PCG/ECGs

Question 1

Phonocardiograms

Answer 1

Mechanical events of the heart are coupled to audible events = auscultation
There are normally 2 audible sounds: lub close of AV then dub close of SL
AV closes more gradually

Question 2

Cardiac gallops

Answer 2

Additional sounds in phonocardiograms

Question 3

Marfan syndrome

Answer 3

Genetic condition where soft collagen is present in aortic walls
Aorta becomes distended as weak collagen cannot cope with ejection pressure
Hole in aorta forms

Question 4

Electrocardiograms

Answer 4

Mechanical event or heart are coupled to electrical changes
Current flows across myocytes > local potentials > small potentials measured on the skin reflecting underlying activity
P WAVE atrial depolarisation
QRS ventricular depolarisation
T WAVE ventricular depolarisation

Atrial repolarisation is masked by QRS
R-R interval is reciprocal measure of heart rate
Long Q-T interval may be observed which is often related to inherited conditions with mutations in myocardial ion channels or drug use