Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures.

Despite the advent of non-fluoroscopic technology, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies over ablation interventions to device implantation. Moreover, many patients receive additional X-ray imaging, such as cardiac computed tomography and others. More and more complex procedures have the risk to increase the radiation exposure, both for the patients and the operators. The professional lifetime attributable excess cancer risk may be around 1 in 100 for the operators, the same as for a patient undergoing repetitive complex procedures. Moreover, recent reports have also hinted at an excess risk of brain tumours among interventional cardiologists. Apart from evaluating the need for and justifying the use of radiation to assist their procedures, physicians have to continuously explore ways to reduce the radiation exposure. After an introduction on how to quantify the radiation exposure and defining its current magnitude in electrophysiology compared with the other sources of radiation, this position paper wants to offer some very practical advice on how to reduce exposure to patients and staff. The text describes how customization of the X-ray system, workflow adaptations, and shielding measures can be implemented in the cath lab. The potential and the pitfalls of different non-fluoroscopic guiding technologies are discussed. Finally, we suggest further improvements that can be implemented by both the physicians and the industry in the future. We are confident that these suggestions are able to reduce patient and operator exposure by more than an order of magnitude, and therefore think that these recommendations are worth reading and implementing by any electrophysiological operator in the field.

Taquicardia por reentrada nodal recurrente en paciente con transposición congénita corregida de grandes vasos. Utilización de mapeo no fluoroscópico / Use of non-fluoroscopic mapping in recurrent atrioventricular nodal reentrant tachycardia in a patient with corrected transposition of the great arteries

La complejidad anatómica y la variabilidad en el sistema de conducción en la transposición congénita corregida de los grandes vasos plantean intervenciones con el uso de recursos tecnológicos que faciliten un desenlace favorable. Describimos un caso de ablación de taquicardia por reentrada intranodal en donde el mapeo no fluoroscópico facilitó una intervención compleja.

The anatomy in congenital corrected transposition of the great arteries is complex and the conduction system may experience large degrees of variation. Invasive procedures should be done with the use of the highest possible technological sources to warrant success. We describe here, a patient with recurrent atrioventricular node reentry tachycardia where non-fluoroscopic navigation system helped in a complex ablation.

A reappraisal on lidocaine-sensitive repetitive, uniform atrial tachycardia.

BACKGROUND: Lidocaine sensitive, repetitive atrial tachycardia is an unusual arrhythmia whose electrophysiologic substrate remains undefined. We aimed to analyze the electropharmacologic characteristics of this arrhythmia with emphasis on its cellular substrate and response to drug challenges. METHODS: We retrospectively analyzed a series of 18 patients from an electrocardiographic and electrophysiologic perspective and the response to pharmacological challenge. RESULTS: There was no evidence of structural heart disease in 12 patients, 4 patients presented with systemic hypertension; one patient had a prior myocardial infarction and one a mitral valve prolapse. The arrhythmia depicted a consistent pattern in nine patients. The first initiating ectopic beat showed a long coupling interval, the cycle length of the second atrial ectopic beat presented the shortest cycle length and a further prolongation was apparent towards the end of the atrial salvos. Conversely, in the other nine cases, the atrial tachycardia cycle length was erratic. The arrhythmia was suppressed by asynchronous atrial pacing at cycle lengths longer than those of the atrial tachycardia. Intravenous lidocaine eliminated the arrhythmia in all patients, but intravenous verapamil suppressed the atrial tachycardia in only two patients while adenosine caused a transient disappearance in 2/8 patients. Only one patient responded to all the three agents. Radiofrequency ablation was successfully performed in 10 patients. CONCLUSIONS: Repetitive uniform atrial tachycardia can be sensitive to lidocaine. In few cases, this rare focal arrhythmia may be also suppressed by adenosine and/or verapamil, which suggests a diversity of electrophysiologic substrates that deserve to be accurately identified.

Brugada phenocopy: new terminology and proposed classification.

Brugada syndrome is a channelopathy characterized on ECG by coved ST-segment elevation (≥2 mm) in the right precordial leads and is associated with an increased risk of malignant ventricular arrhythmias. The term Brugada phenocopy is proposed to describe conditions that induce Brugada-like ECG manifestations in patients without true Brugada syndrome. An extensive review of the literature identified case reports that were classified according to their suspected etiological mechanism. Future directions to learn more about these intriguing cases is discussed.

"Benign" early repolarization versus malignant early abnormalities: clinical-electrocardiographic distinction and genetic basis.

In the great majority of cases the ECG pattern of early repolarization (ERP) is a benign phenomenon observed predominantly in teenagers, young adults, male athletes and the black race. The universally accepted criterion for its diagnosis is the presence, in at least two adjoining leads, of ≥ 1 mm or 0.1 mV ST segment elevation. In benign ERP reciprocal ST segment changes are possible only in lead aVR. In contrast, reciprocal ST segment changes can be observed in several leads in idiopathic ventricular fibrillation (IVF) and acute coronary syndrome. In benign ERP the ST segment and T wave patterns have a relative temporal stability. IVF is an entity with low prevalence, possibly familiar, and characterized by the occurrence of VF events in a young person. More frequently this occurs in male subjects without structural heart disease and with otherwise with normal ECG even using high right accessory leads and/or after ajmaline injection. Several clinical entities cause ST segment elevation include asthenic habitus, acute pericarditis, ST segment elevation myocardial infarction, Brugada syndrome, congenital short QT syndrome, and idiopathic VF. In these circumstances clinical and ECG data are most important for differential diagnosis. In IVF the modifications could be dramatic and predominantly at night during vagotonic predominance when J waves > 2 mm in amplitude. The ST/T abnormalities are dynamic, inconstant, and reversed with isoproterenol. Convex upward J waves, with horizontal/descending ST segments or "lambda-wave" ST shape are suggestive of IVF with early repolarization abnormalities. Premature ventricular contractions with very short coupling and "R on T" phenomenon are characteristics with two pattern: When originate from right ventricular outflow tract left bundle branch block morphology and from peripheral Purkinje network, left bundle branch block pattern. The inherited-familial forms are not frequent in IVF; however mutations were identified in the genes KCNJ8, DPP6, SCN5A, SCN3B, CACNA1C, CACNB2, and CACNA2D1. The management of IVF has class I indication for ICD implantation. Ablation therapy is considered additional to ICD implantation in those patients with repetitive ventricular arrhythmia. Quinidine is a highly efficient drug that prevents recurrence.

Resultados del uso de marcapasos definitivo en pacientes con cardiopatía chagásica y con enfermedad coronaria / Results of the use of definitive pacemakers in patients with chagasic cardiomyopathy and in patients with coronary artery disease

En la mayoría de los países de Latinoamérica, la enfermedad de Chagas es endémica y la miocardiopatía isquémica es la primera causa de afección cardíaca. Ambas entidades conviven generando un modelo biológico y epidemiológico único, y al ser enfermedades de evolución crónica, por diversos motivos pueden requerir el implante de un marcapasos definitivo. El objetivo del presente trabajo fue comparar los motivos de implante, detalles técnicos y evolución de pacientes referidos para tratamiento con marcapasos definitivo y portadores de miocardiopatía chagásica o miocardiopatía isquémica.

Tromboembolismo pulmonar masivo de alto riesgo asociado a foramen oval permeable / High-risk massive pulmonary thromboembolism associated with patent foramen ovale

La alta mortalidad de los pacientes con tromboembolismo pulmonar masivo de alto riesgo amerita un enfoque terapéutico enérgico e invasivo que incluya la embolectomía pulmonar quirúrgica en aquellos pacientes con contraindicación para trombolisis o trombolisis fallida. Describimos un caso de tromboembolismo pulmonar masivo de alto riesgo que recibió tratamiento quirúrgico en vez de trombolisis debido a que al momento del diagnóstico presentaba un trombo móvil a través de un foramen oval permeable con altísima posibilidad de embolismo paradójico arterial.

High mortality rate associated with massive pulmonary embolism requires an aggressive invasive approach including surgical pulmonary embolectomy when thrombolytic therapy has failed or is contraindicated. We describe a case of high-risk massive pulmonary embolism who underwent surgical treatment due to the presence of a mobile intracardiac clot in a patent foramen ovale, and the possible risk of paradoxical arterial embolism.

Ventricular flutter triggered by fever in a patient with Brugada syndrome.

Brugada syndrome is a clinical-electrocardiographic entity predisposing to malignant ventricular arrhythmias. The typical arrhythmia is polymorphic ventricular tachycardia, which can potentially degenerate to ventricular fibrillation. Monomorphic ventricular tachycardia is uncommon. Our group is reporting the case of a 39-year-old man with known Brugada syndrome who developed ventricular flutter while febrile. Fever has previously been shown to unmask Brugada changes and to induce ventricular arrhythmias. The appearance of monomorphic ventricular tachycardia potentially attributable to sodium-channel dysfunction further confounds the mechanism of arrhythmogenesis in Brugada syndrome. This curious occurrence further underlines the likely complex nature of arrhythmogenesis in Brugada syndrome.

Surface fragmented QRS in a patient with hypertrophic cardiomyopathy and malignant arrhythmias: Is there an association?

An 18- year old woman with hypertrophic cardiomyopathy, aborted sudden cardiac death and implanted with an implantable cardioverter defibrillator (ICD), developed progressive fragmentation of her surface 12-lead electrocardiogram (ECG). During the follow-up, she presented with multiple appropriate ICD discharges. Here, we discuss the possible association between surface fragmented ECG and the risk of ventricular arrhythmias in patients with hypertrophic cardiomyopathy.

[Is the head-up tilt-test necessary in patients whit clinical diagnosis of vasovagal syncope? Results using a non-sensitized protocol]. / ¿Es necesaria la prueba de inclinación en pacientes con diagnóstico clínico de síncope vasovagal? Resultados utilizando un protocolo no sensibilizado.

INTRODUCTION: Tilt table testing is a simple, non-invasive, low risk test. A not sensitized protocol has been presented in order to shorten the duration of the test. OBJECTIVE: To determine the usefulness of a not sensitized tilt table testing and to compare the results with the pre-test probability, given by the Calgary's score. METHODS: We included patients≥15 years-old with syncope or presyncope with high probability pretest for a vasovagal origin, using the Calgary' score. RESULTS: Seventy patients were analyzed; age 39±20 years old, 66% female. More than 94% of the patients presented a score≥-1, but only 30% of the tilt tests were positive. A score≥-2 was not associated with the result of tilt test. Most of the patients presented a score of 1 (52) and 2 (11), resulting in positive tilt test 32% y 9%, respectively. Among patients with low pre-test probability there was a greater number of negative results (100% with a score of -2 and 50% with score of -5). CONCLUSIONS: This study showed that in patients with vasovagal syncope suggested by clinical assessment, a not sensitized tilt test did not provide additional information, with a significant number of false negatives.

¿Es necesaria la prueba de inclinación en pacientes con diagnóstico clínico de síncope vasovagal?: Resultados utilizando un protocolo no sensibilizado / Is the head-up tilt-test necessary in patients whit clinical diagnosis of vasovagal syncope?: Results using a non-sensitized protocol

Introducción:La prueba de inclinación es un estudio no invasivo, sencillo y de bajo riesgo, donde la utilización de protocolos no sensibilizados sirven para acortar los tiempos de la prueba. Objetivo:Determinar en pacientes con síncope la utilidad de la prueba de inclinación no sensibilizada con fármacos y comparar los resultados con la probabilidad clínica pre-test. Métodos:Se incluyeron pacientes >15 años de edad, con síncope o presíncope, con clínica sugestiva de origen vasovagal, utilizando la escala de Calgary. Resultados:Se analizaron 70 pacientes; edad: 39 ± 20 años, 66% mujeres. De los pacientes, 94% presentó una puntuación >-1, pero sólo 30% de las pruebas fueron positivas. Una puntuación >-2 no se asoció con el resultado de la prueba. La mayoría de los pacientes presentaron una puntuación de 1 (52) y 2 (11), resultando en una prueba positiva en 32% y 9%, respectivamente. En pacientes con probabilidad pre-test baja, hubo mayor número de pruebas negativas (100% con una puntuación de -2 y 50% con puntuación de -5). Conclusiones:El estudio mostró que en pacientes con síncope vasovagal, sugerido por la evaluación clínica, la prueba de inclinación no sensibilizada no proporcionó información adicional, con un número significativo de falsos negativos.

Introduction:Tilt table testing is a simple, non-invasive, low risk test. A not sensitized protocol has been presented in order to shorten the duration of the test. Objective:To determine the usefulness of a not sensitized tilt table testing and to compare the results with the pre-test probability, given by the Calgary's score. Methods:We included patients >15 years-old with syncope or presyncope with high probability pretest for a vasovagal origin, using the Calgary' score. Results:Seventy patients were analyzed; age 39 ± 20 years old, 66% female. More than 94% of the patients presented a score >-1, but only 30% of the tilt tests were positive. A score >-2 was not associated with the result of tilt test. Most of the patients presented a score of 1 (52) and 2 (11), resulting in positive tilt test 32% y 9%, respectively. Among patients with low pre-test probability there was a greater number of negative results (100% with a score of -2 and 50% with score of -5). Conclusions: This study showed that in patients with vasovagal syncope suggested by clinical assessment, a not sensitized tilt test did not provide additional information, with a significant number of false negatives.

Acquired long QT interval: a case series of multifactorial QT prolongation.

BACKGROUND: Acquired long QT (LQT) interval is thought to be a consequence of drug therapy and electrolyte disturbances. HYPOTHESIS: We characterize the potential effects of polypharmacy in a case series of acquired LQT and torsades de pointes (TdP) in order to determine whether multiple risk factors play a role in the development of LQT. METHODS: The case series consisted of 11 patients presenting to 4 tertiary care hospitals with LQT and ≥ 2 risk factors for developing LQT. Clinical characteristics, medications, electrolyte disturbances, and course in hospital were analyzed. RESULTS: Mean age was 49.1 ± 5.8 years. Eight patients were female. Four had hypertension, 1 had a history of dilated cardiomyopathy, and 1 patient demonstrated complete atrioventricular block. Average QTc interval at presentation was 633.8 ± 29.2 ms. Nine patients developed TdP. In 3, LQT was not initially detected and amiodarone was administered, followed by development of TdP. Patients were taking an average of 2.8 ± 0.3 QT-prolonging medications-an antidepressant in 6 cases and a diuretic in 8 cases. All patients had an electrolyte abnormality; 8 patients presented with severe hypokalemia (<3.0 mmol/L). Average serum potassium and magnesium were 2.82 ± 0.10 mmol/L and 0.75 ± 0.03 mmol/L, respectively. There were no deaths. CONCLUSIONS: This case series highlights the risks of polypharmacy in the development of LQT and TdP. It illustrates the importance of early detection of LQT in patients with multiple risk factors in ensuring appropriate treatment.

Valor del electrocardiograma en el diagnóstico y pronóstico del síndrome de Brugada

El electrocardiograma de 12 derivaciones asociado con las derivadas accesorias (precordiales derechas altas) es el método complementario con el cual se obtiene la mayor información diagnóstica y pronostica en pacientes portadores con síndrome de Brugada. Mediante este método sencillo, económico, reproducible y operador independiente, podemos estudiar las alteraciones tanto de la despolarización como de la repolarización ventricular. También permite el diagnóstico de las distintas arritmias supraventriculares que pueden acontecer así como caracterizar las diferentes taquicardias ventriculares. Por otro lado, el análisis vectocardiográfico con el método de Frank en pacientes con síndrome de Brugada, sugiere la dualidad de los mecanismos fisiopatológicos del patrón electrocardiográfico característico o tipo 1, demostrándose características distintivas y particulares, con respecto a individuos portadores de bloqueo de rama derecha. La compresión de todos estos mecanismos, pueden contribuir a orientar futuros esfuerzos terapéuticos que permitan controlar la disfunción de los canales asociados a esta rara y compleja canalopatía.

Twelve-lead ECG associated to high right parasternal accessory leads is the resource that yields a greatest number of diagnostic and prognostic information in patients carriers of BrS. By this simple, cheap, reproducible, and operator-independent method, depolarization alterations can be studied as well as ventricular repolarization aspects. The method allows diagnosing frequent episodes of atrial fibrillation and other supraventricular arrhythmias, as well as characterizing the different ventricular tachyarrhythmias. The analysis of the Frank VCG (F-VCG) of patients with BrS suggests the duality of the underlying physiopathological mechanisms of the Brugada Type-1 ECG pattern. F-VCG of patients with Brugada type-1 ECG pattern has distinctive characteristics from the F-VCG of individuals with RBBB pattern. The understanding of these mechanisms may help to guide future therapeutic efforts to control the channels dysfunction associated with this intriguing channelopaty.

Interacciones entre dispositivos cardíacos implantables y modalidades fisioterapéuticas: ¿Mito o realidad? / Cardiac implantable devices and physiotherapy practices interaction: Myth or real?

La fisioterapia se ha transformado en una especialidad que claramente incide en la calidad de vida de nuestros pacientes. En poblaciones añosas, el uso de fisioterapia incluye múltiples modalidades para un alto número de distintas enfermedades. Varios informes sobre posibles interacciones negativas entre las distintas modalidades de fisioterapia y los dispositivos cardíacos implantables (marcapasos y cardiodesfibriladores) han sido publicados en los últimos aňos. A pesar de ello, existe muy poca evidencia y guías precisas para identificar cuáles son las modalidades de fisioterapia seguras a utilizar en esta población de pacientes. En la siguiente revisión, nos propusimos resumir las interacciones documentadas entre fisioterapia y dispositivos cardíacos implantables (DCI), discutir el estándar actual de estas prácticas e identificar las principales consideraciones que existen desde la perspectiva de un servicio de electrofisiología cardíaca, para el tratamiento adecuado en estos pacientes. Finalmente, abogamos por fortalecer la colaboración entre fisioterapeutas y electrofisiólogos, con el fin de asegurar una óptima y segura atención de este grupo de pacientes.

Several reports of negative interactions between physiotherapy practices and cardiac rhythm devices (CRDs) have been described in the literature. In spite of this, there is very little evidence to suggest the extent to which it is safe to use physiotherapy practices in this patient population. Here we summarize the documented interactions between physiotherapy and CRDs, discuss the current standard of practice for treating CRD patients, and outline the main considerations that exist from the arrhythmia service perspective in terms of patient and device factors. Finally, we advocate for a stronger cooperation between physiotherapists and the electrophysiology service team in order to safely and effectively deliver optimal physiotherapy care to CRD patients.

Taquicardia auricular focal incesante originada en la orejuela derecha: riesgo de taquicardiomiopatía: rol de la ablación por radiofrecuencia / Incessant focal atrial tachycardia arising from the right appendage: risk of tachycardia mediated cardiomyopathy: role of the radiofrequency ablation

Las taquicardias auriculares focales pueden originarse en distintas regiones de la aurícula derecha, incluidos la crista terminalis, el anillo tricuspídeo, el septum interauricular y la orejuela derecha. Las originadas en esta última región anatómica se caracterizan por presentar un comportamiento incesante y mala respuesta al tratamiento farmacológico antiarrítmico, con desarrollo de taquicardiomiopatía; su tratamiento de elección es la ablación por radiofrecuencia.Presentamos el caso de una infante de 36 meses de edad, con taquicardiomiopatía secundaria a taquicardia auricular incesante de orejuela derecha, a quien se le realizó ablación por radiofrecuencia.

Focal atrial tachycardias originate from different anatomic regions of the right atrium including the crista terminalis, the coronary sinus ostium, the tricuspid annulus, the interatrial septum and the right atrial appendage. The latter are characterized by being incessant and presenting poor response to antiarrhythmic treatment. They frequently evolve into tachycardiomyopathy and radiofrequency ablation is the treatment of choice. We present the case of a 36 month old girl with tachycardiomyopathy as a result of an incessant atrial tachycardia originated in the right atrial appendage. Patient underwent radiofrequency ablation.