Scientific Publications by FDA Staff

Heart Rhythm 2015 Jan;12(1):155-62

Associations of electrocardiographic P-wave characteristics with left atrial function, and diffuse left ventricular fibrosis defined by cardiac magnetic resonance: The PRIMERI Study.

Win TT, Venkatesh BA, Volpe GJ, Mewton N, Rizzi P, Sharma RK, Strauss DG, Lima JA, Tereshchenko LG

BACKGROUND: Abnormal P-terminal force in V1 (PTFV1) is associated with an increased risk of heart failure, stroke, atrial fibrillation (AF) and death. OBJECTIVE: Our goal was to explore associations of left ventricular (LV) diffuse fibrosis with left atrium (LA) function and ECG measures of LA electrical activity. METHODS: AF-free patients (n=91, mean age 59.5, 61.5% men, 65.9% Caucasian) with structural heart disease (wide spatial QRS-T angle>/=105 degrees +/- Selvester QRS score>/=5 on ECG) but LV ejection fraction >35% underwent clinical evaluation, cardiac magnetic resonance and resting ECG. LA function indices were obtained by multimodality tissue tracking using 2 and 4-chamber long-axis images. T1 mapping and late gadolinium enhancement were used to assess diffuse LV fibrosis and presence of scar. P-prime in V1 amplitude (PPaV1) and duration (PPdV1), averaged P-duration, PR interval and P-axis were automatically measured using 12SL TM algorithm. PTFV1 was calculated as product of PPaV1 by PPdV1. RESULTS: In linear regression after adjustment for demographic, body mass index, LA volumemax index, presence of scar and LV mass index, each decile increase in LV interstitial fibrosis was associated with 0.76mV*ms increase in negative abnormal PTFV1 [(95%CI -1.42 to -0.09), P=0.025], 15.3ms prolongation in PPdV1 [(95%CI 6.9 to 23.8), P=0.001], and 5.4ms widening in averaged P-duration [(95%CI 0.9 to10.0), P=0.020]. LV fibrosis did not affect LA function. PPaV1 and PTFV1 were associated with an increase in LA volumes, decrease in LAEF and LA reservoir function. CONCLUSION: LV interstitial fibrosis is associated with abnormal PTFV1, prolonged PPdV1 and P-duration, but does not affect LA function.