WEEK 7 - palpitations Flashcards
(125 cards)
where does the pericardial cavity sit?
between the parietal and visceral layers of the serous pericardium
Cardiomyocyte ________ in unison in order to provide effective pump action to ensure adequate blood _________ of the organs and tissues. Cardiomyocyte make up the bulk of the volume of the heart but constitute only ______ of the total cell number.
Intercalated discs (gap junction) provide an electrical junction from one cell to the next. They transmit _______ currents from one cell to the next. Intercalated discs are made up of 6 hollow tubes (________) that provides an intercellular gap enabling the ___________ to act as an electrically continuous sheet and all myocytes to be activated simultaneously.
Intercalated discs (desmosomes) provide a structural attachment from one cell to the next. They ‘glue’ cells together. Glycoproteins called _________ span the 25nm gap between the cell membranes, and ______ forms the intermediate filaments.
Transverse tubules (t-tubules) are invaginations of the cell membrane which run into the _______ of the cell. They transmit the electrical stimulus rapidly into the interior of the cell. Transverse tubules promote the synchronous activation of the whole depth of the cell despite the fact that the signal to contract is relayed across the external membrane.
- contract
- perfusion
- 30-40%
- ionic
- connexon
- myocardium
- cadherins
- desmin
- interior
inflow of what depolarises the membrane and causes a rise in membrane voltage?
Na+
rapid outflow of what returns the membrane potential to its resting potential?
K+
Lead I detects electrical activity from which aspect of the heart?
left lateral
Lead aVR detects electrical activity from which aspect of the heart?
right atrium
Lead V6 detects electrical activity from which aspect of the heart?
left ventricle
what does each aspect of an ecg look at?
what are narrow complex vs broad complex tachycardias?
- Narrow: Atrial fibrillation, Supraventricular tachycardia eg atrial flutter
- Broad: Ventricular fibrillation
what 3 things could you find on examination with thyrotoxicosis?
goitre, tremor and exophthalmos
what 2 things could you find on examination with anaemia?
pallor of creases, conjunctivae
Flip-flopping – the palpitations are thought to be caused by _____ ______ such as supraventricular or ventricular premature contractions. The flip-flop sensation is thought to result from the forceful contraction following the pause and the sensation that the heart is stopped results from the pause.
extra systoles
Rapid fluttering – result from a sustained ventricular or supraventricular arrhythmia. Furthermore, the sudden cessation of this arrythmia can suggest ________ __________ __________. This is further supported if the patient can stop the palpitations by using _________ manoeuvres.
paroxysmal supraventricular tachycardia
Valsalva
The rhythm of the palpitations may indicate the aetiology of the palpitations (irregularly irregular palpitations indicate _____ _______ as a source of the palpitations). An irregular pounding sensation in the neck can be caused by ____________ _________, and the subsequent atria are contracting against a closed tricuspid and mitral valves, thereby producing _______ _ _____.
- atrial fibrillation
- atrioventricular dissociation
- cannon A waves
Palpitations induced by exercise could be suggestive of _______________, ___________ or ____________.
cardiomyopathy, ischemia or channelopathies
Palpitations can occur during times of catecholamine excess, such as during exercise or at times of stress. The cause of the palpitations during these conditions is often a sustained __________ tachycardia or ____________ ____________. ____________ tachycardias can also be induced at the termination of exercise when the withdrawal of catecholamines is coupled with a surge in the _____ tone.
Many psychiatric conditions can result in palpitations including depression, generalized anxiety disorder, panic attacks, and somatization.
- supraventricular
- ventricular tachyarrhythmia
- supraventricular
- vagal
according to NICE, if the cause of the palpitations remains unclear, what should you do if…..
- If symptoms are relatively infrequent (less than once a week) and last for an hour or more
- If symptoms are short lived but frequent
- If symptoms are short lived and infrequent
If the cause of the palpitations remains unclear:
If symptoms are relatively infrequent (less than once a week) and last for an hour or more, advise the person to attend an Accident and Emergency department, or their GP surgery, for an electrocardiogram (ECG) during the next episode. Provide a letter to be given to the healthcare professional requesting an ECG immediately on presentation during an episode.
If symptoms are short-lived, arrange ambulatory monitoring in primary care if available, or refer to cardiology. The type of monitoring required is dependent on the frequency and duration of symptoms:
If symptoms are short lived but frequent (for example, daily), a 24-hour or 48-hour Holter monitor is appropriate.
If symptoms are short lived and infrequent (for example, less than once a week), a self-activated recorder or an event monitor is appropriate.
what are palpitations?
Palpitations are defined as rapid pulsations or abnormal rapid or irregular beating of the heart. They are common and non-specific. The cause of palpitations could be benign or more life threatening
how can the causes of palpitations be defined according to their underlying pathogenesis?
- High output states: Anaemia or pregnancy
- Structural cardiac causes: valvular heart disease, ischaemic heart disease, hypertension
- Catecholamine excess: high caffeine, illicit drugs, stress, anxiety
what is an arrhythmia?
an abnormality of the heart’s rhythm. It may beat too slowly, too quickly, or irregularly. These abnormalities range from a minor inconvenience or discomfort to a potentially fatal problem. Arrhythmias or heart rhythm problems are experienced by more than 2 million people in the UK.
bradycardia = <__bpm
tachycardia = >__bpm
- 60
- 100
what can cause bradycardias?
occur when depolarisation FAILS to initiate or conduct properly
- SAN disease
- heart block (AVN, His-bundle)