Noninvasive Assessment of Central Circulatory Pressures by Analysis of Ear Densitographic Changes During the Valsalva Maneuver

The ear densitogram was monitored in 21 consecutive patients with various degrees of myocardial function (New York Heart Association class I to IV) during the standardized Valsalva maneuver to evaluate the quantitative relations between the pattern of response and the central circulatory pressures. The ear densitographic first derivative consistently tracked the aortic pulse pressure during the strain phase of the Valsalva maneuver (beat-to-beat correlation [r] range 0.98 to 0.72). The percent decrease of the densitographic pulse derivative during strain correlated with left ventricular end-diastolic pressure at rest (r = 0.62, p less than 0.001), but not with cardiac output, cardiac index and ejection fraction. Multiple stepwise regression was used to take into account multiple aspects (time intervals and pulse amplitudes) of the pattern of response to the Valsalva maneuver. As a result, both correlations improved substantially (r = 0.97, p less than 0.001 for left ventricular end-diastolic pressure, and r = 0.92, p less than 0.001 for pulmonary artery wedge pressure). In conclusion, the combination of several noninvasive indexes obtained by pulse amplitude and interval changes during the strain phase of the Valsalva maneuver seems to be a new and promising method for noninvasive evaluation of the status of left ventricular filling pressures.