HEART RATE VARIABILITY IN PATIENTS WITH UNSTABLE ANGINA

Abstract

Analysis of heart rate variability (HRV) is a noninvasive method of assessing the integrity of neural input to the cardiovascular system (Pagani et al., 1986). Bigger and Coworkers in 1992 have extended •the use of HRV analysis into the clinical domain by demonstrating its value in risk stratification of patients after myocardial infarction . This finding has been confirmed by other investigators (Cripps et a/.,1991) and has also been found in patients with stable coronary artery disease (Rich eta/ .,1988).

The aim of this work is to study H.R.V. parameters in patients with unstable angina and to see if these parameter have any prognostic value. Fifty patients with unstable angina were included in this study. They were selected from CCU at Benha University Hospitalduring the• period from May 2001 to May 2002.Ten healthy control subjects were also included for comparison . All patients are subjected to the following :

1- Thorough history taking and clinical examination to detect risk factors of coronary artery disease and to exclude other causes of chest pain. 2- Resting E.C.G: resting 12 lead. E.C.G. was done to confirm the diagnosis of unstable angina and exclude ST elevation MI, AF and conduction defects. 3- Routine laboratory investigations:

Blood sugar, serum creatinine and cardiac enzymes were done to all patients to exclude M.I., renal failure and diabetes mellitus.