Q. Physical Signs of aortic regurgitation?
Chronic severe aortic regurgitation is characterized by wide pulse pressure and multiple peripheral signs it produces. Sharp rapid upstroke of radial pulse followed by rapid down stroke is called Corrigan's pulse or water hammer pulse and is exaggerated by elevating the wrist. Carotids have two prominent systolic impulses called bisferiens pulse. There may be palpable thrill in carotids due to rapid ejection of increased stroke volume.
Due to rapid run off of blood from aorta in diastole and increased stroke volume, varieties of physician signs are described. Movement of head synchronously with arterial pulsation causes head bob. Auscultation over femoral arteries with gentle compression produces to and fro bruit called Duroziez's sign and it corresponds flow reversal in aorta. The prominent pulse waves may be audible over brachial and other peripheral arteries and are called pistol shot sounds. These interfere with measurement of diastolic blood pressure. In significant aortic regurgitation diastolic blood pressure is usually less than 70 mmHg and systolic blood pressure is elevated causing wide pulse pressure. Normal systolic blood pressure difference between lower and upper limbs of 10-20 mmHg is exaggerated in aortic regurgitation. The difference of more than 60 mmHg suggests severe aortic regurgitation, 40-60 mmHg difference suggest moderate aortic regurgitation and 20-40 mmHg difference mild.
Usually cardiac enlargement is present and left ventricular hyper dynamic apex is palpable outside mid clavicular line. S1
is normal or slightly reduced in intensity. A2 is louder in aortic regurgitation due to aortic root disease while it is muffled in valvular aortic regurgitation. Left ventricular S3 suggest left ventricular dysfunction. Constant ejection click may be audible in bicuspid aortic valve or with root dilatation.
Characteristic murmur is early diastolic murmur which is high pitched and blowing. It is best heard in left parasternal border third left intercostals space at end expiration with patient sitting and bending forward. A cooing or musical murmur suggests everted or perforated cusp (Seagull murmur). A murmur that is better heard on the right side of the sternum suggests aortic root disease. Ejection systolic murmur due to increased systolic flow across aortic valve is common and its presence does not necessarily mean aortic stenosis. Some patients have their cooing early diastolic murmur referred to apex. At apex one may additionally hear Austin Flint (mid diastolic) murmur. This may be due to aortic regurgitation jet pushing the anterior mitral leaflet up and causing relative mitral stenosis or just audibility of low pitched vibrations of aortic regurgitation itself. This needs to be differentiated from associated mitral stenosis. Physical signs of aortic regurgitation are unmistakable, but with cursory and casual examination - one may miss them.