Mechanocardiographic effects of an elevated central venous pressure.

Since 1985 we demonstrated that the increase of left ventricular mean diastolic pressure shortens the interval existing between the onset of the electrocardiographic P-wave and the onset of the left apexcardiographic "a"-wave (Aubert et al., 1981; Mortarino et al., 1985). In particular we showed that left P-"a" time interval shortens below 100 msec when left ventricular mean diastolic pressure rises above 12 mmHg. Our results thus substantiated the previous reports related to the P-4th heart sound shortening and 4th heart sound--1st heart sound increase occurring in patients with left ventricular failure (Shapira et al., 1982). In that same period, Kesteloot and collaborators showed a direct relationship between the velocity of appearance of the right internal jugular pulse (JVP) waves and the value of central venous pressure (CVP) (Minten et al., 1985). Moreover the range of variability of the right P-"a" interval (which is the time elapsing between the onset of the electrocardiographic P-wave and the onset of the "a"-wave on the JVP tracing) is, in adult subjects, of similar magnitude of the left P-"a" interval (respectively 60-140 msec (Fishleder, 1968) and 80-160 msec (Mortarino et al., 1985) suggesting a symmetric effect of an elevation of diastolic pressure on left and right P-"a" intervals. We therefore decided to test this hypothesis in a group of patients.