Pulmonary vascular resistance

Pulmonary vascular resistance is

(a) increased when the haematocrit is abnormally high

(b) decreased when breathing 21% oxygen in 79% helium

(c) increased by the application of 5 cmH2O positive

end-expiratory pressure

(d) increased by hypercapnia

(e) decreased by moderate exercise

Normal ECG

In the normal ECG the

(a) Q wave is normally present in lead V6

(b) T wave is normally inverted in aVR

(c) Q wave is normally present in V1

(d) R wave is larger than the S wave in V1

(e) QRS duration depends on the recording electrode

Fetal haemoglobin

Fetal haemoglobin

(a) forms 60% of circulating haemoglobin at birth

(b) is normally replaced by haemoglobin A (HbA) within

6–9 months

(c) has a sigmoid-shaped dissociation curve

(d) has a greater oxygen content at any given PO2 than adult

haemoglobin

(e) binds 2,3-DPG more avidly than HbA

Myocardial work

Myocardial work increases when there is an increase in

(a) stroke volume

(b) ventricular systolic pressure

(c) contractility

(d) heart rate

(e) systemic vascular resistance

Pulse pressure

Pulse pressure

(a) is the median value between the systolic and the diastolic

blood pressures

(b) is reduced during tachycardia

(c) is determined by the compliance of the arterial tree

(d) decreases in old age

(e) at a given time is the same throughout the arterial tree

Haemophilia

A 31-year-old male with known haemophilia A presents with a fracture of his left

tibia sustained while playing football. The orthopaedic surgeons propose operative

application of an external fixation frame. The patient is unable to grade the severity of

his haemophilia but has had two knee haemarthroses in the previous seven years. As

part of the preoperative preparation of this patient, which one of the following should

be administered intravenously?

a) Fresh frozen plasma

b) Cryoprecipitate

c) Recombinant factor VIII concentrate

d) Recombinant factor IX concentrate

e) Desmopressin

Calcium channel blocking drugs

Which one of the following statements regarding calcium channel blocking drugs is

TRUE?

a) Most of these drugs act on the T-type calcium channel

b) Nifedipine acts mainly by negative inotropy

c) Nimodipine is a class III calcium channel blocking drug

d) Verapamil is a suitable treatment for supraventricular tachycardia

e) Heart block caused by calcium channel blocking drug overdose is treated with

atropine