Medicine - Education Center
Auscultation of the
normal heart reveals 2 sounds which are known as the 1st (S1)
and 2nd (S2) heart sounds respectively. These sounds probably
originate from vibrations caused by the closing of the heart valves in
combination with the quick variations in blood flow and the changes in
tension within cardiac structures as the valves close.
First and Second
Mitral Valve Prolapse
Mitral Valve Prolapse
and Mitral Regurgitation
Aortic valve and
Coarctation of the
Murmurs associated with arterio-venous (left-right) shunts
Patent Ductus Arteriosus
Atrial Septal Defect
||The raw data behind
the heart sounds on this page was provided by Synapse Publishing Incorporated.
Then these sounds underwent extensive audio enhancements eg noise reduction,
frequency enhancement etc at IMC. Finally, the phonocardiographic correlations
were produced at IMC.
The Synapse-IMC Heart
Sounds Joint Venture - yet another education service for you.
These electrocardiograms are recorded on
standard paper where the small squares are 1 mm in size and the large squares are 5 mm in size and
the paper speed is 25 mm/s (5 large squares represent 1 s). The leads consist of the 3 standard leads
I, II and III, the 3 unipolar limb leads AVR, AVL and AVF and the 6 precordial leads V1, V2, V3, V4, V5 and V6.
Although much can be said about ECGs (several textbooks have been written about the topic), we shall stop
this introduction here to examine some ECGs. The ECG files are rather large and will take some time
to appear. We apologize for this although it is beyond our control and hope that your wait will be worthwhile.
Normal Sinus Rhythm
Atrial Fibrillation with Premature Ventricular Complexes
||These electrocardiograms were
provided by Dr Tan Huay Cheem, Senior Registrar, Cardiac Department, National University Hospital,
Singapore. These ECGs were then scanned and the images were enhanced at IMC.
These chest x-rays display the heart in various
pathological states. Again, many complete books have been written on the interpretation of chest x-rays.
However, a few points must be remembered - the correct patient must be matched to the correct x-ray
on the correct day, the x-ray must be centered and interpreted correctly, the size of the normal heart
must be less that half of the transthoracic diameter and the apex of the heart points to the left (except in dextrocardia).
The x-ray images are large files and will take some time to appear. We thank you for your
Multiple Valvular Abnormalities
||These chest x-rays were provided
by the Department of Diagnostic Imaging, Tan Tock Seng Hospital, Singapore. The x-ray films
were then digitalized and enhanced at IMC.
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