Week 7 - Palpitations Flashcards
With regards to the layers of the heart, is the myocardium the
A) inner layer ?
B) middle layer ?
C) outer layer ?
Myocardium = Middle layer
With regards to the layers of the heart, is the endocardium the
A) inner layer ?
B) middle layer ?
C) outer layer ?
Endocardium = inner layer
With regards to the layers of the heart, is the epicardium the
A) inner layer ?
B) middle layer ?
C) outer layer ?
Epicardium = outer layer
Which of the 3 layers of the heart is the thickest layer ?
Myocardium (middle layer)
this is the muscular part of the heart wall
Describe the contraction of heart muscle, in terms of ionic flow.
- Voltage gated Na+ channels open
- Na+ floods in, depolarising the membrane, opening more Na+ channels
- Cell depolarises at 30mV, Na+ channels close
- Ca2+ channels open slowly, causing a plateau in depolarisation. K+ channels stay closed
- Ca2+ channels close. K+ channels open so K+ leaves rapidly, depolarising membrane
Which aspect/area of the heart does Lead I and II detect electrical activity from?
Left lateral
Which aspect/area of the heart does Lead aVR detect electrical activity from?
Right atrium
Which aspect/area of the heart does Lead V6 detect electrical activity from?
Left ventricle
Which ECG leads detect electrical activity from the left lateral aspect of the heart ?
- Lead I
- Lead II
- Lead aVL
Which ECG leads detect electrical activity from the left ventricle of the heart ?
- Lead V5
- Lead V6
Which ECG leads detect electrical activity from the inferior aspect of the heart ?
- Lead III
- Lead aVF
Which ECG leads detect electrical activity from the right atrium of the heart ?
aVR
Which ECG leads detect electrical activity from the right ventricle of the heart ?
- Lead V1
- Lead V2
Which ECG leads detect electrical activity from the ventricular septum of the heart ?
- Lead V3
- Lead V4
What type of arrhythmia can be seen in some anaemia patients and why ?
sinus tachycardia
Hb is low so heart pumps faster to ensure oxygen reaches all organs
What are the clinical signs of heart failure ?
- raised JVP
- basal crepitations
- peripheral oedema
What examination findings are indicative of thyrotoicosis ?
- goitre
- tremor
- exophthalmos
What are the 3 most common descriptions of cardiac-related palpitations ?
- flip flopping in the chest
- rapid fluttering in the chest
- pounding in the neck
What is thought to be the cause of “flip flopping” palpitations ?
Extra systoles, such as premature supraventricular or ventricular contractions
What is thought to be the cause of “rapid fluttering” palpitations ?
Result from a sustained ventricular or supraventricular arrhythmia
What type of pulse rhythm suggests AF as the cause of palpitations?
Irregularly irregular rhythm
What is thought to be the cause of “pounding in the neck” palpitations ?
Atrioventricular dissociation
atria are contracting against closed AV valves
What is thought to be the cause of palpitations induced by exercise ?
- cardiomyopathy
- ischaemia
- channelopathies
What do the rhythm abbreviations SVT and VT mean when talking about palpitations ?
SVT = supraventricular tachycardia
- heart suddenly beats much than normal
- originates from faulty electrical impulses in upper areas of heart (atria or SA/AV nodes)
VT = ventricular tachycardia
- sequence of 3 or more ventricular beats
- frequency higher than 100bpm
What endogenous chemicals/hormones cause palpitations associated with exercise and stress ?
Catecholamine excess
catecholamines = dopamine, noradrenaline, adrenaline
What advice do you give someone who doesn’t wish to stop smoking?
- think about stopping
- let them know they can come back for help if they decide to in the future
- record their smoking status and ask again in future
What advice do you give someone who wants to stop smoking ?
- offer referral to smoking cessation services
- tell them that services offer interventions like behavioural support, advice about treatments, supply/arrange prescriptions for treatment
What are the 5 steps of giving weight advice ?
- Assess patients habits, beliefs, aims etc
- Lifestyle interventions
- Behavioural interventions
- Physical activity interventions
- Dietary help
What is considered a low-calorie diet ?
800-1600 kcal/day
What are some recommended physical activity changes for weight loss ?
- activities that can be incorporated into life e.g brisk walking, cycling, gardening…
- other activities e.g swimming, stair climbing, monitor steps per day
- supervised exercise programmes
What are various ways a patient can protect themselves from stress ?
- eat healthy reduces diet-related diseases and affects mood
- reduce drinking and smoking they often exacerbate problems
- exercise/fresh air relieves stress and releases endorphins
- rest and relax otherwise your body will decide for you later
- be mindful meditation can help the mind in many ways including insomnia
- good sleep
- don’t be hard on yourself*maintain perspective *
When do you request an ECG in the event of palpitations with an unclear cause ?
if symptoms are relatively infrequent (less than once a week) and last for an hour or more then advise the person go to A&E during their next episode and request an immediate ECG
if symptoms are short lived then arrange ambulatory monitoring in primary care if available, or refer to cardiology
What 3 categories can palpitations be put into based on their pathogenesis ?
- high cardiac output states (pregnancy, anaemia)
- structural cardiac issues (valvular heart disease, IHD, hypertension)
- catecholamine excess (high caffeine, stress, anxiety, illicit drugs)
What is considered Bradycardia in an adult ?
Resting HR <60 bpm
What is considered tachycardia in an adult ?
Resting HR >100 bpm
What is the pathophysiology of bradycardia ?
Occur when depolarisation fails to initiate or conduct properly
e.g
- SA node disease
- Heart block (AVN, bundle branch)
What is the pathophysiology of tachycardia ?
Occurs when there is abnormal depolarisation occuring in the heart
e.g
- reentry
- enhanced automaticity
What is SA node disease ?
When the SAN fails to act as pacemaker
What are the 3 forms of SA node disease ?
- sinus bradycardia
- sinus pause
- heart block (SA exit block)
How does sinus bradycardia present on an ECG ?
Normal rhythm but at a rate <60 bpm
What causes sinus bradycardia ?
Most common:
- sleeping
- being an athlete
- old age
If symptomatic:
- sick sinus syndrome
- inflammatory conditions e.g pericarditis
- MI
What is the likely treatment for symptomatic sinus bradycardia ?
Pace maker
What causes sinus pause ?
SA node fails to generate an impulse for a brief period of time, causing a pause and lack of perfusion/O2 during that time
How does sinus pause feel to the patient ?
- missed/skipped a beat
- flutters or palpitations
- hard beats
- dizzy, faint, lightheaded or syncope
What is the treatment for sinus pause ?
- medication, or
- permanent/temporary pacemaker
What is the pathophysiology of SA exit block / heart block ?
Impulses from the SA node get stuck there and cannot leave to depolarise the atria
How many types of heart block there ?
4
What are the types of heart block ?
- 1st degree
- 2nd degree (Mobitz type I)
- 2nd degree (Mobitz type II)
- 3rd degree
What is 1st degree heart block?
Slow conduction through the AV node
What is 2nd degree/Mobitz I heart block ?
Mobitz I = Progressive prolonging of PR interval (between p and QRS) until a P wave is completed blocked
Beats are skipped in a regular pattern
What is 2nd degree/Mobitz II heart block ?
Mobitz II = PR intervals are consistent, but some P waves don’t conduct into a QRS
Beats are skipped in an irregular pattern
What is 3rd degree heart block ?
Complete heart block - no conduction to the ventricles
What is automaticity in terms of tachycardias ?
Automaticity = an area of myocardial cells depolarise faster than the SA node
can be either atrial or ventricular tissue, most occur at a focal site
What is reentry in terms of tachycardias ?
Reentry = electrical pathway connecting 2 areas that shouldn’t be connected, forming a circuit
can be congenital or form due to heart disease
What are 5 types of SVT ?
- AF
- atrial flutter
- atrial tachycardia
- AVNRT (AV nodal reentrant tachycardia)
- AVRT (AV reentry tachycardia)
Different between AVNRT and AVRT…
AVNRT = reentry circuit within AV node
AVRT = reentry circuit through accessory bundle
What do the p waves look like on ECG for each of the SVT types?
AF = absent p waves
Atrial flutter = negative sawtooth in lead II
Atrial tachycardia = differs from sinus p waves
AVNRT = in QRS complex
AVNT = RP < PR
What are the 2 types of VT tachycardias ?
- ventricular tachycardia
- ventricular fibrillation
What type of supraventricular tachycardia (SVT) is Wolff-Parkinson-white (WPW) syndrome ?
Wolff-Parkinson-white syndrome = an AVRT
AVRT = reentry circuit via accessory bundle
What are the diagnostic elements for Wolff-Parkinson-White syndrome ?
- pre-excitation on a 12 lead ECG (short PR interval)
- symptoms
- an SVT
How do they 2 types of Wolff-Parkinson-White syndrome differ on an ECG ?
Type 1 = delta wave and QRS complex are upright in all leads V1-6. A dominant R wave in V1 may be misinterpreted as right BBB
Type 2 = delta wave and QRS complex are negative in V1 and V2, positive in the other V leads. Resembles left BBB
How common/rare is Wolff-Parkinson-white syndrome ?
1 in 3 people
Found in all age groups
Which demographic is seen most commonly in Wolff-Parkinson-white syndrome ?
Young, previously healthy people
What vagal manoeuvre can differentiate between a VT and an SVT ?
The valsalva manoeuvre
slows conduction at the SA or AV nodes so can distinguish between the two easier
Which vagal manoeuvre is used to diagnose carotid sinus hypersensitivity ?
Carotid sinus massage
What type of arrhythmias are vagal manoeuvres the first-line treatment for ?
- haemodynamically stable* SVTs, specifically AVNRTs
List some examples of vagal manoeuvres …
- valsalva manoeuvre
- carotid sinus massage
- gag reflex
- coughing
- diving reflex
- handstand for 30 seconds
- applied abdominal pressure
How do you perform the valsalva manoeuvre?
- lie on back
- take deep breath
- try to exhale without letting air out of your mouth or nose for 10-30 secs
should feel like trying to breath through a blocked straw
How do you perform the carotid sinus massage?
- lie on back
- turn head to one side
- doctor will push on your carotid sinus for 5-10 secs
try again in a minute or on other side of neck if it doesn’t work
How do you perform the diving reflex ?
- sit up
- take several deep breaths
- quickly put whole face into a container of ice water
- stay submerged as long as you can
alternatively use a bag of ice cold water or an ice-cold wet towel
How do you perform the ‘applied abdominal pressure’ manoeuvre?
- lie on back
- fold lower body towards face until feet are past head
- take a breath and strain for 20-30 secs
When are vagal manoeuvres unsafe to do ?
If patient is unstable:
- low BP
- chest pain
- SOB
- hypoxia
- inability to perfuse organs
What is a good way to assess for suspected arrhythmias ?
24-48 hr ECG
What does the DVLA say regarding arrhythmias and driving a car or motorbike ?
- stop driving if it’s caused/will likely cause incapacity
- driving permitted when underlying cause is identified and controlled for >4weeks
What is an ectopic heart beat ?
“Missed beats”
A common cause of palpitations and are usually benign and normal
