Copyright © 2008 Lippincott Williams & Wilkins. 1 Assessment of Cardiovascular Function Hemodynamic Monitoring

Copyright © 2008 Lippincott Williams & Wilkins. 2 Overview of Anatomy and Physiology of the Heart  Three layers of the heart:  Endocardium (inner lining)  Myocardium (muscle fibers)  Epicardium (exterior layer)  Heart is encased in the pericardium  Four chambers  2 atria, 2 ventricles  Heart valves  2 atrioventricular valves, 2 semilunar valves  Coronary arteries  Cardiac conduction system  Three layers of the heart:  Endocardium (inner lining)  Myocardium (muscle fibers)  Epicardium (exterior layer)  Heart is encased in the pericardium  Four chambers  2 atria, 2 ventricles  Heart valves  2 atrioventricular valves, 2 semilunar valves  Coronary arteries  Cardiac conduction system

Copyright © 2008 Lippincott Williams & Wilkins. 3 Structure of the Heart

Copyright © 2008 Lippincott Williams & Wilkins. 4 The Cardiac Cycle  During systole, the heart muscle contracts and blood is ejected from the chambers  During diastole, the heart muscle relaxes and the chambers fill with blood  During systole, the heart muscle contracts and blood is ejected from the chambers  During diastole, the heart muscle relaxes and the chambers fill with blood

Copyright © 2008 Lippincott Williams & Wilkins. 5 The Cardiac Cycle  Muscle contraction is initiated by action potentials the normally originate in the sinoatrial node  Ventricular contraction causes the AV valves (tricuspid and mitral) to close, which indicates the beginning of ventricular systole.  The semilunar valves (aortic and pulmonic) were closed during the previous filling (diastole) period and remain closed during this time  Continued contraction raises pressure in the ventricles above the pressure in the aorta and pulmonary trunk, causing the semilunar valves to open  Blood is ejected from the ventricles, through the semilunar valves, into the pulmonary artery (right) and aorta (left)  Muscle contraction is initiated by action potentials the normally originate in the sinoatrial node  Ventricular contraction causes the AV valves (tricuspid and mitral) to close, which indicates the beginning of ventricular systole.  The semilunar valves (aortic and pulmonic) were closed during the previous filling (diastole) period and remain closed during this time  Continued contraction raises pressure in the ventricles above the pressure in the aorta and pulmonary trunk, causing the semilunar valves to open  Blood is ejected from the ventricles, through the semilunar valves, into the pulmonary artery (right) and aorta (left)

Copyright © 2008 Lippincott Williams & Wilkins. 6 The Cardiac Cycle  Once the ventricles relax and pressures decrease, blood flowing back (from the pulmonary artery and aorta) towards the relaxed ventricles causes the semilunar valves to close.  This is the beginning of ventricular diastole  The AV valves remain closed  When the ventricular pressure becomes lower than the pressure within the atria, the AV valves open and blood flows from the atria into relaxed ventricles. This represents approximately 75% of ventricular filling.  The atria then contract and complete the remainder of ventricular filling  Once the ventricles relax and pressures decrease, blood flowing back (from the pulmonary artery and aorta) towards the relaxed ventricles causes the semilunar valves to close.  This is the beginning of ventricular diastole  The AV valves remain closed  When the ventricular pressure becomes lower than the pressure within the atria, the AV valves open and blood flows from the atria into relaxed ventricles. This represents approximately 75% of ventricular filling.  The atria then contract and complete the remainder of ventricular filling

Copyright © 2008 Lippincott Williams & Wilkins. 7 Coronary Arteries

Copyright © 2008 Lippincott Williams & Wilkins. 8 Cardiac Conduction System

Copyright © 2008 Lippincott Williams & Wilkins. 9 Terms: Cardiac Action Potential  Depolarization: electrical activation of a cell caused by the influx of sodium into the cell while potassium exits the cell  Repolarization: return of the cell to the resting state caused by re-entry of potassium into the cell while sodium exits  Refractory periods:  Effective refractory period: phase in which cells are incapable of depolarizing  Depolarization: electrical activation of a cell caused by the influx of sodium into the cell while potassium exits the cell  Repolarization: return of the cell to the resting state caused by re-entry of potassium into the cell while sodium exits  Refractory periods:  Effective refractory period: phase in which cells are incapable of depolarizing

Copyright © 2008 Lippincott Williams & Wilkins. 10 Cardiac Action Potential

Copyright © 2008 Lippincott Williams & Wilkins. 11 Great Vessel and Heart Chamber Pressures

Copyright © 2008 Lippincott Williams & Wilkins. 12 Cardiac output  Cardiac output refers to the amount of blood pumped by each ventricle during a given period  Average human cardiac output is 5 liters per minute (4-8 is normal)  Stroke volume (SV) refers to the amount of blood ejected per heartbeat  CARDIAC OUTPUT = SV x HR  Cardiac output refers to the amount of blood pumped by each ventricle during a given period  Average human cardiac output is 5 liters per minute (4-8 is normal)  Stroke volume (SV) refers to the amount of blood ejected per heartbeat  CARDIAC OUTPUT = SV x HR

Copyright © 2008 Lippincott Williams & Wilkins. 13 Terms: Cardiac Output  Stroke volume: the amount of blood ejected with each heartbeat  Cardiac output: amount of blood pumped by the ventricle in liters per minute  Preload: degree of stretch of the cardiac muscle fibers at the end of diastole  Contractility: ability of the cardiac muscle to shorten in response to an electrical impulse  Afterload: the resistance to ejection of blood from the ventricle  Ejection fraction: the percent of end-diastolic volume ejected with each heartbeat  Stroke volume: the amount of blood ejected with each heartbeat  Cardiac output: amount of blood pumped by the ventricle in liters per minute  Preload: degree of stretch of the cardiac muscle fibers at the end of diastole  Contractility: ability of the cardiac muscle to shorten in response to an electrical impulse  Afterload: the resistance to ejection of blood from the ventricle  Ejection fraction: the percent of end-diastolic volume ejected with each heartbeat

Copyright © 2008 Lippincott Williams & Wilkins. 14  CO = HR x SV

Copyright © 2008 Lippincott Williams & Wilkins. 15 Hemodynamic Monitoring- Noninvasive  Blood pressure  Orthostatic vital signs  Blood pressure  Orthostatic vital signs

Copyright © 2008 Lippincott Williams & Wilkins. 16 Hemodynamic Monitoring  Blood Pressure Measurement  Systemic blood pressure is exerted on the walls of the arteries during ventricular systole and diastole  Affected by factors such as cardiac output, distension of the arteries, and the volume, velocity and viscosity of blood  Normal: 100/  Blood Pressure Measurement  Systemic blood pressure is exerted on the walls of the arteries during ventricular systole and diastole  Affected by factors such as cardiac output, distension of the arteries, and the volume, velocity and viscosity of blood  Normal: 100/

Copyright © 2008 Lippincott Williams & Wilkins. 17 Hemodynamic Monitoring  Orthostatic (postural) blood pressure/HR measurements  The patient should be supine and flat for 5-10 minutes, then the initial BP and HR are measured  The patient is then placed in the sitting position, with feet dangling. Repeat measurements are taken within 1-3 minutes of position change  Repeat the procedure with the patient in the standing position  Record BP and HR, as well as the patient position that each was taken  Be sure to ask about symptoms of dizziness or feeling faint during position changes - record this as well  Orthostatic (postural) blood pressure/HR measurements  The patient should be supine and flat for 5-10 minutes, then the initial BP and HR are measured  The patient is then placed in the sitting position, with feet dangling. Repeat measurements are taken within 1-3 minutes of position change  Repeat the procedure with the patient in the standing position  Record BP and HR, as well as the patient position that each was taken  Be sure to ask about symptoms of dizziness or feeling faint during position changes - record this as well

Copyright © 2008 Lippincott Williams & Wilkins. 18 Hemodynamic Monitoring- Invasive CVP Pulmonary artery pressure Intra-arterial BP monitoring CVP Pulmonary artery pressure Intra-arterial BP monitoring

Copyright © 2008 Lippincott Williams & Wilkins. 19 Hemodynamic Monitoring  Critically ill patients may require continuous assessment of their hemodynamic status  Special Equipment: see slide 27  Catheter, which is introduced into the appropriate vessel  Flush system for continuous flushing of the catheter  Pressure bag around the flush system to prevent backflow of blood  A transducer to convert the pressure from the vessel into an electrical signal  A monitor to display the signal and reading  Critically ill patients may require continuous assessment of their hemodynamic status  Special Equipment: see slide 27  Catheter, which is introduced into the appropriate vessel  Flush system for continuous flushing of the catheter  Pressure bag around the flush system to prevent backflow of blood  A transducer to convert the pressure from the vessel into an electrical signal  A monitor to display the signal and reading

Copyright © 2008 Lippincott Williams & Wilkins. 20 Hemodynamic Monitoring  Nursing responsibilities  Ensuring that the system is set up and maintained properly  Prior to taking a measurement, ensuring that the stopcock of the transducer is at the level of the right atrium - referred to as the phlebostatic axis (4th intercostal space, midaxillary line  Monitoring for complications  Nursing responsibilities  Ensuring that the system is set up and maintained properly  Prior to taking a measurement, ensuring that the stopcock of the transducer is at the level of the right atrium - referred to as the phlebostatic axis (4th intercostal space, midaxillary line  Monitoring for complications

Copyright © 2008 Lippincott Williams & Wilkins. 21 Hemodynamic Monitoring  Central Venous Pressure Monitoring (CVP)  Normal 2-8 mmHg  Pressure in the vena cava and right atrium  Used to assess right ventricular function and venous blood return to the right side of the heart  Very useful in the assessment of volume status  High CVP may indicate volume overload  Low CVP may indicate volume depletion  Measured via a central line catheter positioned in the vena cava via the internal jugular or subclavian vein  Central Venous Pressure Monitoring (CVP)  Normal 2-8 mmHg  Pressure in the vena cava and right atrium  Used to assess right ventricular function and venous blood return to the right side of the heart  Very useful in the assessment of volume status  High CVP may indicate volume overload  Low CVP may indicate volume depletion  Measured via a central line catheter positioned in the vena cava via the internal jugular or subclavian vein

Copyright © 2008 Lippincott Williams & Wilkins. 22 Phlebostatic Level

Copyright © 2008 Lippincott Williams & Wilkins. 23 Hemodynamic Monitoring  Central Venous Pressure Monitoring (CVP)-Nursing Interventions  Ensure that dressing maintains clean, dry and STERILE  Xray confirmation of catheter placement  Dressing and pressure monitoring system are maintained according to hospital policy  Monitor for signs of infection  Ensure appropriate transducer placement before measurements are recorded  Document CVP  Monitor for other complications: pneumothorax, air embolism  Central Venous Pressure Monitoring (CVP)-Nursing Interventions  Ensure that dressing maintains clean, dry and STERILE  Xray confirmation of catheter placement  Dressing and pressure monitoring system are maintained according to hospital policy  Monitor for signs of infection  Ensure appropriate transducer placement before measurements are recorded  Document CVP  Monitor for other complications: pneumothorax, air embolism

Copyright © 2008 Lippincott Williams & Wilkins. 24 Hemodynamic Monitoring  Pulmonary arterial pressure monitoring (Swan Ganz)  Normal PA pressure 20-30/8-15 mmHg; mean mmHg  Normal pulmonary capillary wedge pressure 6-12 mmHg  Used to evaluate right and left sided cardiac function:  Left ventricular performance  Volume status  Cardiac output  Condition of vascular system (SVR)  Response to cardiovascular infusions  Effects of treatments on cardiac functioning  Inserted via the subclavian or jugular vein, occasionally the femoral vein  Pulmonary arterial pressure monitoring (Swan Ganz)  Normal PA pressure 20-30/8-15 mmHg; mean mmHg  Normal pulmonary capillary wedge pressure 6-12 mmHg  Used to evaluate right and left sided cardiac function:  Left ventricular performance  Volume status  Cardiac output  Condition of vascular system (SVR)  Response to cardiovascular infusions  Effects of treatments on cardiac functioning  Inserted via the subclavian or jugular vein, occasionally the femoral vein

Copyright © 2008 Lippincott Williams & Wilkins. 25 Hemodynamic Monitoring  Pulmonary arterial pressure monitoring  Pulmonary artery pressures reflect volume status, right heart function  Pulmonary capillary wedge pressure reflects left heart function ; the catheter is “wedged” in the pulmonary artery and the balloon is inflated, temporarily obstructing blood flow  This creates a static fluid column, and the catheter senses the pressure in the pulmonary vein - this allows us to estimate the left atrial pressure  Pulmonary arterial pressure monitoring  Pulmonary artery pressures reflect volume status, right heart function  Pulmonary capillary wedge pressure reflects left heart function ; the catheter is “wedged” in the pulmonary artery and the balloon is inflated, temporarily obstructing blood flow  This creates a static fluid column, and the catheter senses the pressure in the pulmonary vein - this allows us to estimate the left atrial pressure

Copyright © 2008 Lippincott Williams & Wilkins. 26 Pulmonary Artery Catheter

Copyright © 2008 Lippincott Williams & Wilkins. 27 Pulmonary Artery Catheter and Pressure Monitoring System

Copyright © 2008 Lippincott Williams & Wilkins. 28 Hemodynamic Monitoring Nursing responsibilities of a PA catheter:  Ensure that dressing maintains clean, dry and STERILE  Xray confirmation of catheter placement  Dressing and pressure monitoring system are maintained according to hospital policy  Monitor for signs of infection  Ensure appropriate transducer placement before measurements are recorded  Document hemodynamic measurements as ordered  During insertion: monitor EKG for dysrhythmias  NEVER leave balloon inflated (risk of PA rupture)  Monitor for other complications: PA rupture, PA embolism, pulmonary infarction, catheter migration, dysrhythmias, air embolus, pneumothorax Nursing responsibilities of a PA catheter:  Ensure that dressing maintains clean, dry and STERILE  Xray confirmation of catheter placement  Dressing and pressure monitoring system are maintained according to hospital policy  Monitor for signs of infection  Ensure appropriate transducer placement before measurements are recorded  Document hemodynamic measurements as ordered  During insertion: monitor EKG for dysrhythmias  NEVER leave balloon inflated (risk of PA rupture)  Monitor for other complications: PA rupture, PA embolism, pulmonary infarction, catheter migration, dysrhythmias, air embolus, pneumothorax

Copyright © 2008 Lippincott Williams & Wilkins. 29 Hemodynamic Monitoring  Intra-arterial Blood Pressure Monitoring  Used to obtain direct and continuous BP measurements in critically ill patients  Placed in the radial, femoral or brachial artery  Intra-arterial Blood Pressure Monitoring  Used to obtain direct and continuous BP measurements in critically ill patients  Placed in the radial, femoral or brachial artery

Copyright © 2008 Lippincott Williams & Wilkins. 30 Hemodynamic Monitoring  Intra-arterial Blood Pressure Monitoring  Nursing Interventions  Ensure that dressing remains clean, dry and sterile  Ensure patency of pressure monitoring and flushing systems, maintain per hospital policy  Ensure appropriate transducer placement when measurements are recorded  Document BP as ordered  Monitor for complications: distal ischemia, hemorrhage, massive ecchymosis, dissection, air embolism, pain, infection  NEVER inject anything into the arterial line  Intra-arterial Blood Pressure Monitoring  Nursing Interventions  Ensure that dressing remains clean, dry and sterile  Ensure patency of pressure monitoring and flushing systems, maintain per hospital policy  Ensure appropriate transducer placement when measurements are recorded  Document BP as ordered  Monitor for complications: distal ischemia, hemorrhage, massive ecchymosis, dissection, air embolism, pain, infection  NEVER inject anything into the arterial line

Copyright © 2008 Lippincott Williams & Wilkins. 31 Arterial Pressure Monitoring System