Electrophysiological characteristics and radiofrequency ablation of right atrial flutter.

This study aimed to elaborate the electrophysiology characteristics and radiofrequency ablation (RFA) results of atrial flutter (AFL) which has not been established in Indonesia. Three multipolar catheters were inserted percutaneously and positioned into coronary sinus (CS), His bundle area and around tricuspid annulus. Eight mm ablation catheter was used to make linear ablation at CTI of typical and reverse typical AFL. Bidirectional block was confirmed by conduction time prolongation of more than 90 msec from low lateral to CS ostium and vice versa, and/or by means of differential pacing. Thirty AFL from 27 patients comprised of 19 typical AFL, 5 reverse typical AFL and 6 atypical AFL enrolled the study. Mean tachycardia cycle length (TCL) were 261.8 ± 42.84, 226.5 ± 41.23, and 195.4 ± 9.19 msec, respectively (p = 0.016). CTI conduction time occupied up to 60% of TCL with mean conduction time of 153.0 ± 67.37 msec. CS activation distributed to three categories which comprised of proximal to distal, distal to proximal and fusion activation. Only nine of 27 patients had no structural heart disease. RFA of symptomatic typical and reverse typical AFL demonstrated 96% success and 4.5 % recurrence rate during 13 ± 8 months follow up. Typical AFL is the predominant type of AFL in our population. The majority of AFL cases suffered from structural heart disease. RFA was highly effective to cure typical and reverse typical AFL.

Left-sided approach of AV junction ablation for drug refractory atrial fibrillation.

AV junction ablation has been proven effective to treat symptomatic atrial fibrillation refractory to antiarrhythmias or fail of pulmonary vein isolation. However, about 15% of conventional right-sided approach AV junction ablation failed to produce complete heart block. This study aimed to characterize His bundle potential at ablation site during conventional or left-sided approach of AV junction ablation. Twenty symptomatic AF patient (age of 60.5 ± 9.28 and 11 are females) underwent conventional AV junction ablation. If 10 applications of radiofrequency energy are failed, then the ablation was performed by left-sided approach. Seventeen patients are successfully ablated by conventional approach. In 3 patients, conventional was failed but successfully ablated by left-sided approach. The His bundle amplitude at ablation site was significantly larger in left-sided than correspondence right-sided (16.0 ± 4.99 mm vs. 6.9 ± 4.02 mm respectively, p = 0.001, 95% CI -14.0 to -4.3). ROC analysis of His bundle potential amplitude recorded from right-sided revealed that cut off point of > 4.87 mm given the sensitivity of 81.3% and specificity of 53.8% for successful right-sided approach of AV junction ablation. In case of failed conventional approach, the left-sided approach is effective for AV junction ablation. An early switch to the left-sided approach may avoid multiple RF applications in patients with a low amplitude His-bundle potential (< 4.87 mm).

QT dispersion, a simple tool to predict ventricular tachyarrhythmias and/or sudden cardiac death after myocardial infarction.

Recent studies showed contradictive results of the relation between QT dispersion and the occurrence of ventricular tachyarrhythmias and/or sudden cardiac death. In addition, beta adrenoreceptors blocking agents, which are known to decrease the incidence of lethal arrhythmias after myocardial infarction, administered to the majority of patients in those studies population. Since β -blocker as secondary prevention drug was underutilized at National Cardiovascular Center Harapan Kita, this study was performed to find out the relation between QT dispersion and ventricular tachyarrhythmias and/or sudden cardiac death after previous myocardial infarction. The QT interval duration, QT dispersion and clinical variables of 36 postinfarction patients with history of sustained ventricular tachyarrhythmias and/or sudden cardiac death (event group) were compared with 75 postinfarction patients without such events (control group). QT dispersion differed significantly between study groups and was increased in the event group (115 ± 41 msec vs 81 ± 25 msec, p < 0.001). Corrected maximal QT interval duration was also prolonged in the event group (534 ± 56 vs 501 ± 35 msec, p < 0.001). Regression analysis showed that increasing QT dispersion was related to the occurrence of ventricular tachyarrhythmias and/or sudden cardiac death with OR of 3.2, 4, and 5.8 for cut-off point of 80, 90, and 100 msec respectively. The QT dispersion could predict the occurrence of ventricle tachyarrhythmias and/or sudden cardiac death in patient with AMI. This study confirmed that the QTd remain useful in free of beta blocking agents state.

Lesión vestibular periférica secundaria al traumatismo encéfalo craneal / Peripheral vestibular lesion after head trauma

La sintomatología otoneurológica se aprecia frecuentemente en el síndrome postcontusional encefálico, predominando síntomas en forma de vértigo postural, desequilibrio corporal, tinnitus e hipoacusia. La actual experiencia clínica y experimental sugiere una clara relación entre la cuantía del traumatismo encéfalo craneal y el grado de secuela vestíbulo-coclear. El análisis de dos grupos de pacientes con síndrome vestíbulo-craneal post-traumatismo encéfalo craneal diferenciados por su perfil evolutivo temporal entrega indicios de que la persistencia de la lesión laberíntica no compensada a nivel de los núcleos vestibulares centrales participa en la génesis del síndrome post contusional mediante la distorsión de los reflejos vestíbulo-ocular y vestíbulo-espinal. El hallazgo de alteraciones concomitantes en dos reflejos de seguimiento ocular (interacción visual-vestibular-oculomotora) en forma de nistagmus optokinético y seguimiento visual pendular reafirman estos supuestos. Paralelamente se analizan la influencia del cerebelo, interacción visual-vestibular y retículo-espinal en el proceso de la compensación vestibular central