Jugular venous pulse (1957) Pt. 3 of 4

the brachial artery pressure family r2 pressure and right ventricular pressure are all around 100 millimeters of mercury the right atrial tracing shown on the right shows a only slightly higher than V both around zero the length of the PR interval can be roughly estimated by noting the time interval between the jugular a wave and the carotid pulse with experience it is not difficult to decide clinically whether the AC interval is more or less normal around north point 1 6 second or obviously prolonged north point 2 4 seconds or more as in the tracing the jugular flipagram is the middle tracing shown a cannon wave is a particular form of giant a wave and occurs when all the energy released by right atrial contraction is translated into pressure because forward flow is impossible going to simultaneous closure of the tricuspid valve this happens regularly in nodal rhythm and partial heart block nodal rhythm in this case was probably caused by digitalis there is very marked sagging v ST segment in LEED v4 in electrocardiogram there immediately following the slow arterial pulse there is a large systolic cannon wave in the jugular pulse this might well be mistaken for tricuspid incompetence but the rhythm is regular and the absence of a pre systolic wave should prevent error independent a waves can also be seen in many cases of complete heart block any type of ectopic beat may cause a cannon wave if the necessary conditions are fulfilled regular cannon waves also occur in paroxysmal nodal tachycardia in this boy with paroxysmal tachycardia rapid cannon waves are conspicuous suggesting that it is nodal in origin in fact it proved to be a chore with two-to-one atrioventricular block alternate atrial contractions coinciding with ventricular systole the speed here is about 180 the a wave disappears of course in atrial fibrillation which should be notice that the ex descent is also inconspicuous since this is commonly so it is logical to conclude that the ex descent depends more on atrial relaxation than on the center of the base the jugular pulse is characterized by a single systolic wave disappearance of the X dissent in tricuspid incompetence with atrial fibrillation is characterized by much larger v waves all the more apparent because of the deep white rot which follows giant B waves from tricuspid incompetence are well seen in this patient that the venous pulse is systolic can be recognized by observing its time relationship to the carotid pulse which is lifting the pointer and the hands is moving up with it in this case the venous valves have become incompetent and the giant V wave is transmitted to the extremities the pulsation can be seen most easily when the legs are raised to critical height just as posture must be used to bring out maximal venous pulsation in the neck when there is normal rhythm in tricuspid incompetence a small X descent is often present but is overshadowed by the giant V