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Biomedical subjects

R Uebis

Publications and source records attributed to R Uebis.

47 records · Page 3Linked to original sources
PubMed1985

[Asystolic pauses in atrial fibrillation. Incidence, dependence on the underlying disease and significance for pacemaker therapy].

The frequency and duration of asystolic pauses in atrial fibrillation was investigated in 100 consecutive patients using 24-hour ECG's obtained by Holter monitoring. Patients were subdivided, according to the length of the maximal RR-interval, into group A (no asystolic pauses over 2 seconds duration), group B (pauses between 2 and 4 seconds) and group C (asystoles over 4 seconds duration). Pauses longer than 2 seconds occurred in 57% of patients, but longer than 4 seconds only in 6 cases. A statistically higher frequency was seen in patients with permanent (78.3%) than in those with paroxysmal (24.5%) atrial fibrillation, and in patients with rheumatic valve disease (82.4%) in comparison with the rest (54.3%). In contrast, pauses over 2 seconds occurred in only 22.2% of general medical ward patients. Up to 50% of all asystoles in groups A and B were registered during the night, whereas a day-night variation for group C was not apparent. No correlation could be demonstrated between dizziness and bradycardic conduction in group A and B, but all patients in group C made such complaints during the monitoring period. Asystoles of up to 4 seconds duration in atrial fibrillation can be regarded as "normal"; longer asystoles must be anticipated particularly in patients with rheumatic valvular disease. It is only here that permanent pacemaker therapy appears to be indicated.

Adult↗
PubMed1985

[Electrocardiogram in acute anterior wall infarct after restoration of the blood supply].

Changes in QRS complexes and ST-T segments were measured in 70 patients after acute anterior-wall myocardial infarction. Intracoronary streptokinase infusion was undertaken in the acute phase in 58 patients, 12 other patients treated conventionally without infusion serving as controls. Precordial ECG mapping employed 48 unipolar precordial leads. If recanalization of an occluded coronary artery was achieved, there was a significant rise in R amplitude (sum of R-wave amplitudes in the 48 leads) from 12.4 +/- 10.9 to 16.2 +/- 11.2 mV, within a period of up to four months after the acute stage. If thrombolysis failed or only conventional treatment had been practised, there was no rise in R-wave amplitude. Renewed occlusion of a vessel previously re-opened by streptokinase infusion produced a reduction in R-wave amplitude from 14.0 +/- 13.0 to 9.8 +/- 11.0 mV. The S-T segment elevation regressed immediately after recanalization of the coronary artery. The S-T segments were iso-electric after four months. Re-occlusion caused renewed S-T segment elevation up to monophasic form. Precordial ECG mapping is thus well suited for serial controls after various re-perfusion measures.

Electrocardiography↗
PubMed1985

[Intracoronary streptokinase in acute myocardial infarct. Experience with 461 patients].

Between March 1980 and July 1984, coronary angiography was performed on 461 consecutive patients (no age limit) with acute myocardial infarction, and the partially or completely obstructing thrombus lysed by selective intracoronary infusion of streptokinase. At the time of first coronary angiography 96 patients (21%) had a high degree of stenosis but no total occlusion of the infarct vessel (group A). In 365 patients (79%) there was complete occlusion which in 315 patients (86%) was removed successfully after an occlusion period of 213 +/- 87 minutes (group B). In 50 patients (14%) (group C) attempts at reperfusion failed. In 129 of 163 patients (79.1%) with one-vessel disease, PTCA (percutaneous transluminal coronary angioplasty) was successful. Patients with multiple-vessel disease and an occlusion time of less than four hours, on the other hand, were treated surgically within the first ten days (78 patients). In the remaining 254 patients conservative treatment was practised. Within the first 30 days there were seven deaths (14%) in group C, while among group A and B patients, under conservative treatment, 16 died (7.8%). After successful PTCA four patients (3.1%) died. The lowest mortality was among patients with a short occlusion time and early bypass operation (2.6%). The most frequent cause of death was cardiogenic shock (20 of 29 patients), more rarely ventricular fibrillation (3) or other causes (4). Ventricular rupture occurred in three patients, one of whom was saved by pericardial tap. One year later the mortality among the conservative group was 21.2%, after successful PTCA or bypass operation 9.3% and 6.4%, respectively.

Aged↗
PubMed1985

Myocardial infarction and thrombolysis. Electrocardiographic short term and long term results using precordial mapping.

In a consecutive series of 56 patients with acute myocardial infarction, ST segment depression and elevation in the electrocardiographic limb leads I, II, and III were summated for each patient before and immediately after intracoronary streptokinase infusion and the results compared with the angiographic findings. Forty three patients had angiographically confirmed reperfusion of an initially occluded vessel and showed a significant decrease in summated ST shift. The ST segment changes in the limb leads virtually returned to normal in all 43 patients, and in most, inverted T waves developed. Thrombolysis was unsuccessful in 10 patients, and the infarct related coronary artery was already patent in three. When these two groups are combined, all 13 patients without reperfusion showed no significant change in summated ST segment shift. During percutaneous transluminal angioplasty inflation of the balloon in the vessel that was previously occluded simulated reocclusion and was followed by new ST elevation if the artery supplied viable myocardium. In a further consecutive study of 54 patients with anterior myocardial infarction, the precordial R waves and Q waves were studied over the four to six months following infarction using a standardised 48 electrode mapping system. All patients underwent a repeat angiogram after four to six months. In 36 patients the infarct related vessel was patent. They showed a significant mean increase in summated precordial R wave amplitude and a reduction in the mean number of precordial leads without R waves. In 18 patients with unsuccessful thrombolysis or reocclusion there was a further reduction in mean summated R wave amplitude and an increased number of precordial leads not showing R waves. Precordial R wave mapping seems to be a valuable non-invasive method of assessing the salvage of myocardium after reperfusion and the damage caused by reocclusion. Loss of R waves in the acute phase of myocardial infarction does not necessarily mean an irreversibly damaged myocardium.

Adult↗
PubMed1985

[Residual stenosis following successful selective lysis of complete thrombotic coronary artery occlusion in acute myocardial infarct].

After successful lysis of a thrombotic coronary obstruction in acute myocardial infarction, both PTCA and bypass surgery can be useful in preventing reocclusion and providing long-term success in selected patients. One condition to perform such measures is a high degree of residual narrowing at the previous site of occlusion. Other investigations concerning the extent and further development of these lesions are methodically inhomogenous and different in their results. Following successful intracoronary lysis of a complete thrombotic occlusion, the remaining stenosis was measured in 106 patients using at least 2 angiographic projections both immediately after reperfusion, and 3 days later. The degree and development of the residual lesion were analysed with special regard to its anatomy and to the occlusion time. During the observation period, no mechanical intervention (PTCA) or bypass surgery took place. The 1st angiogram after thrombolysis revealed an average cross section stenosis of 90.5 +/- 6.2%, which decreased up to the control angiogram to 86.3 +/- 10.6% (p less than 0.05). In only 16 cases there was an improvement of 10% or more, in fact it was not relevant (less than 10%) in 66 patients, and in 24 a slight increase in residual narrowing could even be found. The decrease of eccentric (-5.5 +/- 9.2%) and concentric (-3.3 +/- 5.7%) lesions was not statistically different. Stenoses up to 5 mm of length (-5.7 +/- 7.2%), between 5 and 10 mm (-3.4 +/- 6.7%), and over 10 mm (-4.4 +/- 8.2%) again did not differ significantly. There was no linear correlation between degree of stenosis and total time of occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Trials as Topic↗
PubMed1985

[Stress tolerance of various catheters in the electrical interruption of AV conduction].

To date, only commercially available cardioverters and standard electrode catheters have been used for closed-chest ablation of the atrioventricular conduction system; the latter are primarily designed for temporary pacing and electrophysiological examinations, both procedures requiring rather low voltages and currents. Therefore, the purpose of this experimental study was to assess the electrical charge when using high energies, for instance of 400 joules. A total of 7 different catheters with 2-4 electrodes produced by various manufacturers were tested. After discharging the capacitor (400 joules; commercially available cardioversion unit) the voltage and current were measured using an oscilloscope and the electrical flash was photographed. For temporary pacing previously used and newly sterilized catheters of varying sizes and numbers of electrodes tolerated only one single charge of 400 joules, a completely new catheter only a maximum of 3 discharges. Any additional test resulted in a non directional discharge, caused by an insulation defect. A Josephson catheter (USCI) and a newly developed catheter with modified insulation and electrode material (Cordis) had a higher stability. Both tolerated at least 5 charges per electrode, and in addition the Cordis probe tolerated another 20 charges of the 2nd lead without any non directional discharges. Thus, commercially available electrode catheters are of limited electrical stability when used for closed-chest ablation of the atrioventricular conduction system. For the protection of the patient and to prevent therapeutic failure, a maximum of 3 electrical discharges are possible when using a completely new catheter. As modified catheters demonstrate (currently only available in prototype), the electrical quality could be improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle of His↗
PubMed1984

Determinants of infarct size in patients successfully treated by intracoronary thrombolysis.

In 125 patients successfully treated by intracoronary thrombolysis, data were analyzed to determine the amount of regional wall motion impairment. In 85 patients with complete occlusion of the affected vessel and successful recanalization, ventriculographic study could be performed immediately after recanalization of the vessel and repeated 3 days thereafter. Unexpectedly, no correlation could be seen between the amount of wall motion impairment and the time interval of coronary vessel occlusion. For assessment of other influencing factors two subgroups were analyzed, one with large infarction despite short occlusion time and the other with small infarction despite long occlusion time. The significant differences between these two groups was in regard to the occluded coronary vessels: In the first group, most patients had anterior infarctions caused by left anterior descending (LAD) occlusion, whereas in the second group, there were no LAD occlusions at all. According to the data that we compiled, the location of the occluded coronary vessel was the most important factor in determining infarct size. Taking this into account, recovery of the impaired wall motion up to the third day after infarction was separately analyzed in LAD occlusion or inferior infarction and was found to be more pronounced in the first. Immediate recovery after recanalization however, which could be analyzed in 40 patients who had angiographic studies before recanalization as well as afterwards, was more pronounced in inferior infarction.

Journal Article↗
PubMed1984

[Echocardiographic monitoring of acute myocardial infarct following intracoronary streptolysis treatment].

Two-dimensional echocardiography is helpful in the detection of wall motion abnormalities and in the evaluation of time courses of regional function due to interventions. Of 301 patients with acute myocardial infarction treated with selective intracoronary infusion of streptokinase, 229 (76%) revealed a totally occluded infarct related vessel at the first angiography. In 64 patients a two-dimensional apical long-axis view of good technical quality could be obtained after admission, on the 1st, 2nd and 3rd day and again in the 4th to 6th week and the 9th to 14th month after the acute intervention. The collective was divided into two subgroups according to the different time interval between the beginning of symptoms of infarction and the reopening of the occluded vessel. 35 patients had a total time of occlusion of less than 4 hours (group A), while in 29 others this time exceeded 4 hours or thrombolysis was unsuccessful (group B). Using a computer system, the center of gravity of the end-systolic frame of the left ventricle was used as an inner fix point. 10 end-systolic and end-diastolic area segments were constructed. Regional wall motion was determined as a percentual change of the enclosed area, normalized to the end-diastolic area (% delta F). The ejection fraction was calculated using a disc method. In group A the ejection fraction increased from initially 46 +/- 9% to 51 +/- 8%, 52 +/- 8% (p less than 0.05) and 53 +/- 8% (p less than 0.01) on the 1st, 2nd and 3rd day, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗
PubMed1977

[Sodium nitroprusside in the treatment of left-sided heart failure in acute myocardial infarction (author's transl)].

27 patients (8 women, 19 men) aged 39-79 (mean 61) years with acute transmural mycoardial infarction and limitation of left ventricular function were treated in the acute stage for 24-72 (mean 55) hours with intravenous infusions of sodium nitroprusside in concentrations of 10-200 microng/min. Haemodynamic measurements before and 12 hours after onset of treatment showed a significant reduction in mean arterial pressure by 19%, in end-diastolic pressure in the pulmonary artery by 33% and in the total peripheral resistance by 32%, whereas stroke volume and cardiac index rose by 12% and 17%, respectively. The percentage improvement was most marked in those patients most severely affected. The mortality rate of cardiogenic shock was reduced to 25%. In a control group with haemodynamically similar left ventricular failure the mortality rate was 55%. However, the total mortality was nearly unchanged as the number of sudden unexpected deaths after the fourth day rose from 23 to 50%. Further investigations will show how these sudden deaths, mainly due to arrhythmias, can be prevented.

Adult↗