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Biomedical subjects

L Kappenberger

Publications and source records attributed to L Kappenberger.

At least 199 records · Page 11Linked to original sources

[Effect of heart rate on the refractory period of the accessory atrioventricular pathway in Wolff-Parkinson-White syndrome].

Electrophysiologic investigations have been performed in 13 patients with symptomatic WPW syndrome. The effective refractory periods of the right atrium (AERP), the antegrade effective refractory periods of the accessory pathway (AP-ERP) during sinus rhythm and at different cycle length, the shortest RR-intervals with preexcitation during atrial fibrillation (RR-AF) and the appearance of block in the AP during incremental atrial pacing have been measured. The data collected during sinus rythm (SR) and at different pacing rates were analyzed and compared. During SR (cycle length 851 +/- 157 ms) AERP measured 263 +/- 56 ms and AP-ERP 309 +/- 55 ms. At a cycle length of 450-550 ms, AERP measured 221 +/- 36 ms and AP-ERP 250 +/- 35 ms, and at a cycle length of 400-450 ms AERP was 213 +/- 35 ms and AP-ERP 230 +/- 42 ms. The mean RR-AF was 253 +/- 35 ms. A significant correlation was found between AERP and AP-RP at a cycle length of 400-450 ms (r = 0.92), but not between AP-ERP and RR-AF at any cycle length. Block in the AP occurred at a mean pacing cycle length of 280 +/- 42 ms. The electrophysiologic measurements of patients with syncope did not differ from patients without syncope in our group. The data show that in patients with a long AP-ERP (greater than 290 ms) during SR an increase of the heart rate leads to a significant shortening of the AP-ERP. No relevant correlation was found between AP-ERP and mean RR-AF. Patients with AP-ERP shorter than RR-AF appear to be a high-risk subgroup for ventricular fibrillation during AF.

Adolescent↗

[Percutaneous transluminal coronary angioplasty: results after a 5-year follow-up period].

In the first series of 50 patients in whom percutaneous transluminal coronary angioplasty (PTCA) was attempted, the procedure was successful in 32. 23/32 patients were followed up clinically over 62.2 +/- 5.6 (SD) months. Repeated non-invasive laboratory tests were carried out in 15/23 patients. Moreover, 11/15 patients were restudied by arteriography at the end of the follow-up period. Early recurrence of the stenosis occurred in 5/32 patients (16%) and was again successfully treated by a second PTCA in 2. 3 patients underwent surgery as requested. 22/23 (95%) remained symptom-free during the follow-up period. The results of the non-invasive laboratory tests were in close agreement with the clinical findings. Coronary arteriography performed at the end of the follow-up period revealed an excellent lasting effect of PTCA in 8/11 patients. 2 showed a slight progression of the three stenoses treated by PTCA, and in 1 patient late recurrence of the stenosis was suspected since he had been symptom-free up to 2 weeks prior to restudy. Thus, in patients who are suitable for PTCA, this treatment is of long-lasting effect and represents an excellent alternative to coronary artery bypass surgery.

Adult↗

[The significance of ST elevation in the exercise ECG].

In contrast to ST-segment depression during exercise, the mechanism for ST-segment elevation - a more unusual finding - is controversial and poorly understood. Exercise induced ST-segment elevation of 2 mm and more was observed in 80 of 3000 consecutive patients (2.6%) undergoing bicycle exercise testing using 6 of 12 ECG leads. This abnormality was detected in 70 of 777 patients (9%) with documented previous myocardial infarction and in 10 of 2223 (0.5%) patients without a history of myocardial necrosis and with normal resting ECG. The substantial differences in exercise induced ST-segment elevation between these two groups are: patients with previous myocardial infarction and angiographically documented left ventricular aneurysm revealed progressive asymptomatic ST-segment elevation on an average of 3.4 +/- 1.2 mm persisting for a long time (greater than 3 minutes) during the recovery period. The extent of ST-segment elevation appears to correlate with LV EF and LV volume. These patients should be treated medically (as in 73% of our patients), and cardiac catheterization is indicated only in the presence of severe angina, congestive LV failure and arrhythmias. Patients with normal ECG at rest showed ST-elevation at maximal exercise. ST-segment elevation was associated with chest pain, which was more pronounced and shorter in duration than in the other group (9.1 +/- 2.8 mm, less than 30 sec). ST-elevation was abrupt and not preceded by ST-segment depression. 8 of 10 patients with anterior ST-segment elevation had a left anterior descending artery (LAD) lesion. Therefore, exercise testing in this group predicts significant proximal LAD obstruction accessible for PTCA.

Adult↗

[Transluminal removal of intravascular foreign bodies].

Removal of catheter tip or guide wire emboli is needed for most cases with this complication. An alternative to surgery is transvenous retrieval. The authors present their experience with a simple self-made loop-catheter, which in 11 of 12 cases proved successful for extraction of 9 catheter tips and 3 guide wires located in the central venous system, the right ventricle and the pulmonary artery in 10 patients, and in the aorta in 2. No further complications were caused by this procedure. Due to the serious hazards of embolized foreign bodies there is a need to remove them, and the authors believe that the transluminal route, preferably with the loop catheter, should be the primary approach to this iatrogenic complication.

Adult↗

Anomalous origin of the left thyrocervical trunk as a cause of residual pain after myocardial revascularization with internal mammary artery.

A patient with successful implantation of an internal mammary artery graft in the left anterior descending coronary artery complained of residual but different anginal pain after operation. Ischemia was demonstrated during a manual stress test. Angiography revealed anomalous origin of the thyrocervical trunk from the internal mammary artery. Angina and ischemia disappeared after the trunk was ligated.

Arteries↗

[Considerations on the therapy with physiologic pacemakers].

Physiologic pacemakers offer hemodynamic benefits in comparison to conventional pacing, but demand more detailed diagnosis of the arrhythmia in need of treatment. In order to prevent endless loop tachycardias, ventriculoatrial conduction must be analyzed. Normal sinus node and atrial function should be confirmed in atrial triggered ventricular stimulation. The techniques and values of preimplantation investigations, including intracardiac electrophysiological procedures, are discussed.

Atropine↗

[Binodal disease: diseased sinus node and atrioventricular block].

Atrioventricular (AV) conduction disturbances in patients (pts) with sick sinus syndrome (SSS) are well known, but sinus node function (SNF) in AV block is not well documented. We therefore performed electrophysiological tests to evaluate SNF in 30 pts with high-degree AV block (group 1) and AV conduction in 15 pts with SSS (group 1). These measurements were repeated after vagolysis with atropine in group 2. In group 1 ergometry was performed if the electrophysiological SNF tests were abnormal. Results (mean +/- 1 SD) for group 1 were: sinus node recovery time (SNRT) 1184 +/- 473 ms, corrected SNRT (cSNRT) 337 +/- 394 ms. In 3 pts SNRT or cSNRT was abnormal. In these 3 pts the response of sinus rate to exercise was insufficient. In group 2 SNRT before and after atropine was 2345 +/- 822 ms and 1558 +/- 815 ms respectively (p less than 0.05), cSNRT 1285 +/- 965 ms and 954 +/- 832 ms (n.s.), sinoatrial conduction time 319 +/- 283 ms and 150 +/- 149 ms (n.s.), and Wenckebach point 532 +/- 178 ms and 383 +/- 68 ms (p less than 0.01). His-ventricle time was 48 +/- 5.8 ms. In 6 of these 15 pts impaired AV-conduction was present (defined as Wenckebach point below 500 ms), but normalized in 4 pts after atropine. We postulate that persistence of abnormal SNF and AV conduction after vagolysis is an argument for organic binodal disease. This occurs with equal frequency in both groups in about 10% of patients. Increased vagal tone is common in SSS and uncommon in AV block. In patients with SSS the frequent additional AV conduction delay must be taken into consideration when atrial pacing is considered.

Adult↗

[Gradual coronary dilatation using double balloon catheters].

For the purpose of coronary angioplasty (PTCA) coronary stenoses over 80% usually can only be passed with very small catheters. We therefore developed an instrument with a very small tip-diameter and two balloons of different diameters arranged in line. In 9 cases primary success has been achieved and the degree of stenoses reduced from 89% to 22%. The gradient of 58 mm Hg was only 11 mm Hg after PTCA. When used with caution, the advantages of this catheter in high-degree coronary stenoses is obvious.

Angioplasty, Balloon↗

[Value of electrostimulation in the treatment of tachycardia].

Electrostimulation of the heart is of three-fold value for the treatment of tachyarrhythmias: 1. It proves the presence of an arrhythmogenic abnormality, 2. renders proper diagnosis of the type of tachycardia possible, and 3. forms the base for logical treatment. For therapeutic purposes temporary stimulation of many paroxysmal tachycardias is an alternative to DC-conversion. Initiation of arrhythmias in combination with acute drug testing helps in selecting efficient long-term treatment, especially in ventricular tachycardias. The fact that 50-100% of paroxysmal tachycardias can be interrupted by electrostimulation has rendered possible the development of antitachycardia pacemakers, a principle which may assume great importance in the future.

Anti-Arrhythmia Agents↗

[Harmful interactions of amiodarone and class I anti-arrhythmia agents].

Six patients treated with a combination of amiodarone and class I antiarrhythmic agents for a minor arrhythmia developed atypical ventricular tachycardia "en torsades de pointe". All patients had QT-interval prolongation in the ECG. Combined administration of quinidine and amiodarone in a normal volunteer resulted in an increase in plasma quinidine concentration and in QT prolongation, thus confirming the clinical observation of a clinically relevant interaction between the two drugs.

Adult↗