THE HEART

Left ventricle

ANATOMY AND FUNCTION OF THE HEART

• The heart is a muscular organ a little larger than your fist weighing between 7 and 15 ounces (250 to 300 gm)in female & 300-350gm in male. It is responsible for pumping blood through the blood vessels by repeated, rhythmic contractions. The average heart beats 100,000 times per day pumping about 2,000 gallons (7,571 liters) of blood. The average human heart beating at 72 BPM (beats per minute), will beat approximately 2.5 billion times during a lifetime of 66 years.

• The heart is usually situated in the middle of the thorax with the largest part of the heart slightly offset to the left underneath the breastbone or sternum and is surrounded by the lungs. The sac enclosing the heart is known as the pericardium.

Right Heart Chambers: Pulmonary Pump• Right Atrium (forms most of base of heart)

– Receives O2-poor blood from body via IVC, SVC, Coronary sinus

– Ventral wall (w/Pectinate muscles) and dorsal wall (no pectinate muscles) separated by crista terminalis

– Fossa Ovalis- on interatrial septum, remnant of Foramen Ovale• Right Ventricle

– Receives O2-poor blood from right atrium through tricuspid valve– Pumps blood to lungs via Pulmonary Semilunar Valve in

pulmonary trunk– Trabeculae Carnae- muscle ridges along ventral surface– Chordae Tendinae-fibrous cords running between AV valve

cusps and papilary muscles– Papillary Muscles (3)-cone-shaped muscles within ventricles to

which chordae tendinae are anchored– Moderator Band (septomarginal trabeucla)-muscular band

connecting anterior papillary muscle to interventricular septum

Left Heart Chambers

• Left Atrium– Receives O2-rich blood from 4 Pulmonary Veins

– Pectinate Muscles line only auricle

• Left Ventricle (forms apex of heart)– Receives blood from Left Atrium via bicuspid valve– Pumps blood into aorta via Aortic Semilunar Valve to

body– Same structures as Rt Ventricle: Trabeculae carnae,

Papillary muscles (2), Chordae tendinae– No Moderator band

• Semilunar valves: prevents backflow in large arteries

• Pulmonary Semilunar Valve

– Right Ventricle and Pulmonary Trunk

• Aortic Semilunar Valve

– Left Ventricle and Aorta

• Made of 3 Cusps

– As blood rushes past the cusps are flattened

– As it settles they’re pushed down (valve closed)

Heart valve• Tricuspid Valve: Right AV valve

– 3 Cusps (flaps) made of endocardium and CT– Cusps anchored in Rt. Ventricle by Chordae Tendinae– Chordae Tendinae prevent inversion of cusps into atrium– Flow of blood pushes cusps open– When ventricle is in diastole (relaxed), cusps hang limp in

ventricle– Ventricular contraction increases pressure and forces cusps

closed

• *Bicuspid (Mitral) Valve: Left AV valve– 2 cusps anchored in Left Ventricle by chordae tendinae– Functions same as Rt. AV valve

• They close together

Lifestyles, Fitnessand Rehabilitation

Heart Failure

• What is Heart Failure?– The heart can not meet the functional need of

the body– It elicit anumber of neural, hormonal & renal

responses.– The disease causes HF can classify into

two main groups:– Cardiac (i.e.,iherited heart disease)– Extra cardiac– Pressure over load (e.g., hypertention)– Volume over load (e.g hypervolumia due to

water & sodium retention)

– Increase demand (e.g.,increase metabolism in hyperthyroidism)

– Usually, the heart has been weakened by an underlying condition

The most common cardiac causes

Pump failure

ICHD

Electrical disorder (e.g. , ventrical fibrillation)

Cardiomyopatheis

Valvular failure

Endocarditis

metabolic (Marfan syndrome)

– Heart failure can involve the left or right side of the heart or both

– Usually the left side is affected first– Heart failure occurs when either side of the

heart cannot keep up with the flow of blood blooblood blood blood

Difference between Forward and Backward Heart Failure.

Farward failure is sign and symptom of ischemia due to reduce systolic output

Backward failure is sign of congestion due to inedequate emptying of heart chambers

What is high output failure:

it is charect by a high cardiac out put (high systolic ejection fraction) cause by increase demand typically encounter in Anemia, Thyrotoxicosis, Beriberi and pregnancy. prolong ventricular overload leads ultimately over exhaustion of the heart and heart failure.

• What is Left Heart Failure?– Involves the left ventricle (lower chamber)

of the heart– Systolic failure

• The heart looses it’s ability to contract or pump blood into the circulation

– Diastolic failure• The heart looses it’s ability to relax because it

becomes stiff• Heart cannot fill properly between each beat

FEATURE OF LHF:

• Increase pul venous prssure• Congestion & edema of lungs• RHF• Renal hypoperfusion- oligurea. Act of renin ang-

aldosteron system.• Cereberal ischemia• Intestinal hypoperfusion • Hepatic hypoperfusion

• MORPHOLOGY:• HEART:- hypertrophy & fibrosis in myocardium, • Sec enlargement of left atium• Blood stasis & thrombus formation. LUNGS:- extra cardiac effect menefist more

prominent in lungs• Pulmonary congestion & edema• Perivascular inter trnsudate especialy in inter

lbular septa result in Kerley’s B line on X-ray• Widening of alveolar septa• Accumulation of more iron containg protein in

edema fluid called siderophages

Left Ventricular Hypertrophy: Gross excellent example of concentric left ventricular hypertrophy

Heart, concentric left ventricular hypertrophy -

Smooth muscle cells are proliferating and undergoing hypertrophy in an attempt to cope with rapidly rising blood pressure.

Lung, massive pulmonary hemorrhage and infarct - Pulmonary edema & congestion

Marked interstitial edema with hilar indistinctness, Kerley B lines,

Cardiomegaly and pleural effusion (on the right side) in a patient with heart failure.

• KIDNEYS:-small pin pont petechial hemorrhages , appear as flea bitten patteran

• Fibrinoid necrosis eosinophilic granular changes in blood vessel wall

• In interlobular arteries & arteriole typical onion skin apperance.

BRAIN:-brain is swollen gyri are widende, and sulci are narrow poor demarcation b/w grey & white matter.

HIST. Eiosinophilea of neuron cytoplasm pyknosis & karyorrhexis.

Reactive gliosis.

Border zone (“watershed” )infarcts.wedge shape area of infarct that occur in regions of brain & spinal cord.

The vessel walls contain a smudgy, eosinophilic, fibrin-like material.

Area of acute hemmorhage in thalamus

Cause What is it? How does it cause right-sided heart failure?

Left-sided heart failure Left ventricle does not pump blood efficiently, leading to pressure buildup behind the left side of the heart that eventually causes the right side of the heart to fail

Blood backs up behind the left ventricle into the left atrium, in the lungs, and then eventually in to the right ventricle, which also eventually fails, allowing blood to then back up further into the extremities, the liver, and the other organs.

Chronic lung disease Includes emphysema, embolism, and other causes of pulmonary hypertension

High blood pressure in the pulmonary arteries increases workload of the right ventricle, eventually causing the RVF

CAUSES OF RHF

Coronary artery disease Blockage of the arteries that supply blood to your

heart

CAD can cause left-sided heart failure leading to right-sided heart failure, or can directly cause right-sided heart failure by blocking blood supply to the right ventricle

Pulmonic stenosis Narrowing of the pulmonic valve that limits blood flow out of the right

ventricle

ncreases the work of the right ventricle; similar to chronic lung disease

Tricuspid stenosis Narrowing of the tricuspid

valve Limits blood flow out of the right atrium, causing enlargement of the right atrium and backup of blood flowing to it

Left-to-right shunt An abnormal connection between the left and right side of the heart, usually present from birth

Causes a volume overload of the right ventricle, similar to tricuspid regurgitation

RIGHT SIDE HEART FAILURE

FEATURE OF RHF• Inc venous pressure• Cong &edema of internal organ & soft tissue• Hepatomegaly (nut meg liver)• Congestive splenomegaly• Pitting edema of lower extremities• Hydrothorax, ascities & anasarca

Right ventricular enlargement due to a patent ductus arteriosus in a patient with hyaline membrane disease

Nutmeg liverCongestion and coagulative necrosis of the centrilobular area (left). Inflammation is mild.　

The major signs and symptoms of heart failure.