Basic intervals Basic intervals during sinus rhythm represent a quantitative assessment of the electrical activation of the heart. Normal atrial activation begins at the sinus node, spreads to the low atrium and atrioventricular (AV) junction, and then to the left…
Electrode catheters Basic mapping catheters Catheters used for electrophysiology studies (EPSs) and ablation are composed of multiple insulated wires encased in woven Dacron or polyurethane. Electrodes used in electrophysiology (EP) catheters are usually made of polished platinum-iridium alloy. Platinum is…
Patient preparation Patients should be studied in the postabsorptive state and after beta blockers or other antiarrhythmic agents have been discontinued for at least 5 days. Amiodarone should be withdrawn at least 2 months before the procedure if feasible. A…
Some of the descriptive terms conventionally used for cardiac structures are inaccurate. Conventionally the heart and its associated structures have been described in accordance with their position when the heart has been removed from the body and positioned with the…
Normal excitation of the heart Cardiac electrical activity starts by the spontaneous excitation of “pacemaker” cells in the sinoatrial node in the right atrium. Pacemaker automaticity is due to spontaneous diastolic repolarization of phase 4 that generates rhythmic action potentials…
Bradyarrhythmias are due to sinus nodal disease ( Box 1.1 ) or atrioventricular conduction block ( Box 1.2 ). Box 1.1 Sinus Node Dysfunction (with accompanying symptoms) Sinus bradycardia Sinoatrial exit block Sinus pauses (>3 s) Sinus node arrest Tachycardia-bradycardia…