Perioperative myocardial ischemia in carotid endarterectomy under cervical plexus block and prophylactic nitroglycerin infusion.
Perioperative myocardial ischemia was evaluated in 36 consecutive carotid endarterectomy procedures carried out on patients with a high (72.2%) prevalence of ischemic heart disease. The procedures were performed under cervical plexus block plus a prophylactic intravenous nitroglycerin infusion. Findings of myocardial ischemia on perioperative (48 hours) continuous electrocardiogram recordings were correlated with preoperative cardiac status, perioperative continuous intra-arterial blood pressure measurements, and postoperative cardiac outcome. In two patients, ST segment analysis was un-interpretable because of bundle-branch blocks. Altogether, 64 episodes of significant ST segment depression were detected in 18 (52.9%) of the remaining procedures. In 8 (23.5%) procedures, ST segment depressions occurred either during carotid artery clamping at the time of the largest rise in blood pressure or within 2 hours of declamping, when blood pressure tended to decline. There were four (11.7%) postoperative cardiac events: three myocardial infarctions (one Q wave and two non-Q wave) and one episode of unstable angina pectoris. All four patients with cardiac events had early signs of myocardial ischemia either at the time of cross-clamping, or soon after declamping of the carotid artery. All myocardial infarctions developed following prolonged (> 10 hours) myocardial ischemia, starting with the first 20 hours after surgery. Thus, ST segment depression occurring during clamping or soon after carotid declamping was associated with cardiac complications (sensitivity 100% and specificity 86.6%) and suggests the possible usefulness of on-line ST segment trend monitoring.
Department of Anesthesiology, Hebrew University Hadassah Medical School, Jerusalem, Israel.
G
G
Landesberg
J
J
Erel
H
H
Anner
L A
LA
Eidelman
E
E
Weinmann
M H
MH
Luria
D
D
Admon
J
J
Assaf
D
D
Sapoznikov
Y
Y
Berlatzky
D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000601:surgery; D001794:Blood Pressure / Q000502:physiology; D002339:Carotid Arteries / Q000601:surgery; D002340:Carotid Artery Diseases / Q000601:surgery; D002572:Cervical Plexus; D003250:Constriction; D003327:Coronary Disease / Q000503:physiopathology; D004562:Electrocardiography; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009203:Myocardial Infarction / Q000209:etiology; D017202:Myocardial Ischemia / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D009407:Nerve Block; D009460:Neurologic Examination; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use*; D011446:Prospective Studies; D016896:Treatment Outcome
D005996:Nitroglycerin