| Popis: |
Anatomical studies suggest that sites of coronary spasm are subject to early atherosclerosis. Coronary angiography is unable to confirm the lesions or provide information about their nature. On the other hand, endocoronary ultrasound is able to identify and, it is hoped, to determine the frequency and composition of the lesions. Nineteen patients with chest pain and angiographically normal or subnormal coronary arteries were included in a prospective study (16 men and 3 women: average age 53 +/- 10 years). Four patients had spontaneous spasm and in the other 15, spasm was induced by intravenous injection of ergometrine (6 micrograms/kg). After countering the spasm with isosorbide dinitrate, the site of spasm and adjacent segments were examined by endocoronary ultrasound. Localised vasospasm which was stenotic in 14 cases and obstructive in 5 cases, was observed. The ECG was unchanged in 4 cases and showed ST-T segment changes in 15 cases. The artery affected was the left anterior descending in 10 cases, the left circumflex in 2 cases and the right coronary in 7 cases. A plaque of atheroma, defined as significant intimal thickening, was detected in 18 out of the 19 cases. This atheroma was classified as soft in 17 cases and hard in one case. The authors conclude that vasospasm is not only associated with a plaque of atheroma, nearly always suspected at coronary angiography, but also its composition is nearly always soft (lipidic) from ultrasonographic data. |
