No abstract available.
Dipyridamole* ; Heart Ventricles*

Introduction: A dipyridamole induced stress myocardial perfusion scintigraphy with Tc-99m Sestamibi is utilized for diagnosing coronary artery diseases. The use of dipyridamole as form of pharmacologic stressor has expected hemodynamic changes. Objective: The objective of this study was to determine the association of these changes with the scan parameters in patients with suspected coronary artery disease (CAD). Methodology: A total of 101 patients, with suspected CAD, who underwent a dipyridamole-induced stress myocardial perfusion scintigraphy using Tc-99m Sestamibi from January 2019 to March 2020 were included in this study. The patient databases, monitoring sheets, and scan results were reviewed . Results: The blood pressure responses had no significant association with the scan parameters and results. The normal (> 1.2) and abnormal (<1.2) heart rate ratios (HRR), which is the peak HR/baseline HR, likewise had no significant association with the scan results. However, in terms of the median HRR, the higher ratio of 1.29 (normal scan results) against the ratio of 1.25 (abnormal scan results) was determined to be significant (p-value of 0.032). The HRR also had a direct and indirect weak correlation with stress and rest Left Ventricular Ejection Fraction (LVEF) values (p-values of 0.09 and 0.011) and Summed Rest Score (p-value of 0.007), respectively. For the 12-L ECG, only the baseline normal (P-value of 0.018) and infarct findings (p-value of 0.017) were similarly associated with normal and abnormal scan results, respectively. Conclusion For patients with suspected CAD, the higher HRRs and baseline 12-L ECG of normal and infarct findings relates to the expected scan result. For scan parameters, the higher HRRs were also correlated with higher stress and rest LVEF values, and normal SRS, albeit a weak correlation. Notably, the blood pressure and post-infusion 12-L ECG changes had no significant association. In summary, the higher HRRs indicates normal scan results, normal SRS, and better LVEF values which increases the diagnostic confidence in the interpretation and management, especially in some equivocal cases.
Dipyridamole ; Myocardial perfusion scintigraphy

No abstract available.
Adenosine* ; Dipyridamole* ; Dobutamine* ; Exercise Test*

Background: Left ventricular (LV) eccentricity index (EI) is a measure of the LV shapre obtained with a commonly used quantitative software for mycardial perfusion scintigraphy (MPS). However, there are limited studies evaluating its correlation with other MPS parameters, for which this study was done. Methodology: All patients who underwent 99mTc-sestamibi stress MPS from 2013 to 2015 were screened. A total of 353 patients, 228 (65%) males and 125 (35%) females, met the inclusion criteria. One hundred twenty-nine (37%) underwent exercise stress while 224 (63%) were given dipyridamole. Spearman's rho correlation was used to determine the correlation of rest and post-stress EI with the other study variables. Results: Among males, rest EI showed negative correlation with summed stress score (SSS) (rs = -0.182, p<0.005), transient ischemic dilatation (TID) (rs=-0.172, p=0.009), rest LV end-diastolic volume (EDV) (rs=-0.291, p < 0.001), rest LV end-systolic volume (ESV)(rs=-0.316, p < 0.001), p0-st-streSS LVEDV (rs= -0.218, p < 0.001), and post-stress LVESV (rs= -0.331, p < 0.001). There was positive correlation with rest LV ejection fraction (EF) (rs= 0.291,p < 0.001) and post-stress LVEF (r5 = 0. 336, p < 0. 001). No sig11ifico11t relationship with any of the MPS parameters was observed among females. For both exercise and dipyridamole groups. EI exhibited negative correlation with SSS, and rest and stress LVESV; and positive cotrelation with rest and post-stress LVEF. Significant relationship with rest and stress LVEDV was only observed in the dipyridamole group. Conclusions This study shows that EI is correlated with most, if not all, of the MPS parameters with different levels of association depending on the patient's sex and the type of stress employed. More spherical LV is correlated with more severe perfusion defects, larger LV cavity volumes and poorere LV systolic function.
Technetium Tc 99m Sestamibi ; Dipyridamole

No abstract available.
Coronary Artery Disease* ; Coronary Vessels* ; Dipyridamole* ; Perfusion*

No abstract available.
Dipyridamole* ; Tomography, Emission-Computed, Single-Photon*

Livedo vasculitis clinically shows purpuric papules and recurrent ulcers in the lower extremities, mainly on the ankles, leaving characteristic scars called atrophie blanche after the healing of the ulcers. Its characteristic histopathologic features and clinical evolution indicate that the common pathologic event is occlusion of vessels in the middle and deep dermis. In Korean literature, seven cases of this disease have been reported but the response of the treatment was not, satisfactory. We report three cases of livedo vasculitis cleared by combined ther by of acetylsalicylic acid, dipyridamole and nifedipine, which has not been reported in Korean literatur.
Ankle ; Aspirin* ; Cicatrix ; Dermis ; Dipyridamole* ; Lower Extremity ; Nifedipine* ; Ulcer ; Vasculitis*

Background: Coronary artery disease (CAD) is the most common cardiovascular disease in developing countries. CAD also called coronary heart disease, is a condition in which plaque (plak) builds up inside the coronary arteries. These arteries supply your heart muscle with oxygen-rich blood. Objective: The purpose of the study was to investigate the characteristics and value of gated SPECT MPI with Technetium - 99m sestamibi using dipyridamole stress in diagnosis of CAD. Subjects and method: One hundred and forty - six suspected or known CAD patients, mean age 65.2 \xb1 9.11, underwent gated SPECT MPI with technetium - 99m sestamibi using dipyridamole stress. These patients was performed coronary angiography. Results: Of 146 patients, 33.6% had no adverse reaction to intravenous dipyridamole and no fatal adverse events (myocardial infarction, death ... ) was reported. The most common adverse reactions were headache (49.3%), chest pain (40.4%). Aminophyline was administrated to 25.7% of 146 patients and complete relief of symptoms in 91.3% of these patients. The sensitivity for detection of CAD was 95.2 % and the specificity and accuracy were 78.6% and 91.1 %. When excluded the patients with previous MI, these values were 88.9%; 80.0% and 85.7% respectively. Among the coronary branches, the sensitivity was highest in diagnosis of LAD and highest specificity was LCX lesions. Conclusions: The Technetium - 99m sestamibi gated SPECT using dipyridamole stress is a safety and valuable technique for the detection of CAD. \r\n', u' \r\n', u'
Coronary Artery Disease/epidemiology ; pathology ; Dipyridamole/ administration & ; dosage

No abstract available.
Coronary Angiography* ; Coronary Disease* ; Dipyridamole* ; Tomography, Emission-Computed, Single-Photon*

Some recent investigations revealed that vasodilatory action of adenosine is mainly not mediated by surface A2 receptor and suggested the existence of an intracellular action site. In the present study, we tried to differentiate intracellular from extracellular site of adenosine action in the regulation of coronary flow. In perfused rabbit hearts, concentration-response curve of coronary flow to exogenous adenosine was constructed in the presence or absence of dipyridamole, an inhibitor of transmembrane purine transport. Inhibition of cellular adenosine uptake by dipyridamole suppressed the increase of flow rate while enhancing the decrease in heart rate induced by exogenous adenosine. In another series of experiments, perfused rabbit hearts were subjected to energy deprivation in order to increase the production of endogenous adenosine. Energy deprivation along with dipyridamole administration resulted in higher coronary flow rate. Lower perfusate adenosine concentration was observed along with higher tissue adenosine content in this group. These results implied that coronary flow rate is determined not by interstitial adenosine concentration but by intracellular activity of adenosine. To confirm the effects of dypiridamole in vivo, direct measurement of interstitial adenosine concentration by mycrodialysis along with the assay of intracellular adenosine content was performed after intranenous dipyridamole administration. After dipyridamole infusion, intracellular adenosine content was markedly increased while interstitial adenosine concentration was not altered. In another series of experiments, the right shift of concentration-response curve of adenosine-induced vasodilation by 8-phenyltheophilline, a representative adenosine receptor antagonist, was mostly abolished by prior administration of prazosin, indicating that the influence of 8-PT on the adenosine action is not attributed to the inhibition of A2 receptor but related to the suppression of alpha-adrenoceptor activation. From these results, we concluded that adenosine acts intracellularly to regulate the coronary blood flow.
Adenosine ; Dipyridamole* ; Heart ; Heart Rate ; Prazosin ; Receptors, Purinergic P1 ; Vasodilation*