The Heart - Physiology MCQ ACEM. Top Exam Questions & Answers, Graded A+

The Heart - Physiology MCQ ACEM. Top Exam Questions & Answers, Graded A+ Which is the main risk factor for diastolic dysfunction? 1. Diabetic heart disease 2. Hypertension 3. Coronary heart disease 4. Hypertrophic cardiomyopathy 2. Hypertension Major risk factors include the following - hypertension (major) - hypertrophic cardiomyopathy - coronary heart disease - diabetic heart disease - restrictive cardiomyopathy. Which is CORRECT regarding the ECG? 1. Bipolar leads can be placed at the tips of catheters and inserted into the oesophagus and the heart. 2. The standard unipolar limb leads I, II, III each record the difference in potential between two limbs 3. QT represents ventricular repolarisation 4. U waves are thought to represent repolarization of the papillary muscles or Purkinje fibres. 4. UW are thought to represent repolarization of the papillary muscles or Purkinje fibres. Leads I, II and III are ibipolar leads/i. Augmented and chest leads are in fact iunipolar/i. QT interval represents polarization and polarization of the ventricles. Which substance is a vasodilatory on the heart, but not on skeletal muscle? 1. Histamine 2. Adenosine 3. Potassium 4. Lactate 2. Adenosine Adenosine plays a role in cardiac muscle but not in skeletal muscle Additional substances which are vasodilatory metabolites: - hyperosmolality - hyperkalaemia - lactate - histamine (from injured/inflammed tissues) Other factors which lead to vasodilation: - hypoxia - decreased POsub2sub/ - increased PCOsub2sub/ - hyperthermia.