Eduardo Back Sternick

Appraisal of " Mahaim" Automatic Tachycardia

“Mahaim” Automatic Tachycardia. A series of four patients with right‐sided accessory pathways with long conducting times and decremental properties is reported. All patients underwent radiofrequency catheter ablation, and target areas were guided by a discrete “Mahaim” potential recorded at the lateral aspect of the tricuspid valve. A slow automatic and irregular rhythm with a QRS morphology similar to that of a fully preexcited QRS complex occurred during radiofrequency current delivery. The occurrence of so‐called “Mahaim” automatic tachycardia heralded successful elimination of the accessory pathway in a manner similar to that of junctional automatic rhythm during slow pathway ablation in patients with AV nodal reentrant tachycardia. The observation of an automatic rhythm brought about during radiofrequency current ablation of a Mahaim‐like accessory pathway is electrophysiologic evidence of the accessory AV nodal behavior of this structure.

Sudden cardiac death in patients with chagas heart disease and preserved left ventricular function.

Sudden Cardiac Death in Patients with Chagas Heart Disease and Preserved Left Ventricular Function EDUARDO BACK STERNICK, M.D., PH.D., MARTINO MARTINELLI, M.D., PH.D.,∗ ROGÉRIO CORREIA SAMPAIO, M.D., LUIZ MÁRCIO GERKEN, M.D., RICARDO ALKMIM TEIXEIRA, M.D.,∗ RICARDO SCARPELLI, M.D., MAURÍCIO SCANAVACCA, M.D., PH.D.,∗ SILVANA D ́ORIO NISHIOKA, M.D.,∗ and EDUARDO SOSA, M.D., PH.D.∗ From the Arrhythmia and Electrophysiology Unit, Biocor Instituto, Nova Lima, Brazil, and ∗Arrhythmia and Pacemaker Unit, Heart Institute, São Paulo University, São Paulo, Brazil

Clinical, electrocardiographic, and electrophysiologic characteristics of patients with a fasciculoventricular pathway: The role of PRKAG2 mutation

BACKGROUND The ECG, clinical, and electrophysiologic profiles of patients with a fasciculoventricular pathway are well described. Fasciculoventricular pathways occurring in the setting of glycogen storage cardiomyopathy possess unique features. OBJECTIVE The purpose of this study was to compare the clinical, ECG, and electrophysiologic characteristics of patients with a fasciculoventricular pathway, with or without glycogen storage cardiomyopathy. METHODS Two groups of patients with a fasciculoventricular pathway were compared: group A consisted of 10 patients with the PRKAG2 mutation (Arg302gln), and group B consisted of 9 patients without the mutation. RESULTS Thirty percent of group A patients had left ventricular hypertrophy, and none had an additional accessory pathway. Group B patients had no structural heart disease, and 33% had an additional accessory pathway. Group A patients had a slower resting heart rate (56 ± 7 vs 75 ± 10 bpm, P <0.0001), a wider QRS complex (0.15 ± 0.01 vs 0.11 ± 0.02 ms, P = .0004), and a longer HV interval (34 ± 1 vs 25 ± 3 ms, P = .0003). During long-term follow-up, 50% of group A patients developed complete AV block versus none in group B. Eighty percent of group A patients developed atrial flutter and/or atrial fibrillation. No Group B patient had any arrhythmia during follow-up after successful ablation of additional arrhythmia circuits. No sustained ventricular arrhythmia was induced in any patient from either group. CONCLUSION Patients with a fasciculoventricular pathway associated with the PRKAG2 mutation have distinct clinical, ECG, and electrophysiologic profiles and should be correctly identified because of their ominous long-term prognosis. Patients without the mutation have an excellent arrhythmia-free prognosis after treatment of additional circuits.

Familial Pseudo-Wolff-Parkinson-White Syndrome

Introduction: PRKAG2 plays a role in regulating metabolic pathways, and mutations in this gene are associated with familial ventricular preexcitation, hypertrophic cardiomyopathy, and atrioventricular conduction disturbances. Clinico‐pathologic and experimental data suggest the hypothesis of a glycogen storage disease.

Epilepsy or Syncope? An Analysis of 55 Consecutive Patients with Loss of Consciousness, Convulsions, Falls, and No EEG Abnormalities

Background:  Patients with loss of consciousness and convulsion often have the diagnosis of epilepsy despite normal electroencephalograms (EEGs).

Effects of Right Bundle Branch Block on the Antidromic Circus Movement Tachycardia in Patients with Presumed Atriofascicular Pathways

Background: The typical and most common tachycardia in patients with atriofascicular pathways is a macro reentrant tachycardia, with anterograde conduction over the decrementally conducting bypass tract and retrograde conduction over the right bundle branch‐His‐AV node axis resulting in a short V‐right bundle branch and short V‐H interval.

Characterization of the distal insertion of atriofascicular accessory pathways and mechanisms of QRS patterns in atriofascicular antidromic tachycardia

BACKGROUND The distal insertion of right atriofascicular pathways remains a source of debate. Moreover, there are various morphologies of preexcited QRS complexes involving atriofascicular pathways that have been poorly characterized. OBJECTIVE To characterize the distal insertion of atriofascicular accessory pathways and to provide a mechanism for the change in QRS morphology observed between short and long ventriculo-His (V-H) antidromic atrioventricular reentrant tachycardias (AVRTs) in the same patient. METHODS Thirteen patients with atriofascicular pathways and preexcited AVRT with short V-H and long V-H intervals were studied. For each patient, the tachycardia cycle length, V-H interval, QRS width, and axis were compared. A baseline His-ventricular interval was also recorded. RESULTS The baseline His-ventricular interval was significantly longer than the V-H interval during antidromic AVRT (median 50 ms vs. 10 ms; P < .0001). Retrograde right bundle branch block increased the V-H interval (median 10 ms vs. 85 ms; P < .0001), the tachycardia cycle length (median of 302.5 ms vs. 350 ms; P < .0001), and the QRS width (median 120 ms vs. 140 ms; P < .0002). At least subtle changes in QRS morphology, axis, or QRS width were seen in all patients. CONCLUSIONS The distal insertion of right atriofascicular pathways fuses with the right bundle branch. The various QRS morphologies seen during the change from short V-H to long V-H antidromic AVRT can be explained by fusion, particularly over the left anterior fascicle.

Radiofrequency catheter ablation of an accessory pathway in a patient with Wolff-Parkinson-White and Kartagener's syndrome.

We report a case of a manifest left free wall accessory pathway in a patient with Kartageners syndrome and recurrent episodes of orthodromic atrioventricular reentrant tachycardia. To the best of our knowledge, it is the first report of Wolff‐Parkinson‐White syndrome associated with Kartageners syndrome. Situs inversus and mirror image dextrocardia occurred with no additional detectable cardiac structural abnormalities. Diagnostic and therapeutic electrophysiological study was carried out via transaortic approach and a left‐to‐right reversal of monoplane fluoroscopic image. (PACE 2004; 27:401–404)

The 12-Lead ECG in Patients with Mahaim Fibers

The aim of this review article is to discuss the electrocardiographic presentation of the so called variants of pre‐excitation (“Mahaim fibers”) during sinus rhythm and tachycardia.

Postablation-acquired short atrioventricular Mahaim-type fibers: Observations on their clinical, electrocardiographic, and electrophysiologic profile

BACKGROUND The electrophysiologic characteristics of decrementally conducting accessory pathways (APs) are well described; however, little is known about decrementally conducting APs caused by the radiofrequency ablation of a rapidly conducting AP. OBJECTIVE To report the clinical, electrocardiographic, and electrophysiologic characteristics of 6 patients who developed a decremental AP after an attempt at ablation. METHODS We compared the clinical and electrophysiologic characteristics of 295 consecutive patients with the Wolff-Parkinson-White syndrome who underwent radiofrequency ablation of 311 manifest APs (group A) with those of 6 patients with the Wolff-Parkinson-White syndrome in whom a decrementally conducting AP was detected after an attempt at ablation. RESULTS The AP ablation site in group B patients was at the coronary sinus ostium region in 3 patients, middle cardiac vein in 2 patients, and left posteroseptal region in 1 patient. Sixty-two bypass tracts in group A patients and all 6 in group B patients were ablated at these locations, while 249 bypass tracts in group A patients and none in group B patients were ablated elsewhere (P = .0001). Five of the 6 patients (83%) with acquired Mahaim physiology had an AP located in the venous system. The odds for developing an acquired decremental antegrade atrioventricular AP when it was located inside the venous system were 1 in 6. All group B decremental APs were sensitive to adenosine, but none in 85 group A patients (P <.0001). CONCLUSIONS The risk for developing decremental conduction after the ablation of a rapidly conducting AP is greater for APs inside the coronary venous system. Acquired decremental antegrade atrioventricular APs are electrophysiologically similar to de novo ones. They are capable of being part of an arrhythmia circuit and, therefore, should be targeted for ablation.