CCU Flashcards
What is normal cardiac output?
5 L per min
What is the equation for cardiac output?
CO = SV x HR
What is the equation for blood pressure?
BP = CO x TPR
What is meant by the pulse pressure?
The difference between the systolic and diastolic pressure. It represents the force the heart produces each time it contracts.
What is compliance and what is its relevance to hypertension?
Complications = volume/pressure . Normally, increased transmural pressure dilated a vessel, reducing resistance. If there is reduced compliance, the change in volume reduces so pressure is not reduced as much. Essentially, the vessels are stiff.
How do you calculate the rate from an ECG?
Regular rhythm: 300 / no. of large squares between each R wave.
Very fast rhythm: 1500 / no. of small squares between each R wave.
Irregular or slow rhythm: number of complexes on rhythm strip x 6
What is the main causative organism of infective endocarditis?
Streptococcus viridans
What is a key symptom that would cause you to suspect infective endocarditis?
Tiredness
What is the causative organism of rheumatic fever?
Lancefield group A beta-haemolytic streptococci.
Why can rheumatic fever damage the heart valves?
Antibody to the streptococcus cross-reacts with valve tissue (antigenic mimicry) and may cause permanent damage to the valves.
What are the causes of mitral stenosis?
Rheumatic fever, congenital, infective endocarditis, mucopolysaccharidoses, prosthetic valve, cardial fibroelastosis, malignant carcinoid
What condition are patients with mitral stenosis at risk of developing?
Atrial fibrillation
What are patients with AF at risk of developing?
Thrombi that embolize to peripheral circulation
What is a sign on the face of mitral stenosis?
Malar flush (due to CO2 vasodilation)
How is infective endocarditis diagnosed?
Duke criteria - positive “serial blood cultures” and echocardiogram plus 5 minor criteria.
Definite endocarditis: 2 major or 1 major and 3 minor or all 5 minor criteria .
