Relationship between left atrial functions, P-terminal force and interatrial block in chronic haemodialysis patients.

OBJECTIVE Interatrial block (IAB) connotes a P wave duration ≥ 110 msec on electrocardiography (ECG). P-terminal force corresponds to a biphasic P wave with its terminal negative phase ≥ 40 msec x mm in V1 derivation on ECG. IAB and P-terminal force are closely related parameters and they are accepted as predictors for left atrial dysfunction, left atrial dilatation, atrial fibrillation and strokes. Left atrial functions in chronic haemodialysis patients becomes worse in the course of time because of long standing pressure and volume overload. The aim of this study is to evaluate the relationship between IAB, P-terminal force and left atrial functions. PATIENTS AND METHODS 68 chronic haemodialysis patients and 60 control subjects were included in the study. Conventional echocardiography and left atrial dynamic functions were measured in all cases. The subjects with IAB and P-terminal force on ECG were identified. RESULTS Left ventricular size, wall thickness and left atrial diameters were significantly greater in haemodialysis patients than the control group (p < 0.001). 42 (62%) patients had IAB (≥ 110 msec) and 45 (66%) patients had P-terminal force ( ≥ 40 msec x mm) in the haemodialysis group. Left atrial reservoir, conduit and pump functions were significantly lower in the haemodialysis group than the control group (p < 0.001). There was a statistically significant correlation between left atrial functions, IAB (≥ 110 msec) and P-terminal force (≥ 40msec x mm) in all parameters (p < 0.001). CONCLUSIONS This study showed that decreased left atrial functions in chronic haemodialysis patients are closely correlated with IAB and P-terminal force.