congestive heart failure Flashcards
what does cardioversion mean
synchronised administration of electric shock using electrodes on someones chest, during R waves
restores normal heart rhythm in people with certain types of arrythmias
also can do medicines: amiodarone for AF and verapamil for SVT
what is the frank starling curve and how does it work in a normal heart
relationship between volume of blood in heart rate at end of diastole (EDV or pre-load) and force of contraction of ventricle
if myocardial fibres are stretched by an increased volume of blood, there is an increase in force and velocity of contraction
what happens with a failing heart in terms of the FSC
reduced contractility = incr EDV = heart tries to respond by increasing force of contraction
but a greater EDV required and graph shifts right
heart eventually decompensates
SV will decrease with further increases in EDV
increases venous pressure causing fluid to leak out of blood into alveolar interstitial fluid = pulm oedema
what is heart failure
complex syndrome that can result from any structural or functional cardiac disorder that impairs ability of the heart to function as a pump to support physiological functions
clinical diagnosis
how do you explain heart failure to a patient
your heart cannot cope with pumping the full amount of blood in each heartbeat
what are the causes of heart failure
ischaemic heart disease
structural: valvular disease
congenital: inherited cardiomyopathies, ASD
rate: uncontrolled AF, anaemia (high output state)
pulmonary causes: COPD, pulmonary fibrosis etc and primary pulmonary hypertension
alcohol and drugs
pericardial disease
auto-immune disease eg sarcoidosis
what are the symptoms of heart failure?
- breathlessness, on exertion especially
- peripheral oedema and pulmonary oedema - seen in right and left respectively
- coughing up pink frothy sputum
- orthopnea
- PND
how do you define breathlessness
NYHA
1 - no symptoms or limitations to ordinary activity
2 - mild symptoms and slight limitation
3 - marked limitation even in ADL
4 - severe limitates, symptoms at rest
what are the signs of heart failure
PO raised JVP pitting oedema ascites tachycardia S3 gallop (third heart sound)
how do you diagnose HF
signs and symptoms of typical HF
objective evidence of structural or functional cardiac abnormality at REST, eg cardiomegaly on chest x-ray, S3, echocardiographic abnormalitiy
have to define the cause: heart failure secondary to ……
what investigations do you do for HF
bloods: FBC, haematinics (anaemia can be a cause of HF), U&Es, TFT, glc, LFTs
BNP
(polypeptide secreted by ventricles of the heart in response to excessive stretching of heart muscle cells)
normal levels = No HF, >400 chest x-ray for PO, cardiomegaly ABGs Troponin for MI echocardiography - EF, can show previous MI ECGs
what is ejection fraction
how much blood the left ventricle pumps out with each contraction as a %
eg EF of 60% = 60% of total amount of blood in the left ventricle is pushed out with each heartbeat
can have HF with preserved LV function, EF >45% or HF with LV systolic dysfunction <45%
what is the management for HF?
ABAL:
- ace-inhibitors eg ramipril
- beta blockers eg bisoprolol
- aldosterone antaognists ege spironolactone if symptoms not controlled with A and B
- loop diuretics like furosemide to control fluid
how do ACE-I work for HF
inhibit LV hypertrophy and remodelling, inhibit vasoconstriction and lowers arterial constriction and increases venous capacities
decreases salt and water retention
which b-blockers are licensed for ACE-I
bisoprolol, carvedilol, nebivolol, NOT ATENOLOL
why and when is spironolactone used for HF
-aldosterone receptor antagonists
- treatment when EF <35%, NYHA 2
anti-fibrotic
what is mechanical desynchrony
heart doesn’t contract as one efficient unit
L&R contracts at diff times
LV may contract in segments instead of one unit
What does CRT mean
pacemaker
atrial lead, RV lead, LV lead
passed through coronary sinus and into one of the vessels on the outside lateral wall of the heart
how does a pacemaker work
improve synchronicity between L&R
improves cardiac function
what is an implantable cardiac defibrillation device
used in patients with EF <35%
detect and treats ventricular arrythmias
failure = ccardiovert
what are the guidelines for ACUTE HF: initial
key: single BNP, TTE
initial: IV diuretics, bolus or infusion, inotropes (increase the force of cardiac contractions, for example digoxin)
non-invase ventilation without delay if person has cardiogenic PO and severe dyspnea
invasive ventrilation in people with AHF that leads to resp failure
if diuretic resistance: ultrafiltration
what is the treatment for Acute HF after stabilisation
continue B blockers
start diuretics orally
offer ARB/ACE-I
valvular surgery and PCI
-aortic valve replacement or mitral valve repair
when is digoxin used
for rate control for AF
or worsening or severe HF with reduced EF despite for heart failure
what is AF
uncoordinated, rapid contraction of the atria due to disorganised electrical activity
the blood flow will be turbulent = stasis of blood in atria
what is the main complication of AF
clots to form and risk of stroke»_space;
how do you diagnose AF
manual palpation of irregularly irregular pulse
ECG: no p waves, tachycardia, irregularly irregular
24-hour ECG if paroxysmal suspected
-echo
what is the chads2vasc score
stroke risk to assess stroke risk in people with: AF, atrial flutter
what is the HAS-BLED score
risk of bleeding in people who are starting anti-coagulation
DO NOT offer stroke prevention therapy to people aged under 65 years with Afib and no risk factors other than their sex is female
main anti-coagulants?
DOAC’s: apixaban, dabigatran, rivaroxaban,
warfarin
what is the first line strategy for AF
rate control: beta-blocker: bisoprolol, carvedilol
-CCB: diltiazem, verapamil
- do NOT give if new onset, causing HF, does not have a reversible cause
- aim for HR <90bpm
DOAC’s
digoxin: monotherapy only acceptable in sedentary patients
when can you cardiovert?
if AF <48 hours or if >48 hours and on amiodarone 4 weeks before and 12 months after
what is pharmacological cardioversion
-pharmacological cardioversion: beta blockers, dronedarone, fliconide, amiodarone
what is electrical cardioversion
shocks cells back into normal sinus rhythm, involves placing electrodes on outside
what is parxoysmal AF
<7d or episodic
managing acute, new onset AF?
offer heparin immediately and if patient has signs of haemodynamic instability, perform emergency cardioversion
if patient is stable and AF started <48 hours ago, offer rate or rhythm control
for rhythm control: DC cardiovert or flecainide
for rate; bisoprolol or diltiazem
if stable patient and AF >48, offer rate control first:
if rhythm control is chosen, patient must be be anti-coagulated for >3 weeks
what is IE
rare and potentially fatal infection, caused by bacteria entering blood and settling in endocardium, a heart valve or a blood vessel
who is most at risk of IE
heart valve disease having prosthetic valves hypertrophic cardiomyopathy injecting fungal endocarditis
what are the peripheral signs of endocarditis
petechiae subungual (splinter) haemorrhages osler nodes janeway lesions roth spots - retinal haemorrhages with small, clear centres, rare and observed in 5% of patients
how do you diagnose IE
modified duke criteria : requires 2 major criteria, 1 major and 3 minor criteria or 5 minor criteria
what is the major criteria for IE
positive blood culture IE, evidennce of endocardial involvement
positive echo for IE: intra-cardiac mass on valve or supporting structures, on implanted valve, an abscess, new wound or new regurg
what is the minor criteria for IE
predisposing heart condition, fever >38
aneurysms, emboli, haemorrhages etc
immunological phenomena: glomerulonephritis, olser’s nodes etc
microbioogical phenomena: positive blood culture but does not meet a major criterion on micro-organisms
PCR
echo
what does BCNIE mean
IE in which no causative micro-organism can be grown using the usual blood culture methods
can occur in upto 31% of cases of IE
what is the management for IE
anti-biotics: initially vancomycin or ampicillin, plus an aminoglycoside
IV first then full course orally
surgery for fungal infection, or infection with aggressive anti-biotic resistant bacteria
valve problems
antibiotic prophylaxis for patients with a history of IE undergoing dental or other procedures: amoxocillin or clindamycin
