1. AV sequential and atrial pacing are frequently employed during cardiac surgery as various degrees of heart block are often encountered perioperatively. Prolongation of the PR interval is seen in first-degree heart block here associated with the prolonged QRS complexes often seen during bundle branch blocks. In second-degree heart block the PR interval gradually lengthens until the impulse is no longer conducted to the ventricles. In third-degree block there is no association between atrial and ventricular beats. The atrial and the ventricular contraction are not coordinated.
Source: Chapter 3. Perioperative Rhythm Abnormalities, Cardiac Anesthesia and Transesophageal Echocardiography
Citation: Wasnick JD, Hillel Z, Kramer D, Littwin S, Nicoara A. Cardiac Anesthesia and Transesophageal Echocardiography; 2011 Available at: Accessed: November 01, 2017
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