Intraventricular Conduction Disturbances Intraventricular conduction disturbances are the result of abnormal activation of the ventricles. Normal ventricular activation requires the synchronized participation of the distal components of the atrioventricular (A-V)…
Ectopic Rhythms and Premature Depolarizations Ectopic depolarizations can arise from many areas of the heart, but the surface ECG is markedly limited in its ability to precisely define the origin…
Atrioventricular Conduction The usefulness of intracardiac recording and stimulation techniques in humans was first realized during its application to patients with disorders of atrioventricular (A-V) conduction. Electrophysiologic study allowed confirmation…
Miscellaneous Phenomena Related to Atrioventricular Conduction Concealed conduction, the gap phenomenon, and supernormality are physiologic events that may be considered to be variants of the normal response. These phenomena are…
Electrophysiologic Investigation: General Concepts The electrophysiologic study should consist of a systematic analysis of dysrhythmias by recording and measuring a variety of electrophysiologic events with the patient in the basal…
Sinus Node Function Disorders of sinus node function are an important cause of cardiac syncope. Approximately 50% of permanent pacemakers implanted at our own and other institutions are for the…
Electrophysiologic Investigation: Technical Aspects Personnel The most important aspects for the performance of safe and valuable electrophysiologic studies are the presence and participation of dedicated personnel. The minimum personnel requirements…
Adventitious Sounds: Wheezes PRETEST 1. Describe the mechanism that produces wheezing? 2. What conditions are associated with wheezes? 3. Describe the following types of wheezes: expiratory polyphonic, fixed monophonic, sequential…
Absent and Diminished Breath Sounds PRETEST 1. Which conditions are associated with diminished or absent breath sounds? 2. How does each of these conditions cause diminished or absent breath sounds?…
Adventitious Sounds: Crackles PRETEST 1. What causes crackles? 2. What is the difference between coarse and fine crackles? 3. Describe the characteristics of late inspiratory crackles. 4. Describe the characteristics…
