What is Thrill

• Thrills are palpable vibrations in time with cardiac cycle.
• They are palpable equivalents of heart murmurs.
• The presence of a thrill indicates that the murmur is most of the time organic. 
• Low pitched murmurs of stenotic lesions will produce thrill better than the high pitched murmurs of incompetent lesions
• Stenotic murmurs produce low pitched thrills.
• Regurgitant murmurs produce high pitched thrills

As a general rule apical thrills are diastolic and basal thrills systolic.
However, apical thrill may be systolic (as in severe MR) and basal thrills may be diastolic (as in acute severe AR).
Carotid Thrill (Carotid Shudder)
In aortic stenosis, systolic thrill (Carotid shudder) is palpated over the carotids.
Two type of thrill 

• Systolic thrill are felt along with apical impulse
• Diastolic thrill  A thrill ending in apical impulse is called as diastolic thrill

Pericardial rub - can be palpated as leathery rub

Bruit over the carotid - can be felt in aortic Stenosis

Venous hum at the root of the neck in anemia

Bruit over the interscapular region is seen due to dilated  posterior intercostal artery - in coarctation of aorta.