Use Of Transtelephonic Monitoring On Silent Myocardial Ischemia In Elderly Patients With Coronary Heart Disease

Objective:It is well known that, Coronary Heart Disease (CHD) is common in the elderly, its mortality increases with advancing years. It is said that the higher mortality occurred in elderly patients with CHD, over 85% of the mortality has happened in the patients with CHD beyond 65-year-old. The clinical manifestations of elderly patients with CHD are often atypical and many elderly patients with myocardial ischemia seldom have symptoms of angina pectoris. Thus, the proper detection, assessment, prevention and treatment for myocardial ischemia and arrhythmia in elderly patients with CHD have become more and more important.Transtelephonic Monitoring (TTM) is a newly developed noninvasive diagnostic technique by medical transtelephonic communication and computer systems. Several studies have confirmed that TTM is an effective diagnostic technique of myocardial ischemia. According to the literatures, no data has been published about transtelephonic monitoring on Silent Myocardial Ischemia (SMI) in elderly patients with CHD in China.In our present study, elderly patients with CHD were detected by TTM and Dynamic Electrocardiography (DCG), and the applicable value of TTM for SMI in the patients was evaluated.Subjects and Methods:1. Study subjects200 elderly inpatients with CHD were enrolled which were consistent with the CHD diagnosis criteria of World Health Organization(WHO), including 168 males and 32 females, mean age( 75.7±4.62)yrs. the conditions of all patients had been stable for a month, who were diagnosed as myocardial ischemia by means as follows: coronary angiography (if there was stenosis of >50% in anyone of vessels such as: the left anterior descending branch, left circumflex branch, and right coronary artery, it was considered as positive), Multi-detector Row Spiral CT (MDCT) , the same positive criteria as the former was applied), the past history of myocardial infarction, electrocardiogram or exercise test. the patients whose ST-segments were affected by left ventricular hypertrophy, bundle branch block, serious anemia, disturbances of electrolyte balance, fever, hypertrophic cardiomyopathy, autonomic nerve dysfunction, the use of digitalis or P-blocker and so on were excluded.2. Methods2.1 Common clinic data: the past history of all patients, such as hypertension, diabetes mellitus, hyperlipemia, myocardial ischemia, angina pectoris, cerebral apoplexy and so on.2.2Both of 24-48 hours TTM and 24 hours DCG were performed in the patients within one week when the patients were asymptomatic and in normal daily lives and the episodes of SMI and arrhythmia were recorded.3. Statistical analysisAll data were processed by SPSS11.5 version. The data of two groups were compared byχ~2 test. A value of P < 0.05 was considered significant. Results:1. The positive rates of TTM and DCG for SMI in 200 elderly patients with CHD were 69.50% and 44.00% respectively. There was significant difference between two groups (χ~2 =26.49,P < 0.05) .2. The positive rate of TTM and DCG for SMI, in total, was 73.00%.3. The positive rates of TTM and DCG for SMI in patients with single vessel lesion were 42.86% and 33.33% respectively(χ~2 =0.40,P > 0.05) .The positive rates of TTM and DCG for SMI in patients with double vessel lesion were 70.31% and 43.75% respectively (χ~2=9.21,P < 0.05) and in patients with multivessel lesion were 77.53% and 47.19% respectively (χ~2=17.45,P< 0.05) .4. The positive rates of TTM for SMI in patients with double vessel lesion or multivessel lesion were significant higher than those in patients with single vessel lesion. (χ~2=5.14,P < 0.05;χ~2=9.90,P < 0.05) While there was no significant difference between patients with double vessel lesion and those with multivessel lesion(χ~2=1.02, P>0.05) .5. No significant difference in the positive rates of DCG for SMI among the patients with different pathological changes , including single vessel , double vessel and multivessel lesion (P > 0.05) .6. The positive rates of TTM and DCG for the diagnosis of arrhythmia:6.1. The positive rates of TTM and DCG for the diagnosis of premature atrial contraction were 28.00% and 30.50%.6.2. The positive rates of TTM and DCG for the diagnosis of premature ventricular contraction were 21.00% and 23.00%.6.3. The positive rates of TTM and DCG for the diagnosis of slow arrhythmia were 12.50% and 10.50%.6.4. The positive rates of TTM and DCG for the diagnosis of tachyarrhythmia were 15.50% and 9.00%.The positive rates of TTM and DCG for the diagnosis of premature atrial contraction, premature ventricular contraction and slow arrhythmia had no significant difference (P > 0.05) . The positive rate of TTM in the diagnosis of tachyarrhythmia was much higher than DCG. (P < 0.05) .Conclusion:1. SMI and arrhythmia of elderly patients with CHD can be detected by TTM in time.2. TTM has the higher positive rate of SMI which occurred in elderly patients with CHD who had two or more coronary vessel diseases than single vessel disease. It is consistent with the characteristics of elderly patients with CHD.3. TTM has greatly clinical importance for the diagnosis of SMI in elderly patients with CHD. The detection of SMI is significant increased by combined application of TTM and DCG.