[Systemic embolism after reversion to sinusal rhythm of persistent atrial flutter]. / Embolismo sistémico tras reversión a ritmo sinusal del aleteo auricular persistente.

BACKGROUND: The incidence of embolism in atrial flutter has been underestimated in the routine clinical practice. PATIENTS AND METHODS: In this study the incidence of thromboembolic events after restoration of sinus rhythm (by catheter ablation or cardioversion) was compared in two groups of consecutive patients, with a different anticoagulation protocol. A total of 169 patients were evaluated. A first retrospective analysis of 79 non anticoagulated patients (group I). A second prospective group of 90 patients who were treated with an anticoagulation protocol (group II) similar to that for patients with atrial fibrillation. All had typical atrial flutter of at least one month's duration before the procedure. RESULTS: The mean age of patients in group I was 61 12 years and the mean left ventricular ejection fraction was 57 6%. Patients in group II had a mean age of 61 10 years and the mean left ventricular ejection fraction was 56 9%. No differences were observed regarding prevalence of structural cardiopathy, arterial hypertension, diabetes mellitus, left ventricular dysfunction, atrial size or atrial fibrillation between the two groups of patients. Four patients in the retrospective analysis (5%) had an embolic event associated with the procedure, compared with 0 (0%) in the group of patients treated with the anticoagulation protocol. The efficient anticoagulation was associated with a lower risk of thromboembolic events (p < 0.05). CONCLUSIONS: The incidence of embolic events after reversion to sinusal rhythm of persistent atrial flutter can be decreased. These patients should follow the same recommendations of anticoagulation that apply for patients with persistent atrial fibrillation that are going to be reverted to sinus rhythm.

Embolismo sistémico tras reversión a ritmo sinusaldel aleteo auricular persistente / Systemic embolism after reversion to sinusal rhythm of persistent atrial flutter

Pacientes y métodos. En este estudio se compara la incidencia de eventos tromboembólicos después de restaurar el ritmo sinusal (por ablación con catéter o cardioversión) en dos grupos consecutivos de pacientes con un protocolo de anticoagulación diferente. Se evaluaron 169 pacientes. Un primer análisis retrospectivo de 79 pacientes no anticoagulados (grupo I). Un segundo grupo prospectivo de 90 pacientes se trató con un protocolo de anticoagulación (grupo II) similar al de los pacientes con fibrilación auricular. Todos presentaban aleteo auricular típico de al menos un mes de duración antes del procedimiento. Resultados. Grupo I: la edad media fue 61ñ12 años y la fracción de eyección ventricular izquierda media de 57 ñ 6 por ciento. Grupo II: tuvo una edad media 61 ñ 10 años y fracción de eyección ventricular izquierda media de 56 ñ 9 por ciento. No hubo ninguna diferencia en la prevalencia de cardiopatía estructural, hipertensión arterial, diabetes mellitus, disfunción ventricular izquierda, tamaño auricular o fibrilación auricular entre los dos grupos de pacientes. Cuatro pacientes del análisis retrospectivo (5 por ciento) presentaron un episodio embólico asociado con el procedimiento, comparado con 0 (0 por ciento) de los pacientes tratados con un protocolo de anticoagulación. La anticoagulación eficaz se asoció con un menor riesgo de tromboembolismo (p < 0,05). Conclusiones. Es posible reducir la incidencia de eventos embólicos después de la reversión a ritmo sinusal del aleteo auricular persistente. Estos pacientes deben seguir las mismas recomendaciones de anticoagulación que los pacientes con fibrilación auricular persistente que van a ser revertidos a ritmo sinusal (AU)

Manejo diagnóstico del síncope / Diagnostic management of syncope

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Dysfunction of implantable defibrillators caused by slot machines.

The electrogram storage is a feature offered by the last generation of defibrillators, which enables the physician to establish whether the sensed episode and the electrical therapy delivered by the device was appropriate. The incidence of electromagnetic interferences may be higher than initially suspected with the latest generation of defibrillators. Such interference was documented in 4 out of 100 patients over a 24-month period. The electrical interference occurred in all four of them, while they were playing with slot machines. In the RR interval history, irregular QRS sensing of variable frequency was documented in some episodes. The intervals were irregular and nonphysiological satisfying the rate cut-off criteria in an intermittent and nonsustained way. There may be high risk of electromagnetic interference between slot machines and defibrillators. Our experience calls for a warning to all defibrillator patients and, perhaps some regulatory intervention.

[Clinical usefulness of stored electrograms in implantable defibrillators]. / Utilidad clínica del registro de electrogramas del desfibrilador automático.

BACKGROUND AND PURPOSE: The storage of intracavitary electrograms by the automatic implantable defibrillators is one of the latest advantages. The objective of this study was to determine the clinical utility and limitations of electrograms stored by the new generation of defibrillators. MATERIAL AND METHODS: We have implanted at our institution 43 generators with the facility of storing electrograms; 8 Ventak P2, 17 PRxII, and 1 PRxIII from CPI, 14 Jewel, from Medtronic and 3 Guardian ATP 4215, from Telectronics. All were implanted with an endocavitary system lead, an only one patient needed a subcutaneous patch. Mean age was 57 +/- 16 years, 36 were males and 7 women. The mean left ventricular ejection fraction was 44 +/- 23%. The mean follow up was 6 +/- 8 months (limits 1-20 months). RESULTS: We registered and analyzed a total of 268 episodes in 20 patients. Fourteen (82%) received what was considered appropriate therapy. Three patients (from 17 with any treatment delivered by the defibrillator) presented an inappropriate therapy. The parameters, "onset" and "stability", were differentiated in each arrhythmia, the "onset" is useful to differentiate sinus tachycardia, but not atrial fibrillation, from ventricular tachycardia. Programming a stability value between 30-40 mseg eliminates 88% of inappropriate therapies due to atrial fibrillation. In all patients, the identification of the event, facilitated by the stored electrograms, allowed us to resolve the problem. CONCLUSIONS: The programmable features "onset" and "stability" allowed us to eliminate a significant number of inappropriate therapies. The stored electrograms facilitate the identification of the events, leading to treatment by the generator, and were very useful in guiding the clinical management of the patient.

[The pectoral implant of an automatic defibrillator by cardiologists in an electrophysiology laboratory]. / Implante pectoral de desfibrilador automático por cardiólogos en un laboratorio de electrofisiología.

We have performed 2 implantations of transvenous automatic cardioverter defibrillator in a cardiac laboratory devoted to electrophysiology and pacemaker implantation. This is a preliminary experience with a novel implant strategy. Cardiologists were the primary operators. The automatic cardioverter defibrillator were placed in a subcutaneous pectoral region, with a non-thoracotomy lead system. The automatic cardioverter defibrillator were two Medtronic 7219D PCD Jewel, with a Transvene system. There were no perioperative complications. Acceptable defibrillation threshold were obtained in both patients, 12 and 20 J, respectively. Leads were inserted percutaneously through the left subclavian vein. After 8 months of follow-up the patients continue to tolerate the device satisfactorily. Implantation of automatic cardioverter defibrillator systems by trained cardiologists in an electrophysiology laboratory is safe and feasible. Moreover, its cost-effectiveness is superior, the saving includes the surgeons, and the reduction of stay in unit of intensive care and hospitalization.

[Late potentials analysis in patients with malignant ventricular arrhythmia]. / Análise de potenciais tardios em pacientes com arritmias ventriculares malignas.

PURPOSE: To assess the relationship between late potentials and spontaneous ventricular arrhythmias, organic heart disease, inducibility of arrhythmias at electrophysiological study and ejection fraction. METHODS: The population is comprised by 52 patients (41 men, 11 women with mean age 50 +/- 16 years) with spontaneous clinically documented ventricular tachycardia or ventricular fibrillation. An electrophysiological study was performed with conventional programmed stimulation. Within a week of the test a study of late potentials was also performed. RESULTS: Late potentials were documented in 73% of the patients with ventricular tachycardia and only in 17% of the patients with ventricular fibrillation. Sixty-eight percent of the patients with ischemic cardiopathy presented late potentials and in these, ventricular tachycardia was inducible in 93%. Only one from a group of 7 patients with ventricular arrhythmias and no organic heart disease, presented late potentials. In patients with late potentials, 84% have inducible ventricular tachycardia, but only 26% of patients without late potentials have inducible ventricular tachycardia. The incidence of late potentials was inversely correlated with left ventricular ejection fraction. CONCLUSION: The presence of late potentials was more frequent in patients with ventricular tachycardia than in patients with ventricular fibrillation. The presence of late potentials has a sensibility of 81.5% and a specificity of 78% to detect patients with inducible ventricular tachycardia.

[Anti-tachycardia radiofrequency pacemakers. Experience with 44 cases]. / Les pacemakers antitachycardiques à radio-fréquence. Expérience de 44 cas.

Programmed cardiac stimulation may be performed externally using implanted radiofrequency receiving capsules. Between 1979 and 1984, 44 patients underwent implantation of these devices, 12 with atrial leads for supraventricular tachycardias (8 orthodromic reciprocating tachycardias, 1 intranodal junctional tachycardia and 3 atrial tachycardias), and 32 with ventricular leads for ventricular tachycardias. In the first case the transmitter was given to the patients so that they could terminate the tachycardias themselves. In the second case, the transmitter was kept in the cardiology department. All patients were also prescribed prophylactic antiarrhythmic drugs. The radiofrequency method was effective in 11 out of 12 cases of supraventricular tachycardia with a follow-up period ranging from 24 to 65 months (average 45 +/- 11 months). In the ventricular tachycardia group, the device was used in 11 patients to terminate ventricular tachycardia and in all patients to evaluate the efficacy of the antiarrhythmic therapy by provocative programmed stimulation with a follow-up ranging from 2 to 81 month (average 24 +/- 20 months). This palliative therapeutic method has reduced the number of hospital admissions in these patients. The indications are relatively few because of the efficacy of currently available antiarrhythmic agents and the possibility of radical treatment of tachyarrhythmias by surgery or catheter ablation.

[Acut aortic insufficiency caused by rupture of a normal valve during labor]. / Insuficiencia aórtica aguda por rotura de una valvula normal durante el parto

We are presenting a case of a young woman with sudden onset of heart failure and several episodes of syncope, after a prolonged labor. The findings at physical examination suggested the diagnosis of acute aortic insufficiency, that was confirmed by cardiac catheterization. At surgery, the aortic valve showed a round perforation in the non coronary cusp. Pathological examination of the valve showed no significant abnormality. We conclude that the stress of labor was the cause of the rupture of a previously normal aortic valve.