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Sudden cardiac arrest and syncope triggered by coronary spasm
Ikuko Togashi1, Toshiaki Sato, Kyoko Soejima
1Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, Japan.
International Journal of Cardiology
|June 14, 2011
Summary
Coronary spasm triggering sudden cardiac arrest (SCA) or syncope differs from that causing angina. Daytime ST-segment changes are key indicators in these severe coronary spasm events.
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Background:
- Coronary artery spasm, while generally having a good prognosis, can precipitate life-threatening events like sudden cardiac arrest (SCA) and syncope.
- A hypothesis suggests that the characteristics of coronary spasm leading to lethal arrhythmias may differ from those causing angina alone.
Observation:
- A study compared clinical characteristics of patients experiencing SCA (n=18) or syncope (n=28) due to coronary spasm with those experiencing angina-only (n=52).
- SCA and syncope predominantly occurred during daytime (57% and 68%, respectively).
- Daytime ST-segment changes were more frequent in SCA and syncope groups compared to the angina-only group (50% and 39% vs. 4%, p < 0.01).
Findings:
- Nocturnal angina was less frequent in patients with SCA (33%) and syncope (32%) compared to angina-only patients (83%, p < 0.01).
- Predictors for SCA included severe multivessel spasm, daytime ST-segment changes, and younger age.
- Daytime ST-segment changes and active smoking were associated with syncope.
Implications:
- The circadian pattern of coronary spasm may vary depending on whether it triggers SCA/syncope or typical angina.
- Coronary spasm evaluation is crucial for patients with aborted SCA or unexplained recurrent syncope, even without typical nocturnal angina.
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