Test­ing can some­times serve no use­ful pur­pose

The Washington Times Daily - - Life - DR. DAVID LIPSCHITZ

Fre­quently, I see asymp­to­matic pa­tients who re­port a “clean bill of health” from their car­di­ol­o­gists. Their elec­tro­car­dio­gram, stress test, echocar­dio­gram and CT scan of the heart are nor­mal.

Oc­ca­sion­ally, these pa­tients are be­ing screened be­cause they have a known coro­nary artery dis­ease. But quite fre­quently, they are mid­dle aged or older and are be­ing screened to en­sure no prob­lem ex­ists. With these pa­tients, the tests have no value and the cost is high.

So what are these tests and when should they be done? An elec­tro­car­dio­gram, or EKG, mea­sures the elec­tri­cal ac­tiv­ity of the heart. With each heart­beat, an elec­tri­cal cur­rent be­gins in the top of the heart and moves down a con­duc­tion sys­tem, stim­u­lat­ing the heart to con­tract. Elec­trodes placed on the chest and arm read out this elec­tri­cal ac­tiv­ity. The pat­tern of the read­out can de­tect a new heart at­tack, ev­i­dence of an old one and ir­reg­u­lar­i­ties of the heart­beat.

It is an in­valu­able di­ag­nos­tic tool for some­one who has symp­toms sug­ges­tive of a heart at­tack or to di­ag­nose con­di­tions such as atrial fib­ril­la­tion in which gross ir­reg­u­lar­i­ties of the heart rate can lead to an in­creased risk of strokes and heart fail­ure. How­ever, as a screen­ing test, an EKG has vir­tu­ally no value. It may miss heart prob­lems and just as fre­quently, may show changes sug­gest­ing heart dis­ease that is not present.

A stress test in­volves stim­u­lat­ing the heart to beat faster ei­ther by ex­er­cise us­ing a tread­mill or by mim­ick­ing the ef­fect of ex­er­cise with the in­jec­tion of a med­i­ca­tion (per­san­tine) and a ra­dioac­tive marker that can iden­tify ar­eas of in­ad­e­quate blood sup­ply. This test re­mains a “gold stan­dard” to di­ag­nose coro­nary artery dis­ease in some­one with chest pain or short­ness of breath. How­ever, no study has shown the test to be of value as a screen for coro­nary artery dis­ease in a healthy, asymp­to­matic per­son.

An echocar­dio­gram is a test that al­lows a com­plete eval­u­a­tion of the four cham­bers of the heart and the way in which the heart con­tracts with each heart­beat. It mea­sures the amount of blood that is pumped out of the heart with each beat and can eval­u­ate the func­tion of the heart valves be­tween the cham­bers of the heart and pul­monary and aor­tic ar­ter­ies. This non­in­va­sive pro­ce­dure can iden­tify se­vere weak­ness or dys­func­tion in the way the heart mus­cle con­tracts, as well as di­ag­nose prob­lems with the heart valves. This test never should be used as a screen­ing test in nor­mal in­di­vid­u­als.

Of all the screen­ing tests, the car­diac CT scan is the most prob­lem­atic. Used as a mar­ket­ing tool, this test prom­ises un­wary con­sumers the po­ten­tial of sav­ing lives by per­form­ing this “heart sav­ing” CT scan. Coro­nary artery dis­ease is sus­pected if in­creased cal­cium in the ar­ter­ies is noted. Com­bin­ing a CT scan with the in­jec­tion of a dye can demon­strate sig­nif­i­cant block­ages of coro­nary ar­ter­ies.

In chron­i­cally or se­verely ill in­di­vid­u­als, a car­di­ol­o­gist may pre­fer a less in­va­sive CT scan to an an­giogram to di­ag­nose coro­nary artery dis­ease. The scan pro­vides a great deal of ir­ra­di­a­tion and is of no proven value as a screen­ing test. Par­tic­u­larly egre­gious is the use of a CT scan to screen for heart dis­ease in any­one older than 70. At this age and be­yond, the nar­row­ing of the coro­nary ar­ter­ies is very com­mon.

By iden­ti­fy­ing ex­ces­sive cal­cium, ad­di­tional eval­u­a­tions, in­clud­ing an­giograms, an­gio­plasty and even open-heart surgery, may be done. The pa­tient may be­lieve a heart at­tack will be pre­vented and life pro­longed. Un­for­tu­nately, in­va­sive pro­ce­dures do nei­ther — they re­lieve symp­toms, which these pa­tients do not have.

Preven­tion is the key to man­ag­ing heart dis­ease. It is all about diet, ex­er­cise, stress re­duc­tion and con­trol of blood pres­sure and choles­terol.

As for me, 16 years ago I had a heart at­tack. Since then, I haven’t had an EKG, stress test or echocar­dio­gram. Even with known heart dis­ease, these tests are only needed if new symp­toms, such as chest pain, pal­pi­ta­tions or short­ness of breath, oc­cur.

Un­der­stand that un­nec­es­sary screen­ing tests do more harm than good, and their cost is con­tribut­ing to the col­lapse of our health care sys­tem.

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