Murmurs From Leftto Right Shunts

1. Ventricular septal defect (VSD). Typically holosystolic (same frequency and intensity throughout systole) and may obscure S2. May have a harsh or blowing character and be associated with a thrill.

2. Atrial septal defect. Classic auscultatory findings are persistently and widely split second heart sound (reflecting delayed closure of the pulmonary valve), pulmonary flow murmur, and middiastolic rumble caused by increased flow across the tricuspid valve.

3. Patent ductus arteriosus (PDA). Represents failure of the vessel connecting the aorta and the pulmonary artery to close after birth. Flow is throughout the cardiac cycle, because aortic pressure is higher than pulmonary pressure, except if there is pulmonary hypertension. Typically produces a continuous murmur, peaking at S2.

C. Valvular Heart Disease. Valvular pulmonic or aortic stenosis presents as a systolic ejection murmur and may be associated with a thrill. A systolic click may precede the murmur, which reflects a referred sound of the stenotic valve opening.

D. Outflow Tract Obstruction. Obstruction to flow across the outflow tracts from each ventricle causes a systolic murmur. Intensity of murmur will increase with degree of obstruction. Left ventricular outflow obstruction can be caused by a subaortic membrane or occur in association with hypertrophic cardiomyopathy. The most common cause of right ventricular outflow obstruction in cyanotic patients is infundibular obstruction in tetralogy of Fallot.

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Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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