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 O 2 -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
Receives O 2 -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
Receives O 2 -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)
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, Fitness and 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)
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
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
The heart looses it’s ability to contract or pump blood into the circulation
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
Renal hypoperfusion- oligurea. Act of renin ang-aldosteron system.
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.
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.
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
CAUSES OF RHF 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
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)
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 liver Congestion and coagulative necrosis of the centrilobular area (left). Inflammation is mild.