Back
Chronic Kidney Disease (CKD) is important risk factor of mortality, and cardiovascular disease (CVD) is the principal cause, sudden cardiac death more common. Patients in hemodialysis (HD) have changes in volume and electrolytes during treatment, have continuous pro-inflammatory status, repetitive myocardial injury, all of which are risk factors for arrythmias, evidence of long QT interval indicative of defect in ventricular repolarization. The main of this study is identify electrocardiographic abnormalities in patients with chronic hemodialysis and its relationships with laboratory variables.
A cohort study was carried out in two HD units in Guatemala. Patients over 18 years old were included. Were excluded patients with diagnosis of ischemic heart disease, cardiac arrhythmias, use of pacemakers and medication that prolong the QT interval. The study was carried out on Mondays and Tuesdays, considering these the longest interdialytic period. Before and after HD treatment blood samples (hemoglobin (Hb), calcium (Ca), potassium (K) and magnesium (Mg)) and 12-lead electrocardiogram (ECG) were taken for analysis. ECG were interpreted by two independent cardiologists, without having clinical data on patients. The results were analyzed used the SPSS Statistics 25 tool.
40 patients were included, with a median age of 41y, 83% male, 83% report having diabetes mellitus, 78% systemic hypertension arterial and calcium-antagonist are the most common antihypertensives. The majority have been receiving HD for between 1 and 5 years and 88% have native AVF. HD prescription: median QB of 350ml.min, median net UF was 2500ml, mean UF.hr of 10ml.kg.hr and median Kt/V of 1.48. The laboratory findings, prior to HD the majority of patients had hyperkalemia, hypocalcemia and hypermagnesemia, and after treatment the majority had normal values. The mean serum K difference was -1.75mEq/L +/- 0.77, a median serum Ca difference was +0.93mg/dl (IQ) and a median serum Mg difference was -0.64mg/dl (IQ). Among the findings in the ECG, 25% had left ventricular hypertrophy, 5% left atrial growth, 7% first degree AV block prior to HD and none after treatment, 7% with long QT interval prior to HD which increases to 20% after HD. When the analysis is done comparing the findings before versus after HD (Table 1 and 2), we found statistically significant changes in the correction of electrolytes (p: <0.001). In the clinical variables changes statistically significant were found in mean arterial pressure (p: 0.004). Regarding the other parameters, no statistically significant changes were found.
Was changes significant in electrolytes levels after HD treatment. However, although they are involved in the cardiac conduction system, in our study population no significant changes were found at the electrocardiogram. The ECG only represent one moment in the course of cardiac cycle, not a continuous monitoring during treatment that would probably reveal more findings. We suggest performing cardiac Holter studies during HD treatment.