Cardiac Cycle – PV Loops – Sounds - Murmurs PDF

Cardiac Cycle – PV Loops – Sounds - Murmurs Lecture prepared by : Ricardo Rodriguez-Millan M.D. Harvey Mayrovitz PhD Assistant Professor Professor Department...

Cardiac Cycle – PV Loops – Sounds - Murmurs Lecture prepared by : Ricardo Rodriguez-Millan M.D. Harvey Mayrovitz PhD Assistant Professor Professor Department of Medical Education Department of Medical Education [email protected] [email protected]  Cardiac Cycle Overview Atrial Inlet All valves Outlets “kick” Closed valves close (2) (4) open Atrial Ejection Filling Systole (1) (3) Isovolumic Isovolumic Contract Relax Vent Diastole Vent systole Vent Diastole 120 (2) (4) Ventricle (1) SV (1) EF=SV/EDV Volume (ml) EDV MV opens ESV 0 AP Heart Sounds S4 S1 S2 S3 Dr HN Mayrovitz p qrs 2 of 29 Cardiac aortic 120 mmHg Cycle: Aortic valve Carl opens Pressure Wiggers’s Aortic valve closes Diagram Isovolumic Isovolumic LV Contraction Pressure Relaxation mitral valve mitral opens valve closes 0 mmHg Heart Sounds Atrial Aortic 180 ml Flow Slow 80 Fast Ventricle Diastolic Filling EKG Volume 3 of 29 Dr HN Mayrovitz Ventricular Systole Diastole Atrial Systole Measuring EF via Echocardiography A) 0.50 B) 0.54 C) 0.58 D) 0.62 E) 0.65 Dr HN Mayrovitz 4 of 29 Measuring CO via Echocardiography A) 3.0 B) 3.6 C) 4.2 D) 4.8 E) 5.4 Dr HN Mayrovitz 5 of 29 Carl Wiggers Diagram: Word Review Time is seconds Ventricular systole starts at A and ends at F The mitral valve closes at B From B to C is isovolumic contraction At C the aortic valve opens – Blood Ejection From C to D is maximum ejection From D to F is reduced ejection CàF is Left Ventricle Ejection Time (LVET) Ventricular diastole starts at F and ends at K From F to G muscle is relaxing At G the aortic valve closes From G to H is isovolumic relaxation At H the mitral valve opens From H to I is rapid ventricular filling From I to J is reduced ventricular filling From J to K is atrial contraction (atrial “kick”) Dr HN Mayrovitz 6 of 29 Cardiac Pressure-Volume Loop: Introduction “Decompensation” Left Ventricle Pressure (LVP, mmHg) Peak Isovolumic Pressure Line PIP Line PV Loop Filling ESV EDV Left Ventricle Volume (ml) Dr HN Mayrovitz 7 of 29  Cardiac Pressure-Volume Loop Systolic Pressure 120 Ejection – Continuing Afterload I O “Initial” MAP Afterload Relaxation LV Pressure (mmHg) Diastolic Pressure Exceeded Aortic pressure is a clinical surrogate Isovolumic for true afterload 60 Contraction IO IO MAP is an estimate of average afterload SV Valve State 30 closed I O EDV open Filling 0 ESV 50 100 150 I = Inlet Valves LV Volume (ml) O = Outlet Valves Dr HN Mayrovitz 8 of 29 Afterload Effects and Peak Isovolumic Pressure PIP Fixed End-Systolic Line Contractility point of all P-V loops EFFECTS falls on PIP 1à3 -SV, - EF LV Pressure P-V Loops Fixed with various Preload 1 2 3 AFTERLOADS 3 > 2 >1 Passive Pressure LV Volume EDV Dr HN Mayrovitz 9 of 29  Contractility Effects on P-V Loops -Contractility + Contractility -SV, -EF +SV, +EF P-V Loops LV Pressure Contractility Changes 1 > 2 >3 Fixed Preload 1 2 3 Passive Pressure Dr HN Mayrovitz ESV LV Volume EDV 10 of 29  Interactive Question Doug is a 27-year old electrician who is in good cardiovascular shape If Doug’s P-V loop changes from A to B as shown after exercise which parameter did NOT change? 45s LV Pressure (mmHg) B A A. Contractility B. Preload C. Afterload D. Stroke volume A B E. Ejection Fraction 60 100 140 180 LV Volume (ml) Dr HN Mayrovitz 11 of 29  Decreased Contractility à Increased Preload 1 (beat 1) Decreased Inter-beat -contractility Contractility Leads to 2 (beat 2) Increased Subsequent LV Pressure Preload A Loops with + EDV 2 Initial Loop After 1 2 Contractility 1 3 (beat 3) Loop Prior to Reduction Contractility Reduction Increased Preload EDV1 Dr HN Mayrovitz LV Volume 12 of 29  Positive Inotropic Therapy + Inotropic Therapy Partially Offsets Elevated Preload Loop LV Pressure After Therapy 2 Initial Loop After 1 2 Contractility 1 3 Loop Prior to Reduction Contractility Reduction Reduced Preload EDV1 Dr HN Mayrovitz LV Volume 13 of 29  Interactive Questions: Wiggers vs. PV Loops A 120 B 2 3 F Aortic 100 2 80 1 LV Pressure G 60 E (mmHg) 40 4 4 Atrial H 3 Ventricle 1 0 0 0.2 0.5 seconds 40 80 120 LV Volume (ml) 1. In A: what event is associated with point 2? 2. What does this point correspond to in the PV Loop? 3. In B: what occurs during segment E? 4. Between which two points in A does E correspond? 5. The QRS of the EKG starts closest to which point in B? 6. Which point in A corresponds to this point? 7. If the patient’s HR is 70 what is her cardiac output? 8. The patient’s systolic blood pressure is approximately what value? 9. The patient’s end systolic volume is approximately what value? 10. If there was a 3rd heart sound, during which segment in B would it occur? Dr HN Mayrovitz 14 of 29 Cardio-Hemodynamic Vibrations (heart sounds) Sounds due to blood and wall vibrations caused by accelerations and decelerations Forces causing the vibrations are as a consequence of F = mass x acceleration Blood and heart wall vibrations à low frequency vibrations dominate < ≈ 200 Hz with intensity audibility between about 30 – 100 Hz Intensity depends on magnitude of acceleration or deceleration of event causing vibration High arterial BP tends to produce greater sound since rate of valve closure greater Sound intensity at surface is greatest over areas not intervened by aerated lung or fat Heart sounds are widely distributed whereas valve murmurs tend to be much more localized Rapid Filling The adjacent image illustrates the approximate regions for maximin sensitivity for each valve Dr HN Mayrovitz 15 of 29  Heart Sound #1 S1 Cardio-Hemodynamic vibrations 1 1 Onset of ventricle Systole Inlet Valve closure Where?? Dr HN Mayrovitz 16 of 29  Heart Sound #2 S1 S2 Flow deceleration & Vibrations Sound intensity greater if valves close more rapidly e.g. hypertension 1 2 1 2 Onset of Ventricle ventricle Relaxes Systole Outlet Inlet valve Valve closure closure Where?? Dr HN Mayrovitz 17 of 29  Murmurs Sound produced by turbulent flow Occur if local critical NR exceeded In/distal to organic/structural obstruction (stenosis - valve or vascular) High cardiac output (functional) e.g severe anemia, hyperthyroid, fever etc. High regional flow Dr HN Mayrovitz 18 of 29 For the following slides pick the correct cardiac cycle phase corresponding to the cardiac image on the left and the dark blue area shown on the pressure diagram on the right Dr HN Mayrovitz 19 of 29  Pick the Cardiac Cycle Phase Isovolumic Contraction Rapid Ejection Reduced Ejection Isovolumic Relaxation Rapid Filling Slowed Filling (Diastasis) Atrial Contraction (Atrial Kick) Dr HN Mayrovitz 20 of 29  Pick the Cardiac Cycle Phase Isovolumic Contraction Rapid Ejection Reduced Ejection Isovolumic Relaxation Rapid Filling Slowed Filling (Diastasis) Atrial Contraction (Atrial Kick) Dr HN Mayrovitz 21 of 29  Pick the Cardiac Cycle Phase Isovolumic Contraction Rapid Ejection Reduced Ejection Isovolumic Relaxation Rapid Filling Slowed Filling (Diastasis) Atrial Contraction (Atrial Kick) Dr HN Mayrovitz 22 of 29  Pick the Cardiac Cycle Phase Isovolumic Contraction Rapid Ejection Reduced Ejection Isovolumic Relaxation Rapid Filling Slowed Filling (Diastasis) Atrial Contraction (Atrial Kick) Dr HN Mayrovitz 23 of 29  Pick the Cardiac Cycle Phase Isovolumic Contraction Rapid Ejection Reduced Ejection Isovolumic Relaxation Rapid Filling Slowed Filling (Diastasis) Atrial Contraction (Atrial Kick) Dr HN Mayrovitz 24 of 29  Pick the Cardiac Cycle Phase Isovolumic Contraction Rapid Ejection Reduced Ejection Isovolumic Relaxation Rapid Filling Slowed Filling (Diastasis) Atrial Contraction (Atrial Kick) Dr HN Mayrovitz 25 of 29  Pick the Cardiac Cycle Phase Isovolumic Contraction Rapid Ejection Reduced Ejection Isovolumic Relaxation Rapid Filling Slowed Filling (Diastasis) Atrial Contraction (Atrial Kick) Dr HN Mayrovitz 26 of 29