Search

SUMMARY OBJECTIVE: The main objectives of this investigation were to determine whether there were any relationships between corrected cardiac-electrophysiological balance value and National Institutes of Health Stroke Scale scores at admission and discharge in patients with acute ischemic stroke and to assess whether cardiac-electrophysiological balance value was an independent predictor of high National Institutes of Health Stroke Scale scores (National Institutes of Health Stroke Scale score ≥5). METHODS: In this retrospective and observational study, 231 consecutive adult patients with acute ischemic stroke were evaluated. The cardiac-electrophysiological balance value was obtained by dividing the corrected QT interval by the QRS duration measured from surface electrocardiography. An experienced neurologist used the National Institutes of Health Stroke Scale score to determine the severity of the stroke at the time of admission and before discharge from the neurology care unit. The participants in the study were categorized into two groups: those with minor acute ischemic stroke (National Institutes of Health Stroke Scale score=1–4) and those with moderate-to-severe acute ischemic stroke (National Institutes of Health Stroke Scale scores ≥5). RESULTS: Acute ischemic stroke patients with National Institutes of Health Stroke Scale score ≥5 had higher heart rate, QT, corrected QT interval, T-peak to T-end corrected QT interval, cardiac-electrophysiological balance, and cardiac-electrophysiological balance values compared with those with an National Institutes of Health Stroke Scale score of 1–4. The cardiac-electrophysiological balance value was shown to be independently related to National Institutes of Health Stroke Scale scores ≥5 (OR 1.102, 95%CI 1.036–1.172, p

Objective: Cardiac electrophysiology study (EPS) is an invasive procedure performed for diagnosis and treatment of cardiac arrhythmias. The aim of our study was to assess our 6-year EPS experience and to compare our data with the complication rate published in the literature.Methods: We included 1152 patients who were diagnosed and treated for cardiac arrhythmia in our hospital between 2000-2006. The demographic data of all patients with a presumptive diagnosis of arrhythmia, EPS indications, treatment procedures, and complications were recorded.Results: Six hundred and seventy-three of 1152 (58%) patients enrolled in the study were males with a mean age of 49.6 years, and 479 (42%) were females with a mean age of 48 years. One hundred and fifty-six (13.5%) patients had bradyarrhythmia, 596 (51.8%) patients had supraventricular tachycardia, 400 (34.7%) had ventricular tachycardia. One patient had complete AV block, one patient had hemopericardium, one patient had pericardial tamponade, one patient had pneumothorax, one patient had right thrombophlebitis one patient had sheath fracture, and one patient died after left popliteal embolization. Total mortality rate was 0.6%.Conclusion: The EPS performed in experienced centers with the same team for a long period of time results in low complication rate.

Coronary sinus mapping is commonly used to evaluate left atrial activation. Herein, we propose to use it to assess which right ventricular pacing modality produces the shortest left ventricular activation times (R-LVtime) and the narrowest QRS widths. Three study groups were defined: 54 controls without intraventricular conduction disturbances; 15 patients with left bundle branch block, and 15 patients with right bundle branch block. Left ventricular activation times and QRS widths were evaluated among groups under sinus rhythm, right ventricular apex, right ventricular outflow tract and high output septal zone (SEPHO). Left ventricular activation time was measured as the time elapsed from the surface QRS onset to the most distal left ventricular deflection recorded at coronary sinus. During the above stimulation modalities, coronary sinus mapping reproduced electrical differences that followed mechanical differences measured by tissue doppler imaging. Surprisingly, 33% of the patients with left bundle branch block displayed an early left ventricular activation time, suggesting that these patients would not benefit from resynchronization therapy. SEPHO improved QRS widths and left ventricular activation times in all groups, especially in patients with left bundle branch block, in whom these variables became similar to controls. Left ventricular activation time could be useful to search the optimum pacing site and would also enable detection of non-responders to cardiac resynchronization therapy. Finally, SEPHO resulted the best pacing modality, because it narrowed QRS-complexes and shortened left ventricular activations of patients with left bundle branch block and preserved the physiological depolarization of controls. El mapeo del seno coronario se utiliza comúnmente para evaluar la activación de la aurícula izquierda. Aquí, investigamos su utilidad para evaluar qué modalidad de estimulación ventricular derecha produce los menores tiempos de activación ventricular izquierda (R-LVtime). Se definieron tres grupos: 54 controles; 15 pacientes con bloqueo de rama izquierda y 15 con bloqueo de rama derecha. El ancho de QRS y los tiempos de activación fueron evaluados en cada grupo bajo las siguientes modalidades: ritmo sinusal, ápex del ventrículo derecho, tracto de salida del ventrículo derecho y alta salida en septum (SEPHO). El R-LVtime se midió como el tiempo transcurrido desde el inicio del QRS de superficie y la deflexión ventricular izquierda más distal del seno coronario. Durante las distintas modalidades de estimulación, el mapeo del seno coronario reprodujo diferencias eléctricas acompañadas por diferencias mecánicas que fueron evaluadas mediante Tissue Doppler Imaging. El 33% de los pacientes con bloqueo de rama izquierda mostró R-LVtime tempranos, lo que sugiere que estos pacientes no se beneficiarían con terapia de resincronización. SEPHO mejoró el ancho de QRS y el R-LVtime de todos los grupos, especialmente en los pacientes con bloqueo de rama izquierda. En conclusión, el R-LVtime serviría para identificar el sitio óptimo de estimulación y permitiría detectar ciertos no respondedores a la terapia de resincronización. Además, el SEPHO resultó la mejor modalidad de estimulación porque estrechó el QRS y acortó el R-LVtime de los pacientes con bloqueo de rama izquierda pero no alteró la despolarización fisiológica de los controles. Fil: Bonomini, Maria Paula. Universidad de Buenos Aires. Facultad de Ingenieria. Instituto de Ingeniería Biomédica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderon; Argentina Fil: Ortega, Daniel Felipe. Hospital Universitario Austral; Argentina Fil: Barja, Luis Dante. Hospital Universitario Austral; Argentina Fil: Mangani, Nicolas. Hospital Universitario Austral; Argentina Fil: Paolucci, Analia. Hospital Universitario Austral; Argentina Fil: Logarzo, Emilio. Hospital Universitario Austral; Argentina

The cardiac electrophysiology study EPS is an invasive procedure which tests the electrical conduction system of the heart to assess the electrical activity and conduction pathways of the heart. The EPS is indicated to investigate the cause, location of origin, and best treatment for various abnormal heart rhythm. In this report, we present a review of current literature about the basic principles and clinical uses of the cardiac electrophysiologic study., Kardiyak Elektrofizyolojik çalışma EPS kalbin elektriksel ileti sisteminin inceleyen invaziv bir işlemdir. Kalbin elektriksel aktivitesi ve ileti yollarının değerlendirilmesinde kullanılır. EPS işlemiyle anormal kalp ritimlerinin tanısı, nedenleri, orijin aldığı lokalizasyon ve tedavi yöntemleri belirlenir. Bu derlememizde klinik kardiyak elektrofizyolojik çalışmanın temel esasları ve klinik kullanımlarından literatürler eşliğinde bahsedilecektir.

Resumo: Um homem de 67 anos deu entrada no hospital após episódios de síncope precedidos por mal‐estar geral e desconforto torácico difuso. Sem história familiar de doença cardíaca. O estudo analítico, incluindo d‐dímeros e troponina I, bem como a gasimetria arterial, não mostrou alterações. O eletrocardiograma exibiu um ritmo sinusal com inversão da onda T de V1‐V3. A angioTC foi negativa para tromboembolismo pulmonar.O ecocardiograma transtorácico (ETT) mostrou uma dilatação marcada do ventrículo direito com septo interauricular intacto, sem hipertensão arterial pulmonar.A ressonância magnética cardíaca (RMC) confirmou a dilatação ventricular direita e revelou hipocinesia marcada/acinesia da sua parede lateral. A prova de esforço foi negativa para isquemia.À luz dos critérios de diagnóstico de displasia arritmogénica do ventrículo direito (DAVD), preconizados pela Task Force (TF) de 2010, este doente apresentava dois critérios major (na RMC: acinesia ou discinesia regional do VD e fração de ejeção ≤ 40%; no eletrocardiograma: ondas T invertidas nas derivações pré‐cordiais direitas [V1‐3]) e um minor (no electrocardiograma dinâmico de 24 horas [ECGD/Holter 24 horas] > 500 extrassístoles ventriculares), pelo que o diagnóstico definitivo foi assumido.Após o estudo eletrofisiológico, o doente foi submetido a colocação de cardioversor‐desfibrilhador implantável (CDI) monocâmara, encontrando‐se assintomático desde então.Esta apresentação tardia de DAVD evidencia a importância do rastreio por ETT, complementado por RMC. O risco de morte súbita cardíaca foi aferido pelo estudo eletrofisiológico, conduzindo à implantação do CDI. Estudos de associação genética devem ser oferecidos aos descendentes do paciente. Abstract: A 67‐year‐old man was admitted to our hospital after episodes of syncope preceded by malaise and diffuse neck and chest discomfort. No family history of cardiac disease was reported. Laboratory workup was within normal limits, including D‐dimers, serum troponin I and arterial blood gases. The electrocardiogram showed sinus rhythm with T‐wave inversion in leads V1 to V3. Computed tomography angiography to investigate pulmonary embolism showed no abnormal findings. Transthoracic echocardiography (TTE) displayed massive enlargement of the right ventricle with intact interatrial septum and no pulmonary hypertension. Cardiac magnetic resonance imaging (MRI) confirmed right ventricular (RV) dilatation and revealed marked hypokinesia/akinesia of the lateral wall. Exercise stress testing was negative for ischemia.According to the 2010 Task Force criteria for arrhythmogenic right ventricular dysplasia (ARVD), this patient presented two major criteria (global or regional dysfunction and structural alterations: by MRI, regional RV akinesia or dyskinesia or dyssynchronous RV contraction and RV ejection fraction ≤40%, and repolarization abnormalities: inverted T waves in right precordial leads [V1, V2, and V3]); and one minor criterion (>500 ventricular extrasystoles per 24 hours by Holter), and so a diagnosis of ARVD was made.After electrophysiologic study (EPS) the patient received an implantable cardioverter‐defibrillator (ICD).This late clinical presentation of ARVD highlights the importance of TTE screening, possibly complemented by MRI. The associated risk of sudden death was assessed by EPS leading to the implantation of an ICD. Genetic association studies should be offered to the offspring of all ARVD patients. Palavras‐chave: Displasia arritmogénica do ventrículo direito, Ecocardiografia transtorácica, Ressonância magnética cardíaca, Morte súbita cardíaca, Estudo eletrofisiológico cardíaco, Cardioversor‐desfibrilhador implantável, Keywords: Arrhythmogenic right ventricular dysplasia, Transthoracic echocardiography, Magnetic resonance imaging, Sudden cardiac death, Cardiac electrophysiologic study, Implantable cardioverter‐defibrillator

On theoretical grounds, interstitial current injected and removed using electrodes in close proximity does not cross the membrane, while equilibration of intracellular and interstitial potentials occurs distant from electrodes widely separated. Multisite interstitial stimulation should therefore give rise to interstitial potential differences recorded centrally that depend on intracellular and interstitial micro-impedances, allowing independent measurement. We tested the feasibility of completing such measurements using simulations of multisite stimulation with fine and wide spacing in models that included Luo-Rudy dynamic (LRd) membrane equations. Using two-dimensional models, test data (delta phi o) were generated with isotropic interstitial and intracellular micro-impedances prescribed for one set of simulations, and with anisotropic micro-impedances including unequal ratios (intracellular/interstitial) along and across fibers prescribed for another set of simulations. Micro-impedance measurements were then obtained by making statistical comparisons between delta phi o values and interstitial potential differences from passive bidomain simulations (Delta phi o) in which a wide range of possible micro-impedances were considered. Our findings suggest development of microfabricated devices to implement the multisite stimulation procedure would facilitate routine measurement as a component of cardiac electrophysiologic study.

Five patients that met the electrocardiographic criteria for left middle fascicular block underwent a cardiac electrophysiologic study and electrical endocardial mapping of both right and left ventricles. All patients also fulfilled the electrocardiographic criteria for left anterior fascicular block but no one showed right bundle branch block. The electrical endocardial mapping used the technical procedures described by Josephson et al. elsewhere. Comparisons between the points of endocardial activation to the right and left ventricle were made. The differences between these points are shown in Fig. 1 below. Notice that there are great differences of the activation time of the free walls of both ventricles. This is the result of a conduction delay in the regions 9, 10, 11, and 12 of the electrical endocardial mapping confirming the presence of that left middle fascicular block.

Two patients with incessant or nearly incessant episodes of atrioventricular (AV) reciprocating tachycardia were studied and were found to be unique because of the location of a slowly conducting retrograde AV bypass pathway in the left lateral position. During the tachycardia in both patients, negative P waves were present not only in ECG leads II, III, and aVF, but also in leads I and aVL. The R-P'/P'-R ratios were 1.3 and 1.9, respectively. Cardiac electrophysiologic study revealed that in both tachycardias, retrograde ventriculoatrial conduction occurred utilizing a concealed left lateral AV bypass pathway with a long conduction time. Verapamil prolonged conduction over the AV bypass pathway in both patients. One patient was successfully treated with oral verapamil. The other patient underwent successful surgical interruption of the AV bypass pathway.

Interest in defining the correct protocol to use to initiate and evaluate ventricular tachyarrhythmias has recently grown because of expanding clinical use of cardiac electrophysiologic study. Investigators have been aware of the large influence which seemingly small details of the stimulation technique have upon the results of ventricular stimulation. For example, Swerdlow and colleagues [1] found that a third extrastimulus produced far more false-negative predictions of drug efficacy than a maximum of two extrastimuli. Though uniformity of protocols has increased with each new publication on the topic, there remains considerable divergence from laboratory to laboratory. Furthermore, the rationale for many ‘standard,’ uniformly applied features of existing protocols is not developed.