Innovation in the diagnosis and treatment of cardiac arrhythmias.

The 11th International Dead Sea Symposium on Cardiac Arrhythmias and Device Therapy - the 20th Anniversary of the meeting - was held in Jerusalem, Israel on the 26-29 February 2012. The global meeting was conducted with the goal of providing a venue for a multidisciplinary approach to exchange knowledge in all areas related to arrhythmia care. In addition to presentations of original research and keynote lectures, special educational sessions were offered that included hands-on anatomy training and interesting case presentations.

Bolus injection of acetylcholine terminates atrial fibrillation in rats.

It is well established that a tonic increase in the availability of the atrial muscarinic K(+) channels, either by enhanced vagal tone or by steady infusion of a low-dose of cholinergic or adenosine receptor agonists, promotes the genesis of atrial fibrillation. Here, we aimed to test the hypothesis that bolus administration of a muscarinic receptor agonist would destabilize and terminate atrial arrhythmia by uniformly and transiently activating K(+) channels throughout the atria, and that if the agonist was rapidly hydrolysable, it would dissipate before the more tonic, pro-arrhythmic effects could take hold. The episodes of untreated atrial fibrillation, induced in anesthetized rats by programmed electrical stimulation via trans-esophageal bipolar catheter, lasted on average 8.

"Benign" course and malignant clinical presentations of congenital long QT syndrome.

This report describes the "benign" clinical course of a congenital long QT syndrome (LQTS) simulated acute coronary event in an 85 year old woman who had a history of recurrent syncope accompanied by numerous severe traumatic events from childhood. Her daughter died suddenly. LQTS was diagnosed on the basis of characteristic ECG findings, including a permanently prolonged QT interval, typical dynamic T-wave changes, and runs of torsades de pointes.

Stimulation of unidirectional pulses in excitable systems.

Using a judicious spatial shape of input current pulses (and electrodes), responses of an excitable system (FitzHugh-Nagumo) appear as unidirectional pulses (UDP's) instead of bidirectional ones (in one dimension) or circular ones (in two dimensions). The importance of the UDP's for a possible mechanism for pinpointing the reentry cycle position and for a possible use in tachycardia suppression is discussed.

Multiple-vein thrombosis and pulmonary embolism after pacemaker implantation treated by thrombolysis.

This report describes a patient who suffered multiple-vein thrombosis following permanent pacemaker implantation and developed a pulmonary embolism while on anticoagulation treatment, which was successfully treated by thrombolytic therapy.

Effect of modern pacing algorithms on generator longevity: a predictive analysis.

Pulse generator (PG) longevity is of major importance to the quality of care of pacemaker patients. A series of automatic algorithms affect PG longevity. This study investigated the individual and combined effects of three algorithms incorporated in the Medtronic Kappa 700 pacemaker series: Capture Management periodically measures the stimulation threshold and adjusts the PG output, Sinus Preference allows the sinus rate to prevail in a specified range below the sensor rate, and Search AV allows an extension of the AV interval if spontaneous conduction is observed.

Determinants of geographic variations in pacemakers and implantable cardioverter defibrillators implantation rates.

Despite the established therapeutic efficacy of pacemakers (PMs) and implantable cardioverter defibrillators (ICDs), marked geographic and national variations in their implant rates have been documented. Tabulation of implant rates and identification of variation patterns are of only modest significance as many factors influence geographic variations. This study examined statistical data regarding implant rates and analyzed the determinants behind these variations.

Mexiletine related chronic defibrillation threshold elevation: case report and review of the literature.

Many antiarrhythmic drugs may produce a rise in defibrillation threshold. Mexiletine is a frequently used antiarrhythmic drug in patients with an implantable cardioverter defibrillator, usually thought of as producing no or minimal effects on the defibrillation threshold. The current case report presents a patient with an endocardial implantable cardioverter defibrillator being treated with mexiletine, which precluded the ability to defibrillate the patient.

Cardiac output-based versus empirically programmed AV interval--how different are they?

Aims: To compare empirically programmed and cardiac output-based programming of atrioventricular (AV) interval in patients with dual chamber pacemakers.

Methods And Results: In 19 patients with implanted dual chamber pacemakers due to AV block but otherwise normal hearts, cardiac output was assessed using an impedance cardiography device. In all patients, the AV interval had been previously programmed empirically by an experienced cardiologist.

A simple bedside test of 1-minute heart rate variability during deep breathing as a prognostic index after myocardial infarction.

Background: We evaluate a simple, bedside test that measures 1-minute heart rate variability in deep breathing as a predictor of death after myocardial infarction.

Methods: Bedside heart rate variability was assessed in 185 consecutive patients 5.1 +/- 2.

Single pass lead VDD pacing in children and adolescents.

Implantation of permanent pacemakers in children and adolescents is possible but usually is limited to single chamber generators. The natural growth of these patients may require physiological pacing, but until recently two leads were required for this type of pacing. The single pass lead VDD pacing mode makes possible physiological pacing by using only one lead, for both atrial sensing and ventricular sensing and pacing.