heart failure

Question 1

defintion

Answer 1

inability of the heart to sustain adequate circulation of blood to the tissue

Question 2

arterial blood pressure =

Answer 2

systemic vascular resistance x CO

Question 3

stroke volume =

Answer 3

LVEDV- LVESV

LVEDV = left ventricular end diastolic volume

LVESV = left ventricular end systolic volume

Question 4

normal stroke volume

Answer 4

70ml ( 110-40)

Question 5

normal cardiac output

Answer 5

5 litre/min

Question 6

the proportion of LVEDV that is ejected is the what

what is the formula

Answer 6

ejection fraction - normal 70%

Ejection fraction is a measure of how effectively the heart is pumping.

EF (ejection fraction) = (SV/EDV) x 100. Normally over 60% and can be over 90% in exercising trained athletes.

EF can be compromised by systolic heart failure.

Question 7

heart failure is influenced by what

Answer 7

pump function and state of circulation

Question 8

the heart has two circulations

right side pumps to the lungs - lower resistance and shorter pulmonary circulation and left side pumps blood through systemic tissues and organs so has

Answer 8

higher resistance and long systemic circulation

left side fails more often as works 5 times harder

Question 9

COCO

Answer 9

valves

Question 10

left ventricle will fill up to 120ml with hardly any pressure after this is will be restricted due to stretching of what

Answer 10

pericardium

Question 11

The heart muscle is like an elastic band = the more you stretch the myocardium by filling the more it will recoil back and the more effectively it will eject blood.

the frank-starling relationship assumes that aferload is constant up until point

what 2 factors explain this

Answer 11

2 factors explain this:
Greater contact of actin/myosin interaction
Increased sensitivity of myofibrils to Ca2+ (from SR)

Question 12

heart failure can result from systolic or diastolic dysfunction

Answer 12

Systolic - HFrEF (heart failure with reduced ejection fraction)
Impaired myocardial contraction
Heart cannot empty properly
flabby weak ventricle due to systolic contraction reducing therefore reducing SV

Diastolic - HFpEF (heart failure with preserved ejection fraction)
Impaired myocardial relaxation
Heart cannot fill properly
stiff fibrotic ventricle so diastolic compliance decreases to LVEDP rises to SV falls

heart failure like pump to garden - garden no longer supplied and the tank build up and overflows

Question 13

effects of HR

Answer 13

inability to keep up with venous return therefore increasing the upstream pressure in the circulation

inadequate perfusion of vital organs especially the kidney making the problem worse - RAAS system - renin related in low blood volume to lead to vasoconstriction and sodium retention ( aldosterone)

in HF RAAS activated and make the situation worse as ADH increases too to retain water

Question 14

in the kidney inadequate perfusion is sensed by what

Answer 14

junta-glomerular apparatus - interprets this as hypovolamic shock

Question 15

angiotensin 2 causes what

Answer 15

vasoconstriction

Question 16

aldosterone causes what

Answer 16

sodium and therefore water retention

Question 17

What is the result of an increase in SVR(afterload) resulting from vasoconstriction?

Answer 17

The hydrostatic (physical) pressure in the circulation is a major determinant of fluid movement at the capillary level

Question 18

in the blood vessels hydrostatic pressure gradient pushed fluid out what happens on the interstitial side

Answer 18

osmotic pressure gradient pulls fluid in

overall slightly more fluid leaves the capillary than is reabsorbed - returns via lymphatic system

Question 19

how is pulmonary oedema caused

Answer 19

rise in hydrostatic pressure forcing fluid out

Question 20

if (odemea and increased JVP) fluid congestion and hypo perfusion ( low BP and low renal function) what does the patient present like

Answer 20

cold and wet

Question 21

if no hypo perfusion and no fluid congestion present as

Answer 21

warm and dry

Question 22

if hypo perfusion and no fluid congestion

Answer 22

cold and dry

Question 23

if no hypo perfusion with fluid congestion present present as

Answer 23

warm and wet

Question 24

causes of heart failure

Answer 24

ischaemic heart disease 
valvular disease 
fluid overload 
arrhymais 
intra-cardiac shunts 
cardiomyopathy 
hypertension 
drugs

Question 25

what infections is someone with HF prone to

Answer 25

Because heart failure causes volume overload, she will be more prone to chest and leg infections secondary to pulmonary and peripheral oedema, respectively.

chest infectious and ulcerated celleuritic leg

Question 26

first line treatment for heart failure

Answer 26

The first-line treatment for all patients is both an ACE-inhibitor and a beta-blocker
Second-line treatment is an aldosterone antagonist

Third-line treatment should be initiated by a specialist. Options include ivabradine, sacubitril-valsartan, hydralazine in combination with nitrate, digoxin and cardiac resynchronisation therapy
ivabradine
criteria: sinus rhythm > 75/min and a left ventricular fraction < 35%
sacubitril-valsartan
criteria: left ventricular fraction < 35%
is considered in heart failure with reduced ejection fraction who are symptomatic on ACE inhibitors or ARBs
should be initiated following ACEi or ARB wash-out period
digoxin
digoxin has also not been proven to reduce mortality in patients with heart failure. It may however improve symptoms due to its inotropic properties
it is strongly indicated if there is coexistent atrial fibrillation
hydralazine in combination with nitrate
this may be particularly indicated in Afro-Caribbean patients
cardiac resynchronisation therapy
indications include a widened QRS (e.g. left bundle branch block) complex on ECG