Vol.11, No 3, 2004 pp. 107 - 112
UC 616.127:616.132.2
SILENT MYOCARDIAL ISCHEMIA IN ASYMPTOMATIC PATIENTS
WITH MULTIPLE CORONARY RISK FACTORS
Stevan Ilić, Marina Deljanin Ilić, Dejan Petrović, Ivan Tasić, Dragan Djordjević, Bojan Ilić
Institute for Prevention, Treatment and Rehabilitation of Rheumatic and Cardiovascular Diseases, Niška Banja
E-mail: stevanil@bankerinter.net
Summary. Myocardial ischemia which occurs in the absence of chest pain or its equivalents (silent myocardial ischemia) is common in patients with coronary artery disease. Silent myocardial ischemia may also be found in asymptomatic patients, particularly those with underlying risk factors. It is important for physicians to identify the existence of silent myocardial ischemia because it is predictive of increased cardiac risk.
Objective: To evaluate the frequency and characteristics of silent myocardial ischemia in asymptomatic patients with multiple coronary risk factors ("high coronary risk" patients).
Methods: Study group consisted of 360 male pts (age from 35 to 70 years) with multiple coronary risk factors free of previously diagnosed coronary artery disease. In study pts the most frequent risk factors for coronary artery disease were arterial hypertension (74%) and cigarette smoking (60%). In all pts maximal, or ST segment depression of >= 0.2 mV or symptom-limited exercise test was performed. In those with ST-segmant depression on exercise electrocardiogram, stress echocardiography was additionally performed in order to confirm myocardial ischemia.
Results: Out of 360 patients 290 (81%) patients had neither ST-segment depression nor anginal pain during exercise stress testing, 52 (14%) patients had ischemic type of ST-segment depression on exercise electrocardiogram without chest pain and 18 (5%) patients had ischemic ST-segment depression and the first occurrence of chest pain (symptomatic myocardial ischemia). All patients with symptomatic myocardial ischemia had an echocardiographic marker for ischemia but out of 52 patients with asymtpomatic ST-segment depression 43 patients had echo markers for ischemia (silent miocardial ischemia), while in 9 patients stress echocardiography was without regional wall motion abnormality (false positive exercise electrocardiogram). Thus both types of myocardial ischemia were recorded in 61 (17%) "high coronary risk" patients (12% silent and 5% symptomatic myocardial ischemia). There were no significant difference in regard to magnitude and duration of ST-segment depression and exercise tolerance between patients with symptomatic and silent myocardial ischemia, but wall motion score index was bigger in patients with symptomatic than in those with silent myocardial ischemia (P<0.01).
Conclusion: This study showed that in 12% of asymptomatic "high coronary risk" patients silent myocardial ischemia during exercise test was found. There were no differences between two types of myocardial ischemia in the exercise electrocardiogram but symptomatic ischemia had a higher degree of wall motion abnormality on stress echo than silent myocardial ischemia.
Key words: Silent myocardial ischemia, echocardiography stress test, coronary risk factors
ASIMPTOMATSKA MIOKARDNA ISHEMIJA U ASIMPTOMATSKIH OSOBA
S MULTIPNIM KORONARNIM FAKTORIMA RIZIKA
Kratak sadržaj: Miokardna ishemija koja nije prećena anginoznim bolom ili ekvivalentima anginoznog bola (asimptomatska miokardna ishemija) je česta u bolesnika sa stabilnom i nestabilnom anginom pektoris, kao i u bolesnika s preživljenim infarktom miokarda. Takodje, asimptomatska miokardna ishemija se može otkriti i u asimptomatskih bolesnika s većim brojem faktora rizika za koronarnu bolest.
Cilj rada je odrdjivanje učestalosti i karakteristika asimptomatske miokardne ishemije u osoba bez simptoma miokardne ishemije i bez ranije dijagnostikovane koronarne bolesti, ali s multipnim koronarnim faktorima rizika.
U grupi od 360 muških osoba (starosti izmedju 35 i 70 godina) sa većim brojem faktora rizika (rizikom većim od 20%) za ishemijsku bolest srca (najčešći faktori rizika su bili arterijska hipertenzija - 74% i pušenje duvana - 60%) uradjen je test fizičkim opterećenjem maksimalnog tipa ili je test bio limitiran pojavom simptoma sa ST depresijom ili samo pojavom ST segment depresije >= 0,2 mV. Svim bolesnicima koji su na elektrokardiogramu u testu fizičkim opterećenjem imali depresiju ST segmenta >= 1 mV uradjen je sledećih dana i 2D stress ehokardiografski test radi potvrde postojanja miokardne ishemije.
U grupi od 290 osoba (81%) nije registrovana depresija ST segmenta na elektrokardiogramu, niti se javio anginozni bol u testu fizičkim opterećenjem. U grupi od 52 (14%) bolesnika registrovana je depresija ST segmenta ali bez pojave anginoznog bola ili njegovih ekvivalenata (asimptomatska ST segment depresija) i u grupi od 18 (5%) registrovana je, po prvi put, depresija ST segmenta, koja je praćena angiznim bolom ili njegovim ekvivalentima (simptomatska miokardna ishemija). Svi bolesnici sa simptomatskom miokardnom ishemijom imali su pozitivan stres ehokardiografski test (poremećaj kinetike segmenata leve komore u naporu), dok su u 43 od 52 bolesnika sa asimptomatskom ST segment depresijom u testu fizičkim opterećenjem nadjeni segmentni poremećaji kinetike leve komore (asimptomatska miokardna ishemija), a u 9 bolesnika nisu postojali znaci miokardne ishemije (lažno pozitivan nalaz miokardne ishemije na elektrokardiogramu u opterećenju). Prema tome u 61 (17%) asimptomatskog bolesnika s multipnim koronarnim faktorima rizika nadjena je miokardna ishemia (12% asimptomatska i 5% simptomatska). Nisu nadjene značajne razlike u veličini i trajanju depresije ST segmenta, niti u toleranciji fizičkog napora u bolesnika sa simptomatskom i asimptomatskom miokardnom ishemijom. Medjutim, u bolesnika sa simptomatskom miokardnom ishemijom indeks skora zidne pokretljivosti bio je značajno veći no u bolesnika sa asimptomatskom ishemijom (P<0,01).
U osoba sa "visokim koronarnim rizikom" stres testom asimpotomatska miokardna ishemija je registrovana u 12%. Nema značajnih razlika izmedju simptomatske i asimptomatske ishemije na elektrokardiogramu u testu fizičkim opterećenjem, dok se u bolesnika sa simptomatskom ishemijom stres ehokardiografskim testom otkrivaju veće abnormalnosti u segmentnoj kinetici leve komore.
Ključne reči: Asimptomatska miokardna ishemija, stres ehokardiografski test, koronarni faktori rizika