Search PubMed⌕ Search

Biomedical subjects

L Schamroth

Publications and source records attributed to L Schamroth.

At least 73 records · Page 4Linked to original sources
PubMed1982

The supernormal phase of intraventricular conduction: normalization of intraventricular conduction of premature atrial beats.

This report presents the analysis of a case in which numerous atrial extrasystoles, associated with normal intraventricular conduction, occurred during sinus rhythm conducted with right bundle branch block. The wide overlap of coupling intervals of normally conducted extrasystoles and other extrasystoles with right bundle branch block seemed prima facie to negate the possibility of supernormality. Rearrangement of these intervals, however, to allow for the timing of right bundle branch depolarization with respect to the ensuing QRS complex, resulted in a clear cut separation of all normalized complexes from those with right bundle branch block. All normalized extrasystoles were localized in a zone very early in the cycle. This finding, in the presence of atrial extrasystoles with normal P-R intervals, strongly supports the mechanism of supernormality in this case. Alternate explanations do not appear to be tenable.

Aged↗
PubMed1981

"Supernormal" phase of atrioventricular conduction with concealed capture beats. Significance of odd numbers of P waves between capture beats.

In 1968 Moe and associates postulated multilevel atrioventricular (A-V) block as a mechanism for some forms of the supernormal phase of A-V conduction. In 1971 Schamroth further postulated that, if this were correct, there would only be odd numbers of sinus P waves between the capturing impulses. This report presents two cases of sinus rhythm dissociated from idionodal escape rhythm as a result of high grade A-V block. The rhythm is complicated by manifest and concealed A-V captures during the so-called supernormal phase. There are only odd numbers of P waves between the capturing impulses.

Aged↗
PubMed1981

Reciprocating tachycardia with only odd-numbered beats in the Wolff-Parkinson-White syndrome.

A case of Wolff-Parkinson-White syndrome with reciprocating tachycardia from retrograde Kent's bundle conduction is described. The paroxysms of reciprocating tachycardia manifested with the unusual, and hitherto unreported, feature of only odd-numbered beats. The phenomenon is explained on the basis of alternate anterograde conduction through two A-V nodal pathways.

Atrioventricular Node↗
PubMed1980

The clinical use of intravenous verapamil.

The mechanisms of action and clinical application of verapamil--a calcium ion antagonist--are reviewed. Verapamil is effective and has important application in the treatment of coronary artery spasm, hypertensive crises, and supraventricular tachyarrhythmias.

Angina Pectoris, Variant↗
PubMed1979

The effect of pregnancy on the frontal plane QRS axis.

The electrical axis of the heart is an important parameter in electrocardiographic assessment. Slight degrees of left axis deviation have been attributed to a horizontal heart position resulting from the mechanical effects of abdominal distension, such as the physiological event of pregnancy. This study was undertaken to establish the validity of this concept.

Abdomen↗
PubMed1978

Studies of acute myocardial infarction with intermittent bundle branch and hemiblock.

Two cases of transient hemiblock occurring during the course of acute myocardial infarction are reported. The transient manifestation permits the accurate evaluation of the diagnostic features of the hemiblocks as modified by acute infarction. One case reflects the development of left bundle branch block due to bilateral post-divisional block which inter alia permits the study of left bundle branch block in the presence of acute myocardial infarction.

Aged↗
PubMed1977

Alternation of retrograde conduction times.

A patient with idionodal rhythm with alternation of retrograde conduction times is described. The idionodal escape rhythm is associated with alternating slow and relatively fast retrograde conduction times to the atria. The mechanisms underlying this phenomenon are discussed.

Arrhythmias, Cardiac↗