Search results for "Cardiac Pacing"

Effectiveness of theophylline to increase cyclic AMP levels and force of contraction in electrically paced guinea-pig auricles. Comparison with isopr…

1977

The effects of theophylline (3×10−5 M–5×10−3 M), isoprenaline (10−6 M), excess calcium (7.2 mM) and ouabain (3×10−7 M) on force of contraction and c-AMP content were studied in electrically driven (frequency 3 Hz) left auricles isolated from guinea pigs pretreated with reserpine.

5-Year Outcome of Pulmonary Vein Isolation by Loss of Pace Capture on the Ablation Line Versus Electrical Circumferential Pulmonary Vein Isolation

2017

This study sought to compare long-term arrhythmia-free survival between electrical circumferential pulmonary vein isolation (PVI) and PVI with the endpoint of unexcitability along the ablation line.PVI is the standard ablation strategy of paroxysmal atrial fibrillation, although arrhythmia recurrence in long-term follow-up (FU) is high. The endpoint of unexcitability along the ablation line results in decreased arrhythmia recurrence compared to electrical PVI in 1-year FU.Seventy-four consecutive patients (age 62.5 ± 10.6 years; 70.3% male) with de novo paroxysmal atrial fibrillation who were initially included in our randomized trial and underwent catheter ablation at our institution were …

Invited commentary.

2007

Low-energy epicardial pacing in children: the benefit of autocapture.

1999

Abstract Background . Permanent cardiac pacing in children results commonly in augmented energy consumption because of the high pacing rates and the ample stimulation safety margin applied in children. Cardiovascular anatomy and limited venous access sometimes preclude the otherwise preferred endocardial approach. In this multicenter patient series, we studied the feasibility, safety, and energy saving obtained by a combination of steroid-eluting epicardial leads with autocapture devices capable of ongoing adjustment of the stimulation output to the prevailing threshold. Methods . Autocapture devices (Pacesetter Microny SR+ and Regency SR+; Pacesetter, Solna, Sweden) and steroid-eluting epi…

Device Therapy for Rate Control: Pacing, Resynchronisation and AV Node Ablation

2017

Atrioventricular node ablation (AVNA) is generally reserved for patients whose atrial fibrillation (AF) is refractory all other therapeutic options, since the recipients will often become pacemaker dependent. In such patients, this approach may prove particularly useful, especially if a tachycardia-induced cardiomyopathy is suspected. Historically, an "ablate and pace" approach has involved AVNA and right ventricular pacing, with or without an atrial lead. There is also an evolving role for atrioventricular node ablation in patients with AF who require cardiac resynchronisation therapy for treatment of systolic heart failure. A mortality benefit over pharmacotherapy has been demonstrated in…

Ventricular paired pacing to control intractable junctional tachycardia following open heart surgery in a child.

1989

A 5-month-old girl presented postoperatively with an atrioventricular (A-V) junctional tachycardia at a rate of 245/min following surgical repair of tetralogy of Fallot. The systolic blood pressure dropped to 60 mmHg with this rapid heart rate, and the infant became shocked. Drugs and overdrive pacing were ineffective in suppressing the A-V junctional tachycardia and in improving cardiac output. Ventricular paired pacing was used successfully to halve the mechanically effective ventricular rate and to restore cardiac output. When ventricular paired pacing was stopped after 12 h, the spontaneous rhythm was an atrial rhythm with 1-1 A-V conduction. The patient was discharged in sinus rhythm o…

Dofetilide effects on the inhibition by trains of subthreshold conditioning stimuli.

2004

We investigated the electrophysiological actions of dofetilide upon the ventricular myocardium to determine whether the drug modifies the inhibitory effects of subthreshold stimuli trains upon ventricular refractoriness. In nine Langendorff perfused rabbit hearts, ventricular epicardial electrodes were used to determine the following parameters at baseline and during dofetilide perfusion (0.5 micromolar): effective (ERP) and functional (FRP) refractory periods, conduction velocity (CV), wavelength (WL), and ERP prolongation (inhibitory effect) induced by subthreshold stimuli trains (STr) at pulse frequencies of 100, 300, and 600 Hz. Dofetilide significantly prolongs ventricular refractorine…

The Role of Cardiac Pacing in Heart Block Complicating Acute Myocardial Infarction

1983

The organization of the Coronary Care Unit and the use of electrocardiographic monitoring have allowed a re-evaluation of the incidence of the atrioventricular conduction disturbances in acute myocardial infarction.

Are double potentials markers of a specific zone of the atrioventricular junction in the isolated rabbit heart?

1997

A study is made of the characteristics of the atrial potentials recorded in the Koch triangle and its proximity, their variations on modifying the site of cardiac pacing, and their usefulness as markers of a distinct zone of the AV junction. In 12 isolated and perfused rabbit heart preparations an analysis was made of the endocardial atrial electrograms recorded with a multiple electrode positioned in the AV junction. The electrograms were obtained during spontaneous rhythm and on pacing at the crista terminalis (CT), interatrial septum (IAS), left atrium, and right ventricle. Double potentials were frequently obtained. On pacing at the CT, high-low double potentials (DP [H-L]) were more fr…

Subclinical atrial fibrillation: how hard should we look?

2012

More than three decades ago, an analysis from the Framingham Heart Study revealed that atrial fibrillation (AF) increases the risk of stroke by a factor of five in non-rheumatic AF and by a factor of 17 in rheumatic AF.1 Since then, it has convincingly been shown that anticoagulation is one of the most effective secondary stroke prophylactic treatment options, which reduces the risk of stroke by 2/3,2 even in an older population.3 AF may occur in different types and in an individual patient often starts with paroxysmal AF, but later becomes persistent or permanent AF.4 Interestingly, the risk of stroke or systemic embolism is influenced by cardiovascular risk factors such as hypertension, d…