The Usefulness of Dipyridamole 99mTc-MIBI Myocardial Scintigraphy in the Detection of Coronary Artery Disease

Though exercise T1-201 myocardial perfusion-scintigraphy is an important test in the diagnosis and evaluation of coronary artery disease, this test is limited in cases with poor physical conditions and unstable angina and the physical characteristics of thallium are not ideal for nuclear imaging of the myocardium. Recently, technetium-99m-labelled agent(99mTc-MIBI) has been developed to improved the quality of imaging and for easy usage in myocardial perfusion scan. Therefore, we performed dipyridamole 99mTc-MIBI myocardial scintigraphy and coronary angiography on 25 subjects who were suspeced to have coronary artery disease and the results obtanined were as follows ; 1) The overall diagnostic sensitivity of dipyridamole 99mTc-MIBI perfusion scintigraphy was 73.4%, while specificity was 66.7%. 2) Per vessel sensitivity for coronary artery disease diagnosis by the test was 71.4% and a per vessel specificity for coronary artery disease was 95.7%. 3) In all 75 coronary arteries, LAD had a sensitivity of 66.7%(10/15) and a specificity of 100%(10/10); RCA had a sensitivity of 75%(6/8) and a specificity of 82.4%(14/17); LCX had a sensitivity of 60%(3/5) and a specificity of 100%(20/20). 4) After infusion of dipyridamole, the most frequent adverse effect was chest pain which was seen in 8 cases(32%). The headache was seen in 7 cases(28%). Most of the symptoms were mild in severity and subsided spontaneously but 3 subjects were severe enough to require intravenous administration of aminophylline. In conclusion, dipyridamole 99m2011-06-17Tc-MIBI myocardial perfusion scintigraphy is a useful and safe test for diagnosis of coronary artery disease.

A Clinical Study on the Antihypertensive Effect of Arotinolol

Arotinolol, a new alpha and beta receptor antagonist, was administered in 27 essential hypertensive patients for 8 weeks in order to evaluate the antihypertensive effect and side effects. The dose were 10mg to 15mg given twice a day. The results are as follows : 1) Before medication, systolic and diastolic blood pressure in sitting, supine and erect position were 173.1+/-3.2/105.8+/-1.8, 171.1+/-3.6/86.7+/-2.0 and 169.3+/-2.6/97.2+/-2.1mmHg. 2) After 8 weeks treatment moderated to marked antihypertensive effect was observed in 74.0%(in systolic blood pressure) and 81.4%(in diastolic blood pressure) respectively in sitting position. 3) There was a significant reduction of pulse rate from 73.0+/-2.5 beats per minute on the beginning of the treatment to 63.4+/-5.2 beats per minute after 8 weeks of medication. 4) There was no significant change in hematocrit, WBC, serum lipid, GOT, GPT, BUN and creatinine. But fasting blood sugar was reduced from 95.3mg% to 81.5mg% with treatment. 5) The side effects of arotinolol were gastrointestinal symptoms(15%), fatigue(11%), dizziness(7%) and insomnia(3%). But these side effects were not severe enough to discontinue medication. In summary, arotinolol seemed to be an effective antihypertensive drug in treating mild to moderate hypertension without significant side effects.