[Risk of sudden death in patients with chronic renal failure and hemodialysis]

Cardiovascular mortality in uremic patients treated by hemodialysis overrates ten times cardiovascular mortality in general population. Approximatively 40% of patients on iterative hemodialysis die from cardiac diseases, half of cases by sudden death. Several risk factors for sudden death are well known: QTc interval prolongation, decrease of RR interval <750 msec, decrease of heart rate variability, presence of late ventricular potentials (LVP), presence of high risk ventricular extrasystoles, decrease of ejection fraction (EF) <40 %, presence of left ventricular hypertrophy. Our study evaluated the above-mentioned risk factors for sudden death in patients with chronic renal failure on hemodialysis. We studied 37 patients, 22 males and 15 females, with mean age of 42 years old, without diabetes, heart failure and arrhythmias, without myocardial ischemia on ECG, being on hemodialysis (HD) programme for minimum 1 year (HD parameters are: 4 h x 3/week, qB = 300 ml/min, buffer = bicarbonate, Ca dialysate = 1.75 mmol/l, K dialysate = 2.1 mmol/l, conductivity = 135 mS). The patients were evaluated by echocardiography, standard and Holter ECG. Statistics evaluation was performed in SPSS v.9.0. Program. The results proved that 80% of patients on HD have risk factors for sudden death, which are closely related with age and hyperhydration. Statistics proved that presence of high-risk arrhythmias is connected with heart rate variability and prolongation of QTc interval (favored by HD). 50% of our patients have 2 to 4 risk factors for sudden death, which increase incidence of sudden death in patients on HD.