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Respiratory variations of LV outflow and inflow velocity profiles.

Figure 54. Color Doppler apical 5-chamber
Figure 55. Pulsed Doppler apical 5-chamber, LVOT. Inspiratory reduction of left ventricular outflow
Figure 55. Pulsed Doppler apical 5-chamber, LVOT

Inspiratory reduction of LV outflow peak velocity (red arrow).

Figure 56. Color Doppler apical 4-chamber
Figure 57. Inspiratory reduction of LV inflow (mitral) peak velocities (red arrow).
Figure 57. Pulsed Doppler apical 4-chamber

Inspiratory reduction of LV inflow (mitral) peak velocities (red arrow).

Diagnosis of pericardial tamponade.
Echocardiography. The echocardiographic signs reflect the progressive increase in intra-pericardial pressure, which exceeds initially systolic and then diastolic right atrial pressures, and finally diastolic right ventricular pressure.

Clinical signs. The clinical signs reflect the changes in systemic arterial pressure and cardiac output. The pulsus paradoxus may be absent in some clinical situations.