Search PubMed⌕ Search

Biomedical subjects

I Zupan

Publications and source records attributed to I Zupan.

8 recordsLinked to original sources
PubMed2001

Double vessel extension of spontaneous left main coronary artery dissection in young women treated with thrombolytics.

Spontaneous coronary artery dissection is an extremely rare cause of myocardial infarction. The prognosis and treatment of coronary artery dissection have not yet been defined. We report on a 42-year-old woman who was admitted to the emergency unit of a regional hospital with central chest pain and electrocardiographic signs of extensive acute anterior myocardial infarction (MI). She was treated with thrombolytics, yet her condition deteriorated rapidly, resulting in cardiogenic shock. An angiogram revealed dissection of the left main coronary artery that extended into the anterior descending (LAD) and circumflex arteries (LCX). At autopsy a recent anterolateral MI of the left ventricle was found. Dissection of the left coronary artery system was confirmed. Extension of the dissection may have been due to thrombolytic treatment.

Adult↗
PubMed2001

Left atrial systolic function in relation to electrical and mechanical remodeling in a canine model.

Rapid atrial activation causes electrical remodeling that promotes the occurrence and maintenance of atrial fibrillation. The aim of this research was to compare the relationship between mechanical remodeling and atrial electrophysiology. Eight dogs (beagles) were subjected to rapid atrial pacing (AP) at 400 beats/min for 16 days. After a complete recovery of electrical variables and left ventricular function evaluated by echocardiography, they underwent high-rate ventricular pacing (VP) at 240 beats/min of equal duration. In half of them, the study was started by VP and in the other half by AP. Left atrial systolic function was assessed by transesophageal echocardiography. Atrial effective refractory period (AERP) at a basic cycle length of 400 ms decreased significantly after either type of pacing (AP: 115 +/- 17 ms, VP: 136 +/- 22 ms) compared with baseline values (153 +/- 23 ms); the difference between tachycardias was significant too (p < 0.02). Significant increases (p < 0.05) in left atrial dimensions (LA-A) (AP: 2.41 +/- 0.23 cm ,VP: 2. 43 +/- 0. 34 cm vs. basal: 2. 16 +/- 0. 21 cm) indicated atrial dilatation after either type of pacing, the differences between two groups being insignificant. Atrial reversal pulmonary venous flow (AR velocity) decreased in AP (-0.13 +/- 0. 02 m/s) and VP (-0. 17 +/- 0. 04 m/s). The difference was highly significant as compared to basal values (-0.25 +/- 0.05 m/s) and also with respect to both tachycardias (p < 0.01). In both groups, atrial remodeling occurred in a relatively short period of time. The echocardiographic findings suggested that left atrial systolic function was significantly more disturbed in the AP group than in the VP group. Mechanical changes are an important substrate of electrical remodeling, yet the deterioration of electrical variables was more pronounced in AP than in VP.

Animals↗
PubMed2001

Serum thrombopoietin levels in acute myeloid leukaemia.

To improve our understanding of the regulation of circulating platelet counts (PC) by thrombopoietin (TPO), we studied serum TPO levels and PC before and after myelosuppressive chemotherapy in 12 patients with acute myeloid leukaemia (AML). Serum TPO levels were measured by the quantitative sandwich enzyme-linked immunosorbent assay (Quantikine, RD Systems). At the start of the induction chemotherapy, the patients had a median serum TPO level of 199 pg/ml (range 120-2,150 pg/ml), while 10 to 12 days after the end of chemotherapy, their TPO levels were substantially increased, the median value being 1,907 pg/ml (range 1,049-4,194 pg/ml). The correlation between PC and TPO was statistically significant prior to chemotherapy (p < 0.03) and insignificant after chemotherapy. As a result of chemotherapy, the patients developed aplasia; after the administration of platelet transfusions, their median PC increased to 21 x 10(9)/l (range 5-55 x 10(9)/l), while the median TPO value decreased by 300 pg/ml (range 11-1,125 pg/ml). Our results suggest that platelet mass directly regulates serum TPO levels in acute leukaemia patients prior to chemotherapy and after the administration of platelet transfusions. Serum TPO levels may also be influenced by the cytokine response during complicating infections in patients with chemotherapy-induced cytopenia.

Antineoplastic Agents↗
PubMed1996

Tachycardia induced cardiomyopathy in dogs; relation between chronic supraventricular and chronic ventricular tachycardia.

Long-standing ventricular tachycardia (VT) and supraventricular tachycardia (SVT) can produce a reversible left ventricular dysfunction. The onset of cardiomyopathy and the severity of posttachycardic changes depend at least on three parameters of tachycardia, including its type (VT or SVT), rate and duration. Ten dogs (beagles) were paced at 180 beats/min for 3 weeks. Two pacing modalities, supraventricular and ventricular, were used in each dog. In half of them, the study was started by ventricular, and in the other half by supraventricular high-rate pacing. The alternate pacing modality was applied after complete recovery of left ventricular function. Ventricular function and morphology were evaluated by radionuclide ventriculography, echocardiography and Swan-Ganz catheterisation. Posttachycardic changes were studied in sinus rhythm after cessation of pacing. Left ventricular ejection fraction (LVEF) fell significantly after either type of tachycardia (SVT: 53 +/- 5%, VT: 48 +/- 7%, P < 0.05) compared with baseline values (69.5 +/- 2.3%). Significant increases (P < 0.05) in end-systolic (SVT: 2.1 +/- 0.3 cm, VT: 2.4 +/- 0.2 cm vs. 1.6 +/- 0.3 cm) and end-diastolic dimensions (SVT: 3.0 +/- 0.3 cm, VT: 3.3 +/- 0.4 cm vs. 2.7 +/- 0.3 cm) indicated ventricular dilation in paced animals. Left ventricular pulmonary capillary wedge pressure increased significantly after either type of tachycardia as compared with baseline values (SVT: 7.5 +/- 1.2 mmHg, VT: 8.4 +/- 1.1 mmHg vs. 1.9 +/- 1.5 mmHg, P < 0.05); the difference between tachycardias was not significant. The present study demonstrates that chronic SVT and VT result in left ventricular dysfunction in a relatively short time, even if the heart rate is not very high. Deterioration of left ventricular ejection fraction and dilation of the left ventricle are more marked in chronic VT than in chronic SVT.

Animals↗
PubMed1995

Spontaneous shifts in the sinus node pacemaker complex.

Shifts in sinus node pacemaker complex may occur spontaneously, but occurrence of clinically relevant shifts is very rare. In this report, three patients (2 are siblings) with a history of palpitations and nearly permanent shifts in sinus node pacemaker complex are presented. Often, but not always, the pacemaker shifts followed spontaneous sinoatrial exit blocks. The shifts were probably related to varying vagal tone, since they were eliminated by atropine and exercise. The experience with these patients suggests that sinus pacemaker shifts can be a cause of symptomatic nonrespiratory sinus arrhythmia. A 4-year follow-up period showed no changes in symptoms or in heart rhythm; therefore, a benign course of the disease can be expected.

Adult↗
PubMed1995

Cardiac involvement in Emery-Dreifuss muscular dystrophy: role of a diagnostic pacemaker.

Emery-Dreifuss muscular dystrophy is an X-linked recessive myopathy. Its progression is slow, and it rarely leads to cessation of walking; therefore, it has often been called "benign." On the other hand, cardiac involvement is often severe and sudden death is not uncommon. We describe a family with four affected males, two of whom died suddenly. The case of an affected man with first-degree AV block, incomplete right bundle branch block, and left anterior fascicular block is described in detail. The prophylactic insertion of a diagnostic pacemaker enabled us to follow the progress of conduction disturbances without leaving the patient unprotected. While AV and intraventricular conduction defects were more prominent before pacemaker implantation, sinus node dysfunction became more important during the follow-up.

Adult↗
PubMed1992

Complete cure after a seemingly unsuccessful operation for Wolff-Parkinson-White syndrome.

A 48-year-old man with Wolff-Parkinson-White syndrome and poorly tolerated atrial fibrillation underwent surgical dissection of an accessory pathway. After operation electrocardiogram revealed a very unfavorable outcome: sinus rhythm with persistence of delta waves alternated with sequences of complete atrioventricular block. Therefore, an early reoperation was planned. Fortunately, in the next days conduction through the accessory pathway and signs of atrioventricular block disappeared. Complete cure was observed during long-term follow-up.

Atrial Fibrillation↗