BIO120H1 Lecture Notes - Aortic Stenosis, Diastole, Aortic Valve
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BIO120H1 Full Course Notes
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Document Summary
Ii), the electrical axis of the heart, and the. Cardiac cycle: heart block and branch bundle block. The previous lecture concluded with examples of three different types of heart block (types i, ii and ii). There are other possible blockages of electrical activity in the heart. For example, branch bundles too can be blocked. So, it is possible for conduction to be slowed in either one of the branches, creating either a right or left branch bundle block. Ecg traces created by this condition are very strange - the lines are saw-tooth, or "m" shaped. A relatively common form of arrhythmia is heart flutter; fibrillation is less common but more serious. Flutter and fibrillation can occur in the atria, ventricles or both. Very rapid rates of electrical excitation and contraction in either the atria or the ventricles can produce these conditions. Flutter is more benign, whilst fibrillation is much more dangerous, particularly in the ventricles.
