Cardiovascular Exam 1

Specialized conduction system - the sequence of activation of the heart: From review - on which side (right or left) is depolarization faster and why? What direction is the AP spreading once it's past the AV node and has gone down the ventricle?

(1) Depolarization: 1. SA node fires AP 2. Action potential to Atrial Muscle via cell-to-cell 3. AV node - conduction slows: junctional/small diameter fibers in AV node delay impulse from going to ventricular muscle. 4. Action potenetials travel rapidly through condution system to APEX of heart. 5. Aps spread upward through the ventricular muscles specifically via: 5a) Fibers leave AV node and expand. Enter ventricles at BUNDLE OF HIS aka BASE of septum. 5b) Bundle of His divides into RIGHT AND LEFT BUNDLE BRANCHES that divide down ENDOCARDIAL surfaces of the septum spreading laterally. - *AP moves down LEFT bundle branch FASTER than the right = faster depolarization on the left than the right. - AP spreading from LEFT TO RIGHT ACROSS THE SEPTUM = first vector you see when you depolarize.* 5c) Bundle branch fibers divide into Purkinje fibers = spread impulse into ventricular MYOCARDIUM TO individual myocytes which then conduct via gap junctions.

know the orientation in an axial reference system in the frontal plane of the six leads - need to know augmented leads.

(A) Augmented Chest Leads: are Unipolar (each positive lead goes against a combination of the other electrodes) - Positive electrodes are at Left Arm (AVL), Right Arm (AVR) & Left Leg (AVF). 1. AVL = -30 degrees (relative to lead 1) -> in this, the Q and R waves are small bc both are almost perpendicular (orthogonal) to lead's (electrical) axis. 2. AVR = -150 degrees -> in this, the R wave is downward (unique) bc depolarization of apex is moving away from -150 degrees and towards +30 degrees. 3. AVF = +90 degrees. - Augmented leads and limb leads (see below) detect electrical changes in the FRONTAL PLANE. (B) Einthoven's Triangle (equilateral triangle around heart to measure cardiac depolarization along three electrical axes): Limb Leads are Bipolar. - Electrodes placed: Left Arm (LA), Right Arm (RA), & Left Leg (LL) 1. Lead 1 = LA +, RA- = 0 degrees. 2. Lead 2 = LL+, RA- = 60 degrees. 3. Lead 3 = LL+, LA- = 120 degrees.

(a) Must know - relationship between flow and velocity of flow (hemodynamics) (B) Must know - how velocity changes over the vascular system (hemodynamics) - where is the lowest velocity of blood flow? fastest?

(a) 1. Flow(Q) = volume/time; cm3/min. 2. Velocity (V) = distance/time; cm/min. 3. Velocity (V) = flow / area = (Q in cm3/min)/(A in cm2) = cm/min. -> larger diameter (A) is slower, smaller diameter is faster. (b) Velocity is slower in larger areas (inverse relationship)= Capillaries. Velocity is faster in smaller diameter = Aorta (3cm2) & V. Cavae (10cm2) Flow velocity as a function of cross sectional area in various segments of circulation: SEE PICTURE OF GRAPH FIX DRAW THIS OUT. - While the same total volume of blood (Q) flows through each segment of the circulation, the velocity of any given particle in the blood will vary INVERSELY with the total cross sectional area of that segment. - Thus the lowest velocity of blood flow is through the capillaries which allows time for exchange of fluid and solutes with the tissues.

Must know the ionic basis for phase 4 depolarization (electrophysiology) - what are (& how many) the membrane currents are involved? - Depolarization results from opening or closing of ______. - Repolarization results from opening or closing of ________.

*Ionic basis for PACEMAKER (SLOW AP, in sa & av nodes) activity = Phase 4 Depolarization: A) THREE VOLTAGE GATED membrane currents: 1) Out: K+ decreases. 2) IN: Funny Na+ slowly via non-specific ion channels 3) IN: gradual Ca++ as threshold is approached. B) Depolarization results from opening of voltage-gated L-type Ca++ channels C) Repolarization results from opening of voltage-gated K+ channels.

Must know - the order of depolarization in the ventricles (electrophysiology)

*Spread of Impulse/Depolarization: SEPTUM => APEX => BASE (bundle of His) and ENDOCARDIAL (bundle branches) => EPICARDIUM/subepicardial myocytes (purkinje fibers, myocardium).*

Which of the following is the FIRST to repolarize? Last? a. Bundle branches b. Subepicardial myocytes c. Bundle of his

- b - subepicardial myocytes are first to repolarize (and last to depolarize)* - a - BUNDLE BRANCES R LAST TO REPOLARIZE. *NOTE: ventricular repolarization spreads "backwards" over the pathway of depolarization.

Which of the following is the LAST to depolarize? a. Bundle branches b. Subepicardial myocytes c. Apex d. Septum

- b is answer - Subepicardial myocytes are last Depolarize, first to Repolarize. must know order of ventricular depolarization: SEPTUM -> APEX -> BASE (bundle of his) and endocardial (bundle branches) -> epicardium/SUBEPICARDIAL MYOCYTES (purkinje fibers).

0. Pressure-Volume loop plots what against what? 1. The WIDTH of the pressure volume loop is 2. AREA within pressure-volume loop is 3. filling of the ventricle moves along the _______________ curve. 4. The _______ curve gives the maximal pressure that can be developed under any given left ventricular volume. [Show the relationship between the Wiggers diagram and the pressure-volume loop (cardiac cycle, phys.)] MUST KNOW HOW TO INTERPRET PRESSURE VOLUME LOOP

0. Left ventricular pressure polluted vs. left ventricular volume during single cardiac cycle. 1. width of the loop is the difference between EDV and ESV (= SV) . 2. the area within the loop is the ventricular stroke work (the work done by the ventricle to eject a volume of blood into the aorta). **SW = SV X MAP** 3. filling of the ventricle moves along the END-DIASTOLIC PRESSURE-VOLUME RELATIONSHIP (EDPVR) CURVE. 4. The ESPVR CURVE (END SYSTOLIC PRESSURE-VOLUME RELATIONSHIP) gives the maximal pressure that can be developed under any given left ventricular volume.

1. understand: pressure and flow relationships (must know) WTK - What is the *Total Peripheral Resistance*, aka the resistance for the entire vascular system? (hemodynamics)

1. (A) DeltaP = QR. - Q is flow - Delta P is pressure drop (btwn two points in circulation) & measurement of the potential energy used to overcome the resistance to flow. - R is resistance to flow (B) - For the entire systemic circulation, express (a) equation as: ***P,ao - P,vc = CO*TPR*** - Delta P is "now" pressure drop between aortic mean pressure (P,ao) and venae cave pressure at entrance to the right atrium (Pvc). - Q aka flow is "now" the CO. - R is "now" resistance for the entire vascular system aka TOTAL PERIPHERAL RESISTANCE (TPR). 2. First: CO = HR *SR = 72beats/min * 70 ml/beat = 5040 ml/min. Then: Pao-Pvc = CO * TPR 92mmHG - 4mmHG = 5040ml/min*TPR TPR = 0.0176 mmHg*min/ml

Blood Pressure (BP) Monitoring 1. Smaller cuff (under-cuffing) causes _____ estimation of BP, while larger cuff (over cuffing) causes ____ estimation of BP. 2. Arm position is such that the _____artery is at the ___ level. 3. Lowering the arm leads to _____. Raising the arm above what level leads to_____. 4. When should you refer the patient to the PCP/cardiologist?

1. Always use an appropriate sized cuff for the patient: Pediatric cuff; Adult cuff; Extra large/Thigh cuff. - Smaller cuff (under-cuffing) causes oVER-ESTIMATION of blood pressure - Larger cuff (over-cuffing) causes UNDER-ESTIMATION of blood pressure. Always have the patient rest in the chair momentarily before monitoring the BP. 2. Arm position is such that the CUFF/BRACHIAL ARTERY IS AT THE CARDIAC LEVEL - Seated patient: Have the arm resting on the arm rest of the chair - Lying patient: The arm should be straight down on the side 3. Improper positioning of the arm: Always remember that the cuff should be at the cardiac level LOWERING the arm below heart level leads to an OVER-ESTIMATION of SBP & DBP. RAISING the arm above heart level leads to UNDER-ESTIMATION of BP readings. The magnitude of this error can be as great as 10 mm Hg for SBP & DBP. 4. Measure BP in both arms at the initial examination REFER the patient to the PCP/cardiologist FOR FURTHER EVALUATION IF >20MMHG FOR SBP OR >10MMHG FOR DBP DIFFERENCE OCCURS WITH 3 consecutive readings

describe the conduction system of the heart- *where is the slowest velocity* (electrophysiology) - In atrial and ventricular myocardium, conduction is primarily by ________ contact through _______.

1. Conduction of the action potential: • In atrial and ventricular myocardium it is primarily by cell-cell contact through GAP JUNCTIONS. • gap junctions contain low resistance ion channels that allow depolarizing currents to spread from one cell to adjacent cells • conduction velocity is about 0.5 m/sec Slowest velocity = capillaries.

Mitral incompetence (incompetent mitral valve) or Tricuspid Incompetence - e.g. does NOT close properly. 1. what happens to the blood flow? 2. If it is due to a ventricular septal defect, what type of murmurs do you hear? 3. If it is due to mitral or tricuspid stenosis, what type of murmurs do you hear? (from review, def on exam)

1. Failure of valve to close compeltely -> Blood flow is REGURGITANT = going backwards when heart beats, squirts back into LA. Leads to volume overload, can cause heart failure. 2. From left to right ventricle through a VENTRICULAR SEPTAL DEFECT= PANSYSTOLIC MURMURS 3. regurgitant flow through INCOMPETENT AORTIC OR PULMONIC VALVE. MITRAL OR TRICUSPID STENOSIS = DIASTOLIC MURMURS.

Define / say what each represent: 1. P wave* 2. QRS Complex - Q wave, R wave, S wave* 3. QRS Interval (how long is it) 4. T wave 5. P-R interval (how long is it) 6. P-R segment 7. ST segment 8. QT interval (how long is it) Ventricles REpolarization. VENTRICULAR DEpolarization PLUS ATRIAL DEpolarization. signal proceeding to beginning of QRS complex. plateau phase of ventricular action potential. time to pass through AV node VENTRICULAR Depolarization duration ventricular action potential duration. ATRIAL DEpolarization, immediately after SA node firing. (Must know the Features of ECG waveform including intervals and segments - ecg, phys)

1. P = ATRIAL DEpolarization, immediately after SA node firing. 2. QRS com.= VENTRICULAR DEpolarization PLUS ATRIAL DEpolarization. - Q waves = recording whats happening in septum. - R waves = what's going on in apex (LV mainly, & RV). - S wave = final depolarization of the base of ventricles and going up to the top of the ventricles. 4. T = Ventricles REpolarization. 6. P-R seg = time to pass through AV node (think: bc btwn end of P wave and start of QRS complex on chart). 7. ST = plateau phase of ventricular action potential. 3. QRS int. = 0.6 to 0.1 seconds, VENTRICULAR DEpolarization duration. 8. QT int = 0.2 to 0.4 seconds, ventricular action potential duration. 5. P-R Int = 0.12 to 2 seconds, signal proceeding to beginning of QRS complex.

Two types of myocardial cells: pacemaker cells vs. non-pacemaker cells (electrophysiology) - which spontaneously generate AP's? Where are pacemaker cells located and what specialized cell type are they?

1. Pacemaker cells - SLOWLY and automatically depolarize to the threshold potential at which they fire an all-or-none action potential - are specialized myocardial cells that are located in the sinoatrial (SA) and atrioventricular (AV) nodes. - are auto rhythmic = spontaneously generate action potentials 2. Non-pacemaker cells involved in developing force during each contraction of the heart. They fire action potentials when stimulated. FAST RESPONSE.

Must know - significance of the long refractory period of myocardial cells (electrophysiology) - there are "2 significant things", what are they? - the effective or absolute refractory period comprises phases ____ , during which a new AP cannot be elicited. ___ channels are inactivated. Shorter ERP times for ___ muscle, longer for ____ muscle. The ERP is followed by a ________. - In a cardiac muscle fiber, the refractory period lasts almost as long as _____.

1. Refractory Period: • EFFECTIVE OR ABSOLUTE REFRACTORY PERIOD: the period comprising phases 0, 1, 2 and part of 3, during which a new action potential cannot be elicited. • Na+ channels inactivated • Shorter ERP times for atrial muscle, longer for ventricular. • Followed by a short relative refractory period (not shown) • Cardiac muscle fiber: the refractory period lasts almost as long as the entire muscle TWITCH. 2. Significance of ERP: • Limits the frequency of action potentials and prevents the heart from summing twitches or tetanizing. • Allows time for ventricular filling between beats

1. The phase between S1 and S2 2. The phase between S2 and S1 (red, phys)

1. The ventricular contraction occurs during (red) The phase between S1 and S2 is the Systolic phase. 2. the Atrial Contraction happens during (red): The phase between S2 and S1 is the Diastolic phase. (think: *S2 is end of systole and start of diastole* *S1 is start of systole*)

Match the capillaries with their typical locations: 1. Continuous Capillary 2. Fenestrated Capillary 3. Discontinuous Capillary a. liver, spleen, lymph nodes. b. skeletal muscle, lungs, skin, BBB parts in CNS. c. endocrine glands, kidney glomerulus.

1. b 2. c 3. sinusoidal - a

Cardiac cycle facts to remember: 1. the duration of systole is about ____ of the cycle while diastole is ~ ___ - emptying occurs at ____ pressure while filling is mostly ___ at ____ pressure. 2. systemic and pulmonary blood flow are _____ although SVs can vary from beat to beat 4. Ejection Fraction equation 5. volumes and pressures can change in _____ 6. all valves are closed during ____ contraction and relaxation 7. The major heart sounds are _____ - each occurs when valves ___ and blood becomes ____. 10. The heart pumps its stroke volume in the time between ________. {RED}

1. systole is 1/3, diastole is 2/3. Emptying at high pressure, filling is passive at low pressure. 2. equal 4. SV/EDV = ejection fraction (~55%) 5. exercise or disease 6. isovolumetric 7. S1 and S2-close, turbulent. 10. S1 and S2!

Understand: TPR (must know) - series vs. parallel resistances (hemodynamics)

2. TPR = the frictional resistance to blood flow provided by all the vessels between the aorta and right atrium. 2a. Resistances in series are summed (added together): e.g. TPR = R,aorta + R,arteries 2b. Reciprocals of parallel resistances are summed: (1/TPR)=(1/R,cerebral)+(1/R,coronary).

Augmented leads are in ____ degree intervals. If this interval is changed, what does that mean? (from review)

30 degree intervals. If interval changed - I think (total guess) it means that leads were placed incorrectly.

Aortic Stenosis / Incompetence (from review, DEFINITELY on exam) - sign of this? What can it lead to?

AORTIC STENOSIS (aortic valve damaged) / PULMONIC STENOSIS = flow is interrupted by narrowing of vessels (high pressure aorta squeeze blood back to the ventricles) = doc hears "Systolic ejection murmurs" => severely thick/stiff left ventricular wall => vibration of ventricular wall during systole/contraction => S4 sound (Tennessee)

What is the only conducting pathway from atria into ventricles? a. bundle branches b. AV node c. SA node d. purkinje fibers

AV node Note: AV valves = mitral (bicuspid) & tricuspid valves = btwn atria and ventricles.

Must know how to calculate MAP (hemodynamics)

Aortic pressure fluctuates between the SYSTOLIC PRESSURE (SP) which occurs when the ventricle contracts, and the DIASTOLIC (DP) when it relaxes. - MAP = DP + (SP-DP)/3, where "SP-DP = pulse pressure"

During your examination of the carotids, you notice that the Right and left pulse rate are not the same on both sides = is evidence of what pathology? (medicine)

Auscultation (hear) for Carotid Bruit if partial carotid block is evident by R & L pulse rate disparity aka IF THE RATE IS NOT THE SAME ON BOTH SIDES. - Carotid Bruit is heard over the Carotid with the lesser pulsation - Breath sounds can muffle hearing a bruit: Always have patient hold the breath - CAROTID BRUIT IS ONLY AUDIBLE WITH PARTIAL CAROTID OBSTRUCTION (red). Note: There is no blood flow through a completely blocked Carotid artery

Pulse Pressure 1. What level is associated with uncontrolled Hyperthyroidism ? 2. With uncontrolled hyPOthyroidism?

Average normal Blood Pressure (BP): 120/80 mmHg Pulse Pressure: Difference between the SBP & DBP: Normal Pulse Pressure: 40 mmHg 1. Widened Pulse Pressure: Pulse Pressure: > 40 mmHg - Associated with UNCONTROLLED Hyperthyroidism - Hyperthyroidism →inc. BMR -> inc. SBP. - Inc. Tissue activity & inc. metabolites => vasodilation at the tissue level and dec. DBP . - Thus PP > 40mmHg in the UNCONTROLLED Hyperthyroid patient 2. Narrowed Pulse Pressure: Pulse Pressure: < 40 mmHg - Associated with uncontrolled Hypothyroidism - dec. BMR => dec. SBP. - *Vasoconstriction* of peripheral arterioles => inc. DBP. - Thus PP < 40mmHg in the UNCONTROLLED Hypothyroidism.

Which of the following are histamine sensitive? a. capillaries b. venules c. arterioles d. veins

B is answer - histamine release during inflammation increases vascular permeability (edema).

Which function in microcirculation (may be more than one answer)? a. Fenestrated capillaries b. arterioles c. Venules d. Muscular arteries e. Elastic arteries f. Smooth muscle cells

B, d, e

5. The P-R interval of the EKG is used as an indication of: a) the time for an action potential to travel through the Bundle of His b) the time for an action potential to travel from SA to AV node c) the time it takes for the ventricles to repolarize d) the heart rate

B. P-R int. = signal proceeding to beginning of QRS complex aka BEGINNING OF ATRIUM TO THE VENTRICULAR DEPOLARIZATION. P-R seg. = Time for an AP SIGNAL to travel from sa TO AV NODE.

2. During isovolumic contraction of the left ventricle A. the mitral valve is open B. the aortic valve is open C. the mitral and aortic valves are closed D. the ventricle develops no force or pressure E. dl/dt is maximum

C. KNOW ALL VALVES ARE CLOSED DURING ISOVOLUMETRIC CONTRACTION. Isovolumetric Contraction: - CLOSURE (starts w. it open) OF MITRAL valve (bc inc. pressure, QRS complex initiates vent. contraction) = C WAVE happening in atrium. - Aortic valve is closed. => Ventricular pressure increases quickly W/O change in volume. - MITRAL valve is open (aortic closed) during atrial depolarization (P wave) {of systole which initiates contraction of atrial muscle, driving blood into the ventricles} , OPENS DURING ISOVOLUMETRIC RELAXATION. - aortic valve is open during ventricular ejection. Closed during isovolumetric contraction and isovolumetric relaxation.

4. Which of the following statements regarding cardiac output is NOT TRUE? Cardiac output: A. is equal to stroke volume times heart rate. B. Is equivalent to the pressure drop divided by the total peripheral resistance C. is greater in the peripheral circulation than in the pulmonary circulation. D. can be estimated closely using a Doppler flow meter placed over the ascending aorta. E. can be expected to increase during exercise

C. cardiac output is NOT greater in peripheral circulation than in pulmonary circulation. - Both the systemic and pulmonary blood flow must be equal to the cardiac output although the SVs for the two ventricle may differ on a beat-to-beat level. - volumes and pressures can change in exercise or disease.

factor that contribute to cardiac output (hemodynamics)

Cardiac output (CO): equals the total VOLUME OF BLOOD FLOW through systemic or pulmonary circulation ****CO = HEART RATE x STROKE VOLUME***** ex) For a resting heart rate ~72 beats per min and stroke volume ~ 70 ml/beat ***CO = 72 beats/min x 70 ml/beat = 5040 ml/min****

know the "rules" about dipoles (electrophysiology)

Dipoles - non-invasive measurement of electrical activity. Exist when there's a separation of charge along the muscle strip, where vectors are used to indicate the direction of depolarization/repolarization. NO DIPOLES exist when there's uniformly charged aka ISOELECTRIC aka resting, depolarized, or depolarized states. RULES: 1. No signal is recorded when the strip is isoelectric. 2. WHEN A DIPOLE VECTOR INDICATING DEPOLARIZATION (neg to pos) POINTS TOWARD THE + ELECTRODE, THE SIGNAL IS POSITIVE (it is negative when the vector points away from the + electrode). 3. WHEN A DIPOLE VECTOR INDICATING REpOLARIZATION (pos to neg.) POINTS TOWARD THE + ELECTRODE, THE SIGNAL IS NEGATIVE (it is positive when the vector points away from the + electrode) 4. Electrodes placed perpendicularly to a dipole vector show no deflection.

During atrial systole, the ventricle fills to 100. At the end of ejection, the volume remaining in the ventricle is 40. What is the stroke volume?

EDV (100) - ESV (40) = Stroke volume = 60.

At the end of ejection, the volume remaining in the ventricle is the __________. a. end diastolic volume b. end systolic volume

END SYSTOLIC VOLUME (ESV) = 0 full ventricle = mitral valve opens. EDV is amount of blood in ventricle immediately before a contraction = mitral valve closes.

Match: Epicardium, Endocardium, Myocardium. Tunica Media, Tunica Intima, Tunica adventitia.

Epicardium (Tunica Adventitia) Myocardium (Tunica Media) Endocardium (Tunica Intima)

MUST KNOW - effects of sympathetic and parasympathetic stimulation of the heart (electrophysiology) - which one's slope will be flatter due to decreasing sodium leakage? - which one hyper polarizes the resting potential, which doesn't change the polarity? - vagus nerve with __? cardiac plexus with ___? - Which increases heart rate, which decreases heart rate? - Which involves a positive ionotropic effect?

Even though pacemaker cells are auto-rhythmic, they are controlled by SNS and PNS. 1. PARASYMPATHETIC = VAGUS N. (Ach to SA node) = SLOWS HEART RATE via: - Hyperpolarize resting potential (voltage gated K+ channels close more slowly), - REDUCES SLOPE (from review) of phase 4 depolarization (DEC. Na+ inward / funny CURRENT) [from review] - Decreases Ca++ in late phase 2. SYMPATHETIC = CARDIAC PLEXUS (NE to SA and AV nodes and myocardium) = INC. HEART RATE & FORCE CONTRACTION BC INC. INTRACELL. CA++ {POSITIVE IONOTROPIC EFFECT}. - Polarity doesn't change here, rate of depolarization is increased to be very steep and moves to threshold rapidly (from review). - increased Na+ IN (funny current) in nodes - increased Ca++ IN in all myocardial cells => alters threshold TOWARD more NEGATIVE voltage.

Describe the sequence of events that occur in each chamber during systole and diastole (cardiac cycle, phys) MUST KNOW - events that correspond to the beginning and end of systole; of diastole

Events that occur almost simultaneously with onset of systole: - QRS complex - S1 - c wave (in atrium) - closure of mitral valve - rise in ventricular pressure Events that occur almost simultaneously with onset of diastole: - S2 - closure of aortic valve - INCISURA (dichrotic notch) -drop in ventricular pressure • SYSTOLE- ventricular contraction and ejection of blood. • DIASTOLE - ventricular relaxation and filling with blood • assuming a resting rate of 72 beats per minute, one cycle takes 0.8 seconds.

Atrial Pressure Waves 1. a wave - represents? triggered by? 2. B/C - represents? triggered by? 3. c wave - represents? 4. v wave 5. D wave 6. E wave / F wave [ Important features of Wiggers to know - need to know Show the relationship between the Wiggers diagram and the pressure-volume loop (cardiac cycle, phys.)]

FROM REVIEW: - A = SYSTOLE - C = MITRAL VALVE CLOSES - V = atrial filling and emptying. RISES V. SLOWLY AND LETS ATRIAL FILL DURING THE VENTRICULAR SYSTEM -> RISES IN PRESSURE, NOT SO HIGH AND THEN DROPS AGAIN. (A wave) = atrial SYSTOLE - triggered by P wave {depolarization of atria). ii. small pressure rise as atrium squeezes blood into ventricle (tops off ventricle thats already 95% full of blood from passive beating). (B-C) ISOVOLUMETRIC CONTRACTION i. triggered by QRS complex ii. mitral valve closes (creates the c wave in atrium) iii. Aortic valve is closed iv. pressure rises rapidly v. volume is constant vi. aortic pressure ~ 80 mmHg. - the volume stays constant during isovolumetric contraction, then decreases as blood is ejected into the aorta. (C) opening of aortic valve (ejection of stroke volume from when the aortic valve opens until it closes) i. ventricular pressure exceeds aortic ii. begins ejection phase iii. ejection initially rapid iv. aortic pressure rises (V) atrial filling and emptying (D) reduction in ejection rate i. ventricle approaches the end of contraction (T wave occurring) ii. outward flow declines as kinetic energy of blood decreases iii. ventricular and aortic pressures begin to fall (E-F) isovolumetric relaxation i. forward movement of blood reverses, closing aortic valve. ii. incisura (dichrotic notch) indicates aortic valve closure. iii. ventricular pressure falls precipitously iv. atrial pressure rises as venous inflow fills the atrium v. aortic pressure falls as ejected blood drains away from heart f) opening of mitral valve i. begins rapid filling of ventricle from accumulated blood in atrium ii. rapid filling followed by reduced filling from pulmonary veins.

Must know - major function of each vessel type (slide 22) (hemodynamics) 1. aorta 2. large arteries 3. small arteries 4. arterioles 5. capillaries 6. venules 7. veins 8. vena cava Capacitance Function (blood volume). Exchange, Collection, and capacitance. Collection of venous blood. Distribution and resistance. Pulse dampening and distribution Resistance (pressure and flow regulation) Exchange. Pulse dampening and distribution. Distribution of Arterial Blood.

GREATEST DELTAP (PRESSURE DROP) IS IN ARTERIOLES. GREATEST R IS IN ARTERIOLES. 1. Aorta - PULSE DAMPENING AND DISTRIBUTION - 25mm diameter - 93 mmHg aprox hydrostatic pressure at beginning of this. 2. Large Arteries - DISTRIBUTION OF ARTERIAL BLOOD. - - 1-4mm diameter - 90mmHg aprox hydrostatic pressure at beginning of this. 3. Small Arteries - DISTRIBUTION AND RESISTANCE. - 0.2-1mm diameter - 80mmHg aprox hydrostatic pressure at beginning of this. 4. Arterioles - RESISTANCE (PRESSURE & FLOW REGULATION). - 0.01-0.2 mm diameter - 70 mmHg aprox hydrostatic pressure at beginning of this. 5. Capillaries- - EXCHANGE - 0.006-0.01mm diameter - 30mmHg aprox hydrostatic pressure at beginning of this. 6. Venules - EXCHANGE, COLLECTION, AND CAPACITANCE - 0.01-0.2 mm diameter - 15mmHg aprox hydrostatic pressure at beginning of this. 7. Veins - CAPACITANCE FUNCTION (BLOOD VOLUME). - 0.2-5.0mm diameter - 10mmHg aprox hydrostatic pressure at beginning of this vessel. 8. Vena Cava - COLLECTION OF VENOUS BLOOD. - 35mm diameter - 4mmHg aprox hydrostatic pressure at beginning.

Describe the events that cause the four heart sounds (cardiac cycle, phys) - s1,s2,s3,s4

Heart Sounds = caused by turbulence or vibrations of blood S1 / First heart sound = Mitral (and tricuspid) valves close + sudden rise in ventricular pressure => turbulence of blood in ventricles. S2 /second heart sound= Aortic and pulmonic valves close causing vibrations of blood in the high pressure vessels. S3 = during RAPID FILLING OF BLOOD from atrium to ventricle - normal in children (kentuky) and athletes. In older patients, indicates CHF. (red). S4 = VIBRATION OF THE VENTRICULAR WALL (red) during atrial systole/contraction in some individuals (Tennessee) due a SEVERELY THICKENED & STIFFENED (red) left Ventricular wall/LVH .LVH occurs from HYPERTENSION/HTN OR AORTIC STENOSIS/AS (red)

Describe catheterization of the right and left heart (cardiac cycle, phys) MUST KNOW - how the right and left heart is catherized

LEFT HEART: from the femoral artery, a catheter can advance to aorta, coronary arteries, and left ventricle. RIGHT HEART: "SWAN-GANZ CATHETER: - catheter inserted into a vein can be pushed to the entrance to the right atrium. - balloon at the tip can be inflated so the flow of blood caries the catheter into the atrium, right ventricle, and pulmonary artery. - the catheter tip can be advanced into the pulmonary circulation until it wedges in a small vessel. - forward flow of blood in that vessel is blocked and the transducer detects the "PULMONARY WEDGE PRESSURE" which is a good indicator of left atrial pressure.

Doppler Ultrasound

Measuring cardiac output using an ultrasonic Doppler blood flow meter. •Doppler ultrasound is a non-invasive test that can be used to estimate your blood flow through blood vessels by bouncing high-frequency sound waves (ultrasound) off circulating red blood cells and measuring the frequency change in reflected sound. • Gives V (velocity) and A (area), therefore A (cm2) x V (cm/min) = Q (cm3/min) • This method yields the cardiac output minus coronary circulation.

MUST KNOW - 1. opening and closing of the mitral valve 2. opening and closing of the aortic valve - During atrial depolarization, which is opened and which is closed? - During isovolumetric relaxation, which is open and which is closed?

Mitral opens when ventricles empty, closes when full and ventricular pressure rises. Aortic opens when atria empty, closes when ventricular pressure drops. 1. Mitral Valve OPEN: - opens at end of ventricular ejection (when volume remaining in ventricle is ESV) - isovolumetric relaxation. - atrial depolarization (P wave). Mitral CLOSED: - closure occurs w. onset of systole (contractions & filling) and rise in ventricular pressure. - C wave of atrial pressure - isovolumetric contraction. 2. Aortic Valve OPEN: - during "initial" ventricular ejection. - ventricular pressure > aortic => begins ventricular ejection phase, ejection initially rapid => aortic pressure rises. Aortic CLOSED: - w. onset of diastole and drop in ventricular pressure. - isovolumetric contraction & relaxation. - atrial demoralization (P wave)

Must know the ionic currents that occur at each phase of the NON-pacemaker cell .... action potential (electrophysiology) - fast or slow response? - what causes the depolarization (is it fast or gradual)? - What comes before the plateau phase? What does the plateau phase involve? - What causes the Repolarization? - And lastly, what maintains the testing potential?

Non-pacemaker cell action potentials • True resting potential of ~ (-90 mV) • excited by APs from adjacent cells: not autorhythmic • Divided into 5 numbered phases • Rapid depolarization of non-pacemakers => FAST RESPONSE. (0) Phase 0: rapid influx Na+ through VOLTAGE GATED channels => depolarization towards ENa+ (1) Phase 1: INACTIVATION of Na+ channels plus opening of a "transiently outward" K+ channel. (2) Phase 2: PLATEAU phase involves an inward flux of Ca++ through L-type (long lasting) voltage-gated channels, ICa, balanced by a slow outward K+ current, IKs- voltage stays close to 0. (3) Phase 3: repolarization when Ca++ channels close and potassium efflux returns the membrane to resting potential. (4) Phase 4: small fluxes of Na+ and K+ maintain the resting potential.

what is the difference between passive and active ventricular filling?

Passive filling = increase in volume without increase in pressure. passive occurs when the tricuspid or mitral valve open due to greater pressure in the ventricle than the atrium and begins filling. active is when the atria contract

Must know factors that contribute to resistance to flow (esp. r) - A 5% increase in radius produces a ____% increase in flow at the same P? (hemodynamics)

Poiseuille's Equation - this guy studied flow through cylindrical tubes and found that: R=8nl/ pie*r^4. - n is viscosity of fluid - l is length of tube - r is radius of tube In the circulation, viscosity of fluid and length of tube are essentially constant, but RADIUS of tube can change owing to vasoconstriction and vasodilation. Since r (RADIUS of tube) is raised to the 4th power, a small change in radius has a large effect on flow; e.g. a 5% increase in radius produces > 20% increase in flow at the same P. R1 = 8/r^4 => let r be 1 => R1 = 8 R2 = 8/r => r is 5% increased to 1.05 => 8/(1.05)^4 = 6.584 Q = deltaP/R now becomes: Q= deltaP*pie*r^4 / 8nl Q1 = (1)^4 = 1 Q2 = (1.05)^4 = 1.215

Vital Signs - know pulse and BP (red)

Pulse: Determine the rate/minute: 60-80 beats/min Blood Pressure (BP): Determine the average of 2-4 readings Temperature: Not typically monitored in the Dental setting Respiration: Determine the rate/minute: 12-16/min Other "vitals" of importance in the Dental setting: - Height: Logged in feet & inches - Weight: Weight is listed as lbs. in the Medical Record ... Weight converted to kg. to calculate drug administration during a medical emergency.

Pulse Rate less than 60/min is indicative of _____, while pulse rate more than 100/min is indicative of ____. Under what conditions would these be considered "normal"?

Rate: Pulse Rate is the number of beats/min: Average: 60-80/min Pulse Rate less than 60/min: BRADYCARDIA (red) Regular exercise can lead to a lower pulse rate & this is normal . Beta blockers decrease the heart rate Pulse Rate more than 100/min: TACHYCARDIA (RED) Sudden anxiety, fear or noise can temporarily increase the pulse rate.

This is defined as the difference between EDV and ESV (from review): a. cardiac output b. stroke volume c. heart rate d. blood pressure

Stroke Volume = EDV-ESV ~ 70 ml at rest.

Radial Pulse - how long do you need to count the pulse, and what are you noting the presence of?

Support patient's arm with your hand when taking the Radial pulse The Radial pulse is felt at the wrist just BELOW the THUMB Start counting the pulse only after the patient is relaxed Count the pulse for a minute & note presence of irregularities IRREGULARITIES MAY BE MISSED IF THE PULSE IS FELT FOR JUST 10/15 SECONDS ONLY (red)

1. When mean electrical vector of depolarization is parallel to the electrode axis, how does the electrical signal change? 2. When mean electrical vector of depolarization is perpendicular to the electrode axis, how does the electrical signal change? (Must know, ECG)

The "magnitude" of the recorded voltage is determined by the "direction" of the vector, relative to where you placed the recording electrode. LARGEST pos./neg. signals [maximum amplitude of signal]* = when mean electrical vector of depolarization & electrodes are PARALLEL. No (ZERO) signal detected [zero amplitude]* = vectors and electrodes are at right angles aka PERPENDICULAR. Smaller signal related to cosine of angle* = vectors and electrodes have ACUTE ANGLES btwn. *this is talking about the recorded ecg deflection.

________ presents as an irregularly irregular pulse/rhythm, and CAN BE FATAL (red). a. angina pectoris b. myocardial infarction c. ventricular arrhythmia d. cors pulmones

Ventricular Arrhythmia.

4) Which of the following statements is FALSE? a) Arterioles usually contain an inner elastic lamina b) Fenestrated capillaries have pores within endothelial cells c) Histamine influences permeability of post-capillary venules d) Endothelium lines ALL blood & lymphatic vessels and heart chambers e) Lymphatic vessels provide one-way drainage toward heart

a - elastic laminae absent in arterioles! o

6) Which of the following pairs is IMPROPERLY matched? a) Elephantiasis - venules b) Pulmonary embolism- deep vein thrombosis c) Valves - veins d) Postcapillary venules - extravasation of fluid and wbc's during inflammation e) Microcirculation - arterioles

a. Elephantiasis = Lymphedema that may be caused by lymphatic blockage/damage (e.g. Elephantiasis) or lymphadenectomy.

Which of the following do not have tunica media or tunica adventitia?

answer; venules and capillaries.

This is defined as the 'amount of blood ejected from either the right or left ventricle in one beat': a. cardiac output b. stroke volume c. heart rate

b Recall: CO = HR (beats/min) & SV (ml/beat). It is also the difference between EDV and ESV (other fc).

1 . During a single cardiac cycle, which of the following events occur simultaneously? A. peak ventricular systolic pressure - onset of ejection B. c wave - isovolumic contraction C. peak of the v wave - S1 D. Q wave - a wave

b is answer. C wave = HAPPENS IN ATRIUM = closure mitral valves and (resulting) inc. pressure during isovolumetric contraction. Onset of ejection doesn't occur "WITH" peak of ventricular systolic pressure - Rapid ejection (blood is ejected out of ventricle / ventricular volume decreases and blood goes to atria) FOLLOWING ventricular pressure exceeding aortic pressure causing the aortic (semilunar) valve to open. S1 is turbulence/vibrations due to closure of mitral valve in isovolumetric contraction (ventricles) initiated by QRS complex. *Peak of V wave = S3 (in some), mitral valve opens* [from review] = all blood in atrium goes to ventricle and pressure drops. A wave = S4 (in some) = the in. pressure due to atrial contraction in systole.

12) All of the following are characteristics of atherosclerosis EXCEPT: a) Common disease of larger arteries b) Begins with the appearance of foam cell in the adventitia c) Blood flow impeded due to narrowing of vessel lumina d) Most common form of arteriosclerosis e) Can lead to thrombus formation & stroke

b. - Focal thickening of intima - Increase deposition of ECM components and lipoproteins - Accumulation of foam cells - macrophages, SMCs heavily loaded with lipids - Coronary arteries are predisposed - Blockage can lead to necrosis, infarcts, angina, arrhythmias

Arterioles are very small but it is able to withstand high pressures, what explains this? a. law of hemodynamics b. law of LaPlace Greatest pressure drop occurs where? Greatest resistance occurs where?

b. Law of LaPlace: T = Pr Where T is the wall tension of a vessel (the force needed to prevent the wall from splitting), P is the pressure within the vessel and r is the radius. For a given luminal pressure, T varies with r. Small vessels can withstand high pressures because their radii are small. => GREATEST DELTAP (PRESSURE DROP) IS IN ARTERIOLES. GREATEST R IS IN ARTERIOLES.

Vasa Vasorum are important in... a. Metabolism of large blood vessel walls. b. Nourishing walls of large blood vessels. c. Nourishing walls of small blood vessels d. Metabolism of small blood vessel walls

b. Nourishing walls of large blood vessels.

7) All of the following statements are true EXCEPT: a. Vasa vasorum are important in nourishing the walls of large blood vessels b. Sinusoidal capillaries are common in the liver c. Varicose veins are largely due to thrombi d. Elastic arteries and muscular arteries belong to what is called the microcirculation e. Fenestrated capillaries are characterized by pores within the endothelial cells

c know - Varicose veins (usu. not serious problem, but some cases can be blockage of deeper veins called DVT) = twisted dilated veins near surface of skin. The normally one-way VALVES IN the VEINS that keep blood flowing toward the heart become WEAK/ABSENT => blood collects in legs and ankles, pressure builds up and veins become varicose.

the pulse that is felt in children a) carotid pulse b) radial pulse c) brachial pulse

c Have the patient's arm positioned such that the palm is facing the ceiling From the little finger, go upwards on the arm on the medial side, to just above the elbow Support the patient's arm with your hand & feel the pulse with 2 fingers Brachial pulse is the pulse that is felt in children during a medical emergency The Brachial artery pulsation is used for BP monitoring The Stethoscope is placed over the Brachial artery The stethoscope monitors the Korotkoff sounds which are tapping sounds

Which of the following would result in a Continuous Murmur (heard throughout the cardiac cycle)? a. mitral valve stenosis b. ventricular septal defect c. patent ductus arteriosus (cardiac cycle, phys)

c PATENT DUCTUS ARTERIOSUS: pressure gradient between aorta and pulmonary artery persists in both systole and diastole

Which of the following are considered "leaky" such that most lymph and white blood cells exit from here? a. Small arteries b. Small veins c. Venules d. Arterioles

c is answer: postcapillary venules are leaky = extravasation of fluid and wbc's during inflammation!

Which capillary is considered the most "leaky"? What is the transport mechanism of all the other capillaries? a. continuous capillary b. fenestrated capillary c. discontinuous capillary

c. Sinusoidal capillary (liver) is considered most "leaky" = free exchange of material. CONTINUOUS Capillary has single uninterrupted layer endothelial cells, & Tight JUNCTIONS between cells for passage small molecules. FENESTRATED have PORES within endothelial cells for passage small molecue.s

Death due to DVT is mainly from? a. Embolus formation b. Thrombus Formation c. Urinary Thrombosis d. Pulmonary THrombosis

d Recall: DVT (dangerous condition) = BREAKage of blood clot (THROMBUS) leads to the FORMATION of an EMBOLUS which travels to other parts of body and can cause significant clinical symptoms and death mainly from PULMONARY THROMBOSIS (red).

10) Which of the following pairs is IMPROPERLY matched? a. Mesothelium - epicardium b. Endothelium - endocardium c. Angina pectoris - ischemia d. Deep vein thrombosis - stroke e. Elastic artery - aorta

d. - KNOW - DVT (dangerous condition) = BREAKage of blood clot (THROMBUS) leads to the FORMATION of an EMBOLUS which travels to other parts of body and can cause significant clinical symptoms and death mainly from PULMONARY THROMBOSIS (red).

What is the normal range of mean electrical vectors [of mean electrical axis]? What is a left axis deviation? What is a right axis deviation? (must know, ecg)

from -30 degrees to +90 degrees. - Less than (-30) is left axis deviation. - More than (+90) is right axis deviation.

Incisura (dichrotic notch) must know

indication of the closing of the aortic valve (isovolumetric relaxation).

Normal Pressure Ranges for the LEFT heart: 1. Ventricular 2. aortic 3. atrial [ Important features of Wiggers to know]

normal pressure ranges for the left heart: i) ventricular: 0 - 120 mmHg ii) aortic: 80-120mmHg iii) atrial: 6-~10 mmHg

A Wiggers diagram for the RIGHT HEART has qualitatively all of the features that we saw for the left. Where is presure lower - right or left heart? (from review).

pressure lower in right heart. - • the right ventricle develops a systolic pressure of only 25 mmHg and drops to 0-4 in diastole. - the pulmonary arterial blood pressures are ~ 25/10.

What is an instantaneous mean electrical vector? (must know, ec)

sum of all the individual vectors that represent a given instant in time of depolarization. It is the one "seen" by the recording (+) electrode, & so it is the one that CAN BE DETERMINED AT ANY INSTANT FOLLOWING A STIMULUS. When the SA node fires (ventricles depolarize) => APs go in all directions ("wave" of depolarization that spreads across muscle mass in many different directions) simultaneously. So, if you wanna take snapshot at a given instant in time during depolarization, you'd see many waves of depolarization (arrows represent this)... thats why it is a sum.

muscle layers in the ventricular myocardium (Hemodynamics )

• Ventricular walls: layers of myocardium 1) LONGITUDINAL 2) CIRCUMFERENTIAL 3) OBLIQUE - allows effective pumping upward toward the aortic and pulmonic valves . • Right ventricle= thinner walls = free wall wraps around septum