Download Blood pressure: 150/100, occasionally higher Elevated levels of

Blood pressure: 150/100, occasionally higher
Elevated levels of cholesterol
High LDL and Low HDL
ECG: ST segment elevation
Trop I and cardiac enzyme markers elevated
Progressive breathlessness
Orthopnea
Ankle edema
Respiratory rate: 25/min
Pansystolic heart murmur
Apex beat of heart at anterior axillary line
Heart rate: 110 beats/ minute
CXR: cardiomegaly and interstitial infiltrates
Cardiac enzymes unremarkable
Echocardiography: dilated heart w/ anterior and septal wall hypokinesis apical dilation
Posterior wall contracting vigorously
Mitral regurgitation
Left atrial size normal
HEART AS PUMP AND FUNCTION OF HEART VALVES
-right heart: through lungs; left heart: peripheral organs
-atrium: primer pump for ventricle that helps move blood to ventricle
-ventricle: supply main pump force that propels blood in (1) right: pulmonary, (2) left: peripheral
-cardiac rhythmicity: heart contraction; action potentials
Path: extremities via vena cavas  right atrium  (tricuspid valve) right ventricle  (pulmonary
valve)lungs left atrium via pulmonary veins (mitral valve) left ventricle  (aortic valve) left ventricle
 extremities via aorta
-Sulci: contain coronary vessels, each sulcus marks external boundary between 2 chambers of heart
RIGHT ATRIUM
-
Right and left are separated by interatrial septum;
Fossa ovalis: remnant of foramen ovale, closes after birth
Tricuspid valve: also calle right atrioventricular valve
RIGHT VENTRICLE
-
Trabeculae carneae: bundles of cardiac muscles; convey part of conduction system of heart
Interventricular septum: separates 2 ventricles
LEFT ATRIUM
-
Bicuspid valve: left atrium to left ventricle
MYOCARDIAL THICKNESS AND FUNCTION
-
Atria: thin-walled, deliver to ventricles under less pressure
Ventricles: thick-walled because they deliver blood to greater distances
Right ventricle: smaller workload because it only pumps blood to lungs at lower pressure and
resistance to blood flow is small
Left ventricle: THICKEST deliver to greater distances and to those with high resistance to
bloodflow, so higher pressure.
AUTORHYTHMIC FIBERS: THE CONDUCTION SYSTEM
-
Self-excitable
Fibers repeatedly generate action potentials that trigger heart contractions
- Sinoatrial node: located in right atrial wall, do not have stable resting potential so they
repeatedly depolarize to threshold spontaneously (pacemaker potential). When
threshold is reached, it triggers action potential  atria contract
-
Action potential reaches AV node  enter AV bundle where action potential can
conduct from atria to ventricles
Action potential enters right and left bundle branches
Purkinje fibers conduct action potential at apex of heart to remainder of ventricular
myocardium  ventricles contract
ACTION POTENTIAL AND CONTRACTION OF MUSCLE FIBERS
1. DEPOLARIZATION: contractile fibers have stable resting membrane potential. when fiber is
brought to threshold, voltage gated Na channels open. Inflow of Na produces rapid
depolarization
2. PLATEAU: period of maintained depolarization. Due to opening of voltage gated Ca channels.
Increased Ca in cytosol trigger cytosol
3. REPOLARIZATION: recovery of resting potential. additional K channels open . outflow of K,
restores resting potential
ELECTROCARDIOGRAM (ECG)
-
-
Amplifies heart signals producing 12 different tracings
determines: abnormal conducting pathway, enlarged heart, regions of heart damaged, cause of
chest pain
- P WAVE: small upward deflection. represents atrial depolarization
 Large P: indicate enlargement of atrium
- QRS COMPLEX: begins as a downward deflection, continues as a large, upright,
triangular wave, and ends as a downward wave. Represents rapid ventricular
depolarization
 Enlarged Q: myocardial infarction
 Enlarged R: enlarged ventricles
- T WAVE: dome shaped, represents ventricular repolarization, smaller and wider that
QRS because repolarization occurs more slowly
 Flat T: heart muscle receiving insufficient oxygen (coronary heart disease)
 Elevated T: hyperkalemia- high blood K+ level
- Long P-Q interval: As the action potential is forced to detour around scar tissue caused
by disorders such as coronary artery disease and rheumatic fever
- Elevated S-T segment: acute myocardial infarction
- Depressed S-T: heart receives insufficient oxygen
- Long Q-T: myocardial damage, myocardial ischemia (decreased blood flow), conduction
abnormalities
SYSTOLE: contraction phase; high pressure
DIASTOLE: relaxation phase; low pressure
AUSCULTATION
-
Four heart sounds but in a normal heart only 1st and 2nd are heard.
-
- S1: LUBB sound, closure of AV valves soon after the ventricular systole begins
- S2: DUPP sound, closure of SL valves at beginning of ventricular diastole
Best heard at places slightly away from the valves because sound is carried by blood flow away
HEART MURMUR: clicking, rushing, gurgling noise
- STENOSIS: narrowing of valve opening
CARDIAC OUTPUT
-
Volume of blood ejected from left ventricle (or RV) to aorta (or pulmonary trunk) each minute
stroke volume (SV): volume of blood ejected by ventricle during each contraction
Heart rate(HR): number of beats per minutes
CO= SV * HR
Typical: 75 b/min * 70 ml/ b= 5.25 L/min
During intense: 150 b/ min, SV 130ml/b= 19.5 ml/min
CARDIAC MUSCLE
o
o
o
Atria and Ventricular- contract like skeletal but longer
Excitatory & conductive- conduct weakly because they contain 2 fibrils they exhibit either
automatic rhythmical electrical discharge in the form of action potentials or conduction of the
action potentials through the heart, providing an excitatory system that controls the rhythmical
beating of the heart.
Cardiac muscle as SYNCTIUM
o ATRIAL SYNCTIUM- constitutes walls of 2 atria
o VENTRICULAR SYNCTIUM- walls of 2 ventricles
BLOOD PRESSURE
-
BP is highest in aorta
Systolic pressure: highest, normal about 110
Diastolic pressue: low, 70
EDEMA
-
If filtration exceeds reabsorption
Either excess filtration or inadequate reabsorption
- Increased capillary blood pressure: more fluid filtered
- Increased permeability of capillaries: raise interstitial fluid osmotic pressure by allowing
some plasma proteins to escape
- Decreased concentration of plasma protein: lowers blood colloid osmotic pressure
PULSE
-
TACHYCARDIA: rapid resting heart or pulse rat >100 b/min
BRADYCARDIA: slow resting heart <50 b/min
HEART RATE: 60-100 NORMAL
LDL AND HDL
LDL: bad cholesterol LOW DENSITY LIPOPROTEINS
-
Collects in walls of blood vessels
Cause atherosclerosis: hardening and narrowing of arteries
Some WBC convert LDL to toxic oxidized form  more WBC go here  creates inflammation
High levels increase heart disease
Bloodclot resulting from high LDL can lead to heart attack
HDL : good cholesterol HIGH DENSITY LIPOPROTEINS
-
Removes LDL from where it doesn’t belong
High: 60 mg/dL,
Low: 40 mg/dL
TROP I AND ENZYME CARDIAC MARKERS
-
A person who had had a myocardial infarction would have an area of damaged heart muscle
and so would have elevated cardiac troponin levels in the blood
Trop I : cardiac regulatory proteins that regulate Ca mediated interaction between actin and
myosin
BREATHLESSNESS
-
-
Heart Failure: The shortness of breath in heart failure is caused by the decreased ability of the
heart to fill and empty, producing elevated pressures in the blood vessels around the lung.
Common symptoms of heart failure are difficulty in breathing when lying down (this is a specific
symptom of heart failure), necessity of propping up the head of the bed with many pillows,
wakefulness at night with shortness of breath, cough at night or when lying down, shortness of
breath with activity, swelling of ankles or legs, unusual fatigue with activity, and fluid weight
gain.
Normal respiratory rate: 12-20 per minutes
ORTHOPNEA: shortness of breath while sitting
CARDIOMEGALY: ENLARGED HEART
MITRAL VALVE REGURGITATION: mitral valve does not close properly, leaking backwards from
LV to LA
HYPOKINESIS: decreased contraction