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Lecture Objectives - Heart Failure

• Defining heart failure
• Discuss the causes of HF
• Explain the clinical manifestations of HF
• Describe the physiological responses to heart failure
• Cardiogenic shock
• Outline the diagnostic procedures/tests for HF
• Describe the pharmacological management of HF

Heart Failure Definition (HF)

• Characterized by an underlying structural abnormality or dysfunction resulting in the ventricle's inability to fill with or eject blood properly and is a complex clinical condition
• Also referred to as Congestive Cardiac Failure (CCF)

Heart Failure Types

• Left sided Heart Failure including:
  • Systolic heart failure
  • Diastolic heart failure
• Right Sided Heart Failure

Causes of HF

• CAD can decrease blood supply
  • Infarction and fibrosis from prolonged ischaemia account for 2/3 systolic HF and a reduction in EF
• Dysrhythmias
• Valve disease
  • Regurgitation
  • Stenosis
• Cor pulmonale
• Congenital heart disease (ASD, VSD)
• Rheumatic fever
• Cardiomyopathy
• Diabetes mellitus (diastolic HF)
• Chronic HTN (diastolic HF)

Systolic vs Diastolic Heart Failure

• Systolic heart failure is a problem with contraction
  • Decreased force of contraction / contractility / inotropy
  • Decreased SV and CO
  • EF less than 40% for diagnosis
  • Enlarged ventricles, chamber wall thinner
• Diastolic heart failure is a filling problem
  • Decreased preload
  • Small ventricles and large chamber walls
  • Myocardial hypertrophy and can have normal EF

Clinical Manifestations - Left Heart Failure

• Increased PAP
• Crackles on auscultation
• Pulmonary oedema (congestion)
• Dyspnoea/orthopnoea
• Pink frothy sputum
• Cough
• Decreased BP, CO, CI
• S3 heart sounds
• Fatigue, weak, lethargic (not enough blood going forward)
• Decreased UO
• Rapid/irregular HR

Clinical Manifestations - Right Heart Failure

• Peripheral oedema +/- pitting oedema
• Elevated JVP
• Increased CVP
• Hepatosplenomegaly
• Ascites
• Weight gain
• Nocturia
• Decreased BP, CO, CI
• Fatigue, weakness, lethargy
• Rapid/irregular HR
• Decreased UO

Physiological Responses to Heart Failure

• Sympathetic nervous system response
• Renin-angiotensin-aldosterone system (RAAS)
• Frank-Starling response

Cardiogenic Shock

• Decreased Cardiac output stimulates release, with the following responses
  • Compensatory renin-aldosterone, antidiuretic hormone shifts resulting in adequate or increased blood volume
  • Increased preload, stroke volume and rate
  • Increased SVR
  • Catecholamine (adrenaline and noradrenaline) compensatory release = increase directly
• Myocardial oxygen requirements results in decreased cardiac output, ejection fraction and blood pressure lowers
• Ultimately leads to decreased tissue perfusion and ends with impaired cellular metabolism

Acute and Chronic Heart Failure

• Acute heart failure involves a sudden development of symptoms, and is often severe, including causes such as:
  • Myocardial infarction or an ischaemic,
  • Inflammatory or toxic insult,
  • Acute valve insufficiency, or
  • Pericardial tamponade
• Requires urgent evaluation and management and may respond to treatment and improve rapidly but may occur as a decompensation of chronic heart failure

Chronic Heart Failure

• Chronic heart failure appears gradually over time, with function deteriorating, requiring frequent assessment and adjustments to management, even with intervention
• Note, a person with chronic heart failure may have acute exacerbations but see function decline on a slow but incessant

Diagnostic Procedures

• ECG - basic interpretation of rhythm, reviewed by MO within 1hr
• CXRAY – requires level of understanding, formal report findings include cardiomegaly, pulmonary oedema
• ECHO - nurses do not undertake but must interpret with findings including dilation, hypertrophy, Valves, contractile force, EF %

Management of Heart Failure

• Treat underlying cause with Fibrinolytic, cath lab, CABG, Valve replacement
• Manage fluid volume overload with ACE inhibitors, diuretics (loop, thiazides), fluid restriction, salt restriction
• Improve ventricular function by reducing preload and afterload, and improving contractility, this with Beta blockers (carvedilol, bisoprolol, metoprolol), ACE inhibitors, Digoxin, Antiarrhythmic drugs, IV Calcium, Inotropic therapy (dobutamine, milrinone, levosimendan)

Dobutamine

• Short term inotropic support for acute HF or acute exacerbations of Chronic HF and used to treat HF, cardiogenic shock, sepsis with systolic dysfunction
• Onset of action 2-10minutes continuous IV infusion 250mg/250mls
• Mcg/kg/min 2-20mcg/hg/min
• Positive inotrope elevates CO and positive chronotrope elevating HR minimal
• Beta (β)1 agonists activates – increase contractility leads to decrease in end systolic volume, increasing SV
• Has Beta 2 and Alpha (α) 1 effects (minimal)
• Beta 2 (vasodilation) Decreases afterload SVR can sometimes be seen as a drop in BP initially then gradually improve due to ẞ1 effects
• CO = HR X SR therefore elevating SV & HR + decreasing SVR elevates CO while preserving systemic BP

Lecture Objectives - Haemodynamic Monitoring

• Understanding Haemodynamics
• Non-invasive Haemodynamic monitoring
• Invasive Haemodynamic monitoring
  • Arterial lines
  • Central lines
  • Pulmonary Artery (PA) catheters
• Continuous cardiac monitoring
• Pathology results

Haemodynamic Assessment and Monitoring

• Measuring and monitoring factors that influence the force and blood flow
• Used to assess cardiovascular function in critically ill or unstable patients
• Indicated when standard vital signs measurements are insufficient
• Provides full information required to enable individualised goal directed therapy

Non-invasive patient assessment

• Look for cardiac output drops and inadequate perfusion
• Listen
• Feel
• Pathology

Signs of inadequate perfusion/compromised haemodynamics

• Primary indicators including (skin and GIT)
  • Cool, clammy skin, > cap refill
  • Pallor, cyanotic skin
  • Decreased Bowel sounds and Diarrhoea -Increased NG output
• Secondary Symptoms in the kidneys, liver, and lungs include:
  • Concentrated urine and decreased UO
  • Elevated BUN/Cr/Potassium, elevated ALT/AST/Coags and RR and effort
  • SOB decreases PaO2 and SpO2
• Final symptoms involving the organs including Brain and Heart include:
  • Decreased or an altered LOC
  • Disorientation / Slow reacting pupils and Chest pain
  • Tachycardia/bradycardia/ectopics, and ST elevation

Continuous cardiac monitoring + ECG

• Continuous cardiac monitoring
• 5 lead continuous cardiac monitoring allows rapid assessment and constant evaluation (2 lead display preferred)
• Nurses must have skills at rhythm interpretation (SR, AF, SVT, ST elevation, 1st, 2nd, 3rd degree heart blocks, BBB, atrial and ventricular ectopics, VT, VF, and asystole)
• 12 lead ECG, Pharmacology and Electrolyte knowledge

Mean Arterial Blood Pressure (MAP)

• Average arterial pressure throughout one cardiac cycle during systole and diastole, that is influenced by cardiac output and systemic vascular resistance
• It is a risk indicator and regarded as a perfusion pressure and can be worked out using the formula MAP = DP + 1/3(SP – DP)
• Where DP is the diastolic blood pressure, and SP is the systolic blood pressure.
• MAP values less than 60-65mmHg should be avoided, as low readings can trigger tissue hypoxia

Arterial Catheters Insertion sites

• Allow continuous BP monitoring
• Common sites include:
  • Radial artery which is the most common preferred site that offers Maximum mobility, bleeding control, collateral circulation
  • Brachial artery offer large easy to place catheter but can provide limited collateral circuit
  • Femoral artery placement poses a High infection risk given it close proximity to peritoneum

Arterial Lines Advantages Vs Complications

• Advantages include:
  • Continuous assessment of systemic arterial BP via constant readings and visual trace of waveform
  • Provides important diagnostic information via arterial compliance and stroke volume as well as continuous assessment
  • Aids with treatment as can assess/monitor responses to titrations, and facilitates ease of arterial blood sampling
  • More accurate than manual cuff pressure
• <5% Complications of using Arterial Lines are:
  • Thrombosis clot at catheter insertion site or Embolisation from air during introduction or dislodgement of thrombosis
  • Contaminations from ports leading to Infection
  • Bleeding usually minor if disconnections occur
  • Haematoma and or Vasospasm

Arterial Line Set Up

• Zero transducer to atmospheric pressure and maintained at the Phlebostatic axis at the 4th intercostal border
• Maintain height if transducer with position changes
• Ensure Equip check and Site assessment
• Conduct Patient assessment of NV's by checking Pain, pulses, pallor, parasthesia, paralysis

Central Line Sites

• Are inserted into a large vein close to the heart in locations such as; Superior Vena Cava and or Inferior Vena Cava
  • Includes internal Jugular Vein CVC offering easy access by Subclavian vein CVC
  • Can be done in the femoral Vein in emergency
• The smaller the lumens = more lumens, and are staggered for fluid admin

Advantages of Central Line Vs Complications

• Advantages:

• Easy to quickly access vessels for placement via blood samples or rapid fluid infusions,

• Can administer Fluids and medication but some have restrictions (some meds MUST be given ONLY via central line (noradrenaline))

• Nutrition (TPN) is an option when enteral cannot be used or is not possible, haemodynamic measurements can be taken

• Disadvantages: -- Bleeding as can increase the risk in coagulation disorders

  • Perforate/puncture vessel (usually during insertion)
  • Misplaced/Malpositions such as Arterial cannulation and or Retrograde Catheter (Catheter goes direction to IJ towards head)
  • May trigger Pneumo/Haemothorax, resulting in Embolism (rare) and or Infection

CVP lines and waveforms

• Central Venous Pressure Reflects RV end diastolic pressures and volume at volumes of 2-6 mmHg
• Measured number is unimportant but is interpreted along with all other clinical assessments, in circumstances such as patients with low urine output

Factors that influence CVP measurement

• CVP increases with Hypervolemia, tension pneumothorax, Heart failure and tamponade
• CVP lowers with Hypovolemia and shock

Pulmonary Artery (PA) Catheter

• Intravascular catheters also called swan-Ganz catheter are advanced through the Superior Vena Cava through the right side of the heart
• Are utilized for hemodynamic assessment in right ventricular (RV) failure, pulmonary hypertension & cardiogenic shock assessment
• Allows to assess of Cardiac Output & Wedge Pressure via blood draws and waveform

Monitoring PA catheters

• Nurses are responsible for placing & monitoring
• They conduct Waveform analysis and Thermodilution readings of CO & notify when assessment readings require an action
• Catheters nurse must maintain the PAC once it is in place during the procedure, ensure sterility while also monitoring cardiac rhythm

Diagnostic Pathology results

• RBC and WCC differentials, including LFT's liver function tests, AST, ALT and EUC kidney functions like creatinine
• Conduct Coagulation markers such as coagulation and Cardiac with Troponin assessment , and Glucose

Summarise

• Continuous ECG and mental status monitoring is required, as well as HR and arterial catheter BP
• Must check kidney perfusion with urine outputs, assess preload & refill, warmth
• Regularly assess lactate, oxygenation and biochemestry

Objectives - Anti-dysrhythmic Medications and cardioversion

• Understand Atrial dysrhythmias and the cardiac action potential
• • Describe anti-dysrhythmic medications and their Nursing considerations
• Discuss Cardioversion, and Ventricular dysrhythmias

Bradycardia

• Symptoms treatable with Atropine and Dophamine administered via Transcutaneous or trans venous pacing

Atrial Dysrhythmias

• Arise from multiple ectopic foci which cause atrial conduction to be in disarray

Cardiac Action Potential

• Depolarisation is rapid, and refractory periods are altered by treatment medication

Anti-dysrhythmic Medications

• Work by decreasing the automaticity of cardiac cells, altering conduction speeds and refractory periods Classified into groups including – Class I, la, lb, Ic, Class II, Class III & Class IV

Class I: Anti-dysrhythmic Medications

• Sodium Channel blockers (Quinidine, Flecainide, amlodipine)

Class II :Anti-dysrhythmic Medications

• Beta-Blockers (propranolol, metoprolol)

Class III :Anti-dysrhythmic Medications

• K+ Channel Blockers, Potassium Channel blockers (Amioderone, sotalol)

Class IV :Anti-dysrhythmic Medications

• Ca2+ Channel Blockers, or Calcium Channel Blockers (verapamil, diltiazem)
• Unclassified Anti-dysrhythmics - Digoxin has narrow range that affects contractions and the rate

Contraindicated Dysrhythmic Medication

• Adenosine needs monitoring for flushing, Shortness of breath, but is used for fast rhythms

Considering Nursing Anti-Dysrhythmic Use

• Conduct ECG to ensure Electrolyte and acid balance is maintained
• CCM and BP monitored and ensure Equipment is available for safety

Cardioversion

• Delivery of electrical currents to synchronize and address rhythms, must know if pateint has implanted Electrical devices

Ventricular Dysrhythmias

• Premature contractions triggered by MI causes multiple ectopic beats