ABSTRACT
AIM: To assess QRS voltage changes with lower total amount of biological fluids under ultrafiltration during hemodialysis. MATERIALS AND METHODS: The study included 14 patients with chronic renal failure. An average of 2.5 +/- 0.24 liters of fluid were removed during a session. 12-lead standard ECG was continuously recorded by means of a computer-aided cardiac recorder throughout the session of hemodialysis. Changes in the amplitude of QRS waves were analyzed in each lead. RESULTS: Elevated QRS voltage was most pronounced in the anterior chest leads (v1-v4). Moreover, the potentials corresponding to the propagation of a predominant excitation front over the cardiac surface facing both the anterior chest wall--QRS+ (R wave) and the posterior chest wall--ORS-(S or Q waves) increased in most cases. Voltage changes in these leads were observed in 90% of patients, the amplitude of the waves being increased by more than 0.5 mV. CONCLUSION: During dehydration, lower chest tissue electroconductivity may cause a considerable increase in QRS voltage. This should be kept in mind while analyzing ECG data during both a session of hemodialysis and antihypertensive therapy resulting in some fluid loss, as well as in the treatment of cardiac and renal failure, leading to diminished concomitant edemas.
