- Arterial pulse waveform is composed of percussion wave travelling along an artery which is at a much higher speed than the actual passage of blood with a dicrotic notch which represents the closure of the aortic valve.
- Blood pressure is measured using a cuff that inflates above systolic pressure occluding arterial blood flow. As the cuff is deflated auscultating over the artery will produce a knocking sound
- Korotkov phase 1 sound which comes on when the cuff is inflated to systolic pressure.
- Korotkov phase 5 signifies diastolic pressure - As the cuff is deflated the sound softens and disappears
Clinical findings
- Hypertension BP > 140/90
- Pulse pressure = systolic - diastolic pressure
- Aortic stenosis - low pulse pressure
- Aortic regurgitation - high pulse pressure
- Right arm pressure > Left-arm pressure by 20 mmHg suggests stenosed left subclavian possibly due to dissection or atheroma
- Left arm pressure > right arm pressure by 20 mmHg suggests stenosed right subclavian possibly due to dissection or atheroma
- Arm (brachial) pressure >>ankle suggests peripheral vascular disease(See ABPI) or it could suggest a Coarctation of the aorta
- Right and left arm pressure often varies by 5-10 mmHg in normals