RESUMEN
Most odorants, in addition to the olfactory system, also activate the intranasal trigeminal system. Recent studies have shown that pure trigeminal stimulation activates somatosensory regions as well as regions traditionally thought of as primary olfactory areas. As a main aim of this study we wished to a) ascertain which brain regions are responsive to an "artificially" bimodal odor composed of a trigeminal (CO(2)) and an olfactory stimulant (phenyl ethyl alcohol, PEA) and b) determine if presenting CO(2) and PEA simultaneously activates different brain regions than when presenting them individually. Fifteen men were scanned using functional magnetic resonance imaging while smelling PEA, CO(2), and a mixture of both stimuli (CO(2)PEA) presented simultaneously. Odors were presented monorhinally to the right nostril in a block design. The contrast between CO(2)PEA and baseline revealed areas implicated in the processing of both olfactory and trigeminal stimuli. When the mixture was contrasted with the sum of its single components (CO(2)PEA-{CO(2)+PEA}), activations in integration centers (left superior temporal and right intraparietal sulcus) and in orbitofrontal areas (left medial and lateral orbitofrontal cortex) were detected. The opposite contrast ({CO(2)+PEA}-CO(2)PEA) did not reveal any significant activation. In contrast to studies which have used natural mixed olfactory/trigeminal stimuli, we have shown that the perception of an artificial mixed olfactory/trigeminal stimulus activates, as opposed to inhibiting the olfactory cortex. Further, we also conclude that a mixed olfactory/trigeminal stimulus appears to lead to higher cortical activations than the sum of its parts.
Asunto(s)
Mapeo Encefálico , Encéfalo/irrigación sanguínea , Imagen por Resonancia Magnética , Vías Olfatorias/irrigación sanguínea , Olfato/fisiología , Adulto , Análisis de Varianza , Encéfalo/fisiología , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Persona de Mediana Edad , Odorantes , Vías Olfatorias/fisiología , Oxígeno/sangre , Estimulación QuímicaRESUMEN
We report an implantation of a cardiac re-synchronization system in a patient with persistent left superior vena cava. This anomaly occurs in 0.3 to 0.5% of healthy individuals and remains usually asymptomatic. Variations of the superior vena cava should be considered in venous catheterization and other procedures such as implantation of pacemaker and ICD systems as well as port catheter insertion. In re-synchronization systems, persistent left superior vena cava can be an obstacle for cannulation of the coronary sinus and placement of a transvenous left ventricular lead.
Asunto(s)
Marcapaso Artificial , Implantación de Prótesis/métodos , Vena Cava Superior/anomalías , Vena Cava Superior/cirugía , Fibrilación Ventricular/etiología , Fibrilación Ventricular/prevención & control , Anciano , Humanos , Masculino , Síndrome de la Vena Cava Superior/complicaciones , Síndrome de la Vena Cava Superior/cirugía , Síndrome de la Vena Cava Superior/terapia , Resultado del TratamientoRESUMEN
OBJECTIVE: Rapid ventricular pacing in dogs results in a low output cardiomyopathic state similar to idiopathic dilated cardiomyopathy in man. Cell death by apoptosis may play an important role in the loss of cardiac function. This study investigates the molecular pathways involved in the regulation of apoptosis in dogs with pacing-induced heart failure. METHODS: Apoptosis was identified by terminal transferase nick end-labelling (TUNEL) in the ventricles and atria of dog hearts affected by rapid-ventricular pacing. Western blots were used to determine expression of the components involved in the initiation (Fas, Fas-Ligand, FADD), regulation (Bcl-2, Bax) and execution (caspase-2 and caspase-3) of apoptosis. RESULTS: Pacing-induced heart failure resulted in a significant increase in the number of ventricular and atrial myocyte nuclei undergoing apoptosis as measured by TUNEL. Compared to the samples from control hearts (n=6) the expression of Bcl-2, an inhibitor of apoptosis, was significantly reduced in ventricles from five dogs with pacing-induced heart failure. No change in the expression of the apoptotic inducer Bax was detected. Fas and FADD were significantly elevated in all paced ventricles, and Fas-L was only detected in the paced hearts. Both caspase-2 and caspase-3 were elevated following ventricular pacing. CONCLUSIONS: We have identified components of the signalling pathways along which apoptosis proceeds following the induction of heart failure in dogs. Apoptosis was also detected in the atria raising the possibility that, like human dilated cardiomyopathy, the molecular changes are global.
Asunto(s)
Apoptosis , Cardiomiopatía Dilatada/patología , Miocardio/patología , Animales , Western Blotting , Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada/etiología , Cardiomiopatía Dilatada/metabolismo , Caspasas/metabolismo , Perros , Femenino , Atrios Cardíacos/patología , Ventrículos Cardíacos/metabolismo , Ventrículos Cardíacos/patología , Etiquetado Corte-Fin in Situ , Masculino , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Receptor fas/metabolismoRESUMEN
The effects of the new antiarrhythmic drug AWD-G256 (1) were investigated by clinical electrophysiology (His bundle electrography, programmed electrical stimulation) in 19 patients with supraventricular tachycardias but without structural heart disease. In a maximal dosage of 0.45 mg/kg body mass 1 only minimally affects electrophysiological parameters of the impulse formation and conduction. At this time the therapeutic value of 1 is not clear.
Asunto(s)
Antiarrítmicos/farmacología , Benzofenonas/farmacología , Hidrazonas/farmacología , Adulto , Antiarrítmicos/uso terapéutico , Benzofenonas/uso terapéutico , Fascículo Atrioventricular/efectos de los fármacos , Fascículo Atrioventricular/fisiología , Estimulación Eléctrica , Electrofisiología , Sistema de Conducción Cardíaco/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Humanos , Hidrazonas/uso terapéutico , Masculino , Persona de Mediana Edad , Células de Purkinje/efectos de los fármacos , Nodo Sinoatrial/efectos de los fármacos , Taquicardia Supraventricular/tratamiento farmacológico , Taquicardia Supraventricular/fisiopatologíaRESUMEN
Heart failure and atrial fibrillation often coexist, especially with increasing degree of heart failure severity. Under this constellation, the advantage of cardiac resynchronization therapy (CRT) is still under discussion and displayed as an unresolved problem in the guidelines for cardiac stimulation and resynchronization. If ventricular desynchronization can be documented and response to CRT can be expected, the challenge is to interoperatively seek the best left ventricular electrode position and to postoperatively optimize the device in order to achieve the best therapy performance. This situation encourages the development of individualized methods and to utilize innovative apparatus features in order to consolidate individual decisions and to optimize CRT in heart failure with atrial fibrillation.
Asunto(s)
Fibrilación Atrial/prevención & control , Estimulación Cardíaca Artificial/métodos , Técnicas de Apoyo para la Decisión , Análisis de Falla de Equipo/métodos , Insuficiencia Cardíaca/prevención & control , Marcapaso Artificial , Evaluación de la Tecnología Biomédica/métodos , Algoritmos , Fibrilación Atrial/complicaciones , Insuficiencia Cardíaca/complicaciones , HumanosRESUMEN
A new balloon electrode catheter (10 French) with five or six balloon electrodes placed on the cardiac side was developed for transesophageal atrial pacing and bipolar ECG recording. The diameter of the hemispheric electrodes is 6 mm and the length of the esophageal balloon is 10 cm. The transesophageal atrial pacing threshold was measured with the balloon electrode catheter by transesophageal programmed atrial stimulation (TPS) (n = 54). At the onset of TPS, the feeling, capture (n = 54), and pain voltage threshold (n = 6) were measured by increasing the amplitude of the pacing voltage during high rate bipolar atrial pacing and bipolar atrial ECG recording. In 38 TPS, the capture threshold was lower than the feeling threshold (n = 28). In 16 TPS, the capture threshold was higher than the feeling threshold. In conclusion, painless atrial pacing and excellent ECG recording can be achieved with a multipolar esophageal balloon electrode catheter with a low pacing voltage amplitude and a high P wave amplitude.
Asunto(s)
Estimulación Cardíaca Artificial/métodos , Cateterismo/instrumentación , Electrocardiografía/métodos , Marcapaso Artificial , Electrodos , Diseño de Equipo , Atrios Cardíacos , HumanosRESUMEN
To evaluate the therapeutic significance of noninvasive transesophageal pacing for termination of tachycardias the method of rapid atrial or ventricular transesophageal pacing was used in 233 patients with different tachycardiac arrhythmias. We were able to terminate atrial flutter in 136 of 162 patients by transesophageal rapid atrial stimulation (conversion to sinus rhythm in 75 cases, induction of atrial fibrillation in 61 cases). Atrial tachycardias were interrupted in 17 of 23 patients (sinus rhythm in 11 cases, atrial fibrillation in six cases). AV reciprocating/AV nodal supraventricular reentry tachycardias were terminated in 62 of 63 patients (sinus rhythm in 58 cases, atrial fibrillation in four cases). By transesophageal rapid ventricular pacing ventricular tachycardias could be terminated in ten of 15 patients. The success rate of transesophageal pacing was influenced by the pacing rate, by the type of tachycardiac arrhythmia inclusive by the type of atrial flutter and by the tachycardia's cycle length. Because the success rates are comparable with invasive technique and the procedure is simpler, the noninvasive transesophageal antitachycardiac pacing should be respected as the method of the first choice in patients with supraventricular tachycardias.
Asunto(s)
Aleteo Atrial/terapia , Estimulación Cardíaca Artificial/métodos , Marcapaso Artificial , Taquicardia por Reentrada en el Nodo Atrioventricular/terapia , Taquicardia Ventricular/terapia , Cateterismo/instrumentación , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Recurrent episodes of ventricular tachycardia not responding to medical treatment occurred in a 56-year-old man. Electrophysiological investigation showed ventricular tachycardia due to bundle branch reentry. Using a method similar to catheter ablation of the atrioventricular junction, ablation of the right bundle branch was performed by an electrical shock of 250 joules. While before the ablation ventricular tachycardia occurred several times a day and its induction by programmed ventricular stimulation was facilitated by the administration of antiarrhythmic drugs, no initiation of ventricular tachycardia was possible after ablation of the right bundle branch. Over a follow-up of 30 months the patient has not suffered from tachycardia and the right bundle branch block persists.
Asunto(s)
Fascículo Atrioventricular/cirugía , Electrocoagulación , Sistema de Conducción Cardíaco/cirugía , Taquicardia/cirugía , Electrocardiografía , Electrofisiología , Humanos , Masculino , Persona de Mediana Edad , Taquicardia/complicaciones , Taquicardia/fisiopatologíaRESUMEN
We were able to terminate atrial flutter in 136 of 162 patients by transesophageal rapid atrial stimulation (conversion to sinus rhythm in 75 cases, induction of atrial fibrillation in 61 cases). Atrial tachycardias were interrupted in 17 of 23 patients (sinus rhythm in 11, atrial fibrillation in 6 cases), AV reciprocating resp. AV nodal supraventricular tachycardias were terminated in 32 of 33 patients (sinus rhythm in 28 cases, atrial fibrillation in 4 cases). By transesophageal rapid ventricular and/or atrial pacing, ventricular tachycardias could be terminated in 10 of 15 patients. The success rate of transesophageal pacing is influenced by the type of tachyarrhythmia, by the type of atrial flutter and by the stimulation rate. It is not influenced by the tachycardia's cycle length. Because the success rates are comparable with invasive technique and the procedure is simpler, the non-invasive transesophageal antitachycardia pacing represents a useful method for termination of tachycardic arrhythmias.
Asunto(s)
Cardioversión Eléctrica/instrumentación , Taquicardia/terapia , Adulto , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/fisiopatología , Fibrilación Atrial/terapia , Aleteo Atrial/fisiopatología , Aleteo Atrial/terapia , Nodo Atrioventricular/fisiopatología , Electrocardiografía Ambulatoria/instrumentación , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Taquicardia/fisiopatología , Taquicardia Supraventricular/fisiopatología , Taquicardia Supraventricular/terapiaRESUMEN
In a 46-year-old patient with dilatative cardiomyopathy and medicamentously therapy-resistant focal ventricular tachycardias after endocardial right- and left-ventricular catheter mapping a transvasal electric ablation of the focus of tachycardia was carried out. For this purpose at the left-ventricular-septally localized origin of tachycardia two electroshocks of 100 and 200 J via the electrode catheter positioned there was given. Immediately after ablation a stable sinus rhythm was to be registered; longer persisting recidivations of tachycardia did not appear again subsequently. In the further course the patient suddenly died after transitory haemodynamic improvement, in which case a new, acutely beginning arrhythmia is to be assumed as a prefinal event.
Asunto(s)
Cateterismo Cardíaco , Electrocardiografía , Electrocoagulación , Tabiques Cardíacos/cirugía , Ventrículos Cardíacos/cirugía , Taquicardia Paroxística/cirugía , Complejos Cardíacos Prematuros/fisiopatología , Estimulación Cardíaca Artificial , Cardiomiopatía Hipertrófica/fisiopatología , Tabiques Cardíacos/fisiopatología , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/fisiopatología , Procesamiento de Señales Asistido por Computador , Taquicardia Paroxística/fisiopatologíaRESUMEN
To evaluate the influence of transesophageal atrial pacing of the transthoracic His potential identification, we combined signal-averaged ECG with transesophageal atrial pacing with low threshold for pacing averaging ECG recording. A tripolar 10 French esophageal balloon electrode catheter, with one cylindrical electrode on the tip of the catheter and two balloon electrodes on the cardiac side of the catheter, used in 53 patients, allowed a painless transesophageal atrial pacing and a high signal to noise distance in the signal-averaged ECG. Transesophageal atrial pacing allowed in 37 of 53 patients an identification of His potential by increasing the distance between the end of the atrial potential and the onset of the His potential in the pacing averaging ECG. The esophageal balloon electrode catheter allowed a painless transesophageal atrial pacing with low threshold for atrial capture during a long pacing time and a high signal to noise distance in the pacing averaging ECG. The increasing of the heart rate with transesophageal atrial pacing allowed the transthoracic identification of the His potential in the pacing averaging ECG.
Asunto(s)
Fascículo Atrioventricular/fisiología , Estimulación Cardíaca Artificial , Electrocardiografía/instrumentación , Función Atrial , Estimulación Cardíaca Artificial/métodos , Electrocardiografía/métodos , HumanosRESUMEN
In 6 patients with medicamentously therapy-refractory tachycardias (3 times auricular flutter/auricular fibrillation with very rapid atrioventricular conduction, once focal atrial tachycardia, once paroxysmal atrioventricular reentry tachycardia, once recurrent ventricular tachycardia on the basis of an interventricular reentry) percutaneous transvenous catheter ablations of the atrioventricular conduction region (bundle of His ablation, 5 cases) and the right Tawara branch (1 case), respectively, were performed. During a follow-up period of 2-26 months (on an average 10.5 +/- 8.0 months) a permanent total block in 4 cases could be obtained (3 times AV-block III. once complete right bundle branch block). In two other patients the total AV block receded to the AV block I. and II. respectively, within 2 and 8 days, respectively; in the first case the AV node reentry tachycardias were no more to be evoked, in the second case a tolerable ventricular frequency was the result during the auricular flutter recidivations. In all patients treated by means of catheter ablation after the intervention an impressive improvement of the clinical symptomatology developed. Due to possible complication and the dependence upon the pacemaker of the patients concerned which is to be expected the indication to the ablation should be made only after the exhaustion of all medicamentous possibilities and taking into consideration other electric therapy methods.
Asunto(s)
Fascículo Atrioventricular/cirugía , Electrocirugia , Sistema de Conducción Cardíaco/cirugía , Taquicardia/cirugía , Adulto , Fibrilación Atrial/cirugía , Aleteo Atrial/cirugía , Cateterismo Cardíaco , Electrocardiografía , Femenino , Bloqueo Cardíaco/terapia , Humanos , Masculino , Persona de Mediana Edad , Marcapaso Artificial , Complicaciones Posoperatorias/terapia , Recurrencia , Taquicardia por Reentrada en el Nodo Atrioventricular/cirugíaRESUMEN
Recurrent episodes of ventricular tachycardia not responding to medical treatment occurred in a 56 year old man. Electrophysiological investigation showed ventricular tachycardia due to bundle branch reentry. Using a method similar to catheter ablation of the atrioventricular junction an ablation of the right bundle branch was performed by an electrical shock of 250 J. While before the ablation ventricular tachycardia occurred several times a day, and its induction by programmed ventricular stimulation was facilitated by the administration of antiarrhythmic drugs, no initiation of ventricular tachycardia was possible after ablation of the right bundle branch. Over a follow-up of 4 weeks the patient has not suffered from tachycardia and the artificial right bundle branch block persists.
Asunto(s)
Fascículo Atrioventricular/cirugía , Electrocoagulación/métodos , Sistema de Conducción Cardíaco/cirugía , Taquicardia/cirugía , Estimulación Cardíaca Artificial , Electrocardiografía , Femenino , Vena Femoral , Humanos , Persona de Mediana Edad , Taquicardia por Reentrada en el Nodo Atrioventricular/cirugía , Taquicardia Paroxística/cirugíaRESUMEN
With the noninvasive registration of late ventricular potentials there is the possibility to obtain statements about a regionally delayed excitation of ventricular parts which may refer to an increased inclination to ventricular tachyarrhythmias. Late ventricular potentials in patients with suspicion of primary diseases of the myocardium more frequently appeared both in the case of inducible non-sustained or sustained ventricular tachycardias and in the presence of simultaneous fibrous hypertrophy of the myocardium and interstitial fibrosis in the bioptate of the myocardium than in noninducibility of ventricular tachycardias and in the absence of histological changes of the myocardium. Thus in patients with cardiomyopathies a certain predicting significance seems to be ascribed to the evidence of late potentials in the highly increased signal-averaged ECG both for the ability to evoke ventricular tachycardias by programmed ventricular stimulation and for the presence of more distinct histological changes of the myocardium.
Asunto(s)
Cardiomiopatías/diagnóstico , Electrocardiografía , Miocardio/patología , Adulto , Biopsia , Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada/diagnóstico , Electrocardiografía/instrumentación , Femenino , Humanos , Masculino , Microcomputadores , Persona de Mediana Edad , Procesamiento de Señales Asistido por Computador , Taquicardia/diagnósticoRESUMEN
The electrophysiologic effects and antiarrhythmic efficacy of tiracizine, a new class I antiarrhythmic drug, were studied in 16 patients with documented sustained ventricular tachycardia (VT) after intravenous drug application and in 6 patients after oral drug administration by means of programmed ventricular stimulation (PVS). After intravenous tiracizine (0.3 mg/kg) the VT was no longer inducible by PVS in 3 of 16 patients and became nonsustained in another patient. In 11 of 13 patients with further inducible VT the cycle duration of VT increased after tiracizine (mean 29 ms). After oral tiracizine (150-225 mg/day) the VT induction was suppressed in one patient. In a second patient the VT became nonsustained. Cycle length of VT in 4 patients with persistent induction of VT was longer after therapy (mean 88 ms). Antiarrhythmic efficacy of intravenous or oral tiracizine can be expected in at least one third of patients with VT.
Asunto(s)
Antiarrítmicos/uso terapéutico , Dibenzazepinas/uso terapéutico , Taquicardia/tratamiento farmacológico , Administración Oral , Adulto , Anciano , Dibenzazepinas/administración & dosificación , Dibenzazepinas/farmacología , Estimulación Eléctrica , Electrocardiografía , Femenino , Sistema de Conducción Cardíaco/efectos de los fármacos , Ventrículos Cardíacos/efectos de los fármacos , Humanos , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Taquicardia/fisiopatologíaRESUMEN
UNLABELLED: A high specificity and a high positive prediction has been reached in risk stratification for a sudden cardiac death after acute myocardial infarction (AMI) by combining multiple methods. But sensitivity and negative prediction are still not satisfying. There are the same physiological processes underlying magnetocardiography (MCG) and electrocardiography (ECG). Nevertheless, the signals in each method contain different information. METHODS: We studied the cardiac magnetic fields in 50 patients after AMI and in 32 probands and calculated the magnetic late field (LF), according to Simsons late potential (LP) analysis. We defined normal values, according to the 95% confidence interval of the probands (QRS < =97 ms, RMS > = 0. 6, LAS < 25 ms). RESULTS: We compared the results of LF and LP analysis regarding pathologic-nonpathologic and found 76% of the patients with the same results in both methods. Four patients had magnetic signals with low amplitude in the ST segment in contrast to the ECG result, while 6 patients with a "LP positive" diagnosis based on RMS and LAS only, did not show LF. In addition, we have found the magnetic QRS complex to be shorter than the electrical one. DISCUSSION: In general, the results of LF measurement are similar to the ones of LP measurement. Presumably, there are intracardial currents, which are not detectable by ECG. Further studies are needed to evaluate the prognostic value in patients at high risk for cardiac arrhythmias.