Cardiology - Miscellaneous Flashcards
Effect of diabetes on cardiac?
- higher CAD risk
- abnormal LV systolic and diastolic dysfunction
- coronary MICROVASCULAR disease
- endothelial dysfunction
- autonomic dysfunction
Thiamine deficiency (Beri Beri) effects of cardiac system?
High output failure
Dilated cardiomyopathy
Hyperhomocysteinaemia effects on cardiac system?
Premature atherosclerosis
Obesity effects on cardiac system?
- LVH
- Excessive LV filling presure on exertion
HypERthyroidism effect on cardiac system?
SVT
HTN
AF (in 15%)
Means-Lerman Scratch: systolic pleuropericardial rub at left 2nd ICS on EXPIRATION
Means-Lerman Scratch
= systolic pleuropericardial rub at left 2nd ICS on EXPIRATION
Hypothyroidism effects on cardiac disease
- decreased cardiac output
- decreased stroke volume
- decreased HR
- decreased pulse pressure
Cardiac Tumours:
What is the most common cancer to metastasise to the heart?
Metastatic melanoma
Cardiac Tumours:
What is Carney Complex?
Carney Complex: mutation in tumour suppressor PRKAR1A Autosomal Dominant Blue naevi Myxoma Endocrine overactivity - Cushing's - Testicular tumor - Pituitary adenoma
Cardiac Tumours:
What mutation is seen in Carney Complex?
Mutation in tumour suppressor gene PRKAR1A
What clinical features would represent an atrial myxoma?
- AF
- Mid-diastolic murmur with ‘tumour plop’
- Embolism
What murmur do you hear with an atrial myoxoma?
Mid-diastolic murmur with ‘tumour plop’
If a Carney Complex atrial myxoma what is the problem with surgical resection?
Carney complex myxoma often recur.
Normal myxoma recurrence in 5-15% after resection
What is Loeffler’s Endocarditis?
Eosinophilic endocardial disease
Associated with restrictive cardiomyopathy
What is Fabry’s Disease and how is it related to the heart?
X linked recessive deficiency of alpha-galactosidase A.
Associated with restrictive cardiomyopathy
What is Kaussmaul’s sign?
INCREASE in JVP on inspiration
Is carotid sinus hypersensitivity more common in males or females?
Which age group?
Males more common
Increased age
Also more commonly right-sided hypersensitivity
On carotid massage when is it diagnostic for carotid sinus hypersensitivity?
Reproducible on massage and if:
- Asystole >3 seconds (indicates cardioinhibitory CSH)
- Decrease in SBP of >50mmHg independent of HR (indicates vasodepressor CSH)
When would you do a pacemaker in carotid sinus hypersensitivity?
If it is cardioinhibitory (ie carotid sinus massage reproduces symptoms and has asystole >3 seconds)
or if mixed carotid sinus hypersensitivity
A patient has syncope/dizziness/falls on turning their head or tight fitted collars….what do you think of?
Carotid sinus hypersensitivity
How does DIGOXIN work? (5 ways)
1) Cardiac Glycoside: direct VASOCONSTRICTION in smooth muscle (arterial and venous)
2) POSITIVE Inotrope:
Direct inhibition of membrane bound NaK-ATPas –> increases intracellular Ca
- associated increase in slow inward Ca current during action potential
3) SLOWED conduction
4) INCREASED REFRACTORY PERIOD by stimulation of vagal tone
5) PARASYMPATHETIC PROPERTIES: hypersensitises carotid baroreceptor and stimulates central vagal nuclei
Causes of supratherapeutic digoxin level:
1) renal impairment
2) MI and acidosis –> suppression of Na/K ATPase
3) Hypothyroidism –> decreased renal excretion
4) Drugs
Drugs that INCREASE digoxin level
Verapamil/Diltiazem
Erythromycin
Tetracyclines
Paroxetine
Drugs that DECREASE digoxin level
Rifampin
Visual changes in digoxin toxicity
Yellow-green distortion Xanthopsia (yellow halo around eyes) Transient scotoma Decreased acuity Photophobia
GIT complications of digoxin toxicity
General (anorexia / n+v / diarrhoea)
Mesenteric ischaemia after rapid IV infusion
Cardiac complications of digoxin toxicity
palpitations
syncope
peripheral oedema
bradycardia + hypotension
Neuro complications of digoxin toxicity
drowsiness/fatigue/confusion neuralgia and headache paraesthesia and neuropathic pain hallucinations seizures
ECG findings of digoxin toxicity
AV block Sinus bradycardia Torsades ST reverse tick Short QT Flattened/inverted T waves
Dialysis of digoxin?
DON’T DIALYSE DIGOXIN TOXICITY!!! (minimal clearance)
Treatment of digoxin toxicity?
Acute: charcoal within 6-8 hours
Treat K abnormality BUT DON’T USE CALCIUM (delays depolarisation and precipitates VT)
Treat hypoMg
Digibind
(if unavailable then use phenytoin or lidocaine –> dissociates inotrope and dysrhythmic action of digoxin)
Arrythmias: DON’T USE CCBs!!!! (as these increase digoxin levels)
Classic ECG findings of hypokalaemia
U waves Small or absent T waves Prolonged PR ST depression Long QT
** “in hypokalaemia U have no Pot and no T, but a long PR and a long QT” ***
Classic ECG findings of hypothermia:
Bradycardia J waves 1st degree HB Long QT Atrial and ventricular arrythmias
JVP Physiology:
what are ‘a’ waves and what abnormalities might you see?
‘a’ waves = atrial contraction
(first bump on the JVP)
LARGE: due to atrial pressure (ie tricuspid or pulmonary stenosis, or pulmonary HTN)
ABSENT: AF
CANNON: due to atrial contractions against CLOSED tricuspid in:
- complete HB
- ventricular tachycardias/ectopics
- single chamber pacing
JVP Physiology:
When might you see ‘cannon’ a waves and why do they occur?
CANNON: due to atrial contractions against CLOSED tricuspid in:
- complete HB
- ventricular tachycardias/ectopics
- single chamber pacing
JVP Physiology:
What is the ‘c’ wave?
= closure of tricuspid valve
NOT usually seen
(2nd little bump after the ‘a’ wave on the JVP)
JVP Physiology:
What is the ‘v’ wave?
= passive filling of blood into atrium against closed tricuspid valve
(3rd bump)
GIANT: tricuspid regurg / RHF
JVP Physiology:
What is the ‘x’ descent?
= fall in atrial pressure during ventricular systole
2nd ‘trough’
JVP Physiology:
What is the ‘y’ descent?
= opening of tricuspid valve
final downward bit of the JVP
JVP Physiology:
What part of the JVP represents atrial contraction?
‘a’ wave
JVP Physiology:
What part of the JVP represents closure of the tricuspid valve?
‘c’ wave (not usually seen)
JVP Physiology:
What part of the JVP represents passive filling of blood into the atrium against a closed tricuspid valve?
‘v’ wave
JVP Physiology:
What part of the JVP represents fall in atrial pressure during ventricular systole?
‘x’ descent
JVP Physiology:
What part of the JVP represents opening of the tricuspid valve?
‘y’ descent
Who does fibromuscular dysplasia tend to affect?
Women in childbearing years
Which arteries does fibromuscular dysplasia affect?
Medium sized arteries
How does fibromuscular dysplasia present?
Usually asymptomatic
RENAL: involved in 60 - 70%
–> renovascular hypertension
CNS: in 25-30%
- -> stroke
- -> sudden onset exposive headache and neck stiffness suggests FMD-associated aneurysm
- -> predisposing factor in 15% of spontaneous carotid cervical dissections
VISCERAL: abdo pains or ischaemic bowel
LIMBS: intermittent claudication
How do you diagnose fibromuscular dysplasia?
CTA
Management of fibromuscular dysplasia?
Nil treatment if asymptomatic
Antiplatelets
Surgery if RENAL FMD
When is the onset of radiation cardiotoxicity?
5-20 years
With which cancer is pericardial effusion associated with radiation cardiotoxicity?
Oesophageal cancer
Which valves are associated with valvular disease relating to radiation cardiotoxicity?
Left sided valves more affected.
Increased risk if also using anthracycline
With what chemotherapy agent is short term chemo cardiotoxicity associated?
5-Fluorouaracil is associated with high incidence of chest pain and ECG changes (death in 2-8%)
Usually resolve within 7 days
With which chemo agents are associated with long term chemo cardiotoxicity?
Anthracyclines
Trastuzumab
Kinase inhibitors
Important facts about trastuzumab-induced chemo cardiotoxicity?
- increased risk of >50 YEARS OLD or if PREVIOUS ANTHRACYCLINES
- REVERSIBLE
- NOT dose related (so can rechallenge later)
When and what is affected in anthracycline-induced chemo cardiotoxicity?
- symptoms usually occur within a few months, but can occur up to 20 years later
- subclinical decline in systolic and diastolic dysfunction
What are the risk factors for anthracycline-induced chemo cardiotoxicity?
- Cumulative dose (STRONGEST RF)
- -> Incidence <1% if cumulative <400)
- age at treatment
- concomitant therapy with other cardiac toxics
- chest radiation
- pre-existing cardiac disease
How can you modify the response to anthracyclines in anthracycline-induced chemo cardiotoxicity?
- liposome encapsulation
- infusion rather than bolus
- structural analogues (epirubicin / mitoxantrone)
- adjunctive cardioprotective agents (ie: dexrazoxone = EDTA chelator which reduces risk)