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Biomedical subjects

J Jakopin

Publications and source records attributed to J Jakopin.

11 recordsLinked to original sources
PubMed1985

Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study.

Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combined electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates.

Aged↗
PubMed1984

Electrophysiological effects of ethmozin on sinus nodal function in patients with and without sinus node dysfunction.

The electrophysiological effects of intravenously administered ethmozin (1 mg kg-1) on sinus node function were examined in 32 patients. Based on their clinical data and the results of the initial study, patients were subdivided into group A (n = 12), those with sick sinus syndrome and sinus node recovery time (SNRT) greater than 1500 ms, and group B (n = 20), those without overt sinus node dysfunction and a normal SNRT. The mean sinus cycle length did not change significantly in either group after ethmozin . SNRT was prolonged by ethmozin in group A whereas in group B the increase of SNRT was not significant. Corrected SNRT increased after ethmozin in both subgroups but with a much more pronounced increase in group A. Sinoatrial conduction time was not significantly changed in any group. The lengthening of SNRT in the majority of patients with sick sinus syndrome implies that ethmozin might prolong post-tachycardia pauses in these patients. This drug should therefore be administered cautiously to persons with signs indicative of dysfunction of the sinus node.

Adolescent↗
PubMed1983

Latent sinoatrial conduction disturbances in symptomatic patients with Wolff-Parkinson-White syndrome.

Sinoatrial conduction abnormalities were studied in fourteen patients with Wolff-Parkinson-White (WPW) syndrome and frequent attacks of supraventricular paroxysmal tachycardia. Sinoatrial conduction time (SACT), obtained by the method of constant atrial pacing, was prolonged in all but two patients. The mean value was 277 +/- 56 ms (mean +/- SD). SACT was measured in the same way in sixteen patients without signs of pre-excitation or sinoatrial disease; SACT was significantly shorter (p less than 0.001) than in the WPW group of patients. The prolongation of SACT in patients with WPW syndrome was confirmed by measuring SACT by the alternative method of programmed atrial stimulation. SACT was found to be prolonged in eight patients (mean +/- SD = 239 +/- 47 ms). Whether our results should be attributed to WPW syndrome or frequent supraventricular tachycardias--both being a characteristic feature of our patients--remains uncertain. The results of this study, however, indicate that in symptomatic patients with WPW syndrome and frequent episodes of supraventricular tachycardia, sinoatrial conduction is frequently impaired. Slackening of the sinoatrial conduction is a possible predisposing factor for initiation of tachycardias in the WPW syndrome.

Adult↗
PubMed1982

Induced concealed dissimilar atrial rhythms.

Electrophysiologic studies, including intra-atrial recordings and atrial stimulation, were performed in two patients with suspected sick sinus syndrome. Premature atrial stimuli induced atrial flutter in both patients. The arrhythmia was concealed, i.e., it was recordable only by intracavitary electrogram and invisible on surface electrocardiogram. In one case, simultaneous atrial fibrillation could be recorded in a segment of the right atrium. In this patient, the rhythm on the surface electrocardiogram changed during the study to "upper nodal" rhythm, though the atrial electrogram showed continuation of A waves at the same rate as before during sinus rhythm. It seems that atrial changes, which are frequently encountered in sick sinus syndrome, are a predisposing factor for spontaneous or inducible concealed atrial arrhythmias.

Atrial Flutter↗
PubMed1979

The relation of heart rhythm to postextrasystolic potentiation.

In 9 patients with various forms of heart rhythms and rates, all of whom had a temporary pacemaker electrode inserted, several single premature ventricular contractions (PVC) with various coupling intervals (CI) were induced. The relative systolic area of the carotid pulse curve in the postextrasystolic beat was used as an indicator of the degree of postextrasystolic potentiation (PESP). A close correlation between PESP and CI was found only in sinus rhythm patients (r = -0.85). The patients with junctional and ventricular rhythms had no PESP regardless of CI or the degree of heart failure. Compensatory pause (CP) in these patients surprisingly related (r = 0.95) to heart rate, slower rates having a shorter relative CP.

Cardiac Complexes, Premature↗