6. CVS Flashcards
What is cardiac tamponade?
When the pericardium fills with fluid so the heart can’t fill and contract and eventually stops.
What causes cardiac tamponade?
Pericardial effusion (infection), or haemorrhagic effusion.
How is cardiac tamponade treated?
Pericardiocentesis -aspiration of fluid within pericardium..
What is pericarditis?
Infection of the pericardium leading to pericardial effusion.
What can pericarditis cause?
Cardiac tamponade.
What is an atrial septal defect?
Hole in the atrial septum that allows communication between atria.
What is the blood shunting direction in an atrial septal defect?
Left to right due to pressure.
What can a complication of atrial septal defect be?
Huge left to right flow overloads the right ventricle and leads to right heart failure.
What is a ventricular septal defect?
A hole in the ventricular septum, usually in the membranous portion, that allows communication between the ventricles.
What is the direction of blood shunting in a ventricular septal defect?
Left to right shunt due to pressure.
What is Eisenmenger syndrome?
Left to right shunting from a ventricular septal defect causes pulmonary hypertension, if this increases enough, the pressure gradient reverses and there is a paradoxical shunt.
What is a patent ductus arteriosus?
The ductus arteriosus stays open after birth so there is communication between the aorta and pulmonary trunk/arteries so blood does the pulmonary circuit twice and there is pulmonary hypertension.
What is a patent foramen ovale?
The foramen ovale doesn’t close at birth, mostly asymptomatic as only small.
What is a possible complication of patent foramen ovale?
A venous embolism can join the systemic circulation via the ovale.
What is coarctation of the aorta?
Constricting of the aorta in the region near the ductus arteriosus causing hypoperfusion in the distal vessels and hypertension in proximal vessels.
What is tetralogy of Fallot?
4 key defects giving rise to a cyanotic patient due to circulation of deoxgenated blood.
What are the 4 defects of tetralogy of Fallot?
Ventricular septum misalignment, pulmonary stenosis, VSD, over-riding aorta.
What are the consequences of the defects in tetralogy of Fallot?
Ventricular septum misalignment leads to right ventricular hypertrophy, pulmonary stenosis causes right ventricle hypertension. These lead to shunting of blood right to left through VSD. More deoxygenated blood circulates through misaligned aorta taking blood from RV.
What is tricuspid atresia?
Missing or close tricuspid valve so there is no pulmonary circuit.
How is tricuspid atresia managed?
Need a right to left ASD and a VSD or PDA to allow access to lungs.
What is transposition of great arteries?
The spiral septum doesn’t form correctly so the aorta is connected to RV and pulmonary trunk to LV so there are two separate circuits in parallel.
How is transposition of great arteries managed?
A PDA needs to be opened and maintained.
What is hypoplastic left heart?
The LV and ascending aorta are undeveloped or absent, LA is small and PDA is maintained so right ventricle takes over systemic and pulmonary circulation.
What is needed for hypoplastic left heart to be viable?
PDA to allow blood into aorta past ascending section, and communication between LA and RA via ASD.
What is pulmonary atresia?
No pulmonary valve so no access to pulmonary circuit.
What is needed for pulmonary atresia to be viable?
A PDA.
What is aortic atresia?
No aortic valve so no access to systemic circulation.
What is needed for aortic atresia to be viable?
PDA, ASD/VSD to stop accumulation in left side of the heart.
What is hyperkalaemia?
Too much K+ in the blood so too much K+ in the ECF, so less steep concentration gradient and permanently depolarised membrane.
What is the consequence of hyperkalaemia on the heart?
Na+ channels are inactivated due to the permanent depolarisation from less steep K+ concentration gradient. This causes bradycardia, bundle blocks, and eventually heart failure.
What are the ECG features of hyperkalaemia?
Prolonged QRS complex, prolonged PR interval, tented T waves.
What is hypokalaemia?
Too little K+ in the blood so too little K+ in ECF, so concentration is steeper and membrane is permanently hyperpolarised.
What is the consequence of hypokalaemia on the heart?
Permanently hyperpolarised membrane causes hyperexcitability of Na+ channels so tachycardia, atrial or ventricular fibrillation and eventually cardiac arrest.
What are the ECG features of hypokalaemia?
Enlarged P waves, shortened PR interval, T wave flattening/ inversion.
What is atrial fibrillation?
Lack of a discernable P wave.
Why is atrial fibrillation not fatal?
Most filling of the ventricles occurs in diastole.
What are ventricular ectopics?
Ventricles occasionally contract without an impulse from the SAN, so initiated by AVN instead.
What is the result of ventricular ectopics?
Different shaped QRS complex - wider and taller.
What is long QT syndrome?
Genetic or acquired syndrome that leads to abnormal repolarisation of the heart and therefore prolonged QT interval.
What is the risk of long QT syndrome?
Longer QT interval allows a greater chance for re-entry arrhythmias. More likely to develop torsades de pointes, or ventricular tachycardia that progresses to VF.
What is torsades de pointed?
Associated with prolonged QT interval, it is a type of ventricular tachycardia that gives the appearance of winding round the baseline in 3d on the ECG, normally self-resolves in a few seconds but can develop into VF.
What is ventricular tachycardia?
Increased rate of contraction of the ventricles, more QRS complexes on ECG with some P waves visible.
Wat does ventricular tachycardia lead to?
Ventricular fibrillation.
What is ventricular fibrillation?
The ventricles no longer contract in a coordinated manner.