RSS Feeds
Transient Ischemic Attack after Air Contrast Echocardiography in Patients with Septal Aneurysm
The Editors welcome submissions for possible publication in the Letters section. Authors of letters should:
•Include no more than 300 words of text, three authors, and five references
•Type with double-spacing
•Send three copies of the letter, an authors' form signed by all authors, and a cover letter describing any conflicts of interest related to the contents of the letter.
Letters commenting on an Annals article will be considered if they are received within 6 weeks of the time the article was published. Only some of the letters received can be published. Published letters are edited and may be shortened; tables and figures are included only selectively. Authors will be notified that the letter has been received. If the letter is selected for publication, the author will be notified about 3 weeks before the publication date. Unpublished letters cannot be returned.
Annals welcomes electronically submitted letters.
TO THE EDITOR:
Intravenous air is frequently used during echocardiography to show right-to-left heart shunting [1]. Small amounts are considered safe because of the lung's filtering action. Associated cerebral ischemic symptoms have not been reported either because of their infrequency or subtlety or because of a reluctance to report an iatrogenic complication. We have done 46 air contrast studies in patients in whom atrial septal aneurysm was diagnosed during routine echocardiography. Right-to-left shunts were found in seven patients, and transient ischemic attacks occurred in three patients.
Contrast echocardiography [2] was done using 10 mL of agitated air and normal saline. No patient had a history of transient ischemic attack. In two patients, transcranial Doppler studies were done during or after the procedure. Air emboli were identified in both patients for as long as 2 hours by their characteristic audio “chirps” and transcranial Doppler waveform [3].
All symptoms appeared when patients arose, and they resolved in minutes or hours. Neurologic deficits consisted of dizziness and paraparesis with numbness in patients with large shunts; diplopia, left hemiparesis, and right seventh-nerve weakness in patients with moderate shunts; and left upper extremity numbness and paresthesias in patients with small shunts.
Air embolism appeared to be responsible for the observed symptoms because no patient had a history of transient ischemic attack and because symptoms occurred soon after procedures done with documented intracranial air emboli. Clinicians should exercise care when injecting air bubbles, given the risk for neurologic deficits. Vigorous agitation of the air contrast to reduce bubble size does not completely eliminate this risk. Use of a more soluble gas, such as oxygen or carbon dioxide, may be prudent. Further, because of the risk for paradoxical air embolism in patients with unsuspected right-to-left heart shunts, great care should be exercised in the flushing and proper connection of intravenous lines in all patients.
The Editors welcome submissions for possible publication in the Letters section. Authors of letters should:
•Include no more than 300 words of text, three authors, and five references
•Type with double-spacing
•Send three copies of the letter, an authors' form signed by all authors, and a cover letter describing any conflicts of interest related to the contents of the letter.
Letters commenting on an Annals article will be considered if they are received within 6 weeks of the time the article was published. Only some of the letters received can be published. Published letters are edited and may be shortened; tables and figures are included only selectively. Authors will be notified that the letter has been received. If the letter is selected for publication, the author will be notified about 3 weeks before the publication date. Unpublished letters cannot be returned.
Annals welcomes electronically submitted letters.
- Copyright ©2004 by the American College of Physicians
