Cardiology: The Fickle Heart

Many a layman who has just had an electrocardiogram takes his doctor's verdict of "ECG normal" as an assurance of a long and healthy life. Cardiologists know better. The repetitive squiggles on the ECG paper are simply a graphic recording of the electrical impulses that signal the heart's contractions. While an ECG will reveal some types of heart abnormality, and specifically whether a man has recently had a heart attack, it has limited predictive value—a fact made dramatically clear in the case of Lyndon B. Johnson, then Majority Leader of the Senate,...