W15 55 cardiac conditions requiring surgical intervention and their dental implications Flashcards
What are the signs of heart disease?
Peripheries - temperature (HF pt cold to touch), capillary refill time, corneal arcus, xanthelasma, cyanosis, oedema, clubbing
Pulse
Heaves and thrills
Heart sounds
What are some symptoms of heart disease?
Chest pain
Dyspnoea
Orthopnoea
Paroxysmal nocturnal dyspnoea
(Pre-) syncope
Palpitation
Ankle swelling
What are common heart conditions causing chest pain?
Angina pectoris - myocardial ischaemia (chest pain relating to the heart)
Pericarditis pain - pericardial inflammation
Pleuritis pain - pleural inflammation
What is the CCS classification of angina?
I - angina on strenuous prolonged exertion
II - slight limitation of ordinary activity eg walking or climbing upstairs rapidly
III - marked limitation of ordinary activity
IV - discomfort/pain with any physical activity or at rest
What pain does angina cause?
Constricting discomfort in chest, neck, shoulders, jaw or arms
What is pericarditic pain?
Sharp, stabbing pain, quick onset, relieved by leaning forward, exacerbated by lying flat or deep breathing
What is pleuritis pain?
Sharp, stabbing chest pain occurring at a set point upon inspiration
What is ankle swelling an indication of?
Right heart failure - back pressure
Through Starlings forces, how does ankle swelling occur? (Pg532 img)
Pressure in the right heart at the end of diastole is higher, causing back pressure through the capillaries. This rises capillary hydrostatic pressure, so more of a shift of fluid outside the capillaries in the interstitial tissues than in capillaries themselves.
What is dyspnoea indicative of?
Suggestive of ischaemia or heart failure (or both)
How does dyspnoea occur?
Due to left ventricle failing to increase output during exercise —> pulmonary venous pressure (back pressure) —> pulmonary oedema
Oedema increases the distance for gas exchange to occur, so it occurs slower, with CO2 rising, giving the feeling of breathlessness.
Is oxygen a treatment for dyspnoea?
Dyspnea is very more commonly hypercarbonaemia than hypoxia, so oxygen is not a treatment for dyspnoea.
What happens if diabetic patients complain of dyspnoea?
It’s identical to them talking about chest pain (because diabetic neuropathy means they don’t feel chest pain in the same way), they probably have angina
What happens to Starling’s curve in health vs heart failure? (PG533 GRAPH)
Preload = volume in heart at end of diastole (end of receiving the blood)
As you increase preload, (as EDV increases), SV increases. Plateaus in a healthy individual.
In heart failure, preload will increase but stroke volume will go down.
Why does orthopnoea occur?
Redistribution of blood from legs to lungs
Increases left-ventricular pre-load, decreased vital capacity and decreased pulmonary compliance
What is preload?
Volume in heart at the end of diastole
Why does paroxysmal nocturnal dyspnoea occur? (mechanism not well understood)
Left ventricle suddenly unable to match output of right ventricle
Likely due to adrenergic activity during sleep. Also a manifestation of sudden left HF.
What is pre-syncope vs syncope?
Pre-syncope is dizziness, lightheadedness, visual disturbance, muscular weakness
Syncope is loss of consciousness
How does syncope happen in a fixed cardiac output state?
Syncope occurs due to a reduction in cerebral perfusion
Patients will severe aortic stenosis = narrowing of aortic valve. Have a thick stroke volume eg 50ml as opposed to a healthy 70ml. Rate dependent, if can’t increase HR anymore, and you put more physical demand on them, they will become pre-syncope
Pacemaker dependent patients - stops you from going lower than a HR of a certain pulse. Can’t match exercise demands so if you want to run the pacemaker won’t go higher.
How can syncope happen due to a sudden loss in vascular resistance?
Syncope occurs due to a reduction in cerebral perfusion
Eg Suddenly going from cold to hot, or something frightens them etc.
How do cardiac output, stroke volume, heart rate and mean arterial blood pressure relate to perfusion?
CO = SV X HR
MAP = CO X SVR
Tissue perfusion requires flow and pressure. Perfusion is a state where you are providing nutrients. Needs a pressure gradient and flow to restore that gradient.
What is palpitation?
Awareness of heartbeat - fast, irregular, heavy, pauses
What can temperature indicate for peripheral perfusion?
Cool = poor blood flow
Hot = increases blood flow (vasodilated) - often septic patients
What can capillary refill time indicate for peripheral perfusion?
Pressure on thumb nail until skin blanches, release and count how long to refill
Normal = <2s
Very abnormal >6s
What can peripheral cyanosis indicate for peripheral perfusion?
(Blue around edges)
High oxygen extraction from the blood - poor blood flow
Signs of hypercholesterolaemia
Corneal arcus - white ring around the iris
Xanthalasma - fatty deposits under eyelids
How is severity graded for oedema?
Height - ankle, mid-calf, sacral, nipples (probably very unwell eg HF)
Water retention - water follows the sodium
By what mechanism does oedema occur?
Eg in myocardial dysfunction like ischaemia heart disease, there is a decrease in DV
This activates RAAS, retaining salt and thus water
Increases circulating volume
Stretches the heart more (in health this will meet with the increased SV), but dysfunctional hearts will lead to worse HF
(Thus drugs acting on RAAS system can help treat HF)
What else does SV lead to according to Le Plass’s law?
Decreased SV leads to an increase LV diastolic volume and pressure
This changes the shape of the heart, eg thickness and geometry, ventricular remodelling
When increasing muscle muscle of the heart, it increases the oxygen demands since more muscle is doing work, and also increases stiffness and compliance, and thus pressures further feeding back into the loop of dysfunction
(the law explains how increasing pressure or volume in heart leads to adverse heart remodelling).
What should pulse be at different ages?
Rate - should be 50-100 in an adult
Upto 160 when younger but down to 100 by age 5
What can different pulses indicate?
Character:
Normal
Slow rising - aortic stenosis
Water hammer - aortic regurgitation
Volume - felt centrally (carotids, femoral, brachial)
What are the 2 heart sounds?
I - closure of atria-ventricular valves
II - closure of semi-lunar valves
It is unusual to have more than 2 heart sounds, what can it indicate?
Indicates sign of very high cardiac output state
What is a heart murmur?
Turbulent blood flow
When does turbulence occur?
Turbulence occurs when a fluid is passing through an aperture at a too high velocity, causing a murmur (whoosh) sound.
When and where can a murmur occur?
Systole or diastole
Systole occurs after you hear the first heart sound (lub)
Diastole occurs after the second heart sound (dub)
It is heard on the precordium. How loud should be considered.