Gefahrliche Interaktionen zwischen Amiodaron und Antiarrhythmika der Klasse I. [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

Transluminale Entfernung endovasaler Fremdkorper. [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

Stufenweise Koronardilatation mit Doppelballonkatheter. [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

Die Bedeutung der ST-Hebung im Belastungs-Ekg. [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

Die chirurgische Behandlung von Herzrhythmusstorungen. [Surgical treatment of heart rhythm disorders]

Six patients underwent cardiac surgery for refractory tachyarrhythmias. Four had Wolff-Parkinson-White syndrome and 2 ventricular tachycardias after myocardial infarction. The results of preoperative electrophysiologic studies corresponded in 5 cases to intraoperative findings of epicardial and pace-mapping. These patients were free of symptoms for the 4-16 months' follow-up. In one patient with divergent results, tachycardia and preexcitation returned two months postoperatively. In the light of the foregoing the authors suggest surgical treatment for 1. preexcitation with life-threatening arrhythmias, 2. refractory ventricular tachycardias with coronary artery disease and 3. preexcitation in patients undergoing open heart surgery for other reasons

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

Stufenweise Koronardilatation (PTCA) mit Doppelballonkatheter. [Graded coronary dilatation (PTCA) with a double balloon catheter]

In coronary angioplasty (PTCA) stenoses over 80% can usually be passed with very small catheters only. To pass stenoses with different catheters during one procedure may be dangerous because of dissection. We therefore developed an instrument with very small tip-diameter and two balloons of different diameters in series. In 9 cases primary success was achieved and the degree of stenoses reduced from 90% to 23%. The gradient was 58 mmHg and remained only 11 mmHg after PTCA. When used with caution, the advantage of this catheter in high degree coronary stenoses is obvious

Combination Tones in Violins

In this study we investigate the appearance of combination tones in violins. Most authors in recent times have emphasised that combination tones occur inside the ear exclusively (intra-aural). This assumption will be subjected to scrutiny based on evidence found in an empirical study in which combination tones were measured outside the ear (extra-aural). Measurements were performed in which a violinist played two tones of a partic-ular musical interval simultaneously. This was recorded and subsequently analysed using a Fourier Transformation. In addition to the partial tones of the primary interval, the resulting spectrum showed frequencies corresponding to combination tones. Similar measurements on the viola and violoncello also revealed the exis-tence of extra-aural combination tones. Such frequencies may influence the timbre of simultaneous intervals played on string instruments. In another experiment the violin was excited using an electrodynamic mini-shaker with the aim of localising the origin of extra-aural combination tones. A newly devised tone matrix was used as a theoretical approach which computes all potential combination tones that may occur between any pair of partial tones. The detailed analysis of musical intervals by both the frequency spectrum and the tone matrix shows characteristic mirror and point symmetries in the partial tone structure. The discussion focuses mainly on the audibility of extra-aural combination tones and on ‘the combination tone 1’. This research opens up new perspectives and questions relevant for interpreters, composers, violin makers and violin acousticians