Stylianos Tzeis

Cryoablation Versus Radiofrequency Energy for the Ablation of Atrioventricular Nodal Reentrant Tachycardia (the CYRANO Study) Results From a Large Multicenter Prospective Randomized Trial

Background— Cryoablation has emerged as an alternative to radiofrequency catheter ablation (RFCA) for the treatment of atrioventricular (AV) nodal reentrant tachycardia (AVNRT). The purpose of this prospective randomized study was to test whether cryoablation is as effective as RFCA during both short-term and long-term follow-up with a lower risk of permanent AV block. Methods and Results— A total of 509 patients underwent slow pathway cryoablation (n=251) or RFCA (n=258). The primary end point was immediate ablation failure, permanent AV block, and AVNRT recurrence during a 6-month follow-up. Secondary end points included procedural parameters, device functionality, and pain perception. Significantly more patients in the cryoablation group than the RFCA group reached the primary end point (12.6% versus 6.3%; P=0.018). Whereas immediate ablation success (96.8% versus 98.4%) and occurrence of permanent AV block (0% versus 0.4%) did not differ, AVNRT recurrence was significantly more frequent in the cryoablation group (9.4% versus 4.4%; P=0.029). In the cryoablation group, procedure duration was longer (138±54 versus 123±48 minutes; P=0.0012) and more device problems occurred (13 versus 2 patients; P=0.033). Pain perception was lower in the cryoablation group (P<0.001). Conclusions— Cryoablation for AVNRT is as effective as RFCA over the short term but is associated with a higher recurrence rate at the 6-month follow-up. The risk of permanent AV block does not differ significantly between cryoablation and RFCA. The potential benefits of cryoenergy relative to ablation safety and pain perception are counterbalanced by longer procedure times, more device problems, and a high recurrence rate. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00196222.

Cost-effectiveness of atrial fibrillation catheter ablation

Radiofrequency catheter ablation has become an established treatment option for the management of patients with atrial fibrillation (AF). Although the concept of a rhythm control strategy devoid of the adverse events related to antiarrhythmic treatment seems highly attractive, further steps are needed in order to improve our understanding of the underlying pathophysiology, refine our ablative techniques, and increase our therapeutic efficacy. Furthermore, the increased cost of AF catheter ablation combined with the substantial number of potential candidates also mandates the evaluation of this invasive treatment through a cost-effectiveness prism. In the present review, we recapitulate the existing evidence pertaining to cost-effectiveness of AF catheter ablation as well as the shortcomings, peculiarities, and distinctive aspects of such a cost-to-benefit analysis.

Correlation of Mechanical Dyssynchrony with QRS Duration Measured by Signal‐Averaged Electrocardiography

Background: Preimplantation left ventricular dyssynchrony is considered a prerequisite for a beneficial response to cardiac resynchronization therapy (CRT). However, electrical dyssynchrony estimated by QRS duration (QRSd) on ECG has not been proven to be an optimal surrogate of mechanical dyssynchrony. We evaluated the correlation of mechanical dyssynchrony with QRSd as measured by signal‐averaged electrocardiography (SAECG) in comparison with measurements based on conventional surface ECG and with onscreen measurements based on digital ECG.

Monitoring capabilities of cardiac rhythm management devices

Since the advent of the first generation pacemakers, solely providing rate support, we have witnessed a technological outburst in the type and complexity of implantable devices. The introduction of implantable cardioverter defibrillators and later of cardiac resynchronization therapy devices enriched our therapeutic arsenal for the management of patients with heart failure and/or high risk of sudden cardiac death. In addition, during the last decade, newer generation cardiac rhythm management devices (CRMs) have been capable to provide a continuously expanding pool of diagnostic information derived by novel monitoring capabilities. Although at present the clinical role of this information is undervalued, it is evident that the clinical exploitation of data derived by CRMs may transform the standards of care for our patients by providing timely applied individualized diagnosis and treatment. In this context, even in the absence of solid data supporting the use of this information in everyday clinical practice, improving our familiarity with currently available monitoring algorithms is a prerequisite for the electrophysiologist who keeps in pace with the rapidly evolving technologies of CRMs and is prepared for their future role on clinical practice.

Cryoablation Versus Radiofrequency Energy for the Ablation of Atrioventricular Nodal Reentrant Tachycardia (the CYRANO Study)

Background— Cryoablation has emerged as an alternative to radiofrequency catheter ablation (RFCA) for the treatment of atrioventricular (AV) nodal reentrant tachycardia (AVNRT). The purpose of this prospective randomized study was to test whether cryoablation is as effective as RFCA during both short-term and long-term follow-up with a lower risk of permanent AV block. Methods and Results— A total of 509 patients underwent slow pathway cryoablation (n=251) or RFCA (n=258). The primary end point was immediate ablation failure, permanent AV block, and AVNRT recurrence during a 6-month follow-up. Secondary end points included procedural parameters, device functionality, and pain perception. Significantly more patients in the cryoablation group than the RFCA group reached the primary end point (12.6% versus 6.3%; P=0.018). Whereas immediate ablation success (96.8% versus 98.4%) and occurrence of permanent AV block (0% versus 0.4%) did not differ, AVNRT recurrence was significantly more frequent in the cryoablation group (9.4% versus 4.4%; P=0.029). In the cryoablation group, procedure duration was longer (138±54 versus 123±48 minutes; P=0.0012) and more device problems occurred (13 versus 2 patients; P=0.033). Pain perception was lower in the cryoablation group (P<0.001). Conclusions— Cryoablation for AVNRT is as effective as RFCA over the short term but is associated with a higher recurrence rate at the 6-month follow-up. The risk of permanent AV block does not differ significantly between cryoablation and RFCA. The potential benefits of cryoenergy relative to ablation safety and pain perception are counterbalanced by longer procedure times, more device problems, and a high recurrence rate. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00196222.

Modification of cardiometabolic risk through cannabinoid type-1 receptor antagonism.

Large-scale epidemiological studies show that hypertension, diabetes, and dyslipidaemia are highly prevalent among obese individuals. Regrettably, preventive efforts have failed to abolish the increasing prevalence of obesity worldwide. The endocannabinoid system is implicated in the regulation of appetite, food intake, lipids, and glucose metabolism. Rimonabant is the first type-1 endocannabinoid receptor blocker that has been shown to improve the serum lipid profile, insulin and glucose levels, and blood pressure. In particular, the RIO (rimonabant in obesity) studies documented the beneficial metabolic effects of rimonabant. These favorable metabolic effects exceed by about 50% those anticipated by weight reduction, possibly due to modulation of the endocannabinoid system in peripheral tissues. The beneficial effects, however, seem to come at the cost of an increased risk of psychiatric disorders. However, given the efficacy of this treatment and the magnitude of the obesity problem, rimonabant may prove to be a valuable adjunct in targeting obesity-related cardiovascular risk factors.

Cryoablation Versus Radiofrequency Energy for the Ablation of Atrioventricular Nodal Reentrant Tachycardia (the CYRANO Study)Clinical Perspective: Results From a Large Multicenter Prospective Randomized Trial

Background— Cryoablation has emerged as an alternative to radiofrequency catheter ablation (RFCA) for the treatment of atrioventricular (AV) nodal reentrant tachycardia (AVNRT). The purpose of this prospective randomized study was to test whether cryoablation is as effective as RFCA during both short-term and long-term follow-up with a lower risk of permanent AV block. Methods and Results— A total of 509 patients underwent slow pathway cryoablation (n=251) or RFCA (n=258). The primary end point was immediate ablation failure, permanent AV block, and AVNRT recurrence during a 6-month follow-up. Secondary end points included procedural parameters, device functionality, and pain perception. Significantly more patients in the cryoablation group than the RFCA group reached the primary end point (12.6% versus 6.3%; P=0.018). Whereas immediate ablation success (96.8% versus 98.4%) and occurrence of permanent AV block (0% versus 0.4%) did not differ, AVNRT recurrence was significantly more frequent in the cryoablation group (9.4% versus 4.4%; P=0.029). In the cryoablation group, procedure duration was longer (138±54 versus 123±48 minutes; P=0.0012) and more device problems occurred (13 versus 2 patients; P=0.033). Pain perception was lower in the cryoablation group (P<0.001). Conclusions— Cryoablation for AVNRT is as effective as RFCA over the short term but is associated with a higher recurrence rate at the 6-month follow-up. The risk of permanent AV block does not differ significantly between cryoablation and RFCA. The potential benefits of cryoenergy relative to ablation safety and pain perception are counterbalanced by longer procedure times, more device problems, and a high recurrence rate. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00196222.

Cryoablation Versus Radiofrequency Energy for the Ablation of Atrioventricular Nodal Reentrant Tachycardia (the CYRANO Study)Clinical Perspective

Background— Cryoablation has emerged as an alternative to radiofrequency catheter ablation (RFCA) for the treatment of atrioventricular (AV) nodal reentrant tachycardia (AVNRT). The purpose of this prospective randomized study was to test whether cryoablation is as effective as RFCA during both short-term and long-term follow-up with a lower risk of permanent AV block. Methods and Results— A total of 509 patients underwent slow pathway cryoablation (n=251) or RFCA (n=258). The primary end point was immediate ablation failure, permanent AV block, and AVNRT recurrence during a 6-month follow-up. Secondary end points included procedural parameters, device functionality, and pain perception. Significantly more patients in the cryoablation group than the RFCA group reached the primary end point (12.6% versus 6.3%; P=0.018). Whereas immediate ablation success (96.8% versus 98.4%) and occurrence of permanent AV block (0% versus 0.4%) did not differ, AVNRT recurrence was significantly more frequent in the cryoablation group (9.4% versus 4.4%; P=0.029). In the cryoablation group, procedure duration was longer (138±54 versus 123±48 minutes; P=0.0012) and more device problems occurred (13 versus 2 patients; P=0.033). Pain perception was lower in the cryoablation group (P<0.001). Conclusions— Cryoablation for AVNRT is as effective as RFCA over the short term but is associated with a higher recurrence rate at the 6-month follow-up. The risk of permanent AV block does not differ significantly between cryoablation and RFCA. The potential benefits of cryoenergy relative to ablation safety and pain perception are counterbalanced by longer procedure times, more device problems, and a high recurrence rate. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00196222.

Schrittmacheralgorithmen zur Minimierung der rechtsventrikulären Stimulation

Recent large, prospective, multi-centre trials have demonstrated detrimental effects of unnecessary right ventricular pacing. This review summarizes the results of the major trials and sheds light on the potential mechanisms that cause the unfavourable outcome. Different programming strategies to avoid unnecessary pacing in dual chamber pacemakers and implantable cardioverters defibrillators - especially in respect of every day clinical practise - are discussed.

Double transvenous left ventricular lead implantation for the maintenance of cardiac resynchronisation therapy

ZusammenfassungDieser Fallbericht beschreibt die Implantation einer zweiten transvenösen Koronarsinuselektrode zusätzlich zu einer nicht-extrahierbaren alten Koronarsinuselektrode zur Fortsetzung der kardialen Resynchronisationstherapie bei einem 48jährigen Patienten mit schwerster Herzinsuffizienz.AbstractThis case reports about the feasibility of the transvenous implantation of a second coronary sinus lead in addition to a non-extractable old left ventricular lead for the continuation of cardiac resynchronization therapy in a 48-year old patient with severe heart failure.