Life-threatening and life-saving inappropriate implantable cardioverter defibrillator shocks

An implantable cardioverter defibrillator (ICD) lead dislodgement into the right atrium is a dangerous situation, particularly in patients in atrial fibrillation because atrial fibrillation can be sensed as ventricular fibrillation and true ventricular fibrillation induced with an inappropriate shock. In the presence of shocks, ICD interrogation should be performed as soon as possible

Rendiment clínic de la prova en taula basculant en l'estudi dels malalts amb síncope. Anàlisi dels resultats amb un nou protocol

Se presentan los resultados de la realización de la prueba en tabla basculante en 177 pacientes con sincopes de causa desconocida y en 18 individuos control, sanos y sin antecedentes sincopales, utilizando un protocolo (protocolo "Vall d'Hebron"), con una inclinación de 75 grados, 30 minutos sin fármacos y 20 minutos adicionales con infusión de isoproterenol. En el grupo de controles sanos, hubo 1 sola respuesta positiva (5,5%), lo que representa una especificidad de la prueba del 94,5%. Los pacientes se dividieron en tres grupos: grupo I, sin cardiopatía y ECG normal (n=135), grupo II, sin cardiopatía y con anomalías en el ECG basal (n=30) y grupo III, con cardiopatía estructural (n=12). La tasa de respuesta fue significativamente mas alta entre los pacientes sin cardiopatía (grupos I y II), 112 (60%), que entre los pacientes portadores de cardiopatía, 3 (25%) (p=0,02). Dentro del grupo I, los pacientes en los que la clínica sincopal había estado precedida de síntomas vegetativos o en relación al ortostatismo, presentaron una tasa de respuestas significativamente mas alta (76,2%) que en los que el sincope había sido brusco (52,4%) (p=0,01). Dentro del grupo II, los pacientes que eran portadores de marcapasos VVI definitivos y recidiva sincopal, presentaron una elevada tasa de respuesta positivas (92%), comparado con los pacientes con trastorno de conducción intraventricular en el ECG (23%) (p=0,0007). Los pacientes en los que la respuesta positiva se presento bajo la infusión de isoproterenol, presentaron una frecuencia cardiaca significativamente mas alta que los pacientes en los que la respuesta se presento sin infusión de isoproterenol. En aquellos pacientes con respuesta cardioinhibidora severa, la implantación de un marcapasos A-V secuencial, no evito la presencia de hipotensión y sincope. Se concluye que el protocolo "Vall d'Hebron", tiene una buena especificidad y sensibilidad, que la tasa de respuestas a la prueba en tabla basculante depende de las características clínicas de los episodios sincopales y de la presencia de cardiopatía subyacente, y que la estimulación bicameral no evita la presencia de respuesta positiva a la prueba en tabla basculante en pacientes con una primera prueba con respuesta cardioinhibidora severa.The results of a new Head Up Tilt Test protocol ("Vall d'Hebron" protocol), performed in 177 patients with syncope of unknown origin and in 18 healthy individuals without previous syncopal episodes (control group) are analyzed. The protocol consisted in a head up tilt inclination of 75º, without drug administration during the initital 30 minutes, followed by intravenous infusion of isoproeterenol. A positive response was observed in only 1 control subject (5.5%), what means a specificity of 94,5%. Patients were classfied in 3 groups: 1) Without structural heart disease and normal ECG (N=135); 2) Without structural heart disease and abnormal ECG (N= 30) and 3) with structural heart disease (N= 12). A positive response was observed in a significant higher proportion of patients of groups 1 and 2 (N =112, [60%]), as comparted with group 3 ( N=3, [25%]), p=0,02). In patients belonging to group 1, the rate of positive responses was significantly higher in those in which syncope was preceded by prodromal symptoms or it was related to orthostatism (76,2%), as compared with those in which syncope was sudden (52,4%), (p=0,01). In patients belonging to group 2, the rate of positive reponses was significantly higher in those that had implanted a permanent pacemaker and who had recurrent syncopal episodes (92%), when compared with those with intraventricular conduction defects (23%), (p=0.0007)In those patients in which the positive response was elicited with isoproterenol infusion, heart rate during the positive response, was signifigicantly higher than in those in which the positive response was elicited in drug free phase.In those patients with a severe cardioinhibitory response during tilt test, sequential atrio ventricular pacing did not prevent the presence of hypotension and syncopeIt can be concluded that "Vall de Hebron" protocol: 1) Has a good specificicty and sensitivity. 2) The rate of positive responses depends on the clinical characteristics of syncopal episodes as well as on the presence or absence of structural heart disease and 3) In patients with a severe cardioinhibitory response at baseline tilt test, sequential atrio-ventricular pacing, does not prevent a positive response to the test

Rendiment clínic de la prova en taula basculant en l'estudi dels malalts amb síncope : análisi dels resultats amb un nou protocol

Consultable des del TDXTítol obtingut de la portada digitalitzadaSe presentan los resultados de la realización de la prueba en tabla basculante en 177 pacientes con sincopes de causa desconocida y en 18 individuos control, sanos y sin antecedentes sincopales, utilizando un protocolo (protocolo "Vall d'Hebron"), con una inclinación de 75 grados, 30 minutos sin fármacos y 20 minutos adicionales con infusión de isoproterenol. En el grupo de controles sanos, hubo 1 sola respuesta positiva (5,5%), lo que representa una especificidad de la prueba del 94,5%. Los pacientes se dividieron en tres grupos: grupo I, sin cardiopatía y ECG normal (n=135), grupo II, sin cardiopatía y con anomalías en el ECG basal (n=30) y grupo III, con cardiopatía estructural (n=12). La tasa de respuesta fue significativamente mas alta entre los pacientes sin cardiopatía (grupos I y II), 112 (60%), que entre los pacientes portadores de cardiopatía, 3 (25%) (p=0,02). Dentro del grupo I, los pacientes en los que la clínica sincopal había estado precedida de síntomas vegetativos o en relación al ortostatismo, presentaron una tasa de respuestas significativamente mas alta (76,2%) que en los que el sincope había sido brusco (52,4%) (p=0,01). Dentro del grupo II, los pacientes que eran portadores de marcapasos VVI definitivos y recidiva sincopal, presentaron una elevada tasa de respuesta positivas (92%), comparado con los pacientes con trastorno de conducción intraventricular en el ECG (23%) (p=0,0007). Los pacientes en los que la respuesta positiva se presento bajo la infusión de isoproterenol, presentaron una frecuencia cardiaca significativamente mas alta que los pacientes en los que la respuesta se presento sin infusión de isoproterenol. En aquellos pacientes con respuesta cardioinhibidora severa, la implantación de un marcapasos A-V secuencial, no evito la presencia de hipotensión y sincope. Se concluye que el protocolo "Vall d'Hebron", tiene una buena especificidad y sensibilidad, que la tasa de respuestas a la prueba en tabla basculante depende de las características clínicas de los episodios sincopales y de la presencia de cardiopatía subyacente, y que la estimulación bicameral no evita la presencia de respuesta positiva a la prueba en tabla basculante en pacientes con una primera prueba con respuesta cardioinhibidora severa.The results of a new Head Up Tilt Test protocol («Vall d'Hebron» protocol), performed in 177 patients with syncope of unknown origin and in 18 healthy individuals without previous syncopal episodes (control group) are analyzed. The protocol consisted in a head up tilt inclination of 75º, without drug administration during the initital 30 minutes, followed by intravenous infusion of isoproeterenol. A positive response was observed in only 1 control subject (5.5%), what means a specificity of 94,5%. Patients were classfied in 3 groups: 1) Without structural heart disease and normal ECG (N=135); 2) Without structural heart disease and abnormal ECG (N= 30) and 3) with structural heart disease (N= 12). A positive response was observed in a significant higher proportion of patients of groups 1 and 2 (N =112, [60%]), as comparted with group 3 ( N=3, [25%]), p=0,02). In patients belonging to group 1, the rate of positive responses was significantly higher in those in which syncope was preceded by prodromal symptoms or it was related to orthostatism (76,2%), as compared with those in which syncope was sudden (52,4%), (p=0,01). In patients belonging to group 2, the rate of positive reponses was significantly higher in those that had implanted a permanent pacemaker and who had recurrent syncopal episodes (92%), when compared with those with intraventricular conduction defects (23%), (p=0.0007) In those patients in which the positive response was elicited with isoproterenol infusion, heart rate during the positive response, was signifigicantly higher than in those in which the positive response was elicited in drug free phase. In those patients with a severe cardioinhibitory response during tilt test, sequential atrio ventricular pacing did not prevent the presence of hypotension and syncope It can be concluded that «Vall de Hebron» protocol: 1) Has a good specificicty and sensitivity. 2) The rate of positive responses depends on the clinical characteristics of syncopal episodes as well as on the presence or absence of structural heart disease and 3) In patients with a severe cardioinhibitory response at baseline tilt test, sequential atrio-ventricular pacing, does not prevent a positive response to the test

Life-threatening and life-saving inappropriate implantable cardioverter defibrillator shocks

An implantable cardioverter defibrillator (ICD) lead dislodgement into the right atrium is a dangerous situation, particularly in patients in atrial fibrillation because atrial fibrillation can be sensed as ventricular fibrillation and true ventricular fibrillation induced with an inappropriate shock. In the presence of shocks, ICD interrogation should be performed as soon as possible

Diagnosis, management, and outcomes of patients with syncope and bundle branch block

Although patients with syncope and bundle branch block (BBB) are at high risk of developing atrio-ventricular block, syncope may be due to other aetiologies. We performed a prospective, observational study of the clinical outcomes of patients with syncope and BBB following a systematic diagnostic approach. Patients with ≥1 syncope in the last 6 months, with QRS duration ≥120 ms, were prospectively studied following a three-phase diagnostic strategy: Phase I, initial evaluation; Phase II, electrophysiological study (EPS); and Phase III, insertion of an implantable loop recorder (ILR). Overall, 323 patients (left ventricular ejection fraction 56 ± 12%) were studied. The aetiological diagnosis was established in 267 (82.7%) patients (102 at initial evaluation, 113 upon EPS, and 52 upon ILR) with the following aetiologies: bradyarrhythmia (202), carotid sinus syndrome (20), ventricular tachycardia (18), neurally mediated (9), orthostatic hypotension (4), drug-induced (3), secondary to cardiopulmonary disease (2), supraventricular tachycardia (1), bradycardia-tachycardia (1), and non-arrhythmic (7). A pacemaker was implanted in 220 (68.1%), an implantable cardioverter defibrillator in 19 (5.8%), and radiofrequency catheter ablation was performed in 3 patients. Twenty patients (6%) had died at an average follow-up of 19.2 ± 8.2 months. In patients with syncope, BBB, and mean left ventricular ejection fraction of 56 ± 12%, a systematic diagnostic approach achieves a high rate of aetiological diagnosis and allows to select specific treatment

Sex-Related Differences in Patients With Unexplained Syncope and Bundle Branch Block : Lower Risk of AV Block and Lesser Need for Cardiac Pacing in Women

To analyze if there are sex-related differences in patients with unexplained syncope and bundle branch block (BBB). Despite increasing awareness that sex is a major determinant of the incidence, etiology, and the outcomes of different arrhythmias, no studies have examined differences in presentation and outcomes between men and women with syncope and BBB. Cohort study of consecutive patients with unexplained syncope and BBB was included from January 2010 to January 2021 with a median follow-up time of 3.4 years [interquartile range (IQR) 1.7-6.0 years]. They were evaluated by a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor (ICM). Of the 443 patients included in the study, 165 (37.2%) were women. Compared with men, women had less diabetes (25.5 vs. 39.9%, p = 0.002) and less history of ischemic heart disease (IHD; 13.3 vs. 25.9%, p = 0.002). Left bundle branch block (LBBB) was more frequent in women (55.2 vs. 27.7%, p < 0.001) while right bundle branch block (RBBB) was more frequent in men (41.5 vs. 67.7%, p < 0.001). His to ventricle (HV) interval in the EPS was shorter in women (58 ms [IQR 52-71] vs. 60 ms [IQR 52-73], p = 0.035) and less women had an HV interval longer than 70 ms (28.5 vs. 38.1%, p = 0.039), however, EPS and ICM offered a similar diagnostic yield in both sexes (40.6 vs. 48.9% and 48.4% vs. 51.1%, respectively). Women had a lower risk of developing atrioventricular block (AVB) (adjusted odds ratio [OR] 0.44-95% CI 0.26-0.74, p = 0.002) and of requiring permanent pacemaker implantation (adjusted hazard ratio [HR] 0.72-95% CI: 0.52-0.99, p = 0.046). The mortality rate was lower in women (4.5 per 100 person-years [95% CI 3.1-6.4 per 100 person-years] vs. 7.3 per 100 person-years [95% CI 5.9-9.1 per 100 person-years]). Compared to men, women with unexplained syncope and BBB have a lower risk of AVB and of requiring cardiac pacing. A stepwise diagnostic approach has a similar diagnostic yield in both sexes, and it seems appropriate to guide the treatment and avoid unnecessary pacemaker implantation, especially in women. Risk of AVB and need for cardiac pacing. Left: Percentage of patients diagnosed with aAVB/sCD in both sexes. Right-top: Multivariate logistic regression analyses for risk of aAVB/sCD. Odds ratio and 95% CI are plotted. Right-bottom: Kaplan-Meier pacemaker-free survival estimates curves in both sexes. aAVB/sCD, advanced atrio-ventricular block or severe conduction disturbances; HR, hazard ratio; CI, confidence interval; y.o, years old; IHD, ischemic heart disease; LVEF, left ventricular ejection fraction; BBB, bundle branch block; LBBB, left bundle branch block; RBBB, right bundle branch block; LAFB, left anterior fascicular block