P wave analysis and left ventricular systolic function in chronic heart failure. possible insights form the P wave - PP interval spectral coherence

Background - Chronic increase in left ventricular filling pressure represents one of the most important mechanism underlying the structural, as well as the electrical, atrial chamber remodeling leading to atrial fibrillation. The present pilot pathophysiological study sought to investigate possible relationship between short-period cross-spectral coherence of P-Q, R-R and P-P intervals and echocardiographic indices of left ventricular and atrial function. Method and Results - Electrocardiographic single lead short-term cross-spectral analysis on P-Q and P-P intervals was performed in 31 patients with chronic heart failure (CHF). Twenty age and therapy matched hypertensive patients acted as control group. The interval between the beginning of P wave and its peak (Ppeak) was also analyzed. Patients with CHF showed a significant lower PQ → PP and Ppeak → PP coherence (p<0.001) than the counterpart. At multivariate analysis only Ppeak → PP was independently associated to left ventricular ejection fraction (r2: 0.312; b: 60; β: 0.559; p<0.0001) and atrial volume (r2: -0.160; b: -0.15; β:-0.400, p <0.05). Conclusions - Ppeak → PP coherence might be a simple marker of left ventricular and atrial function. Whether this index could be a useful noninvasive marker of increased left ventricular filling pressure and, possibly, of atrial fibrillation risk needs to be test in larger prospective study.