Characteristic feature of PDA murmur?
Ans. c (Loudest at the time of S2) (Ref. Harrison 18th/ ch. 236)In most adults with PDA, pulmonary pressures are normal and a gradient and shunt from aorta to pulmonary artery persist throughout the cardiac cycle, resulting in a characteristic thrill and a continuous "machinery" murmur with late systolic accentuation at the upper left sternal edgePATENT DUCTUS ARTERIOSUSThe ductus arteriosus is a vessel leading from the bifurcation of the pulmonary artery to the aorta just distal to the left subclavian artery. Normally, the vascular channel is open in the fetus but closes immediately after birth. The flow across the ductus is determined by the pressure and resistance relationships between the systemic and pulmonary circulations and by the cross-sectional area and length of the ductus. In adults who were bom with a large left-to-right shunt through the ductus arteriosus, pulmonary vascular obstruction (Eisenmenger syndrome) with pulmonary hypertension, right-to- left shunting, and cyanosis have usually developed. Severe pulmonary vascular disease results in reversal of flow through the ductus; unoxygenated blood is shunted to the descending aorta; and the toes-but not the fingers-become cyanotic and clubbed, a finding termed differential cyanosis. The leading causes of death in adults with patent ductus are cardiac failure and infective endocarditis.Treatment: Patent Ductus ArteriosusIn the absence of severe pulmonary vascular disease and predominant left-to-right shunting of blood, the patent ductus should be surgically ligated or divided. Transcatheter closure using coils, buttons, plugs, and umbrellas has become common place for appropriately shaped defects.Causes of characteristic murmursEarly systolic MurmursAcute MRVSD (Muscular, Nonrestrictive with pulmonary hypertension)TR with normal pulmonary artery pressureMid-systolic MurmursSupravalvular-supravalvular aortic stenosis, coarctation of the aortaValvular-AS and aortic sclerosisSubvalvular-discrete, tunnel or HOCMIncreased flow, hyperkinetic states, AR, complete heart blockDilation of ascending aorta, atheroma, aortitisSupravalvular-pulmonary artery stenosisValvular-pulmonic valve stenosisSubvalvular-infundibular stenosis (dynamic)Increased flow, hyperkinetic states, left-to-right shunt (e.g., ASD)Dilation of pulmonary arteryLate systolic MurmursMVP, acute myocardial ischemiaTVPHolosystolic MurmursAtrioventricular valve regurgitation (MR, TR)Left-to-right shunt at ventricular level (VSD)Early Diastolic MurmursAortic regurgitationValvular: congenital (bicuspid valve), rheumatic deformity, endocarditis, prolapse, trauma, post-valvulotomyDilation of valve ring: aorta dissection, annulo-aortic ectasia, cystic medial degeneration, hypertension, ankylosing spondylitisWidening of commissures: syphilis contdPulmonic regurgitationValvular: post-valvulotomy, endocarditis, rheumatic fever, carcinoidDilation of valve ring: pulmonary hypertension; Marfan syndromeCongenital: isolated or associated with tetralogy of Fallot, VSD, pulmonic stenosisMid-Diastolic MurmursMitral stenosisCarey-Coombs murmur (mid-diastolic apical murmur in acute rheumatic fever)Increased flow across nonstenotic mitral valve (e.g., MR, VSD, PDA, high-output states, and complete heart block)Tricuspid stenosisIncreased flow across nonstenotic tricuspid valve (e.g., TR, ASD, and anomalous pulmonary venous return)Left and right atrial tumors (myxoma)Severe AR (Austin Flint murmur)Continuous MurmursPatent ductus arteriosusCoronary AV fistulaRuptured sinus of Valsalva aneurysmAortic septal defectCervical venous humAnomalous left coronary arteryProximal coronary artery stenosisMammary souffle of pregnancyPulmonary artery branch stenosisBronchial collateral circulationSmall (restrictive) ASD with MSIntercostal AV fistula
Prominent in left 2nd intercostal space
Prominent in left infraclavicular space
Loudest at the time of S2
Associated with thrill
C.V.S.