An innovative application of anatomic electromagnetic voltage mapping in a patient with Ebstein's anomaly undergoing permanent pacemaker implantation.

A novel application of the Biosense CARTO System anatomic electromagnetic voltage mapping is presented, utilized as a guide for permanent pacemaker placement. The technique is illustrated in the successful implantation of an atrial lead in a patient with Ebstein's anomaly characterized by a severely dilated right atrium and extremely low-amplitude voltage signals, requiring a DDD pacemaker. Electromagnetic voltage mapping can be used in selected patients with structural heart disease to determine the optimal site for permanent pacemaker lead placement.

Muscarinic receptor stimulation with edrophonium hydrochloride does not elevate ventricular fibrillation thresholds in humans.

INTRODUCTION: Although decreased vagal tone, as measured by heart rate variability is a risk factor for ventricular fibrillation (VF) and sudden cardiac death, it is unknown whether increasing vagal tone has an antiarrhythmic effect. The purpose of this study was to determine whether edrophonium hydrochloride (HCI), a vagomimetic agent, increases VF threshold. METHODS AND RESULTS: Twenty-eight consecutive patients with previously implanted defibrillators had two inductions of VF by monophasic direct-current shocks delivered at 10 to 30 msec after the T wave peak, escalating energies (0.4, 1, then 3 J) until VF was induced. If VF was not induced, this protocol was repeated at the T wave peak and then at 10 to 30 msec before the T wave until VF was induced. Patients were randomized to receive edrophonium HCl (12 to 18 mg) or no drug before repeating the protocol for the second VF induction. The mean sinus cycle length increased from 782 to 872 msec in the group receiving edrophonium HCI (P = 0.006 ). In the control group, the mean sinus cycle length remained unchanged (838 vs 858 msec). The mean energy to induce VF, coupling interval relative to the T wave, and the number of attempts to induce VF were not different between VF induction attempts 1 and 2, and they were not different between the group receiving edrophonium HCl and the control group. CONCLUSION: In a sedated patient population with implantable defibrillators, edrophonium HCI infusion prolongs sinus cycle length but does not change inducibility of VF using T wave shocks.

Analysis of charges and complications of permanent pacemaker implantation in the cardiac catheterization laboratory versus the operating room.

During the last two decades, an increasing number of permanent pacemakers have been implanted outside of the operating room (OR) by nonsurgeons. Previous investigators have demonstrated that pacemakers can be safely implanted in the cardiac catheterization laboratory with no increase in complications or infections. This is the first study of its kind to simultaneously evaluate cost, length of hospitalization, and complications between pacemakers implanted in the OR by surgeons with those implanted in the catheterization laboratory by an electrophysiologist. A total of 254 consecutive pacemaker implants were analyzed over a 2-year period. The OR group consisted of 122 patients with a mean age of 64 +/- 21 years versus 132 patients in the catheterization laboratory group with a mean age of 65 +/- 17 years. The indication and type of pacemaker implanted were similar among both groups with 78% of OR patients and 73% of catheterization laboratory patients receiving dual chamber devices. The average cost for pacemaker implantation in our study was significantly higher in the OR group $5,464 +/- $1,670 versus $2,682 +/- $8 for the catheterization laboratory group (P < 0.001). There was a reduction in preimplant days in the catheterization laboratory group 3.16 +/- 12.40 days versus 5.65 +/- 9.54 days in the OR group (P < 0.05). Complications were minimal and there were no significant differences between the two groups. This study confirms that pacemakers can be safely implanted in the catheterization laboratory by nonsurgeons with no increase in complications and a significant reduction in hospital costs.

Identificaçäo da via lenta na reentrada nodal atrioventricular usando o intervalo atrioventricular mais curto / Slow pathway identification in AV nodal reentry using shortest atrioventricular interval

Em 10 pacientes consecutivos, realizou-se o mapeamento da parede septal do átrio direito durante taquicardia supraventricular por reentrada nodal AV, para comprovar a hipótese de que o intervalo AV mais curto identificava a área de conduçäo da via lenta. O septo atrial foi dividido em quatro zonas distintas. Em sete dos pacientes o intervalo AV anterógrado mais curto foi encontrado na zona 3; em dois, na zona 4; no último, na zona 2. A modificaçäo por radiofreqüência da via lenta foi obtida com sucesso, em todos os pacientes, na área de conduçäo AV mais curta. O intervalo AV durante ritmo sinusal permaneceu inalterado antes e após a ablaçäo. Após um seguimento de 21ñ4 meses, nenhum deles teve recorrência dos sintomas.