Helmut Kuehnert

Catheter-based renal denervation for drug-resistant hypertension by using a standard electrophysiology catheter.

AIMS The endovascular application of low-dose radiofrequency (RF) energy to the renal arteries results in effective ablation of sympathetic nerve fibres leading to a significant lowering of blood pressure (BP). This study aims to examine the feasibility and safety of renal denervation by the use of a standard electrophysiology (EP) catheter. METHODS AND RESULTS Twelve patients (mean age 62±14 years, nine male) with drug resistant hypertension despite medical treatment with at least four antihypertensive drugs underwent renal denervation by using a standard steerable RF ablation catheter with a 7 Fr diameter (Marinr®; Medtronic Inc., Minneapolis, MN, USA). Low-power RF applications have been applied along the length of both renal arteries, consecutively. Assessment of 24 hour ambulatory BP was done at baseline, at one, and at three months following RF ablation. The mean reduction of 24 hour ambulatory BP was -11/-7 mmHg at one month and -24/-14 mmHg at three months (p<0.01 for systolic and p<0.03 for diastolic blood pressure) with unchanged medication. No vascular complications have been observed in the short-term follow-up. The renal function as assessed by serum creatinine and proteinuria remained unchanged from baseline. CONCLUSIONS Our preliminary results indicate that the use of a standard RF ablation catheter is feasible and safe for sympathetic renal denervation as shown by a significant lowering of mean 24 hour ambulatory BP in comparison to baseline during short-term follow-up. Whether the use of a standard EP catheter for sympathetic renal denervation indeed improves the long-term outcome in resistant hypertension, however, remains to be investigated.

Catheter-based radiofrequency ablation therapy of the renal sympathetic-nerve system for drug resistant hypertension in a patient with end-stage renal disease

Sympathetic overactivity is a major contributor to the pathogenesis and progression of human hypertension [1]. Especially, renal sympathetic activation is combined with renal vasoconstriction, increased renin secretion, and enhanced sodium and water reabsorption, contributing to the development of systemic hypertension [1]. Two recent reports of a novel catheter-based technique for renal sympathetic denervation offer a promising new therapeutic option for patients with resistant hypertension [2,3]. Percutaneous catheterbased radiofrequency ablation therapy can modify renal nerves that carry either efferent sympathetic and also afferent sensory fibers. Since hypertension is present in the vast majority of patients with chronic and end-stage renal failure [4] and sympathetic overactivity is a hallmark of patients with chronic renal disease and renal failure, this catheter-based technique may be also used in patients with chronic kidney disease. Here we report for the first time the successful treatment of hypertension with this novel technique in a patient with endstage renal disease. A 36-year old male patient with end-stage renal disease caused by a hereditary Alport syndrome and drug resistant hypertension was admitted to our university hospital. The mean blood pressure was 186/117 mm Hg proven by a 24-h ambulatory blood pressure monitoring despite medical therapy with six different antihypertensive

Successful use of a wearable cardioverter-defibrillator in myocarditis with normal ejection fraction

Sudden cardiac death (SCD) is generally defined as an unexpected death due to cardiovascular causes. In the majority of cardiac arrest patients, a structural or functional abnormality can be identified. Coronary artery disease is the most common cause of SCD [1]. In younger individuals, SCD often occurs during exercise, where hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy accounts for most of these cases [2]. Myocarditis comprises 5–11% of SCD in individuals less than 40 years of age [3]. In these cases, symptoms before the fatal event are rare [4]. Secondary prevention of SCD needs ICD therapy after documented cardiac arrest unless a transient or correctable cause of the arrhythmic trigger can be identified [5]. The treatment strategy for patients with ventricular fibrillation associated with a ‘‘transient’’ or ‘‘correctable’’ cause is not clear. These patients have a similar mortality rate as the survivors of ventricular fibrillation arrest in the observational registry of the AVID trial [6]. In myocarditis complicated by ventricular tachycardia (VT) or ventricular fibrillation (VF), antiarrhythmic drugs or an ICD implantation have not yet been studied in controlled trials. Because acute myocarditis often represents a transient condition from which recovery is common, the implantation of a permanent ICD should not be routine. Current guidelines do not recommend ICD therapy in a patient with acute myocarditis [5]. The debatable content of this statement is demonstrated with this presented case.

Left Ventricular Lead Position and Nonspecific Conduction Delay Are Predictors of Mortality in Patients During Cardiac Resynchronization Therapy

BACKGROUND Cardiac resynchronization therapy (CRT) is an established treatment of severe systolic heart failure with intraventricular conduction delay. The influence on mortality of the left ventricular (LV) pacing site and the type of bundle-branch block during CRT is unclear. OBJECTIVES This study investigates the clinical significance of LV lead position, as well as nonspecific conduction delay, in CRT. METHODS 143 consecutive patients (mean age, 63.9 ± 8.9 years; 121 men) underwent implantation of a CRT device according to established criteria. At the time of implantation, the LV lead position and the type of bundle-branch block were recorded. The etiology of the heart failure was ischemic in 49 patients (34.3%) and nonischemic in 94 patients (65.7%). RESULTS After a median follow-up of 19 months, 39 patients (27.3%) died, most of them (72%) of cardiovascular causes. The mortality was significantly higher in patients with an anterior or anterolateral LV lead position (P = 0.03). Multivariate analysis suggests that an anterior or anterolateral LV lead position, a nonspecific conduction delay, male sex, and a New York Heart Association functional class worse than III, are all independent predictors of mortality during the follow-up period. CONCLUSION LV lead position and nonspecific conduction delay are predictors of mortality in patients during cardiac resynchronization therapy.

[Implantation of a re-synchronization device in a patient with persistent left superior vena cava-a case report].

SummaryWe report an implantation of a cardiac resynchronisation system in a patient with persistent left superior vena cava. This anomaly occurs in 0.3 to 0.5% of healthy individuals and remains usually asymptomatic. Variations of the superior vena cava should be considered in venous catheterization and other procedures such as implantation of pacemaker and ICD systems as well as port catheter insertion. In resynchronisation systems, persistent left superior vena cava can be an obstacle for cannulation of the coronary sinus and placement of a transvenous left ventricular lead.ZusammenfassungWir berichten über die Implantation eines Resynchronisationssystems bei einem Patient mit persistierender oberer Hohlvene. Diese Variante tritt mit einer Häufigkeit von 0,3 to 0,5% auf und ist in der Regel asymptomatisch. Varianten der oberen Hohlvene können die Anlage zentralvenöser Zugänge sowie die Implantation von Herzschrittmachern, ICD- und Portsystemen behindern und haben Konsequenzen für die Elektrodenplatzierung der linksventrikulären Elektrode von Resynchronisationssystemen.

Unmasked superoparaseptal pathway conduction due to atrial fibrillation in a patient with left ventricular dysfunction. Rapid recovery after successful radiofrequency ablation.

We report the case of a 56-year-old woman with newly diagnosed atrial fibrillation (AF) and severe left ventricular (LV) dysfunction caused by rapid conduction via an accessory pathway (AP), mimicking left bundle branch block, as the first clinical manifestation of Wolff–Parkinson–White (WPW) syndrome. Electrical cardioversion of the AF revealed a short PR interval and a delta wave, which was positive in leads I, II, aVL, and V2 and negative in lead V1 with a transition zone between V1 and V2. Radiofrequency catheter ablation of a superoparaseptal pathway was accompanied by rapid recovery from LV systolic dysfunction.ZusammenfassungWir berichten über eine 56-jährige Patientin mit neu diagnostiziertem Vorhofflimmern (VHF) und schwerer linksventrikulärer (LV) Dysfunktion aufgrund einer tachykarden Überleitung über eine akzessorische Leitungsbahn, die einen Linksschenkelblock vortäuschte, als klinische Erstmanifestation eines Wolff-Parkinson-White-Syndroms. Eine elektrische Kardioversion des VHF demaskierte ein kurzes PR-Intervall und eine Delta-Welle, die positiv in den Ableitungen I, II, aVL und V2, und negativ in Ableitung V1 war und einen R/S-Umschlag zwischen V1 und V2 aufwies. Nach Radiofrequenz-Katheterablation einer superoparaseptalen Bahn kam es zu einer raschen Erholung der systolischen LV-Funktion.

Unmasked superoparaseptal pathway conduction due to atrial fibrillation in a patient with left ventricular dysfunction@@@Demaskierung einer superoparaseptalen akzessorischen Leitungsbahn durch neu aufgetretenes Vorhofflimmern bei einer Patientin mit eingeschränkter linksventrikulärer Pumpfunktion.: Rapid recovery after successful radiofrequency ablation@@@Rasche Besserung der LV-Funktion nach erfolgreicher Radiofrequenzablation

We report the case of a 56-year-old woman with newly diagnosed atrial fibrillation (AF) and severe left ventricular (LV) dysfunction caused by rapid conduction via an accessory pathway (AP), mimicking left bundle branch block, as the first clinical manifestation of Wolff–Parkinson–White (WPW) syndrome. Electrical cardioversion of the AF revealed a short PR interval and a delta wave, which was positive in leads I, II, aVL, and V2 and negative in lead V1 with a transition zone between V1 and V2. Radiofrequency catheter ablation of a superoparaseptal pathway was accompanied by rapid recovery from LV systolic dysfunction.ZusammenfassungWir berichten über eine 56-jährige Patientin mit neu diagnostiziertem Vorhofflimmern (VHF) und schwerer linksventrikulärer (LV) Dysfunktion aufgrund einer tachykarden Überleitung über eine akzessorische Leitungsbahn, die einen Linksschenkelblock vortäuschte, als klinische Erstmanifestation eines Wolff-Parkinson-White-Syndroms. Eine elektrische Kardioversion des VHF demaskierte ein kurzes PR-Intervall und eine Delta-Welle, die positiv in den Ableitungen I, II, aVL und V2, und negativ in Ableitung V1 war und einen R/S-Umschlag zwischen V1 und V2 aufwies. Nach Radiofrequenz-Katheterablation einer superoparaseptalen Bahn kam es zu einer raschen Erholung der systolischen LV-Funktion.

New frontiers of supraventricular tachycardia and atrial flutter evaluation and catheter ablation

Radiofrequency catheter ablation (RFCA) has revolutionized treatment for tachyarrhythmias and has become first-line therapy for some tachycardias. Although developed in the 1980s and widely applied in the 1990s, the technique is still in development. Transesophageal atrial pacing (TAP) can used for initiation and termination of supraventricular tachycardia (SVT). Methods: The paroxysmal SVT include a wide spectrum of disorders including, in descending order of frequency, atrial flutter, atrioventricular (AV) nodal reentry, Wolff-Parkinson-White syndrome, and atrial tachycardia. While not lifethreatening in most cases, they may cause important symptoms, such as palpitations, chest discomfort, breathlessness, anxiety, and syncope, which significantly impair quality of life. Medical therapy has variable efficacy, and most patients are not rendered free of symptoms. Research over the past several decades has revealed fundamental mechanisms involved in the initiation and maintenance of all of these arrhythmias. Knowledge of mechanisms has in turn led to highly effective surgical and catheter-based treatments. The supraventricular arrhythmias and their treatment are de-scribed in this report. SVT initiation was analysed with programmed TAP in 49 patients with palpitations (age 47 ± 17 years, 24 females, 25 males). Results: In comparison to antiarrhythmic drug therapy the radiofrequency catheter ablation in patients suffering from atrial flutter, atrioventricular nodal reentry, atrioventricular reentry and atrial tachycardia is the better choice in most cases. TAP SVT initiation was possible in 23 patients before RFCA. Atrial cycle length of SVT was 320 ± 59 ms. We initiated AV nodal reentrant tachycardia (AVNRT, n=15), atrial tachycardia (AT, n=6) and AV reentrant tachycardia with Kent pathway conduction (AVRT, n=2) before RFCA. Conclusions: Radiofrequency catheter ablation is a successful and safe method to cure most patients with paroxysmal supraventricular tachycardias. TAP allowed initiation and termination of SVT especially in outpatients.

Novel telemetric signal averaging ECG approach to determine electrical atrial and ventricular conduction delays in implantable cardioverter defibrillator patients

Cardiac resynchronization therapy (CRT) with biventricular pacing is an established therapy for heart failure (HF) patients (P) with ventricular desynchronization and reduced left ventricular (LV) ejection fraction. The aim of this study was to evaluate electrical right atrial (RA), left atrial (LA), right ventricular (RV) and LV conduction delay with novel telemetric signal averaging electrocardiography (SAECG) in implantable cardioverter defibrillator (ICD) P to better select P for CRT and to improve hemodynamics in cardiac pacing. Methods: ICD-P (n=8, age 70.8 ± 9.0 years; 2 females, 6 males) with VVI-ICD (n=4), DDD-ICD (n=3) and CRT-ICD (n=1) (Medtronic, Inc., Minneapolis, MN, USA) were analysed with telemetric ECG recording by Medronic programmer 2090, ECG cable 2090AB, PCSU1000 oscilloscope with Pc-Lab2000 software (Velleman®) and novel National Intruments LabView SAECG software. Results: Electrical RA conduction delay (RACD) was measured between onset and offset of RA deflection in the RAECG. Interatrial conduction delay (IACD) was measured between onset of RA deflection and onset of far-field LA deflection in the RAECG. Interventricular conduction delay (IVCD) was measured between onset of RV deflection in the RVECG and onset of LV deflection in the LVECG. Telemetric SAECG recording was possible in all ICD-P with a mean of 11.7 ± 4.4 SAECG heart beats, 97.6 ± 33.7 ms QRS duration, 81.5 ± 44.6 ms RACD, 62.8 ± 28.4 ms RV conduction delay, 143.7 ± 71.4 ms right cardiac AV delay, 41.5 ms LA conduction delay, 101.6 ms LV conduction delay, 176.8 ms left cardiac AV delay, 53.6 ms IACD and 93 ms IVCD. Conclusions: Determination of RA, LA, RV and LV conduction delay, IACD, IVCD, right and left cardiac AV delay by telemetric SAECG recording using LabView SAECG technique may be useful parameters of atrial and ventricular desynchronization to improve P selection for CRT and hemodynamics in cardiac pacing.

Left atrial and left ventricular conduction delay by transesophageal electrocardiography with hemispherical electrodes in sinus rhythm cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) with biventricular (BV) pacing is an established therapy in approximately twothirds of symptomatic heart failure (HF) patients (P) with left bundle branch block (LBBB). The aim of this study was to evaluate left atrial (LA) conduction delay (LACD) and left ventricular (LV) conduction delay (LVCD) using preimplantational transesophageal electrocardiography (ECG) in sinus rhythm (SR) CRT responder (R) and non-responder (NR). Methods: SR HF P (n=52, age 63.6±10.4 years; 6 females, 46 males) with New York Heart Association (NYHA) class 3.0±0.2, 24.4±7.1 % LV ejection fraction and 171.2±37.6 ms QRS duration (QRSD) were measured by bipolar filtered transesophageal LA and LV ECG recording with hemispherical electrodes (HE) TO catheter (Osypka AG, Rheinfelden, Germany). LACD was measured between onset of P-wave in the surface ECG and onset of LA deflection in the LA ECG. LVCD was measured between onset of QRS in the surface ECG and onset of LV deflection in the LV ECG. Results: There were 78.8 % SR CRT R (n=41) with 171.2±36.9 ms QRSD, 73.3±25.7 ms LACD, 80.0±24.0 ms LVCD and 2.3±0.5 QRSD-LVCD-ratio. SR CRT R QRSD correlated with LACD (r=0.688, P<0.001) and LVCD (r=0.699, P<0.001). There were 21.2 % SR CRT NR (n=11) with 153.4±22.4 ms QRSD (P=0.133), 69.8±24.8 ms LACD (n=6, P=0.767), 54.2±31.0 ms LVCD (P<0.0046) and 3.9±2.5 QRSD-LVCD-ratio (P<0.001). SR CRT NR QRSD not correlated with IACD (r=-0.218, P=0.678) and IVCD (r=0.042, P=0.903). During a 22.8±21.3 month CRT follow-up, the CRT R NYHA class improved from 3.1±0.3 to 1.9±0.3 (P<0.001). In CRT NR, NYHA class not improved (2.9±0.4 to 2.9±0.2, P=1) during 11.2±9.8 months BV pacing. Conclusions: Transesophageal LA and LV ECG with HE can be utilized to analyse LACD and LVCD in HF P. Preimplantational LVCD and QRSD-LVCD-ratio may be additional useful parameters to improve P selection for SR CRT.