LITHUANIAN UNIVERSITY OF HEALTH SCIENCES LUHS LIBRARY REPOSITORY

Širdies ritmo sutrikimų, variabilumo ir kairiojo skilvelio disfunkcijos prognozinės vertės ūminiu miokardo infarkto periodu nustatymas

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dc.contributor.author Bakšytė, Giedrė
dc.date.accessioned 2017-08-21T08:22:55Z
dc.date.available 2017-08-21T08:22:55Z
dc.date.issued 2005
dc.identifier.uri http://repository.lsmuni.lt/handle/1/70005
dc.description.abstract The scientific novelty of the study A large number of reports have demonstrated that depressed heart rate variability after myocardial infarction (MI), left ventricular dysfunction and arrhythmias are powerful predictors of mortality. Nevertheless there is a lack of detailed assessment of heart rate variability in the acute period of MI, especially during the first 24 hours, from long-term (24-h) recordings, and the value of different parameters of heart rate variability in predicting dangerous complications of MI was not fully evaluated. The indications of complex and constant monitoring of heart rate variability, left ventricular function, arrhythmias in acute MI are not based on scientific studies as well as their value in predicting the effect of different methods of management, course and outcomes of critical cardiac conditions. Thus, the current study differs from all the earlier studies in that we assessed heart rate variability in the very early period of myocardial infarction (the first and the third day) using long time recordings (24 h), both – time-domain and frequency-domain –methods, and evaluated its changes in relation to arrhythmias and left ventricular function, using not only conventional 2D-echocardiography but also left ventricular long axis function assessment by M-mode and tissue Doppler imaging. The aim of the study The aim of the study was to determine the association between heart rate variability, cardiac arrhythmias and left ventricular dysfunction in patients with acute myocardial infarction and their prognostic value for the course of the disease and the outcome. The objectives of the study 1. To assess the heart rate variability in patients with acute myocardial infarction from the first, third and 12-14th day ECG recordings and to determine its changes in association with infarct site, extent, the course of the disease and left ventricular dysfunction; 2. To determine the prevalence, characteristics and time of appearance of arrhythmias in the same group of patients in association with left ventricular systolic and diastolic function, extent of coronary artery disease and course of the infarction; 3. To assess left ventricular systolic and diastolic function in patients with acute myocardial infarction in association with infarct site, the extent of coronary artery lesions and course of the infarction; 4. To characterize the association between heart rate variability, arrhythmias and left ventricular systolic and diastolic function in patients with acute myocardial infarction; 5. To characterize the prognostic value of heart rate variability, arrhythmias and left ventricular systolic and diastolic function for the course and the outcome of myocardial infarction. METHODS We prospectively studied 108 consecutive patients admitted to the Intensive Care Unit of the Department of Cardiology of Kaunas Medical University Hospital between 2002 and 2004 with acute myocardial infarction defined as follows: 1) chest pain lasting 20 min or more, not responding to nitroglycerine; 2) ST-segment elevations or (presumed) new left bundle-branch block on admission ECG and/or 3) elevated markers of myocardial necrosis (troponin I). Exclusion criteria were chest pain lasting for more than 24 hours, pacemaker rhythm, rhythm other than sinus rhythm, hemodynamically significant valvular heart disease, patient’s refuse to participate in the study. All the patients gave informed consent for the research protocol, which has been approved by the institutional review board. The study protocol included the following stages: 1) history and physical examination on admission; 2) 24-lead ECG; 3) laboratory examinations on admission and if needed later; 4) 24-h ECG monitoring on the first and the third day of admission and 1h ECG monitoring before discharge on the 12-14th day; 5) chest x-ray; 6) echocardiography performed at days 2-4; 7) coronary angiography and PCI or fibrinolysis on admission for those with ST-segment elevation and no contraindications; 8) further pharmacological and non-pharmacological treatment according to the European Guidelines on Management of Acute Myocardial Infarction (European Heart Journal 2003;24:28-66). In-hospital prognostic end-points were death and non-fatal events: post-infarction angina, progressive heart failure, pulmonary edema and cardiogenic shock. Conclusions 1. In patients with acute myocardial infarction heart rate variability parameters are decreased already on day 1. On day 3 spectral components further decrease while time-domain indexes remain unchanged; 2. HRV parameters (mean NN, HRV triangular index, LF, HF, TP) are significantly lower in anterior myocardial infarction on day 1 as compared to non-anterior infarction. HRV (mean NN, TINN, LF) is lower in Q wave MI as compared to non-Q wave MI on day 1; 3. Patients with in-hospital complications (post-infarction angina, progressive heart failure, pulmonary edema, cardiogenic shock) have significantly lower HRV parameters (mean NN, SDNN index, pNN50, triangular index, TINN and all spectral components) already on day 1 as compared to patients without complications; 4. Late (48 hours or more) ventricular arrhythmias (premature ventricular complexes, ventricular tachycardia and/or fibrillation), atrial fibrillation/flutter are significantly more frequent in patients with severe LV systolic dysfunction (EF<40%), >2 coronary artery disease, in-hospital complications (post-infarction angina, progressive heart failure, pulmonary edema, cardiogenic shock); 5. Left ventricular systolic (higher WMI, lower left ventricular mitral annulus motion systolic parameters) and diastolic (shorter DT, lower left ventricular mitral annulus motion diastolic parameters) function is significantly more severely impaired in patients with anterior myocardial infarction and in-hospital complications (post-infarction angina, progressive heart failure, pulmonary edema, cardiogenic shock). One-coronary artery disease is associated with significantly higher LV EF, lower WMI and LV volumes as compared to 2- and 3-coronary artery disease; 6. HRV parameters have significant and moderate-weak correlation with left ventricular systolic and diastolic function parameters, the strongest association was observed between SDNN index on day 3 and MAM amplitude (r=0.73). HRV parameters (pNN50, triangular index, TINN, LF, HF on day 1 and triangular index, TINN, LF on day 3) are significantly lower in patients with late ventricular arrhythmias. 7. LF on day 3, left ventricular end-systolic volume, atrial fibrillation/flutter and inotropic agent administration on day 1 are statistically significant independent predictors of in-hospital complications (post-infarction angina, progressive heart failure, pulmonary edema, cardiogenic shock). The average predictive efficacy of these variables is 96.5%.
dc.language.iso lit
dc.subject Prognostic value.
dc.subject Heart rate variability
dc.subject Kairiojo skilvelio disfunkcija
dc.subject Širdies ritmo variabilumas
dc.subject Arrhythmias
dc.subject Prognozinė vertė
dc.subject Left ventricular dysfunction
dc.subject Ūminis miokardo infarktas
dc.subject Acute myocardial infarction
dc.subject Ritmo sutrikimai
dc.title Širdies ritmo sutrikimų, variabilumo ir kairiojo skilvelio disfunkcijos prognozinės vertės ūminiu miokardo infarkto periodu nustatymas
dc.title.alternative Prognostic value of cardiac arrhythmias, heart rate variability and left ventricular dysfunction in patients with acute myocardial infarction
dc.type Disertacijos santrauka


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