Jacob Atié

Atrial-oesophageal fistula following percutaneous radiofrequency catheter ablation of atrial fibrillation: the risk still persists

Aims Atrial‐oesophageal fistula is a serious complication related to ablation of atrial fibrillation. As its occurrence is rare, there is a great lack of information about their mechanisms, incidence, presentations, and treatment. The objective of this manuscript is to present a series of cases of atrial‐oesophageal fistula in Brazil, focusing on incidence, clinical presentation, and follow‐up. Methods and results This is a retrospective multicentre registry of atrial‐oesophageal fistula cases that occurred in eight Brazilian centres from 2003 to 2015. Ten cases (0.113%) of atrial‐oesophageal fistula were reported in 8863 ablation procedures in the period. Most of the subjects were male (70%) with age 59.6 ± 9.3 years. Eight centres were reference units in atrial fibrillation ablation with an experience over than 200 procedures at the time of fistula occurrence. Oesophageal temperature monitoring was performed in eight cases using coated sensors in six. The first atrial‐oesophageal fistula clinical manifestation was typically fever (in six patients), with a median onset time of 16.5 (12‐43) days after ablation. There was a delay of 7.8 ± 3.3 days between the first manifestation and the diagnosis in five patients. The treatment was surgical in six cases, clinical in three and stenting in one. Seven patients died (70%) and two developed permanent neurological sequelae. Conclusion Atrial‐oesophageal fistula remains a serious complication following AF ablation despite the incorporation of protective measures and increased technical experience of the groups. The high morbidity and mortality despite the treatment indicates the need to develop adequate preventive strategies.

Estudo prospectivo das repercussões de baixas doses de remifentanil na função sinoatrial e na condução e refratariedade cardíaca

BACKGROUND AND OBJECTIVESnRemifentanil is an opiod with fast onset of action and short acting, and its use in short-duration procedures has increased in the last few years. Bradycardia and asystole are among the side effects reported. The objective of this study was to evaluate the effects of this drug in cardiac conduction and refractory period in human beings.nnnMETHODSnA prospective study with 16 patients, ages 18 to 65, both genders, ASA I to III, undergoing elective intracardiac electrophysiological study, was undertaken. Patients with disorders of the sinoatrial node and those with severe cardiac blocks were excluded. In the laboratory of electrophysiology, patients were sedated with midazolam (0.03 mg.kg-1) after 5 minutes the degree of sedation and degree of pain, systolic and diastolic blood pressure, heart rate and respiratory rate, and oxygen saturation were evaluated. The electrophysiologist evaluated cardiac conduction (duration of the QRS complex, and AA, AH, HV, and PA intervals), duration of sinoatrial node recovery, and cardiac refractory period (refractory period of the right atrium, right ventricle, and atrioventricular node). After the initial measurements, remifentanil was administered (bolus of 0.5 microg.kg-1 + infusion of 0.05 microg.kg-1.min-1) and, after 20 minutes, the same parameters were evaluated.nnnRESULTSnThere was a reduction in systolic and diastolic blood pressure (p = 0.0001) between M0 and M1, and significant differences in respiratory rate and oxygen saturation, which were not statistically significant. The atrium-His interval (p = 0.006), recovery time of the sinoatrial node (p = 0.0004), refractory period of the right atrium (p = 0.001), and refractory period of the sinoatrial node (p = 0.0001) were all increased; however, there were no differences in heart rate between M0 and M1.nnnCONCLUSIONSnRemifentanil changes cardiac electrophysiological parameters and, in doses higher than the ones used in this study, can cause sinus bradycardia, asystole, and conduction defects.JUSTIFICATIVA Y OBJETIVOS: El remifentanil es un opioide con inicio y fin de accion rapidos, cuyo uso en procedimientos de corta duracion se ha venido propagando en los ultimos anos. Entre los efectos colaterales descritos, hay relatos de bradicardia y asistolia. El objetivo de este estudio fue evaluar los efectos de este farmaco en la conduccion y refractariedad cardiaca, en humanos. METODO: Estudio prospectivo de 16 pacientes, entre 18 y 65 anos, de ambos sexos, ASA I a III, que se sometieron a estudio electrofisiologico intra cardiaco electivo. Se excluyeron pacientes con enfermedades del nodulo sino-atrial y los portadores de bloqueos cardiacos graves. En el laboratorio de electrofisiologia, los pacientes fueron inicialmente sedados con midazolam (0,03 mg.kg-1), 5 minutos despues (M0) se evaluo el grado de sedacion e intensidad de dolor, presiones arteriales sistolica y diastolica, frecuencias cardiaca y respiratoria y saturacion de oxigeno. El electrofisiologista evaluo las variables de conduccion cardiaca (duracion del QRS, intervalos AA, AH, HV y PA), el tiempo de recuperacion del nodulo sino-atrial y las variables de refractariedad cardiaca (periodo refractario del atrio derecho, periodo refractario del ventriculo derecho y periodo refractario del nodulo atrio ventricular). Despues de las medidas iniciales el remifentanil fue introducido (bolo de 0,5 µg.kg-1 + infusion de 0,05 µg.kg-1.min-1) y despues de 20 minutos las mismas variables fueron evaluadas nuevamente (M1). RESULTADOS: Se observo disminucion de las presiones sistolica y diastolica (p = 0.0001) entre M0 y M1, sin diferencia estadistica significativa de la frecuencia respiratoria o de la saturacion de oxigeno. Hubo aumento del intervalo atrio-His (p = 0,006) y del tiempo de recuperacion del nodulo sino-atrial (p = 0,0004), del periodo refractario del atrio derecho (p = 0,001) y del periodo refractario del nodulo atrio ventricular (p = 0,0001), pero no hubo disminucion de la frecuencia cardiaca basal entre M0 e M1. CONCLUSIONES: El remifentanil altero las variables electrofisiologicas cardiacas, lo que en dosis mayores que las estudiadas podria causar bradicardia sinusal, asistolia y disturbios de conduccion.

Prospective study on the repercussions of low doses of remifentanil on sinoatrial function and in cardiac conduction and refractory period

BACKGROUND AND OBJECTIVESnRemifentanil is an opiod with fast onset of action and short acting, and its use in short-duration procedures has increased in the last few years. Bradycardia and asystole are among the side effects reported. The objective of this study was to evaluate the effects of this drug in cardiac conduction and refractory period in human beings.nnnMETHODSnA prospective study with 16 patients, ages 18 to 65, both genders, ASA I to III, undergoing elective intracardiac electrophysiological study, was undertaken. Patients with disorders of the sinoatrial node and those with severe cardiac blocks were excluded. In the laboratory of electrophysiology, patients were sedated with midazolam (0.03 mg.kg-1) after 5 minutes the degree of sedation and degree of pain, systolic and diastolic blood pressure, heart rate and respiratory rate, and oxygen saturation were evaluated. The electrophysiologist evaluated cardiac conduction (duration of the QRS complex, and AA, AH, HV, and PA intervals), duration of sinoatrial node recovery, and cardiac refractory period (refractory period of the right atrium, right ventricle, and atrioventricular node). After the initial measurements, remifentanil was administered (bolus of 0.5 microg.kg-1 + infusion of 0.05 microg.kg-1.min-1) and, after 20 minutes, the same parameters were evaluated.nnnRESULTSnThere was a reduction in systolic and diastolic blood pressure (p = 0.0001) between M0 and M1, and significant differences in respiratory rate and oxygen saturation, which were not statistically significant. The atrium-His interval (p = 0.006), recovery time of the sinoatrial node (p = 0.0004), refractory period of the right atrium (p = 0.001), and refractory period of the sinoatrial node (p = 0.0001) were all increased; however, there were no differences in heart rate between M0 and M1.nnnCONCLUSIONSnRemifentanil changes cardiac electrophysiological parameters and, in doses higher than the ones used in this study, can cause sinus bradycardia, asystole, and conduction defects.JUSTIFICATIVA Y OBJETIVOS: El remifentanil es un opioide con inicio y fin de accion rapidos, cuyo uso en procedimientos de corta duracion se ha venido propagando en los ultimos anos. Entre los efectos colaterales descritos, hay relatos de bradicardia y asistolia. El objetivo de este estudio fue evaluar los efectos de este farmaco en la conduccion y refractariedad cardiaca, en humanos. METODO: Estudio prospectivo de 16 pacientes, entre 18 y 65 anos, de ambos sexos, ASA I a III, que se sometieron a estudio electrofisiologico intra cardiaco electivo. Se excluyeron pacientes con enfermedades del nodulo sino-atrial y los portadores de bloqueos cardiacos graves. En el laboratorio de electrofisiologia, los pacientes fueron inicialmente sedados con midazolam (0,03 mg.kg-1), 5 minutos despues (M0) se evaluo el grado de sedacion e intensidad de dolor, presiones arteriales sistolica y diastolica, frecuencias cardiaca y respiratoria y saturacion de oxigeno. El electrofisiologista evaluo las variables de conduccion cardiaca (duracion del QRS, intervalos AA, AH, HV y PA), el tiempo de recuperacion del nodulo sino-atrial y las variables de refractariedad cardiaca (periodo refractario del atrio derecho, periodo refractario del ventriculo derecho y periodo refractario del nodulo atrio ventricular). Despues de las medidas iniciales el remifentanil fue introducido (bolo de 0,5 µg.kg-1 + infusion de 0,05 µg.kg-1.min-1) y despues de 20 minutos las mismas variables fueron evaluadas nuevamente (M1). RESULTADOS: Se observo disminucion de las presiones sistolica y diastolica (p = 0.0001) entre M0 y M1, sin diferencia estadistica significativa de la frecuencia respiratoria o de la saturacion de oxigeno. Hubo aumento del intervalo atrio-His (p = 0,006) y del tiempo de recuperacion del nodulo sino-atrial (p = 0,0004), del periodo refractario del atrio derecho (p = 0,001) y del periodo refractario del nodulo atrio ventricular (p = 0,0001), pero no hubo disminucion de la frecuencia cardiaca basal entre M0 e M1. CONCLUSIONES: El remifentanil altero las variables electrofisiologicas cardiacas, lo que en dosis mayores que las estudiadas podria causar bradicardia sinusal, asistolia y disturbios de conduccion.

Intra-His bundle block: clinical, electrocardiographic, and electrophysiologic characteristics

OBJECTIVEnTo assess the clinical, electrocardiographic, and electrophysiologic characteristics of patients (pt) with intra-His bundle block undergoing an electrophysiologic study (EPS).nnnMETHODSnWe analyzed the characteristics of 16 pt with second-degree atrioventricular block and symptoms of syncope or dyspnea, or both, undergoing conventional EPS.nnnRESULTSnIntra-His bundle block was documented in 16 pt during an EPS. In 15 (94%) pt, the atrioventricular block was recorded in sinus rhythm; 4 (25%) pt had intra-His Wenckebach phenomenon, which correlated with Mobitz I (MI) atrioventricular block on the electrocardiogram. Seven (44%) pt had 2:1 atrioventricular block, 2 of whom were asymptomatic (12.5%). One (6%) pt had intra- and infra-His bundle block. Clinically, 11 (68%) pt had syncope or presyncope, 3 (18%) had dyspnea on exertion, and 2 (12.5%) were asymptomatic. Eight (50%) pt had bundle-branch block as follows: 4 (25%) pt had left bundle-branch block, and 4 (25%) had right bundle-branch block. Left anterosuperior divisional block was observed in 3 pt (19%), 2 of whom with associated right bundle-branch block.nnnCONCLUSIONnIntra-His bundle block was observed in 11% of the pt with second-degree atrioventricular block, syncope or presyncope, or both, it being the most frequent clinical presentation. Intra-His bundle block was more common in the elderly (> 60 years) and among females. The most frequent electrocardiographic presentations were second-degree Mobitz I or type 2:1 atrioventricular block.

Safety and feasibility of transcatheter renal sympathetic denervation using different types of catheter and various radiofrequency settings

Background To evaluate in vivo the feasibility and safety of renal sympathetic denervation (RSD) with different catheters and various radiofrequency protocols. Methods and results Twenty-two pigs were included. First 2 pigs were enrolled in a feasibility protocol using one catheter and power from 5 W to 20 W. The next 10 pigs underwent RSD with three different catheters and four different RF-power settings of 5 W, 8 W, 10 W and 12 W in one minute per lesion (Protocol 1). The following 10 (Pigs 13 to 22) underwent RSD with five types of catheters (including the Symplicity® catheter), powers of 8 W and 10 W and two minutes RF-application (Protocol 2). Angiographic data were obtained at baseline, during and after RSD. At last, renal arteries were excised and analyzed macroscopically. The first pig developed severe renal stenoses with lesions of 15 to 20 W correlated with macroscopic alterations. The second feasibility pig did not develop renal stenosis with 5 and 8 W. In Protocol 1 from 60 RF-lesions, we observed 7 stenoses (≥ 30%). Three were severe (one of 80% with 10 W and two of 80% with 12 W). In Protocol 2 from 57 lesions we observed only 1 stenosis of 50% with 8 W with Symplicity® catheter. Severe stenosis was not observed. Conclusion In this study, renal sympathetic denervation showed safety using five types of catheters when applying RF-energy less than 10 W, within main stems of arteries larger than 3.0 mm diameter and a distance between lesions of at least 1 time catheter tip length.

Estudio prospectivo de las repercusiones de bajas dosis de remifentanil en la función sinoatrial en la conducción y refractariedad cardiaca

BACKGROUND AND OBJECTIVESnRemifentanil is an opiod with fast onset of action and short acting, and its use in short-duration procedures has increased in the last few years. Bradycardia and asystole are among the side effects reported. The objective of this study was to evaluate the effects of this drug in cardiac conduction and refractory period in human beings.nnnMETHODSnA prospective study with 16 patients, ages 18 to 65, both genders, ASA I to III, undergoing elective intracardiac electrophysiological study, was undertaken. Patients with disorders of the sinoatrial node and those with severe cardiac blocks were excluded. In the laboratory of electrophysiology, patients were sedated with midazolam (0.03 mg.kg-1) after 5 minutes the degree of sedation and degree of pain, systolic and diastolic blood pressure, heart rate and respiratory rate, and oxygen saturation were evaluated. The electrophysiologist evaluated cardiac conduction (duration of the QRS complex, and AA, AH, HV, and PA intervals), duration of sinoatrial node recovery, and cardiac refractory period (refractory period of the right atrium, right ventricle, and atrioventricular node). After the initial measurements, remifentanil was administered (bolus of 0.5 microg.kg-1 + infusion of 0.05 microg.kg-1.min-1) and, after 20 minutes, the same parameters were evaluated.nnnRESULTSnThere was a reduction in systolic and diastolic blood pressure (p = 0.0001) between M0 and M1, and significant differences in respiratory rate and oxygen saturation, which were not statistically significant. The atrium-His interval (p = 0.006), recovery time of the sinoatrial node (p = 0.0004), refractory period of the right atrium (p = 0.001), and refractory period of the sinoatrial node (p = 0.0001) were all increased; however, there were no differences in heart rate between M0 and M1.nnnCONCLUSIONSnRemifentanil changes cardiac electrophysiological parameters and, in doses higher than the ones used in this study, can cause sinus bradycardia, asystole, and conduction defects.JUSTIFICATIVA Y OBJETIVOS: El remifentanil es un opioide con inicio y fin de accion rapidos, cuyo uso en procedimientos de corta duracion se ha venido propagando en los ultimos anos. Entre los efectos colaterales descritos, hay relatos de bradicardia y asistolia. El objetivo de este estudio fue evaluar los efectos de este farmaco en la conduccion y refractariedad cardiaca, en humanos. METODO: Estudio prospectivo de 16 pacientes, entre 18 y 65 anos, de ambos sexos, ASA I a III, que se sometieron a estudio electrofisiologico intra cardiaco electivo. Se excluyeron pacientes con enfermedades del nodulo sino-atrial y los portadores de bloqueos cardiacos graves. En el laboratorio de electrofisiologia, los pacientes fueron inicialmente sedados con midazolam (0,03 mg.kg-1), 5 minutos despues (M0) se evaluo el grado de sedacion e intensidad de dolor, presiones arteriales sistolica y diastolica, frecuencias cardiaca y respiratoria y saturacion de oxigeno. El electrofisiologista evaluo las variables de conduccion cardiaca (duracion del QRS, intervalos AA, AH, HV y PA), el tiempo de recuperacion del nodulo sino-atrial y las variables de refractariedad cardiaca (periodo refractario del atrio derecho, periodo refractario del ventriculo derecho y periodo refractario del nodulo atrio ventricular). Despues de las medidas iniciales el remifentanil fue introducido (bolo de 0,5 µg.kg-1 + infusion de 0,05 µg.kg-1.min-1) y despues de 20 minutos las mismas variables fueron evaluadas nuevamente (M1). RESULTADOS: Se observo disminucion de las presiones sistolica y diastolica (p = 0.0001) entre M0 y M1, sin diferencia estadistica significativa de la frecuencia respiratoria o de la saturacion de oxigeno. Hubo aumento del intervalo atrio-His (p = 0,006) y del tiempo de recuperacion del nodulo sino-atrial (p = 0,0004), del periodo refractario del atrio derecho (p = 0,001) y del periodo refractario del nodulo atrio ventricular (p = 0,0001), pero no hubo disminucion de la frecuencia cardiaca basal entre M0 e M1. CONCLUSIONES: El remifentanil altero las variables electrofisiologicas cardiacas, lo que en dosis mayores que las estudiadas podria causar bradicardia sinusal, asistolia y disturbios de conduccion.