<prompt> True about Pulsus bisferiens:Double peak, one is systole and another in diastoleDouble peak, both in systoleSeen in patients with dilated cardiomyopathySeen only when aortic stenosis is associated with aortic regurgitation  <response>: Ans. b Double peak, both in systole. Ref. Harrison Medicine 16th ed., 1305 1416.ARTERIAL PULSESVARIOUS ARTERIAL PULSESMECHANISMETIOLOGYPulsus paradoxusDecrease in SBP 10 mm Hg that normally accompanies decrease in arterial pulse amplitude during inspiration.It refers to a fall in systolic pressure 10 mmHg with inspiration.Airway obstruction accentuated Pericardial effusion Pericardial temponadeQ Pulmonary embolism massive SVC obstruction Hemorrhagic shock Severe obstructive lung disease Tension pneumothorax.Pulsus bigeminusRegular alteration of pressure pulse amplitude, but it is caused by a premature ventricular contraction that follows each regular beat.PVCsPulsus alternansRegular alteration of pressure pulse amplitude, despite regular rhythm.defined by beat-to-beat variability of pulse amplitude. And is present only when every other phase 1 Korotkoff sound is audible as the cuff pressure is lowered slowly, typically in a patient with a regular heart rhythm and independent of the respiratory cycle LVFsevere left ventricular systolic heart failure PAT after premature beatsPulsus bisferiens OR Bifid pulse percussion tidal waveTwo systolic peaks MH 2006.A bifid pulse is easily appreciated in patients on intra-aortic balloon counterpulsation IABP, in whom the second pulse is diastolic in timing.Advanced ARHOCM A bifid pulse described in patients with HOCM, with inscription of percussion and tidal wavesDicrotic pulse2 palpable waves, 1 in systole 1 in diastoleDCMPulsus parvus hypokineticSmall weak pulseA weak and delayed pulse pulsus parvus et tardus defines severe aortic stenosis AS. LVF, MS, Restrictive pericardial diseasePulsus tardusDelayed systolic peak ASHyperkinetic CHB, Anemia, Fever, Exercise, HyperthyroidismAnacrotic pulseA slow, notched, or interrupted upstroke with a thrill or shudder.Some patients with ASCorrigans or water- hammer pulseThe carotid upstroke has a sharp rise and rapid fall-off.Chronic severe ARBounding pulse VSD, Chronic AR Ruptured sinus of Valsalva MR, HypertensionNote: The character of the pulse is best appreciated at the carotid level. 