Video
<youtube>j9w1qylp4TY</youtube> <youtube>zvWzm7ICzhw</youtube> <youtube>GVxJJ2DBPiQ</youtube>
<flashow>http://nl.ecgpedia.org/images/b/bc/Normal_SR_vector.swf%7Cheight=350px</flashow> <flashow>http://nl.ecgpedia.org/images/5/50/Single_cardiomyocyte.swf%7Cheight=350px%7Cwidth=350px</flashow>