Coronary dilation with standard dose dipyridamole and dipyridamole combined with handgrip.
0
Citation
0
Reference
20
Related Paper
Abstract:
Intravenous dipyridamole is widely used to produce coronary vasodilation during cardiac imaging procedures. However, the routinely used dose of dipyridamole (0.56 mg/kg IV over 4 min) does not always result in maximal coronary dilation. The addition of isometric handgrip during dipyridamole coronary dilation has been reported to substantially increase coronary blood flow over dipyridamole alone. We compared the coronary vasodilation resulting from infusion of the standard dose of dipyridamole with that resulting from a maximally dilating dose of intracoronary papaverine in 12 patients with angiographically normal coronary arteries. We also assessed the effect on coronary blood flow velocity of the addition of isometric handgrip during dipyridamole coronary dilation. Changes in coronary blood flow velocity were measured with a 3F coronary Doppler catheter. The coronary flow reserve (peak/resting coronary flow velocity ratio) after dipyridamole (3.7 +/- 1.2 [mean +/- SD] was less than that seen after papave...Keywords:
Dipyridamole
Coronary vasodilator
Coronary flow reserve
Coronary steal
Coronary circulation
Cite
Dipyridamole increases adenosine levels and augments coronary collateralization in patients with coronary ischemia. This pilot study tested whether a 6‐month course of sustained‐release dipyridamole/aspirin improves coronary flow reserve and left ventricular systolic function in patients with ischemic cardiomyopathy. Six outpatients with coronary artery disease and left ventricular ejection fraction (LVEF) <40% were treated with sustained‐release dipyridamole 200 mg/aspirin 25 mg twice daily for 6 months. Myocardial function and perfusion, including coronary sinus flow at rest and during intravenous dipyridamole‐induced hyperemia, were measured using velocity‐encoded cine magnetic resonance stress perfusion studies at baseline, 3 months, and 6 months. There was no change in heart failure or angina class at 6 months. LVEF increased by 39%±64% (31.0%±13.3% at baseline vs 38.3%±10.7% at 6 months; P =.01), hyperemic coronary sinus flow increased more than 2‐fold (219.6±121.3 mL/min vs 509.4±349.3 mL/min; P =.01), and stress‐induced relative myocardial perfusion increased by 35%±13% (9.4%±3.4% vs 13.9%±8.5%; P =.004). Sustained‐release dipyridamole improved hyperemic myocardial blood flow and left ventricular systolic function in patients with ischemic cardiomyopathy.
Dipyridamole
Ischemic Cardiomyopathy
Coronary circulation
Coronary steal
Cite
Citations (33)
Dipyridamole
Coronary flow reserve
Circumflex
Coronary vasodilator
Coronary arteries
Coronary circulation
Coronary vessel
Cite
Citations (470)
Dipyridamole
Coronary flow reserve
Coronary vessel
Coronary circulation
Cite
Citations (2)
The effects of 0.25 mg/kg dipyridamole on left ventricular (LV) pressures, LV dP/dt, heart rate, aortic pressures, left circumflex coronary blood flow, and left circumflex coronary arterial diameters and on calculations of late diastolic coronary resistance and large coronary cross-sectional area were studied in 15 conscious dogs. Injection of dipyridamole, a drug that has a mechanism of action dependent on myocardial adenosine production, caused sustained increases in mean coronary blood flow (244 +/- 28%), large coronary arterial cross-sectional area (28 +/- 3.2%), heart rate (32 +/- 3.6%), and LV dP/dt (23 +/- 3.0%) and reductions in late diastolic coronary resistance (73 +/- 2.4%) and mean arterial pressure (14 +/- 1.9%). Neither beta-adrenergic-receptor blockade alone nor in conjunction with constant heart rate affected the dilation of large coronary arteries to dipyridamole significantly. Ganglionic blockade with hexamethonium also had little effect on the response of large and small coronary vessels to dipyridamole. Surprisingly neither beta-adrenergic-receptor nor ganglionic blockade abolished the rise in LV dP/dt observed after dipyridamole. Aminophylline, however, effectively eliminated the dilation of large coronary arteries and resistance coronary vessels in response to dipyridamole. In summary, as long as dipyridamole does not induce severe sustained hypotension it exerts potent effects on both coronary arterial resistance and large coronary arteries in the conscious dog. The coronary dilation is independent of reflex adrenergic activation, but appears dependent on myocardial adenosine production.
Dipyridamole
Coronary arteries
Coronary circulation
Aminophylline
Coronary steal
Circumflex
Cite
Citations (52)
Many studies have shown that coronary flow reserve is reduced in patients with chest pain and angiographically normal coronary arteries. The methods used to assess coronary blood flow have varied, but in nearly all reports dipyridamole has been used to bring about vasodilatation. This study was designed to assess whether the apparent impairment of coronary flow reserve seen with dipyridamole could be reproduced with either papaverine or adenosine, which induce maximum coronary blood flow by different mechanisms.25 patients with chest pain and angiographically normal coronary arteries were studied with an intracoronary Doppler flow probe and quantitative angiography to determine epicardial coronary artery area, coronary blood flow velocity, coronary flow reserve, and coronary vascular resistance index (CVRI, the ratio of resistance after intervention to basal resistance). All patients received papaverine 8 mg. Eight patients with positive exercise tests received intracoronary papaverine (8 and 10 mg), intracoronary adenosine (6, 20, 60 micrograms), and high-dose intravenous dipyridamole (0.84 mg/kg).The velocity ratio (peak after intervention: baseline) (mean (SEM)) after 8 mg papaverine was 3.3 (0.2) (n = 25) and the coronary flow reserve was 4.1 (0.3) (n = 25). There were no differences between patients with a positive (n = 16) or negative (n = 9) exercise test. In eight patients coronary flow reserve was measured after increasing doses of papaverine, adenosine, and dipyridamole. Coronary flow reserve was 4.5 (0.3) with papaverine, 4.8 (0.3) with adenosine, and 3.5 (0.4) with dipyridamole (p = 0.08 v papaverine and adenosine). CVRI was 0.22 (0.01) with papaverine, 0.21 (0.02) with adenosine, and 0.29 (0.03) with dipyridamole (p < 0.05 v papaverine, p = 0.09 v adenosine).These results indicate that measurement of coronary flow reserve and CVRI in patients with chest pain and normal coronary arteries depends on the pharmacological stimulus. Normal values were obtained with papaverine in all patients, irrespective of the exercise test response. In patients with a positive exercise test significantly lower values were obtained with dipyridamole than with papaverine, or adenosine. The reported impairment of coronary flow reserve in patients with angina and normal coronary arteries may reflect the variability in response to different pharmacological agents. The mechanism underlying this variability is unknown, but may involve an abnormality of adenosine metabolism in the myocardium.
Dipyridamole
Coronary flow reserve
Coronary arteries
Coronary vasodilator
Coronary circulation
Cite
Citations (46)
Dipyridamole
Coronary steal
Cite
Citations (6)
The effects of Dipyridamole (Persantin) on the coronary blood flow (the great cardiac vein flow and coronary sinus ostial flow), the femoral arterial pressure, the coronary vascular resistance and the heart rate were measured continuously in man.The newly devised method of the continuous local thermodilution method enabled us to perform the exact measurement of the above mentioned variables in man.The increase of the coronary blood flow was seen definitely in the non-ischemic group and, therefore, the decrease in the coronary vascular resistance occurred in 30 sec and continued for more than 20 min. In the myocardial ischemic group, some patients showed the similar response to the non-ischemic group. However, some patients showed no increase of the flow, even though the coronary vascular resistance decreased in all cases in this group. The heart rate increased slightly in all cases.
Dipyridamole
Cite
Citations (2)
The effects of 0.56 mg/kg dipyridamok on left ventricular systolic function under different degrees of coronary stenosis induced by microconstrictor were examined with invasive methods in 21 open chest dogs. This study suggests that in mfld coronary stenosis, left ventricular diastolic pressure (LVDP) decreased by 22%, and cardiac function improved after dipyridamole was used, and when coronary artery was in critical stenosis and dipyridamolc was indused LVDP in-crease by 55%. In the sametime coronary blood flow, left ventricular systolic pressure , (dp/dt)max and (-dp/df)max teased significantly (dropped by 25%, 33%, 37% and 51% respectively). But it is not suitable for clinical treatments of myocardial ischemia with this dosage(0.56mg/kg). Smaller dosage of dipyridamolc should be used in the treatment of coronary heart diseases.
Dipyridamole
Ventricular Function
Ventricular pressure
Cite
Citations (0)
Effects of trapidil, a non-nitrate type coronary vasodilator, nitroglycerin and dipyridamole on epicardial coronary diameter and total coronary resistance were studied in anesthetized open-chest dogs. The epicardial coronary diameter of the left circumflex coronary artery was measured by sonomicrometry and total coronary resistance was calculated by aortic pressure and coronary blood flow. Intravenous administration of Trapidil, as well as nitroglycerin, produced transient decreases in total coronary resistance followed by sustained dilation of the large coronary artery. Dipyridamole increased coronary blood flow by 2.7-fold, whereas diameter of the large coronary artery decreased along with the reduction of aortic pressure. The first peak of the biphasic increases in coronary blood flow and subsequent dilation of the large coronary artery appeared after an i.v. bolus administration of trapidil or nitroglycerin and remained even after beta adrenergic blockade. Intracoronary administration of either drug produced monophasic increases in coronary blood flow along with subsequent dilation of the large coronary artery. Thus, trapidil, like nitroglycerin, directly dilates the large and small coronary arteries.
Dipyridamole
Coronary vasodilator
Aortic pressure
Coronary circulation
Coronary steal
Coronary vessel
Cite
Citations (12)
This study examined the systemic and coronary hemodynamic effects of dipyridamole on experimental myocardial infarcts. Electrograms were recorded from the left ventricular surface 15min. after ligation of the left anterior descending coronary artery. Average ST segment elevation and number of sites with ST segment elevation greater than 2mV., indices of the magnitude and extent of acute myocardial ischemic injury, were increased in 9 dogs following intravenous infusion of dipyridamole (0.01-0.05mg./Kg./mm.) from 4.6±0.3 (Mean value±SEM) during control simple occlusion to 6.8±0.9mV. (p<0.025), and 6.2±0.6 to 8.1±1.2 (p<0.05), respectively. This was accompanied by significant decreases in mean blood pressure from 105±5 to 79±6mm.Hg (p<0.025) and in mean value of coronary perfusion pressure index (Mean blood pressure×Heart rate×Diastolic duration in aortic pressure) from 4, 100±180 to 3, 130±210mm.Hg sec./min. (p<0.01), respectively. Coronary blood flow measured by a flow probe applied around the root of the circumflex coronary artery was markedly increased from the mean value of 115±6 during control occlusion to 284±45 (arbitrary unit, p<0.01).Thus, we concluded that dipyridamole does have deleteriou effects on acute myocardial ischemic injury by reducing coronary perfusion pressure which importantly influence the blood supply to the ischemic zone of myocardium, in spite of augmented total coronary blood flow.
Dipyridamole
Coronary occlusion
Coronary steal
Coronary perfusion pressure
Coronary circulation
Cite
Citations (6)