EKG Readings Can be Wrong
Reported November 19, 2009
(Ivanhoe Newswire) — Measurements on the electrocardiogram (EKG) can often mislead physicians into diagnosing the heart condition left ventricular hypertrophy (LVH), requiring further screening tests before a definitive conclusion can be reached.
A study of 500 patients found a false positive reading of between 77 and 82 percent in patients screened by EKG, and a false negative reading between 6 and 7 percent in the same patient population. The EKG also showed a high negative predictive reading, which reflects the absence of LVH.
Researchers compared patients EKG data with coronary CT scans, which are considered highly accurate for diagnosing LVH. An EKG, measures electrical activity of a heartbeat; a CT scan produces clear, detailed images of the heart.
“The EKG criteria for diagnosing left ventricular hypertrophy have a very poor sensitivity,” Mohamad Sinno, M.D., cardiology fellow at Henry Ford Hospital and lead author of the study, was quoted as saying. “So when the EKG shows left ventricular hypertrophy, it doesn’t allow the physician to make an accurate assessment, and further screening tools such as cardiac CT, MRI scan, or an echocardiogram are warranted.”
LVH, a condition in which the lower-left chamber of the heart grows abnormally thick, affects more than 16 percent of the adult population in the United States. It is caused by an underlying medical condition, most commonly high blood pressure, but frequently symptoms do not manifest until late in the disease process. Left untreated, LVH is an independent predictor of serious or fatal cardiovascular disease.
SOURCE: Presented at the American Heart Association Annual Scientific Conference, Orlando, FL, November 14-18, 2009