Persistent ST Elevation and New Regional Wall Motion Abnormalities without Evidence of Coronary Artery Obstruction after Surgical Repair of an Endocarditic Aortic Valve
Erik R. Perschau DO and Yong G. Peng MD, PhD
Department of Anesthesiology, University of Florida, Gainesville, Florida
ABSTRACT
Perioperative myocardial infarction is an important complication of adult
cardiac surgery. Its cause typically relates to underlying coronary disease
or intraoperative factors such as spasm, emboli, coronary thrombosis.
Intraoperative modalities commonly employed to diagnose myocardial ischemia
include the electrocardiogram, transesophageal echocardiography (TEE), and
the pulmonary artery catheter. Presence of regional wall motion
abnormalities (RWMA) in TEE is considered the most sensitive method of
detecting intraoperative myocardial ischemia.1,2 We present a case that
highlights important limitations of these diagnostic modalities.
A 53 year old male with bacterial endocarditis presented for surgical
repair/replacement of the infected aortic valve. Preoperative coronary
andiography demonstrated normal coronary arteries, normal contractile
function of all wall segments and progressive aortic insufficiency. After
debridement and repair of his native valve the patient developed persistent
ST segment elevation and regional wall motion abnormalities consistent with
acute myocardial infarction in the territory of the right coronary artery.
Inspection of the right coronary showed no abnormalities. Therefore,
coronary angiography was repeated immediately after wound closure. Again the
coronaries were found to be normal and widely patent. The patient’s
ST-segment elevations resolved along with the RWMA over the course of the
next two days. Serologic markers of myocardial ischemia were abnormal
postoperatively. Their values were in excess of those seen after uneventful
cardiac surgery, but less than those characteristic of perioperative
myocardial infarction.
In summary, we present a case wherein clinical scenario, EKG, and TEE
pointed towards an acute myocardial infarction, although angiography
repeatedly showed unobstructed coronaries. This case highlights the
diagnostic help provided by EKG and TEE as well as the inherent limitations
of these monitors in delineating the etiology of impaired cardiac function.
References:
1. Selbst et al, “Myocardial Ischemia Monitoring,” International
Anesthesiology Clinics 2002;40:133-46
2. Comunale et al, “The Concordance of Intraopreative Left Ventricular Wall
Motion Abnormalities and Electrocardiographic ST Segment Changes,”
Anesthesiology 1998 April;88(4):945-54
