Failure of digital echocardiography to accurately diagnose intracardiac shunts.
BACKGROUND
Intravenous agitated saline injection during transthoracic echocardiography assists in the detection of right to left intracardiac and intrapulmonary shunts. Whether digital echocardiography offers comparable sensitivity and specificity to analog tape recording to assess shunts is unknown. Technical differences between methods could lead to significant differences in shunt detection.


METHODS
Agitated saline was injected intravenously at rest and with Valsalva in 189 consecutive patient studies (406 injections). Echocardiographers assessed presence and degree of left ventricle contrast on simultaneously recorded analog tape and digital echocardiography images in blinded fashion.


RESULTS
Digital echocardiography had low overall sensitivity (rest 0.50, valsalva 0.63, late 0.39) compared to analog tape. Longer clip lengths improved sensitivity for detection of late contrast passage (rest 0.50, valsalva 0.67, late 0.46).


CONCLUSIONS
Digital echocardiography saline contrast studies have poor sensitivity for assessment of intracardiac shunts versus analog tape, and increasing clip length only modestly increases sensitivity. Joint Photographic Experts Group digital compression losses may be an important cause of failure to detect intracardiac shunts, including patent foramen ovale.
Rahmouni
Hind W
HW
Department of Medicine, Cardiovascular Division, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Keane
Martin G
MG
Silvestry
Frank E
FE
St John Sutton
Martin G
MG
Ferrari
Victor A
VA
Scott
Craig H
CH
Wiegers
Susan E
SE
D000368:Aged; D016507:Cardiology Service, Hospital; D015331:Cohort Studies; D003287:Contrast Media; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000175:diagnosis / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D012965:Sodium Chloride
D003287:Contrast Media; D012965:Sodium Chloride