Relation of interatrial duration and p wave terminal force as a novel indicator of severe mitral regurgitation.

OBJECTIVES Interatrial duration is defined as prolonged p wave on electrocardiogram. p waves with a negative terminal phase recorded in V1 enclosing an area of one small square on the electrocardiogram is significantly and strongly correlated with interatrial duration. The aim of study was to investigate whether interatrial duration with p terminal force can be used as reflection of echocardiographic severity of mitral regurgitation. MATERIALS AND METHODS Sixty two consecutive patients with mitral regurgitation. were prospectively studied. Age/gender matched 57 subjects who had normal mitral structure and did not have mitral regurgitation. Patients with mitral regurgitation referred to a single cardiac center for echocardiography and who met the entry criteria documented moderate or severe mitral regurgitation with sinus were included. The interatrial duration was defined on the routine 12-lead electrocardiogram (50 mm/s, 10 mm/mV) using the greatest duration of p waves from D2, D3, AVF and V1. RESULTS There was a positive correlation between interatrial duration (>/= 110 ms) and effective regurgitant orifice (r = 0.3, p < 0.001). However, left atrial diameter and brain natriuretic peptide were significantly higher in cases with mitral regurgitation. There was also strong correlation between interatrial duration (>/= 110 ms) and p terminal force and left atrial diameter. ROC analysis revealed that interatrial duration of > 110 msec. could predict of severe mitral regurgitation with 88% sensitivity and 100% specificity. CONCLUSIONS Severe mitral regurgitation, left atrial diameter was correlated with p terminal force and interatrial duration. Significant interatrial duration (>/= 110 ms) and p terminal force might be considered as novel indicators of severe mitral regurgitation.