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Normal heart sounds are heard when

valves are closing, not opening

first heart sound

closure of AV valves at beginning of systole. Caused by the vibration of the blood and ventricle walls.

second heart sound

closure of semilunar sounds at end of systole. Caused by the sudden snap closure

Duration of the 1st and 2nd heart sound

first 0.14 sec - second 0.11

Which has higher frequency and why

Second - taughtness of valve and high elasticity of the arterial walls

third heart sound

faint sound associated with blood flowing into ventricles at the beginning of the middle third of diastole

fourth heart sound

atrial heart sound - faint sound of atrial contraction at ~ the beginning of the 3rd third of diastole caused by rush of blood into ventricles

Chest Surface Areas for Auscultation of Normal Heart Sounds

1-aortic area is upward along the aorta
2-pulmonic area is upward along the pulmonary artery.
3-Tricuspid area is over the right ventricle, 4-Mitral area is over the apex of the left ventricle

Loud and long 1st heart sound and no 2,3 or 4

Aortic stenosis - causes the loudest murmur of all

low and prolonged 1st sound, and no 2,3 or 4

mitral regurgitation

normal 1st and a combined long 2nd, 3rd and 4th

aortic regurgitation

normal 1st and 2nd then an audible 3rd and slightly more audible 4th

mitral stenosis - causes the weakest murmur of all

prolonged and merged 1-4 with 1 being loudest

patent ductus arteriosus

Valvular lesions

Often caused by Rheumatic fever.
Mitral valve receives more trauma so it is often most damaged
aortic valve is second most damaged due to higher pressure

What do the lesions cause?

leaflets become stuck together - stenosed., making them scarred and solid so they do not close = ventricles contract=regurgitation of blood

Heart murmur of Aortic Stenosis

pressure in left ventricle rises to 300-400 mmHg while pressure in aorta is normal. Causes jetting effect of blood during systole=severe turbulence vibrations when blood is ejected and a loud murmur


sound vibrations of aortic stenosis felt with the hand on the upper chest and lower neck, a phenomenon known as a "thrill."

Heart murmur of aortic regurgitation

no murmur in systole. During diastole blood flows backward from high pressure in aorta from turbulence of blood jetting backward into the low pressure ventricle

Heart Murmur of Mitral Regurgitation

blood flows backward through the mitral valve into the left atrium during systole. causing high frequency "blowing," swishing sound in the left atrium.

Heart Murmur of Mitral Stenosis

Blood passes with difficulty through the stenosed mitral valve from the low pressure left atrium into the left ventricle. Lack of high pressure so abnormal sounds are not heard. After partial filling, the ventricle has stretched enough for blood to reverberate, and a low rumbling murmur begins.

What murmurs occur only during systole?

aortic stenosis and mitral regurgitation

What murmurs occur only during diastole

aortic regurgitation and mitral stenosis

In aortic stenosis and aortic regurgitation the net stroke volume output is


What compensations of the circulation occur in aortic stenosis and aortic regurgitation?

1. Hypertrophy of the left ventricle due to increased ventricular load
2.Increase in blood volume due to slight decrease in arterial pressure plus peripheral circulatory reflexes caused by decreased pressure and red cell mass increases due to slight tissue hypoxia.

What type of heart disease causes the left ventricular mass to increase 4-5X?

Aortic regurgitation

What type of heart disease causes the left intraventricular pressure to rise to as much as 400mmHg in systolic peak?

Aortic stenosis

In the early stages of aortic stenosis and regurgitation what prevents significant abnormalities in the person at rest?

the ability of the left ventricle to adapt to the changes - so person may have little or no symptoms initially while disease progresses

At critical stage of aortic valve lesions what occurs?

left ventricle cannot keep up with demand, dilates, CO falls, blood dams up in left atrium and lungs. Left atrial pressure rises >25-40mmHg causing pulmonary edema

In what type of heart disease is blood flow from the left atrium into the left ventricle impeded?

mitral stenosis

In what heart disease does much of the blood flow in the left ventricle during diastole leak into the left atrium during systole?

mitral regurgitation

The buildup of blood in the left atrium causes progressive increase in left atrial pressure (25 mmHg - 40 mmHg), and this eventually results in

development of serious pulmonary edema.

What causes atrial fibrillation?

An enlarged left atrium due to high left atrial pressure causing enlargement of the left atrium which affects the cardiac electrical pathways leading to circus movements causing atrial fibrillation

What are the Compensations in Early Mitral Valvular Disease?

1. Blood volume increases due to diminished excretion of water and salt by the kidneys=increases venous return to the heart
2. increase in atrial pressure, blood damming in lungs all the way to pulmonary artery. Edema causes pulmonary-arteriolar constriction. All combined cause increased pressure and hypertrophy of the right heart which compensates for increased load.

Effects of exercise in patients with aortic valvular lesions

acute left ventricular failure followed by acute pulmonary edema.

Effects of exercise in patients with mitral disease

damming of blood in the lungs that serious or lethal pulmonary edema may occur in as little as 10 minutes.

Three major types of congenital anomalies of the heart and its associated vessels:

1. stenosis
2. left-to-right shunt - Patent Ductus Arteriosus
3. right-to-left shunt
4. coarctation of the aorta

coarctation of the aorta causes

arterial pressure in the upper body to be much greater than the lower body - must use collateral vessels

Ductus Arteriosus

pulmonary pressure is high, aortic pressure is low, blood shunts

Ductus Arteriosus after birth

lungs inflate, pressure in pulmonary artery falls and pressure in aorta rises. Blood begins to flow backward through the ductus from the aorta into the pulmonary artery. Ductus occludes and becomes ligamentum arteriosum.

Patent Ductus Arteriosus-steps in disease

Remains open. 1. As child grows pressure in aorta increases and pressure in pulmonary decreases further. Blood back flows from aorta to pulmonary. Over time the high aortic pressure makes opening larger and condition worsens. 2. 2x through lungs for every 1x in systemic-arterial blood more O2 than normal

Major effects of patent ductus arteriosus are

1. decreased cardiac and respiratory reserve due to lower net blood flow thru body
2. high pulmonary pressure due to excess flow thru lungs->pulmonary congestion->pulmonary edema

machinery murmur

the murmur of patent ductus arteriosus load 1st and merged 2-4 but less loud

Tetraology of Fallot

overrding of the aorta
pulmonary stenosis
enlarged right ventricle causing boot shaped heart - left ventricle extends out

Pentalogy of Fallot

Tetralogy of Fallot plus an atrial septal defect or patent foramen ovale

What is the abnormal circulation in Tetraology of Fallot?

75% of venous blood passes from right ventricle to aorta without getting oxygenated

Signs of Tetraology of Fallot

high systolic pressure in the right ventricle
enlarged right ventricle
angiogram showing abnormal blood flow through septum and in overriding aorta

One of the most common causes of congenital anomalies


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