Helmut Kühnert

Diagnostic value of carotid sinus hypersensitivity.

VOLKMANN, H., ET AL.: Diagnostic Value of Carotid Sinus Hypersensitivity. In order to evaluate the diagnostic value of carotid sinus hypersensitivity (CSH) we have investigated 163 asymptomatic patients (88 male, 75 female, mean age 57.9 ± 22.7 years) and 210 symptomatic patients (108 males, 102 females, mean age 61.1 ± 28.1 years) with syncopes or dizziness. Thirty two of the 163 asymptomatic patients (20%) and 87 of the 210 symptomatic patients (41%) showed CSH (asystole ≥ 3 sec during carotid sinus pressure). Male patients had a higher number of CSH than female (28% vs 10% in the asymptomatic group, 48% vs 34% in the symptomatic group). Electrophysiological investigations were performed in all 210 symptomatic patients. Normal electrophysiological results had 94 of the 210 patients. Thirty seven of these 94 patients showed CSH (39%). Prolonged sinus node recovery time (SNRT) and/or prolonged sinoatrial conduction time (SACT) were evaluated in 38 patients. Seventeen of the 38 patients had CSH (45%]. Disorders of atrioventricular (AV) conduction were evaluated in 43 patients. Seventeen of the 43 patients showed CSH (40%). Thirty‐five patients had both AV conduction disorders and prolonged SNRT or SACT. Sixteen of these 35 patients showed CSH (46%). In conclusion, no significant difference was found between patients with and without pathological electrophysiological results. The CSH is without value for predicting sinus node dysfunction and AV conduction disorder.

Transesophageal left ventricular posterior wall potential in heart failure patients with biventricular pacing / Transösophageales linksventrikuläres Potenzial der posterioren Wand bei Patienten mit Herzinsuffizienz und biventrikulärer Stimulation

Abstract Introduction: Biventricular (BV) pacing is an established therapy for heart failure (HF) patients with intraventricular conduction delay, but not all patients improved clinically. We investigated the interventricular delay (IVD) by means of the transesophageal left ventricular posterior wall potential (LVPWP). Materials and methods, and Results: A total of 18 HF patients (age 62±9 years; 15 males) with NYHA class 3.1±0.3, LV ejection fraction 22±7%, left bundle branch block and a QRS duration (QRSD) of 171±27 ms were analyzed using transesophageal LVPWP before implantation of a BV pacing device. The median follow up was 14±14 months. In 14 responders, IVD was 81±25 ms with a QRSD/IVD ratio of 2.2±0.3 with reclassification of NYHA class 3.1±0.3 to 2.0±0.5 (p<0.001) and an increase in LV ejection fraction from 22±7% to 36±11% (p=0.001) during long-term BV pacing. In four non-responders, transesophageal IVD was significantly smaller at 30±11 ms (p=0.001). Conclusion: Transesophageal IVD may be a useful method to detect responders to BV pacing. Transesophageal LVPWP may be a simple and useful technique to detect clinical responders to BV pacing in HF patients. Zusammenfassung Einleitung: Die biventrikuläre (BV) Stimulation ist eine etablierte Therapie bei Patienten mit Herzinsuffizienz (HF) und intraventrikulärem Leitungsdelay, aber nicht alle Patienten verbessern sich klinisch. Wir haben das interventrikuläre Delay (IVD) mit dem transösophagealen linksventrikulären Potenzial der posterioren Wand (LVPWP) untersucht. Material und Methode und Ergebnisse: Elf HF-Patienten (Alter 62±9 Jahre; 15 Männer) mit NYHA Klasse 3,1±0,3, LV Ejektionsfraktion 22±7%, Linksschenkelblock und QRS-Dauer (QRSD) 171±27 ms wurden mit dem transösophagealen LVPWP vor Implantation eines BV Schrittmachers analysiert. Der Median der Nachuntersuchung betrug 14±14 Monate. Bei 14 Respondern betrug das IVD 81±25 ms mit einem QRSD/IVD Verhältnis von 2,2±0,3. Es verbesserte sich die NYHA Klasse von 3,1±0,3 auf 2,0±0,5 (p<0,001) und erhöhte sich die LV Ejektionsfraktion von 22±7 auf 36±11% (p=0,001) während der BV Stimulation über lange Zeit. Bei 4 Nonrespondern war das transösophageale IVD signifikant geringer mit 30±11 ms (p=0,001). Schlussfolgerung: Das transösophageale IVD stellt möglicherweise eine brauchbare Methode zur Erkennung von Respondern für die BV Stimulation dar. Das transösophageale LVPWP ist möglicherweise eine einfache und brauchbare Technik zur Erkennung von klinischen Respondern für die BV Stimulation bei HF-Patienten.

Electrophysiological evaluation of tachycardias using transesophageal pacing and recording.

VOLKMANN, H., ET AL: Electrophysiological Evaluation of Tachycardias Using Transesophageal Pacing and Recording. Programmed electrical stimulation of the heart to initiate and terminate tachycardia has been useful in the evaluation of supraventricular and ventricular tachyarrhythmias. A wide use of these procedures, however, failed because of the expense of the invasive approach as well as the lack of physician experience in smaller hospitals. These disadvantages of the invasive proceeding can be abolished by transesophageal pacing. In our study, supraventricular tachycardias were initiated by programmed transesophageal atrial stimulation in 251 patients [AV node reentry in 75 patients, orthodromic AV reciprocating tachycardia using accessory pathway in 97 patients, antidromic AV reciprocating tachycardia in 11 patients, and atrial reentry in 39 patients). The stimulation protocol included one and two extrastimuli during sinus rhythm and after a pacing drive at different cycle lengths. The electrophysiological mechanism of tachycardias was determined by surface ECG, VA interval (esophageal lead), initiation mode at programmed transesophageal stimulation and by behavior of AV conduction and refractoriness. In 29 patients the mechanism of tachycardia was not clear. Invasive electraphysiological study was done in 219 of these 251 patients. In only nine patients, the supported mechanism of tachycardia was not confirmed by invasive investigation. In 11 patients, the etectrophysiological mechanism remained uncertain. In conclusion, the noninvasive transesophageal pacing is an appropriate method for evaluation of supraventricular tachycardia. It allows serial drug testing in a simple manner for finding an effective antiarrhythmic treatment.

Termination of Tachycardias by Transesophageal Electrical Pacing

To evaluate the therapeutic significance of noninvasive transesophageal pacing for termination of tachycardias the method of rapid atrial or ventricular transesophageal pacing was used in 233 patients with different tachycardiac arrhythmias. We were able to terminate atrial flutter in 136 of 162 patients by transesophageal rapid atrial stimulation (conversion to sinus rhythm in 75 cases, induction of atrial fibrillation in 61 cases). Atrial tachycardias were interrupted in 17 of 23 patients (sinus rhythm in 11 cases, atrial fibrillation in six cases). AV reciprocating/AV nodal supravenrricular reentry tachycardias were terminated in 62 of 63 patients (sinus rhythm in 58 cases, atrial fibrillation in four cases). By transesophageal rapid ventricular pacing ventricular tachycardias could be terminated in ten of 15 patients. The success rate of transesophageal pacing was influenced by the pacing rate, by the type of tachycardiac arrhythmia inclusive by the type of atrial flutter and by the tachycardias cycle length. Because the success rates are comparable with invasive technique and the procedure is simpler, the noninvasive transesophageal antitachycardiac pacing should be respected as the method of the first choice in patients with supraven‐tricular tachycardias.

Bundle Branch Reentrant Tachycardia Treated by Transvenous Catheter Ablation of the Right Bundle Branch

Recurrent episodes of ventricuiar tachycardia not responding to medical treatment occurred in a 56‐year‐old man. Electrophysiological investigation showed ventricular tachycardia due to bundle branch reentry. Using a method similar to catheter ablation of the atrioventricular junction, ablation of the right bundle branch was performed by an electrical shock of 250 joules. While before the ablation ventricular tachycardia occurred several times a day and its induction by programmed ventricular stimulation was facilitated by the administration of antiarrhythmic drugs, no initiation of ventricular tachycardia was possible after ablation of the right bundle branch. Over a follow‐up of 30 months the patient has not suffered from tachycardia and the right bundle branch block persists.

Termination of atrial flutter by directed transesophageal atrial pacing during transesophageal echocardiography / Terminierung von Vorhofflattern mit gerichteter transösophagealer Vorhofstimulation bei transösophagealer Echokardiographie

Abstract Introduction: The purpose of this study was to evaluate termination of atrial flutter (AFL) by directed rapid transesophageal atrial pacing (TAP) with and without simultaneous transesophageal echocardiography (TEE) performed using a novel TEE tube electrode. Materials and methods, and Results: A total of 16 AFL patients (age 63±12 years; 13 males) with mean AFL cycle length of 224±24 ms (n=12) and mean ventricular cycle length of 448±47 ms (n=12) were analyzed using either an esophageal TO electrode (n=10) or a novel TEE tube electrode consisting of a tube with four hemispherical electrodes that is pulled over the echo probe (n=6). AFL could be terminated by directed rapid TAP using an esophageal TO electrode, leading to induction of atrial fibrillation (AF) (n=6), induction of AF and spontaneous conversion to sinus rhythm (SR) (n=3), and with conversion to SR (n=1). AFL could also be terminated by directed rapid TAP using the TEE tube electrode, with induction of AF (n=3) or induction of AF and spontaneous conversion to SR (n=3). Conclusion: AFL can be terminated by directed rapid TAP with hemispherical electrodes with and without simultaneous TEE. TAP with the directed TEE tube electrode is a safe, simple, and useful method for terminating AFL. Zusammenfassung Einleitung: Die Terminierung von Vorhofflattern (AFL) mit gerichteter hochfrequenter transösophagealer Vorhofstimulation (TAP) wurde mit und ohne simultane transösophageale Echokardiographie (TEE) mit einer neuen TEE-Schlauchelektrode evaluiert. Material und Methode und Ergebnisse: 16 AFL Patienten (Alter 63±12 Jahre; 13 Männer) mit einer mittleren AFL-Periodendauer von 224±24 ms (n=12) und einer mittleren ventrikulären Periodendauer von 448±47 ms (n=12) wurden mittels Ösophaguselektrode „TO” (n=10) oder neuer „TEE-Schlauchelektrode”, die aus einem Schlauch mit 4 halbkugelförmigen Elektroden besteht und über die Echokardiographiesonde gezogen wird (n=6), analysiert. AFL konnte mit gerichteter hochfrequenter TAP und TO-Elektrode durch Induktion von Vorhofflimmern (AF) (n=6), Induktion von AF mit spontaner Konversion in den Sinusrhythmus (SR) (n=3) und Konversion in den SR (n=1) terminiert werden. AFL konnte mit gerichteter hochfrequenter TAP und TEE-Schlauchelektrode durch Induktion von AF (n=3) und Induktion von AF mit spontaner Konversion in den SR (n=3) terminiert werden. Schlussfolgerung: AFL kann durch gerichtete hochfrequente TAP mit halbkugelförmigen Elektroden mit und ohne simultane TEE terminiert werden. TAP mit der gerichteten TEE-Schlauchelektrode ist eine sichere, einfache und praktikable Methode zur Terminierung von AFL.

Non-surgical extraction of right cardiac thrombus in transit

In two hemodynamically unstable patients, massive pulmonary embolism and free‐floating right cardiac thrombi were diagnosed. Thrombolytic therapy was contraindicated and surgical treatment was rejected. In these two cases, we describe a successful non‐surgical, percutaneous extraction of mobile right cardiac thrombi. Cathet. Cardiovasc. Intervent. 51:316–319, 2000.

Optimization of the atrioventricular delay during cardiac resynchronization therapy using a device for non-invasive measurement of cardiac index at rest and during exercise

AIMS It is not clear whether cardiac resynchronization therapy (CRT) should only be optimized at rest or whether it is necessary to perform CRT optimization during exercise. Our study aims to answer this question by using an inert gas rebreathing method (Innocor®). METHODS AND RESULTS Twenty-seven patients with congestive heart failure and implanted CRT devices were included in the study. The aetiology of the heart failure was ischaemic in nine (33%) patients. Patients had low left ventricular ejection fraction (29 ± 8%) and enlarged LV end-diastolic diameters (63 ± 7 mm). Atrioventricular delay (AVD) was optimized at rest according to cardiac index (CI), measured by inert gas rebreathing (Innocor®). Thereafter, patients performed standardized, steady-state bicycle exercise at 30 W in sitting body position. Three AVDs were tested during exercise in a random sequence: optimized resting AVD (AVD(opt)) according to baseline measurement; AVD(opt) - 30 ms; and AVD(opt) + 30 ms. Cardiac index was measured in each AVD by inert gas rebreathing. Cardiac index increased significantly during exercise. However, neither AVD(opt) shortening nor prolongation during exercise had significant effect on CI (shortening of AVD(opt) - 30 ms was accompanied by a reduction of CI of 4.8%, prolongation of AVD(opt) + 30 ms was accompanied by a reduction of CI of 7.7%). CONCLUSION Shortening or lengthening of the AVD during exercise has no impact on CI in CRT patients. On the basis of our results, we conclude that in CRT patients the AVD should be programmed, fixed even during exercise.

Unexpanded, irretrievable stent in the proximal right coronary artery: successful management with stent graft implantation.

Stent loss and failure of retrieval are rare; nevertheless, complications have to be taken into account during percutaneous coronary intervention. Here we report a case of an unexpanded, irretrievable Palmaz‐Schatz stent in the proximal right coronary artery near to the ostium and the successful management by implanting a synthetic stent graft. Cathet. Cardiovasc. Intervent. 46:344–349, 1999.

Esophageal Balloon Electrode Catheter for Transthoracic Recording of His‐Bundle Potential with Transesophageal Atrial Pacing

To evaluate the influence of transesophageal atrial pacing of the transthoracic His potential identification, we combined signal‐averaged ECG with transesophageal atrial pacing with low threshold for pacing averaging ECG recording. A tripolar 10 French esophageal balloon electrode catheter, with one cylindrical electrode on the tip of the catheter and two balloon electrodes on the cardiac side of the catheter, used in 53 patients, allowed a painless transesophageal atrial pacing and a high signal to noise distance in the signal‐averaged ECG. Transesophageal atrial pacing allowed in 37 of 53 patients an identification of His potential by increasing the distance between the end of the atrial potential and the onset of the His potential in the pacing averaging ECG. The esophageal balloon electrode catheter allowed a painless transesophageal atrial pacing with low threshold for atrial capture during a long pacing time and a high signal to noise distance in the pacing averaging ECG. The increasing of the heart rate with transesophageal atrial pacing allowed the transthoracic identification of the His potential in the pacing averaging ECG.