Mitral valve myxoma: a case of mistaken identity.

A case of a rare mitral valve myxoma is reported in a 61-year-old gentleman who presented with recurrent embolic events. The mass was initially diagnosed as thrombus on cardiac MRI, but was later confirmed to be myxomatous in origin, at surgery, and histological examination.

Permanent left atrial pacing: a 2-year follow-up of coronary sinus leads.

Left atrial pacing is feasible via the coronary sinus. However, long-term characteristics of coronary sinus pacing parameters are largely undefined as yet. This study assessed the feasibility and long-term pacing parameters of coronary sinus pacing. Twenty four patients (13 men, 11 women) with a history of paroxysmal AF refractory to drug therapy underwent biatrial pacemaker implantation. Leads were sited in the high right atrium or right atrial appendage and in either proximal (PCS) or distal coronary sinus (DCS). Pacemaker parameters were measured at implant, 24 hours postimplant, 1 month, 3 months, and at 3 monthly intervals over a period of 2 years. Threshold, impedance, and energy requirements (E = Threshold2/impedance x pulse width) were measured. There was one lead displacement from the PCS within 24 hours postimplant. There were no other acute or chronic complications. The energy values at implant and at 2 years were 0.49 +/- 0.47 and 2.18 +/- 1.69 mJ for the PCS leads and 0.94 +/- 1.47 and 1.27 +/- 0.75 mJ for the DCS leads. P values were >0.05 at all points and suggested no significant difference between the two sites over the long-term. Chronic coronary sinus pacing is a safe and feasible technique. There was no significant difference in energy parameters for leads positioned in the proximal or distal coronary sites. The trends seen at both sites for chronic changes in pacing characteristics are analogous to those described for endocardial leads at other sites.

Biatrial pacing for paroxysmal atrial fibrillation: a randomized prospective study into the suppression of paroxysmal atrial fibrillation using biatrial pacing.

OBJECTIVES: The purpose of this study was twofold: to assess whether biatrial pacing is superior to single-site pacing and capable of reducing the frequency of episodes of paroxysmal atrial fibrillation (PAF); and to compare pacing of the proximal coronary sinus (PCS) with the distal coronary sinus (DCS) and the effects of sequential or simultaneous biatrial pacing. BACKGROUND: Interatrial conduction abnormalities have a role in the initiation of PAF. Biatrial pacing alters the site and timing of atrial depolarization and may benefit those with drug-resistant PAF. METHODS: Nineteen patients with PAF who were intolerant of or refractory to medication were studied. All received right atrial (RA) and coronary sinus (CS) leads (either PCS or DCS). For three months the pacemaker was set in sensing mode only. Subsequently each patient completed three-month periods in random order in the following modes: RA pacing, CS pacing, biatrial pacing using inter-atrial delays of 15 and 70 ms. RESULTS: Sixteen patients received a benefit from one or more pacing modes. The greatest reduction in PAF episodes was seen during biatrial pacing, especially with leads sited at the high right atrium (HRA) and distal CS (p = 0.0048). There was no difference for sequential or simultaneous pacing. Three patients derived no benefit. CONCLUSIONS: In selected patients, biatrial pacing causes a significant decrease in atrial fibrillation episodes. Optimal lead sites were at the HRA and DCS. Simultaneous pacing conferred no benefit over sequential pacing.

Reversion and maintenance of sinus rhythm in patients with permanent atrial fibrillation by internal cardioversion followed by biatrial pacing.

Patients in atrialfibrillation (AF) who fail external cardioversion are usually regarded as in permanent AF. Internal cardioversion may revert many such patients into sinus rhythm (SR) but the majority relapse rapidly into AF. We investigated whether internal cardioversion followed by biatrial pacing is an effective to restore and subsequently maintain SR in patients with permanent AF. Patients in permanent AF underwent internal cardioversion that was followed by biatrial temporary pacing for 48 hours. Those who remained in SR received a permanent biatrial pacemaker programmed to a rate responsive mode with a lower rate 90 beats/min. Primary end point of the study included maintenance in SR 3 months after internal cardioversion. Sixteen patients (14 men, 57 +/- 11 years) were cardioverted. The median duration of AF was 24 months (quartiles, Q1 = 8.5 and Q3 = 102) and mean left atrium diameter was 48 +/- 04 mm. A permanent biatrial pacemaker was implanted in 11 patients. At a mean fallow-up of 15 months (range 4 to 24), 8 patients remained in SR for more than 3 months. AF was eliminated in 5 patients, while in two a second internal cardioversion on amiodarone was required. Antiarrhythmic therapy was used in half of our population and did not predict the long-term maintenance of SR. Following internal cardioversion with continuous biatrial pacing, 50% of patients with permanent AF were maintained for prolonged periods in SR. This is a new modality of treatment of permanent AF directed to the maintenance of SR that provides a further therapeutic option in end-stage AF.