The y descent, or diastolic collapse, is produced mainly by the tricuspid valve opening and the rapid inflow of blood into the right ventricle. A rapid, deep y descent in early diastole occurs with severe tricuspid regurgitation (see Fig. 10-45/1). A venous pulse characterized by a sharp y descent, a deep y trough, and a rapid ascent to the baseline is seen in patients with constrictive pericarditis or with severe right-sided heart failure. A slow y descent in the JVP suggests an obstruction to RV filling and may be the only abnormal finding in patients with tricuspid stenosis or right atrial myxoma (see Fig. 10-45.B). In both constrictive pericarditis and severe right-sided heart failure, the venous pressure is elevated with a sharp ydip in the JVP (see Chap. 72). The presence of a large positive systolic venous wave favors the diagnosis of severe heart failure.
Large a waves in the JVP during arrhythmias are present when the P wave (atrial contraction) occurs between the onset of the QRS complex and the termination of the T wave (see Fig. 1046 G). Such cannon a waves may occur regularly in junctional rhythm. More commonly, they occur irregularly when AV dissociation accompanies premature ventricular beats, ventricular tachycardia, or complete heart block. The a wave is absent in patients with atrial fibrillation, and flutter a waves at a regular rate of 250 to 300 per minute occasionally are observed in patients with atrial flutter and varying degrees of AV block. Patients with multifocal atrial tachycardia often have prominent and somewhat variable a waves in the JVP. In these patients, many of whom have pulmonary hypertension secondary to lung disease, the a waves are often very large.
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...