Zero to Finals Cardio Flashcards
Summarise what chronic heart failure means.
Chronic heart failure is essentially the chronic version of acute heart failure. It is caused by either impaired left ventricular contraction (“systolic heart failure”) or left ventricular relaxation (“diastolic heart failure”). This impaired left ventricular function results in a chronic back-pressure of blood trying to flow into and through the left side of the heart.
How does heart failure present?
Breathlessness worsened by exertion
Cough. They may produce frothy white/pink sputum.
Orthopnoea (the sensation of shortness of breathing when lying flat, relieves by sitting or standing). Ask them how many pillows they use at night.
Paroxysmal Nocturnal Dyspnoea (see below)
Peripheral oedema (swollen ankles)
What causes chronic heart failure?
- Ischaemic Heart Disease
- Valvular Heart Disease (commonly aortic stenosis)
- Hypertension
- Arrhythmias (commonly atrial fibrillation)
What is the first line treatment for chronic heart failure?
ACE inhibitor (e.g. ramipril titrated as tolerated up to 10mg once daily)
Beta Blocker (e.g. bisoprolol titrated as tolerated up to 10mg once daily)
Aldosterone antagonist when symptoms not controlled with A and B (spironolactone or eplerenone)
Loop diuretics improves symptoms (e.g. furosemide 40mg once daily)
When are aldosterone antagnoists introduced to manage heart failure?
Aldosterone antagonists are used when there is a reduced ejection fraction and symptoms are not controlled with an ACEi and beta blocker.
Patients should have their U&Es monitored closely whilst on diuretics, ACE inhibitors and aldosterone antagonists as all three medications can cause electrolyte disturbances.
Patients should have their U&Es monitored closely whilst on diuretics, ACE inhibitors and aldosterone antagonists as all three medications can cause electrolyte disturbances.
Other than medications how else are heart failure paitents managed?
- Surgical treatment in severe aortic stenosis or mitral regurgitation.
- Refer to specialist (NT-proBNP > 2,000 ng/litre warrants urgent referral).
- Yearly flu and pneumococcal vaccine
- Stop smoking
- Optimise treatment of co-morbidities
- Exercise at tolerated
What is acute left ventricular failure?
You will come across acute left ventricular failure often during your medical jobs.
This occurs when the left ventricle is unable to adequately move blood through the left side of the heart and out into the body. This causes a backlog of blood (like too many buses waiting to pick up people at a bus stop) that increases the amount of blood stuck in the left atrium, pulmonary veins and lungs. As the vessels in these areas are engorged with blood due to the increased volume and pressure they leak fluid and are unable to reabsorb fluid from the surrounding tissues. This causes pulmonary oedema, which is where the lung tissues and alveoli become full of interstitial fluid. This interferes with the normal gas exchange in the lungs, causing shortness of breath, oxygen desaturation and the other signs and symptoms.
What triggers acute left ventricular failure?
- Iatrogenic (e.g. aggressive IV fluids in frail elderly patient with impaired left ventricular function)
- Sepsis
- Myocardial Infarction
- Arrhythmias
How does ALVF present?
Acute LVF typical presents as a rapid onset breathlessness. This is exacerbated by lying flat and improves on sitting up. Acute LVF causes a type 1 respiratory failure (low oxygen without an increase in carbon dioxide in the blood).
There may also be signs and symptoms related to underlying cause, for example:
Chest pain in ACS
Fever in sepsis
Palpitations in arrhythmias
Top tip:
When you are on the wards and a nurse asks you to review a patient that has just started desaturating ask yourself how much fluid that patient has been given and whether they might not be able to process that much. For example, an 85 year old lady with chronic kidney disease and aortic stenosis is prescribed 2 litres of fluid over 4 hours and then starts to drop her oxygen saturations. This is a common scenario and a dose of IV furosemide can often work like magic to clear some fluid and ease their breathing.
Investigations to do in ALVF:
History
Clinical Examination
ECG (to look for ischaemia and arrhythmias)
Arterial Blood Gas (ABG)
Chest Xray
Bloods (routine bloods for infection, kidney function, BNP and consider troponin if suspecting MI)
How is acute LVF managed?
Use the simple mnemonic Pour SOD for acute LVF:
Pour away (stop) their IV fluids
Sit up
Oxygen
Diuretics
How does furosemide work?
It is a loop diuretic that works by blocking sodium reabsorption in the ascending loop of Henle. It is indicated for the treatment of fluid overload and resistant hypertension. Furosemide can affect electrolytes, causing low sodium, potassium, magnesium, and calcium.
Causes excretion of sodium and water.
How does spironolactone and eplerenone work?
Eplerenone and spironolactone are aldosterone antagonists. These cause diuresis by blocking sodium re-uptake in the distal convoluted tubule of the nephrons. Indications for these medications include ascites, nephrotic syndrome, Conn’s syndrome, and chronic heart failure.
What is the first line treatment for a patient with heart failure with reduced LVEF?
Patients with heart failure with reduced LVEF should be given a beta blocker and an ACE inhibitor as first-line treatment.
Mnemonic for treating chronic HF:
The way I remember heart failure drugs is by thinking that in heart failure the heart is BASHED up due to the damage it’s accumulated. So I remember the BASH drugs
B - Beta blocker
A - ACEi
S - Spironolactone
H - Hydralazine (+ Nitrates)
e
D - Digoxin
On auscultation of the heart in LHF what may be heard on auscultation?
A third heart sound is one of the possible features of left-sided heart failure.
Describe Afib, whats the obvious feature on an ECG?
Atrial fibrillation is where the contraction of the atria is uncoordinated, rapid and irregularly. This due to disorganised electrical activity that overrides the normal, organised activity from the sinoatrial node. An ECG will show an absence of p waves.
How does Afib present?
Palpitations
Shortness of breath
Syncope (dizziness or fainting)
Symptoms of associated conditions (e.g. stroke, sepsis or thyrotoxicosis)
What are the two differentials for an irregularly irregular pulse?
Atrial fibrillation
Ventricular ectopics
What are the most common causes of AF?
Most common causes of AF (remember that AF affects mrs SMITH)
- Sepsis
- Mitral Valve Pathology (stenosis or regurgitation)
- Ischemic Heart Disease
- Thyrotoxicosis
- Hypertension
What are the two principles for treating AF?
There are two principles to treating atrial fibrillation:
- Rate or rhythm control
- Anticoagulation to prevent stroke
Rhythm or rate control first?
NICE guidelines (2014) suggest all patients with AF should have rate control as first line unless:
- There is reversible cause for their AF
- Their AF is of new onset (within the last 48 hours)
- Their AF is causing heart failure
- They remain symptomatic despite being effectively rate controlled
What are the three options for rate control?
- Beta blocker is first line (e.g. atenolol 50-100mg once daily).
- Calcium-channel blocker (e.g. diltiazem) (not preferable in heart failure).
- Digoxin (only in sedentary people, needs monitoring and risk of toxicity).
When is rhythm control offered to AF patients?
- IMPORTANT!!
Rhythm control can be offered to patients where:
- There is a reversible cause for their AF
- Their AF is of new onset (<48 hours)
- Their AF is causing heart failure
- They remain symptomatic despite being effectively rate controlled
What is rhythm control?
CARDIOVERSION!!
The aim of rhythm control is to return the patient to normal sinus rhythm. This can be achieved through a single “cardioversion” event that puts the patient back in to sinus rhythm or long term medical rhythm control that sustains a normal rhythm.
What are the two types of cardioversion?
- Immediate cardioversion if the AF has been present for less than 48 hours or they are severely haemodynamically unstable.
- Delayed cardioversion if the AF has been present for more than 48 hours and they are stable.
What is delayed cardioversion?
In delayed cardioversion the patient should be anticoagulated (see below) for a minimum of 3 weeks prior to cardioversion. Anticoagulation is essential because during the 48 hours prior to cardioversion they may have developed a blood clot in the atria and reverting them back to sinus rhythm carries a high risk of mobilising that clot and causing a stroke. They should have rate control whilst waiting for cardioversion.
Pharmacological cardioversion options:
Flecanide
Amiodarone (the drug of choice in patients with structural heart disease)
Explain electrical cardioversion:
The aim of electrical cardioversion is to rapidly shock the heart back into sinus rhythm. This involves sedation or a general anaesthetic and using a cardiac defibrillator machine to deliver controlled shocks in an attempt to restore sinus rhythm.
Explain what medications are used for long term rhythm control in AF:
- Beta blockers are first line for rhythm control.
- Dronedarone is second line for maintaining normal rhythm where patients have had successful cardioversion.
- Amiodarone is useful in patients with heart failure or left ventricular dysfunction.
What is meant by paroxysmal AF?
Paroxysmal AF is when the AF comes and goes in episodes
How is paroxysmal AF managed?
Paroxysmal AF is when the AF comes and goes in episodes, usually not lasting more than 48 hours. Patients should still be anti coagulated based on CHADSVASc score. They may be appropriate for a “pill in the pocket” approach. This is where they take a pill to terminated their atrial fibrillation only when they feel the symptoms of AF starting. To be appropriate for a pill in the pocket approach they need to have infrequent episodes without any underlying structural heart disease. They also need to be able to identify when they are in AF and understand when the treatment is appropriate.
Flecanide is the usual treatment for a “pill in the pocket” approach.
How does warfarin work?
Warfarin is a vitamin K antagonist. Vitamin K is essential for the functioning of several clotting factors and warfarin blocks vitamin K. It prolongs the prothrombin time, which is the time it takes for blood to clot.
What is INR?
A measure of the prothrombin time.
Target INR for AF:
2-3
How DOAC’s compare to warfarin:
- No monitoring is required
- No major interaction problems
- Equal or slightly better than warfarin at preventing strokes in AF
- Equal or slightly less risk of bleeding than warfarin
CHA2DVASC2 score
This is a tool for assessing whether a patient with atrial fibrillation should be started on anticoagulation. It is essentially a list of risk factors, and if you have one or more of these risk factors then anticoagulation should be considered or started. The higher the score the higher the risk of developing a stroke or TIA and the greater the benefit from anticoagulation.
- 0: no anticoagulation
- 1: consider anticoagulation
- >1: offer anticoagulation
C – Congestive heart failure
H – Hypertension
A2 – Age >75 (Scores 2)
D – Diabetes
S2 – Stroke or TIA previously (Scores 2)
V – Vascular disease
A – Age 65-74
S – Sex (female)
HASBLED score:
H
A
S
B
L
E
D
H – Hypertension
A – Abnormal renal and liver function
S – Stroke
B – Bleeding
L – Labile INRs (whilst on warfarin)
E – Elderly
D – Drugs or alcohol
When is adenosine contraindicated?
Asthma
Shockable vs non shockable rhythms
What factors are anti-coagulated by warfarin?
1972
When is diltiazem contraindicated?
HF
How is broad complex tachycardia managed?
Loading dose of amiodarone followed by 24 hour infusion
How is narrow complex tachycardia managed?
Regular
vagal manoeuvres followed by IV adenosine
if above unsuccessful consider diagnosis of atrial flutter and control rate (e.g. beta-blockers)
Irregular
probable atrial fibrillation
if onset < 48 hr consider electrical or chemical cardioversion
rate control: beta-blockers are usually first-line unless there is a contraindication
Narrow complex tachycardia = SVT
Narrow complex tachycardia = SVT
