2. Initial event in cardiac muscle contraction
calcium mediated opening of T channels
adrenoceptor mediated opening of calcium channels
decreased calcium influx
How long does it take to reach a steady state with digoxin given as 1000 mcg IV loading does and 250 mcg daily, t½ of digoxin = 24 hours.
Idiopathic dilated cardiomyopathy
The best predictor of sudden death is?
A)Ejection fraction of <25%
B)Left ventricular dilatation
C)Bundle branch block
FRACP 1999 (Paper 2)
A forty year old male athlete, asymptomatic except for awareness of occasional palpitations. BP normal, pulse 68 bpm and regular. ECG normal.
Holter tracing while asleep – shows Wenkebach block
The best management is:
Exercise stress test
A sixty year old female who is asymptomatic presents for pre operative assessment for an inguinal hernia repair. No chest pain on exertion. Physical examination is normal.
ECG: sinus rhythm, right axis deviation, right bundle branch block with some ST (if any). Next best action:
dobutamine stress echo
Dipyridamole thallium scan
Proceed with surgery
An 87 year old man presents with lightheadedness on a hot day. He has no other significant medical history. Which of the following in this otherwise well elderly gentleman is going to be the cause of his symptoms.
A)Basal stimulation his aldosterone and renin
C)Atrial naturetic factor
A 55year old man presents to the emergency department with 4 hours of epigastric discomfort. On examination he is diaphoretic but no other abnormalities are found. An ECG is shown on the 2nd to last page of the Concord questions. What is the diagnosis?
Which of the following is least likely to be involved in vascular smooth muscle contraction?
A)Increased calmodulin activation
B)Myosin actin interaction
C)Formation of cross links
D)Fall in intracellular calcium