Reentrant Arrhythmias
Day 5: Reentrant Arrhythmias Print Section Listen Reentry—a disorder of impulse transmission Mechanisms of reentry Reentry requires: At least two conduction pathways Variable block in one of the pathways If…
Chamber Abnormalities and Intraventricular Conduction Defects
Day 2: Chamber Abnormalities and Intraventricular Conduction Defects Print Section Listen General statements Echocardiography and other newer imaging techniques, not the electrocardiogram (ECG), are the gold standards for assessing chamber…
Electronic Pacemakers
Day 10: Electronic Pacemakers Print Section Listen Pacemaker nomenclature—a standardized 5-letter code, recently designated “NBG”, has been developed to indicate various pacemaker functions. The first letter refers to the chamber(s)…
The Basics
Day 1: The Basics Print Section Listen Cardiac muscle has two unique properties that predispose it to the two common types of arrhythmias Automaticity As opposed to skeletal muscle, all…
Medication and Electrolyte Effects; Miscellaneous Conditions
Day 9: Medication and Electrolyte Effects; Miscellaneous Conditions Print Section Listen Medication effects Digoxin (Day 9-01) Digoxin has a narrow therapeutic to toxic ratio, and is potent stimulator of arrhythmias….
Extrasystoles and Preexcitation Syndromes
Day 7: Extrasystoles and Preexcitation Syndromes Print Section Listen Extrasystoles Mechanisms of extrasystoles Reentry Most extrasystoles, particularly if they are monomorphic, bear a constant relationship to the preceding QRS complex…
Ischemia and Infarction
Day 4: Ischemia and Infarction Print Section Listen The ST segment and T wave in ischemia There are over 100 identified causes of ST segment and T wave changes, so…
Ectopic Arrhythmias and Triggered Activity
Day 6: Ectopic Arrhythmias and Triggered Activity Print Section Listen Ectopy—a disorder of impulse formation Mechanisms of ectopic arrhythmias Ectopic arrhythmias require: Default—slowing of the normal dominant sinus pacemaker which…
SA and AV Nodal Conduction Abnormalities
Day 3: SA and AV Nodal Conduction Abnormalities Print Section Listen Intracardiac electrograms Conduction disturbances in the surface ECG have their genesis in specific locations in the conduction system. …
The Differential Diagnosis of Wide-QRS Tachycardias
Day 8: The Differential Diagnosis of Wide-QRS Tachycardias Print Section Listen Basic considerations Wide QRS tachycardias represent either VT or SVT with aberrant conduction. VT and SVT represent vastly different…
