Descent

Hypertension Exercise Program

Latest Treatments for High Blood Pressure

Get Instant Access

This is the major fall in atrial pressure in systole and is caused by RV contraction pulling on the closed tricuspid valve and ring (26,40).

Its presence requires:

1. A good RV systolic function

2. An intact tricuspid valve

Pulmonary Hypertension

Pulmonary Hypertension

Cardiac Descent

Fig. 12. Jugular venous pulse (JVP) and jugular venous flow (JVF) velocity recordings from a patient with pulmonary hypertension in a decompensated state. Note the more prominent y descent compared to the x' descent in the JVP. It corresponds to the dominant diastolic flow (Df) compared to the systolic flow (Sf). The added diagrams of the heart help explain the pathophysiology of the JVP contour abnormality. Thickness of arrows refers to flow velocities. (Modified and reprinted from ref. 41. Copyright 2005 with permission from Excerpta Medica Inc.)

Fig. 12. Jugular venous pulse (JVP) and jugular venous flow (JVF) velocity recordings from a patient with pulmonary hypertension in a decompensated state. Note the more prominent y descent compared to the x' descent in the JVP. It corresponds to the dominant diastolic flow (Df) compared to the systolic flow (Sf). The added diagrams of the heart help explain the pathophysiology of the JVP contour abnormality. Thickness of arrows refers to flow velocities. (Modified and reprinted from ref. 41. Copyright 2005 with permission from Excerpta Medica Inc.)

In fact, a good and dominant x' descent in the jugulars indicates good RV systolic function. The flow velocity peak in the jugulars during the x' descent is always dominant (Figs. 2C and 7D). When there is RV systolic dysfunction, the x' descent is diminished and eventually may become totally absent when RV function becomes poor. In pulmonary hypertension, during the late stages when decompensation sets in, the x' descent becomes diminished and eventually becomes lost (Figs. 12 and 13) (41). In acute LV failure such as caused by acute myocardial infarction, the RV function may still be good, as indicated by the presence of a good x' descent. In patients with cardiomyopathy with poor ventricular function, if the x' descent is preserved it would indicate sparing of the RV as might be the case in ischemic cardiomyopathy (47).

While mild to moderate degrees of tricuspid regurgitation with normal RV systolic pressure (usually <25 mmHg) could still be consistent with the presence of a preserved x' descent, more than moderate degrees of tricuspid regurgitation particularly, in the presence of elevated RV systolic pressure, is incompatible with a well-preserved x' descent. Significant degrees oftricuspid regurgitation would clearly lead to early buildup of RA pressure and therefore counteract or abolish the x' descent. The loss of x' descent and early buildup of the large-amplitude v wave (sometimes termed the "cv" wave) followed by the diastolic y descent are characteristic of significant tricuspid regurgitation (Fig. 7G). The v wave of tricuspid regurgitation is characteristically associated with systolic flow reversal in the jugulars. The v wave in the right atrium is clearly in such cases a result of the actual regurgitant flow into the atrium. Because of its large amplitude of rise together with retrograde flow into the jugulars, it can be recognized from a distance in the jugulars as the large v wave ascent followed by the y descent, which can be timed. The rise will be systolic and can be timed with the radial pulse. Unlike the a wave, it tends to last longer, and much longer than the duration of the arterial pulse (40).

The lack of atrial contraction in atrial fibrillation leads to a decrease in Starling effect on the ventricle. This leads to a decrease in ventricular contraction and function causing

Pulmonary Hypertension, single y descent ecg

Pulmonary Hypertension, single y descent ecg

Fig. 13. Jugular venous pulse recording from a patient with right ventricular (RV) decompensation with pulmonary hypertension secondary to significant mitral regurgitation associated with ischemic heart disease. Note the x descent and the corresponding atrial relaxation flow (arrow). The X descent cannot be seen, and there is a prominent y descent and a corresponding Df. There may be mild tricuspid regurgitation but not enough to overcome the buffering effect of the right atrium (RA), and no systolic retrograde flow can be seen on the jugular venous flow (JVF). The JVF tracing does not fall below the zero flow line. Diagrams have been added to explain the pathophysiology of the flow pattern. (Modified and reprinted from ref. 41. Copyright 2005 with permission from Excerpta Medica Inc.)

Fig. 13. Jugular venous pulse recording from a patient with right ventricular (RV) decompensation with pulmonary hypertension secondary to significant mitral regurgitation associated with ischemic heart disease. Note the x descent and the corresponding atrial relaxation flow (arrow). The X descent cannot be seen, and there is a prominent y descent and a corresponding Df. There may be mild tricuspid regurgitation but not enough to overcome the buffering effect of the right atrium (RA), and no systolic retrograde flow can be seen on the jugular venous flow (JVF). The JVF tracing does not fall below the zero flow line. Diagrams have been added to explain the pathophysiology of the flow pattern. (Modified and reprinted from ref. 41. Copyright 2005 with permission from Excerpta Medica Inc.)

Severe Mitral Regurgitation

Fig. 14. Recordings from a patient with severe mitral regurgitation. Single diastolic flow (Df) in the jugular venous flow (JVF) velocity, corresponding to a single y descent on the jugular venous pulse (JVP). This is because of the Bernheim effect. (Reproduced with kind permission from ref. 47.)

a diminished x' descent (Fig. 3). In recent onset atrial fibrillation with preserved RV function, the x' descent may be still recognized in the jugulars. However, in longstanding atrial fibrillation, the x' descent tends to be absent because of co-existing RV dysfunction and some degree of tricuspid regurgitation.

Very rarely in patients with severe mitral regurgitation, the interatrial septum may be seen to bulge into the right atrium during systole. This would tend to diminish the full effect of the descent of the base on the right atrium. This decreases the x' descent (systolic flow). This effect is termed the Bernheim effect on the atrial septum (9,40,47,50) (Figs. 14, 15A,B) (Table 1).

Fig. 15. Four chamber views of the two-dimensional echocardiograms from the same patient with severe mitral regurgitation with freeze frames in systole (A) and diastole (B) together with their line diagrams. In systole (A) indicated by the closed mitral and the tricuspid valves, the bulge of the interatrial septum into the right atrium (RA) decreasing the volume in RA is well seen. In diastole (B), as shown by the open mitral and tricuspid valves, the interatrial septum is more straight and the right atrial dimension is larger (see the text).

Fig. 15. Four chamber views of the two-dimensional echocardiograms from the same patient with severe mitral regurgitation with freeze frames in systole (A) and diastole (B) together with their line diagrams. In systole (A) indicated by the closed mitral and the tricuspid valves, the bulge of the interatrial septum into the right atrium (RA) decreasing the volume in RA is well seen. In diastole (B), as shown by the open mitral and tricuspid valves, the interatrial septum is more straight and the right atrial dimension is larger (see the text).

Table 1

Causes of Decreased x Descent

1. Diminished right ventricular (RV) contraction, e.g.,

• RV failure in pulmonary hypertension

• Post-cardiac surgery RV damage

• RV infarction

2. Atrial fibrillation because of loss of Starling effect

3. Bernheim effect in severe mitral regurgitation0

a Rare occurrence.

Was this article helpful?

0 0
Relaxation Audio Sounds Lazy Summer Day

Relaxation Audio Sounds Lazy Summer Day

This is an audio all about guiding you to relaxation. This is a Relaxation Audio Sounds with sounds from Lazy Summer Day.

Get My Free MP3 Audio


Post a comment