Correlation between asymptomatic intradialytic hypotension and regional left ventricular dysfunction in hemodialysis patients

Cardiovascular disease and heart failure are common in dialysis patients. Recurrent subclinical myocardial ischemia is an important event which may lead to the heart failure. We examined whether this phenomenon occurs secondary to the intradialytic hypotension in hemodialysis patients. Twelve patients prone to intradialytic hypotension who had been on maintenance hemodialysis for more than 12 months and 15 hemodialysis patients without any history of intradialytic hypotension were included in this study. Echocardiography was performed before hemodialysis [baseline], and at 60 minutes and 120 minutes during hemodialysis [climax], and 30 minutes postdialysis [recovery]. Left ventricular end-diastolic diameter, left ventricular systolic diameter, left ventricular ejection fraction, fractional shortening of left ventricular, and regional wall motion abnormality score and index were measured during the four stages in all patients. Regional wall motion abnormality preceded reduction in the left ventricular ejection fraction and fractional shortening in patients with intradialytic hypotension. However, decreased systolic blood pressure and increased regional wall motion abnormality were accompanied. This study showed that reversible myocardial dysfunction occurs during the hemodialysis. It may be contributed to the intradialytic hypotension. In addition, we showed that regional wall motion abnormality less frequently occurred in patients without intradialytic hypotension. This suggests that confronting with intradialytic hypotension may prevent cardiovascular dysfunction

effect of the type of hemodialysis buffer on the QTc interval in Patients on chronic hemodialysis

Identifying the sources of variation in QTc measurements is important for preventing arrhythmias during and after hemodialysis. The present study was designed to determine the correlation between the type of hemodialysis buffer and the changes in QTc interval in patients on chronic hemodialysis. Fifty-nine patients on chronic hemodialysis who referred in winter 2007 to hemodialysis centers of Ghaem and Hashemi Nejad hospitals, in Mashhad, Iran, were divided into two groups according to their last dialysate buffer: acetate or bicarbonate. Electrocardiography, arterial blood gas parameters, serum K+, Na+, ionized calcium, and albumin levels were measured prior to and after hemodialysis in all patients. All arterial blood gas parameters and serum electrolytes concentrations were increased except K+ levels that were significantly decreased with hemodialysis. PCO[3] and QTc intervals were slightly increased in all patients, however this increase was not statistically significant. We found that the type of dialysate affected the QTc interval, HCO[3], base excess, base excess of extra cellular fluid, and base buffer changes with no effect on ionized calcium, pH, PCO[2], and serum albumin concentration. QTc interval was prolonged by using bicarbonate and shortened by using acetate dialysate buffer. We found no correlation between the variations of QTc interval and serum electrolytes or arterial blood gas parameters in either group Bicarbonate buffer use in hemodialysis prolonged QTc interval and acetate buffer shortened it. This effect is independent of serum electrolytes and pH changes during hemodialysis. The effect of bicarbonate buffer is probably due to more tolerability of ultra filtration, more effective edema reduction and augmented body electro-conductivity