Cardiovascular system

Size of your fist .5" x 3.5"

Pulsation arising at the apex of the heart to put the left ventricle

• Right atrium and right ventricle,
• left a tram left ventricle

• endocardium: inner lining of the heart, chambers and valves
• myocardium: actual muscle
• pericardium: sac surrounds the heart: composed of visceral and parietal layer
• pericardial space: small amount of fluid in space acts as a lubricant-there's friction caused by movement of the layers with each contraction, contains about 50 mL of serious

Coronary arteries branch off just as the aorta leaves the heart.

• Right coronary artery-supplies blood to the all right anterior surface of the heart and part of
• the posterior LV. (IWMI, PWMI) 90 % of people AV node.

LMCA – branches into the left circumflex (supplies the posterior and lateral LA/LV - LWMI), and the LAD (supplies the anterior heart to apex – AWMI).

• Deficiency of blood due to constriction or obstruction of a blood vessel.
• Results in tissue hypoxia which reduces the mechanical & electrical activity of the heart

May be reversible, depending on length of time ischemia occurs and the extent of muscle involved.

Permanent loss of blood flow to myocardium-results in cell death, overall effect depends on the size of area deprived of O2.---alternate routes are developed in time to nourish the endangered myocardium, collateral blood supply. Causes are emboli, atherosclerotic plaque buildup in the arterial blood supply.

• Conduction system is composed of specialized nerve tissue responsible for creating and transporting the electrical impulse, or action potential.
• Cardiac cells have the ability to transmit electrical impulses.

• Depolarization - Rapid influx of sodium & calcium ions into the cell & outflux of potassium ions—shift in electrolytes.
• Causes muscle fibers to shorten and contract.
• Electrical activity is synchronous with mechanical activity. Cells become positive inside.

• Repolarization: electrical recovery, resting phase,
• potassium moves back in,
• sodium & calcium return to extracellular space.
• Cell returns to negative state.

• SA node - It is the pacemaker of the heart,
• it creates an electrical impulse, right atria near entrance of superior vena cava.
• Intrinsic rate of 60-100.

• 1.Internodal pathways to reach the left atrium.
• 2.AV node – rate of 40-60.
• 5. Impulse terminates in the Purkinje fibers which trigger a uniform ventricular contraction.

Atrioventricular valves: Tricuspid valve, Mitral valve – First heart sound S1.

Semilunar valves: Aortic, pulmonic – Second heart sound S2.

Chordae Tendeneae – attach to the cusps of the mitral and tricuspid valves. They are anchored in the Papillary muscles of the ventricles. Prevent eversion of the valve leaflets during ventricular contraction.

Tricuspid and mitral (Atrioventricluar) prevent back flow of blood into the atria during contraction;

• pulmonic and aortic (semilunar) prevent regurgitation into ventricles at end of each ventricular contraction:
• All keep blood flowing in one direction

Right coronary artery – Supplies blood to the right anterior surface of the heart and part of the posterior LV. (IWMI, PWMI) 90 % of people AV node.

LMCA – branches into the left circumflex (supplies the posterior and lateral LA/LV - LWMI), and the LAD (supplies the anterior heart to apex – AWMI).

Coronary veins – dump into the coronary sinus which drains directly into the right atrium.

• 2.P, QRS, & T waves
• 3.P wave—depolarization of fibers in atria—lasts .06-.12 seconds
• 4.PR Interval - .12-.20 sec Conduction through A-V node.
• 5.The QRS - .04-.10 seconds, ventricular contraction
• 6.T wave—ventricular repolarization
• 7.U wave—if seen—not normally seen—delayed ventricular repolarization, may be associated with hypokalemia, Digoxin toxicity.

Total amount of blood pumped by each ventricle in 1 minute.

• Normal adult at rest is 4L to 8L.
• Measured by HR times Stroke Volume
• (amount of blood ejected from the ventricle with each heartbeat – approx. 70cc).

Volume of blood in ventricles at end of diastole before next contraction—it determines the amount of stretch placed on myocardial fibers

Contractility of the heart refers to the ability of the heart to depolarize, the force of contraction.

It is affected by the autonomic nervous system.

Peripheral resistance which Left ventricle must pump against---affected by size of ventricle, wall tension, and arterial blood pressure.

Starling’s Law. Up to a point the more myocardial fibers are stretched the greater the force of contraction

•Barorecptors in aortic arch and carotids responsive to stretch

•Chemoreceptors in aortic arch and carotids responsive to pH, PO2 and PCo2

•Information conveyed to vasomotor center in brainstem

•Release of Epinephrine and Norepinephrine

•Epi and NE stimulate β-1 Receptors

•NE stimulates α-1 receptors

•Increases Heart rate, conduction, contractility, and peripheral vasoconstriction.

•Mediated by Vagus Nerve

•Slows Heart Rate, Contractility and Conduction.

No Effect on periphery

• Arteries
• capillaries
• veins

• Arteries—carries O2 blood
• except for pulmonary artery—thick walls & elastic tissue, high pressure--major control of arterial BP

• Veins—carry no O2 blood
• except for pulmonary veins—return blood to right atrium—thin walled and large in diameter vessels—low pressure, high volume

Capillaries—endothelial cells-no elastic or muscle tissue—thin walled vessels

conduction defects, arrythmias, ischemia

continually looks at heart rate

Patient keeps monitor on for 24-48 hours and must keep a log of activities at all times—information is stored in holter monitor and printed out at a later time

Stress testing: patient walks on treadmill or stationary bicycle—leads are placed on chest and watch BP, and O2 level—stop test if peak HR, peak exercise tolerance, chest pain, significant ST segment depression (indicates ischemia). Helps diagnose left ventricular function.

• •Indicate damage to myocardial cells.
• •Markers of MI

• •CK-MB
• –> 5% of total
• –Rise in 3-12 hours
• –Peak in 24 hours
• –Return to baseline in 48-72 hours
• •Troponin T < 0.1 ng/ml is normal.
• •Troponin I < 0.4 ng/ml is normal.
• •Troponins
• –Elevate within 3 hours
• –Peak in 24-48 hours
• –Return to baseline in 5-14 days

Looks at valve function, ventricular function and presence of CAD

Vein for right cath.

Artery for left cath

• Assess patient for allergy to Iodine, Shellfish or contrast Dyes.
• Dye injection causes flushing sensation.
• Patient can be sedated but awake

MI, Embolus, Ventricular Puncture, Bleeding, Hematoma, Allergic Reaction, Arrhythmias, Death.

• •Informed Consent
• •NPO 6-12 hours prior.
• •Assess Allergy History
• •Post-Procedure must keep leg straight for 6 hours.
• •Monitor V/S, peripheral pulses, puncture site.

• *Invasive study to diagnose, induce and treat arrhythmias.
• •Catheter inserted to right side of heart via femoral vein.
• •Electrodes detect site of arrhythmia.
• •Can ablate aberrant conduction pathways.
• •Requires informed consent, NPO 6-8 hours prior.

• •High rates of atherosclerosis
• •Increased incidence of Hypertension.
• •Increased rates of Valvular Calcification
• •Decreased Heart Rate response to Exercise.
• •Decreased Baroreceptor Function

• 1.Difficult to differentiate normal aging from disease.
• 2.Decreased CV reserve.
• 3.Increased risk of orthostatic hypotension

• •Hypertension
• •Hyperlipidemia
• •Diabetes
• •Smoking
• •Excessive ETOH
• •Obesity
• •Sedentary Lifestyle

• •Family History
• •Age
• •Race
• •Sex

• •Past Medical History
• •Past Surgical History
• •Family History
• •Social History
• •Review of Systems

Any heart disease, MI, Angina, Cardiac testing, Arrhythmias, Valve Disease, Rheumatic Fever, Diabetes, HTN, Meds

Any PTCA, CABG, Valve replacement etc.

Any relatives with CV disease age at onset, death.

Smoking, Alcohol, Drug use, Diet, Exercise

Fatigue, Chest Pain, Syncope, Dyspnea, Palpitations, Claudication, Edema, PND, Orthopnea

• 1. BP, Pulse, Resp, O2 sat
• 2. JVD, Carotids palpation and auscultation for bruits
• 3.PMI, heaves, lifts, thrills.
• 4.S1 S2 rate rhythm, murmurs, rubs, gallops
• 5.AAA or bruits.
• 6.Peripheral Pulses, Cap refill, Color, temperature, Edema

It measures the time it takes to get to the AV node

it is where depolarization of the ventrical takes place

LAV node takes over