Mapeo y ablación exitosa, desde el interior de la vena cardíaca magna, de extrasístoles ventriculares originados en el techo (summit) del ventrículo izquierdo / Mapping and successful ablation, from within the great cardiac vein, of premature ventricular contractions originating from the summit of the left ventricle

RESUMEN Se presenta el caso de una paciente de 43 años, con antecedentes de salud aparente, hasta varias semanas previas a su ingreso, cuando comenzó a presentar síncopes precedidos de palpitaciones. Se realizó estudio electrofisiológico y se demostró precocidad en la porción distal del electrodo de registro de seno coronario, que corresponde a la vena cardíaca magna (interventricular anterior) y techo (summit) del ventrículo izquierdo. A pesar del excelente registro precoz se estudiaron estructuras vecinas como el tracto de salida del ventrículo izquierdo en la cúspide coronaria izquierda, aquí el mapeo eléctrico (pace mapping) no fue concordante total. En el sitio de la precocidad obtenida dentro del sistema venoso cardíaco se realizó mapeo concordante 100%, con una precocidad del catéter de ablación de -30 milisegundos. Se decidió ablación con incrementos progresivos de temperatura y potencia con corte de impedancia (termomapping) y se logró el éxito de la ablación sin reproducibilidad de la arritmia y excelente evolución posterior.

ABSTRACT The case of a 43-year-old female patient is presented, with an apparent history of good health, up to several weeks prior to admission, when she began to present syncopes preceded by palpitations. An electrophysiological study was performed and prematurity in the distal portion of the coronary sinus recording electrode was demonstrated, which corresponds to the great cardiac vein (anterior interventricular vein) and summit of the left ventricle. Despite the excellent early registration, neighboring structures were studied, such as the left ventricular outflow tract in the left coronary cusp, here the pace mapping was not totally concordant. At the site of the precocity obtained within the cardiac venous system, a 100% concordant mapping was achieved, with an ablation catheter's precocity of -30 milliseconds. The ablation was decided with progressive increases in temperature and power with thermomapping and the success of the ablation was achieved without reproducibility of the arrhythmia and excellent subsequent evolution.

Real-time premature ventricular contractions detection based on Redundant Discrete Wavelet Transform

Abstract Introduction Premature Ventricular Contraction (PVC) is among the most common types of ventricular cardiac arrhythmia. However, it only poses danger if the person suffers from a heart disease, such as heart failure. Hence, this is an important factor to consider in heart disease people. This paper presents an ECG real-time analysis system for PVC detection. Methods This system is based on threshold adaptive methods and Redundant Discrete Wavelet Transform (RDWT), with a real-time approach. This analysis is based on wavelet coefficients energy for PVC detection. It is presented also a study to find the most indicated wavelet mother for ECG analysis application among the following wavelet families: Daubechies, Coiflets and Symlets. The system detection performance was validated on the MIT-BIH Arrhythmia Database. Results The best results were verified with db2 wavelet mother: the Sensitivity Se = 99.18%, Positive Predictive Value P+ = 99.15% and Specificity Sp = 99.94%, on 80.872 annotated beats, and 61.2 s processing speed for a half-hour record. Conclusion The proposed system exhibits reliable PVC detection, with real-time approach, and a simple algorithmic structure that can be implemented in many platforms.

Differentiating origins of outflow tract ventricular arrhythmias: a comparison of three different electrocardiographic algorithms

Our objective is to evaluate the accuracy of three algorithms in differentiating the origins of outflow tract ventricular arrhythmias (OTVAs). This study involved 110 consecutive patients with OTVAs for whom a standard 12-lead surface electrocardiogram (ECG) showed typical left bundle branch block morphology with an inferior axis. All the ECG tracings were retrospectively analyzed using the following three recently published ECG algorithms: 1) the transitional zone (TZ) index, 2) the V2 transition ratio, and 3) V2 R wave duration and R/S wave amplitude indices. Considering all patients, the V2 transition ratio had the highest sensitivity (92.3%), while the R wave duration and R/S wave amplitude indices in V2 had the highest specificity (93.9%). The latter finding had a maximal area under the ROC curve of 0.925. In patients with left ventricular (LV) rotation, the V2 transition ratio had the highest sensitivity (94.1%), while the R wave duration and R/S wave amplitude indices in V2 had the highest specificity (87.5%). The former finding had a maximal area under the ROC curve of 0.892. All three published ECG algorithms are effective in differentiating the origin of OTVAs, while the V2 transition ratio, and the V2 R wave duration and R/S wave amplitude indices are the most sensitive and specific algorithms, respectively. Amongst all of the patients, the V2 R wave duration and R/S wave amplitude algorithm had the maximal area under the ROC curve, but in patients with LV rotation the V2 transition ratio algorithm had the maximum area under the ROC curve.

Radiofrequency ablation can reverse the structural remodeling caused by frequent premature ventricular contractions originating from the right ventricular outflow tract even in a normal heart

OBJECTIVE: The aim of this study was to evaluate whether frequent premature ventricular contractions originating from the right ventricular outflow tract remodel the cardiac structure and function in patients with a “seemingly normal heart” and whether radiofrequency ablation can reverse this remodeling. METHODS: Sixty-eight patients with idiopathic frequent premature ventricular contractions originating from the right ventricular outflow tract and normal heart structure and function were enrolled in this study. The patients were divided into three groups according to the therapeutic method: radiofrequency ablation group (24 cases), anti-arrhythmia drug group (26 cases), and control group (18 cases without any treatment). Clinical Registration number: ChiCTR-ONRC-12002834 RESULTS: The basic patient characteristics were comparable between the three groups, except for the premature ventricular contraction rate, which was significantly lower in the control group. After six months of follow up, the premature ventricular contraction rate was significantly reduced in the radiofrequency ablation group, which was accompanied by a significant decrease in the following cardiac cavity inner diameters, as determined by echocardiography: right atrium (33.33±3.78 vs. 30.05±2.60 mm, p = 0.001), right ventricle (23.24±2.40 vs. 21.05±2.16 mm, p = 0.020), and left ventricle (44.76±4.33 vs. 41.71±3.44 mm, p = 0.025). These results were similar in the anti-arrhythmia drug group, although this group exhibited a smaller extent of change (right atrium: 33.94±3.25 vs. 31.27±3.11 mm, p = 0.024; right ventricle: 22.97±3.09 vs. 21.64±2.33 mm, p = 0.049; left ventricle: 45.92±6.38 vs. 43.84±5.67 mm, p = 0.039), but not in the control group (p>0.05). There was a tendency toward improvement in the cardiac functions in both the radiofrequency ablation and anti-arrhythmia drug groups. However, ...

What are we missing? Arrhythmia detection in the pediatric intensive care unit.

OBJECTIVES: To test the hypothesis that instituting a process of routine daily review of rhythm alarms in non-cardiac patients in the pediatric intensive care unit would yield clinically important disturbances that would otherwise go undetected. STUDY DESIGN: A prospective observational study was performed over a consecutive 28-day period. Total bedside monitor alarms, rhythm alarms, and heart rate (HR) trends were recorded. Rhythm alarm recordings were reviewed independently by two study team members. Medical records for patients with critical arrhythmias were reviewed to evaluate for prior knowledge of the event and to correlate with clinical data. RESULTS: We evaluated 86 patients (343 patient-days). There were 54,656 total monitor alarms (159.3 alarms/patient-day), of which 19,970 (37%) were rhythm alarms, including 4032 (20%) critical arrhythmias. Fifty-six percent of the critical alarms were artifactual. Seventeen of the 1786 ventricular tachycardia alarms represented true episodes that occurred in 5 patients. Two patients' care were altered as a result of detection of the arrhythmia in the review process. Eight hundred sixty-five (98%) of the 883 true critical alarms reviewed were for extreme HR. Eighty-three percent (5172) of the 6239 true non-critical alarms reviewed were HR alarms. CONCLUSIONS: Daily review of rhythm alarms improves detection of clinically relevant arrhythmias in non-cardiac pediatric intensive care unit patients.