Giant 'a' waves in JVP occur in all except

Ans. b (TR). (Ref. Harrison, Principles of Medicine, 18lh/Chapter 227.)JVP: It has 3 positive and 2 negative waves. Right IJV is best to estimate JVP.1.A (positive wave)Is due to venous distension due to RA contraction.# Large a waves-TS, pulmonary hypertension, PS, arrhythmia# Cannon a waves -Irregular -CHB/AV dissociation with ventricular tachycardia.# Cannon a waves -Regular -junctional rhythm,# Absent a wave -AF.# Increased delay between a wave and carotid pulse -primary AV block.2.C wave (positive wave)bulging of tricuspid valve into RA during RV isovolumetric systole and by impact of CCA adjacent to JVC. (AIIMS 2007 Nov)3.X descent (negative wave)occurs due to both, atrial relaxation and downward displacement of tricuspid valve during systole.# Accentuated -constrictive pericarditis# Reduced nadir -RV dilatation# Reversed C -TR.4.V wave (positive wave)increasing volume of blood in RA during ventricular systole when tricuspid valve is closed.# Prominent v wave -TR# Combination of prominent V wave + obliteration of X descent = single large positive sinusoidal wave5.Y descent (negative wave)The negative descending limb produced by opening of tricuspid valve and subsequent rapid inflow of blood in RV.# Rapid Y descent -severe TR# Sharp Y descent, deep Y through and rapid ascent to base line -constrictive pericarditis or right sided heart failure.# Slow Y descent -TS or RA myxoma.6.Kussmaul's signincrease, rather than decrease in CVP during inspiration, seen in right sided heart failure (Constrictive pericarditis and RV infarction). Sharp Y descent is known as Freidrich's sign.