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Biomedical subjects

S S Barold

Publications and source records attributed to S S Barold.

At least 91 records · Page 5Linked to original sources
PubMed1995

Pure atrial-based lower rate timing of dual chamber pacemakers: implications for upper rate limitation.

The release of dual chamber pulse generators with atrial-based lower rate timing has added a new dimension to the complexity of pacemaker function and electrocardiography. This discussion focuses on the concept that in pulse generators with pure atrial-based lower rate timing, preservation of the atrial lower rate interval takes hierarchical precedence over all other timing intervals including the ventricular-based upper rate interval. Under certain circumstances whenever upper rate limitation requires extension of the programmed AV interval, a DDD pulse generator with pure atrial-based lower rate timing can violate its atrial-driven upper rate interval to provide constancy of the lower rate interval. Such behavior also has important implications for upper rate control in devices that function in the DDI (DDIR) or DDDR mode with pure atrial-based lower rate timing.

Atrial Function↗
PubMed1994

Panoramic display of the orderly sequenced 12-lead ECG.

The standard 12-lead electrocardiogram (ECG) has been developed over many years. The ECG has had a long and successful history of providing diagnostic information in clinical medicine. Cardiac arrhythmias have been elucidated by deductive reasoning from continuous ECG recordings with confirmation from electrophysiologic studies. Recently, there has been renewed interest in the morphology of the QRS complex, ST-segment, and T wave, which raises the important question of considering whether the usual method of display provides maximal diagnostic capabilities. The conventional display provides a logical visualization of precordial lead recordings representing the horizontal plane, but does not provide a logical visualization of the limb lead recordings representing the frontal plane. Many clinical problems require the consideration of serial ECGs necessitating the comparison of separate pages. An alternate format presenting serial recordings on a single page would be advantageous. Some automated ECG analysis systems already include the capability for multiple display formats, but these have not yet been widely used in clinical practice. This point of view paper introduces a new display format for the standard 12-lead ECG that includes: (1) a presentation of an orderly sequence of leads to facilitate scanning through different points in space and (2) a presentation of recordings of 12-lead sequences to facilitate scanning through different points in time. This display format could either replace or supplement the conventional ECG format.

Arrhythmias, Cardiac↗
PubMed1994

Erythromycin-induced QT prolongation and polymorphic ventricular tachycardia (torsades de pointes): case report and review.

Although uncommon, ventricular arrhythmias associated with erythromycin use have been reported previously, usually in the presence of heart disease and/or situations causing abnormal cardiac electrophysiology (such as bradycardia, hypokalemia, and the administration of other cardioactive drugs). We report a case of QT prolongation and polymorphic ventricular tachycardia (torsades de pointes) that was precipitated by the intravenous administration of erythromycin. In contrast to most other previously described patients, our patient did not demonstrate significant heart disease or other apparent factors contributing to the genesis of the arrhythmia.

Adult↗
PubMed1992

Unusual Wenckebach upper rate response of an atrial-based DDD pacemaker.

We describe in this report an unusual form of Wenckebach upper rate response produced by a DDD pulse generator with atrial-based lower rate timing. The pacemaker maintained the programmed upper and lower rate intervals at the expense of a prolonged atrial paced-ventricular paced AV interval. This form of upper rate behavior eliminated the longer cycle (containing the unsensed P wave) that occurs at the end of the pacemaker Wenckebach sequence during traditional DDD pacing with ventricular-based lower rate timing.

Adult↗