using pairs of ultrasonic crystals to measure regional myocardial function in control, marginally ischemic, and ischemic segments of the left ventricle in dogs. Prior to coronary occlusion (CO), percent shortening in control (normal) segments increased by an average of 51.4 +/- 4.6% in the beat after a premature ventricular contraction (post-PVC beat), and this response changed little after coronary occlusion. During the 1st min after CO, in ischemic segments, systolic expansion developed but was replaced by active shortening in post-PVC beats; however, after 3 min of CO (average) and thereafter, there was no net positive shortening in post-PVC beats. In marginally ischemic segments early after CO, hypokinesia developed, but there was marked augmentation of percent shortening (208.6 +/- 32.6%) which persisted in post-PVC beats even after 2 h. It is concluded that loss of postextrasystolic potentiation occurs rapidly in ischemic regions after CO and is not indicative of irreversible damage; partially ischemic regions retain this mechanism for prolonged periods.

Antifibrillatory effects of α1-adrenoceptor blocking drugs in experimental coronary artery occlusion and reperfusion

1993 ◽  
Vol 71 (2) ◽  
pp. 103-111 ◽  
Author(s):  
B. G. Benfey
Keyword(s):  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Guinea Pig ◽  
Ventricular Arrhythmias ◽  
Coronary Occlusion ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Coronary Reperfusion ◽  
Isolated Hearts ◽  
Anesthetized Dogs

The myocardium of animals and man possesses α1-adrenoceptors in addition to β-adrenoceptors. Ischemia increases sympathetic tone, and ventricular arrhythmias can occur by β- and α1-adrenoceptor stimulation. I believe that α1-adrenoceptor blocking drugs have antifibrillatory effects and will review the data that support this condition. The effect of α1,-adrenoceptor blocking drugs on the incidence of ventricular fibrillation in acute coronary artery occlusion and (or) reperfusion has been determined in 24 studies in conscious and anesthetized dogs and rats, anesthetized cats and pigs, and rat and guinea-pig isolated hearts. The drugs reduced the incidence of fibrillation from 35 to 24% in coronary occlusion and from 61 to 29% in reperfusion.Key words: heart, coronary occlusion, coronary reperfusion, ventricular fibrillation, α1-adrenoceptor blocking drugs.

A new thermal sensor for surface-based measurement of local myocardial perfusion

1983 ◽  
Vol 244 (3) ◽  
pp. H449-H453
Author(s):  
F. S. Castellana ◽  
R. B. Case ◽  
R. Skalak ◽  
J. M. Cho
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Reactive Hyperemia ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Tissue Blood Flow ◽  
Thermal Sensor ◽  
Epicardial Surface ◽  
Continuous Surface ◽  
Flow Changes

The transient response of a new thermal sensor for continuous surface-based measurement of local tissue blood flow was evaluated in the beating dog heart. The sensor is 2.5 mm square, tests on the heart, and responds to flow changes only within a region of tissue 3-4 mm below its location on the epicardial surface. Initial studies demonstrate excellent sensitivity, good frequency response with a time constant of the order of 10-11 s, and an ability to continuously monitor changes in local myocardial blood flow during a variety of well-understood interventions, including coronary artery occlusion, reactive hyperemia, and intravenous administration of nitroglycerin and dipyridamole.

Two females with coronary artery occlusion caused by presumed Kawasaki disease would have delivered without recognition of ischaemic heart disease

2020 ◽  
Vol 30 (6) ◽  
pp. 785-789
Author(s):  
Etsuko Tsuda ◽  
Takashi Noda ◽  
Teruo Noguchi
Keyword(s):  
Heart Disease ◽  
Coronary Artery ◽  
Kawasaki Disease ◽  
Ischaemic Heart Disease ◽  
Right Coronary Artery ◽  
Coronary Artery Calcification ◽  
Artery Aneurysm ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Premature Ventricular Contractions

AbstractWe report two females with coronary artery occlusion caused by presumed Kawasaki disease that delivered children without any special treatment. After a 58-year-old female had ventricular tachycardia, a giant coronary artery aneurysm with calcification at the bifurcation of the left coronary artery and segmental stenosis of the right coronary artery were pointed out by CT angiography. She had an episode of sepsis when 3 years old. Further, she remembered chest pain during sleep after that episode. She had delivered twice without any complication during her 20s. Her diagnosis was undiagnosed coronary artery lesions caused by presumed Kawasaki disease and a previous myocardial infarction, and she underwent radiofrequency catheter ablation and implantable cardioverter defibrillator implantation. The other 48-year-old female was accidentally discovered to have coronary artery calcification on CT, while experiencing pneumonia. Her CT angiograms revealed a right coronary artery occlusion and coronary artery calcification at segments 1, 6, and 11. She had a history of “scarlet fever” before 12 months. Premature ventricular contractions were detected, while delivering her first child when 31 years old. However, she was not diagnosed as ischaemic heart disease and delivered twice by a vaginal delivery without any complication. Current guidelines recommend systemic anti-coagulation and anti-platelet therapy for all patients with giant aneurysms resulting from Kawasaki disease in childhood. The two women reported here were fortunate not to have had complications during pregnancy and delivery despite their severe coronary artery aneurysms, which were unrecognised clinically until later in life. They were lucky cases.

Regional myocardial function and metabolism during acute coronary artery occlusion

1982 ◽  
Vol 242 (6) ◽  
pp. H980-H989 ◽  
Author(s):  
H. Kanaide ◽  
R. Yoshimura ◽  
N. Makino ◽  
M. Nakamura
Keyword(s):  
Coronary Artery ◽  
Oxygen Saturation ◽  
Fiber Optics ◽  
Myocardial Function ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Isolated Rat Heart ◽  
Wall Thickening ◽  
Regional Ischemia ◽  
Systolic Wall Thickening

Regional changes in myocardial function and oxidative metabolism during acute coronary artery occlusion were recorded spectrophotometrically by incorporating fiber optics in the isolated rat heart perfused by Langendorff's procedure. Oxygen saturation of myoglobin, reduction of cytochrome aa3, and the dynamic wall thickness of the left ventricle were continuously and concurrently measured from absorbancy increments at 581-592 nm, 605-630 nm, and 568-592 nm, respectively. In contrast to a gradual decrease in the extent of systolic wall thickening in anoxia, observed decreases in both the extent and the duration of systolic wall thickening and the appearance of a late systolic bulge occurred within 5 s after the onset of regional ischemia. After 10 s of both anoxia and regional ischemia, oxygen saturation of myoglobin decreased by 50%, but fluorescence of nicotinamide adenine dinucleotide remained at aerobic level which indicated that mitochondrial oxidative energy production might still be maintained. Thus early and pronounced dysfunction of the ischemic region appeared to precede a substantial loss of ATP production.

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