Radiofrequency ablation for the pre-excitation syndrome of functionally corrected transposition of great arteries.

We reported a 57-year-old female patient who had functionally corrected transposition of the great arteries, severe tricuspid insufficiency, enlarged left atrium and functional right ventricle, which were successfully performed radiofrequency ablation.

Electro-vectorcardiographic demonstration of bifascicular block associated with ventricular preexcitation.

Down syndrome occurs more frequently in the offsprings of older pregnant women and may be associated with atrioventricular septal defect. This refers to a broad spectrum of malformations characterized by a deficiency of the atrioventricular septum and abnormalities of the atrioventricular valves caused by an abnormal fusion of the superior and inferior endocardial cushions with the midportion of the atrial septum and the muscular portion of the ventricular septum.

Preexcitation syndrome: experimental study on the electrocardiogram of antegradely conducting accessory pathway.

BACKGROUND: Preexcitation syndrome is characterized by a dominant delta wave on the baseline electrocardiogram (ECG), resulting from the change in QRS initial vector by the accessory pathway (AP). This study is to explore the effect of ventricular preexcitation on the QRS initial, maximal and terminal vector in an experimental rabbit with preexcitation syndrome induced by programmed electrical stimulation. METHODS: Rabbits (n = 10) were randomized for the experimental model of ventricular preexcitation. Sensing and stimulating electrode catheters were placed in the high right atrium and along epicardial surface of atrioventricular groove of the left ventricular anterior wall, respectively. Programmed premature stimulation S2 was synchronized with P wave and utilized to stimulate the ventricle. The ECG recorded the electrical activity of the heart. As compared with the QRS complex during sinus rhythm, paced QRS was assessed regarding the initial, maximal and terminal vector. PS2 interval and PR interval were also measured and analyzed. RESULTS: Preexcitation was successfully simulated by ventricular pacing in the rabbits, including (1) Complete preexcitation: PS2 interval was less than PR interval; the difference was more than or equal to 47.00 ± 7.53 ms. (2) Incomplete preexcitation: PS2 interval was less than PR interval; the difference was less than 47.00 ± 7.53 ms. (3) Incomplete latent preexcitation: PS2 interval was more than or equal to PR interval; the difference was less than or equal to 13.00 ± 3.50 ms. (4) Complete latent preexcitation: PS2 interval was more than or equal to PR interval; the difference was more than 13.00 ± 3.50 ms. CONCLUSIONS: The difference in the relative conduction velocity of the atrioventricular node versus the AP pathways determines the degree of preexcitation and different manifestation on ECG. The QRS terminal vector also reflects the ventricle preexcitation, indicating a valuable sign for the diagnosis of atypical or latent preexcitation.

Specificity of wide QRS complex tachycardia criteria and algorithms in patients with ventricular preexcitation.

BACKGROUND: Despite substantial progress in the field of differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (SVT) with wide QRS complexes, differentiation between VT and preexcited SVT remains largely unresolved due to significant overlap in QRS morphology. Our aim was to assess the specificities of various single ECG criteria and sets of criteria (Brugada algorithm, aVR algorithm, Steurer algorithm, and the VT score) for diagnosis of VT in a sizable cohort of patients with preexcitation. METHODS: We performed a retrospective study of consecutive accessory pathway ablation procedures to identify preexcited tachycardias. Among 670 accessory pathway ablation procedures, 329 cases with good quality ECG with either bona fide preexcited SVT (n = 30) or a surrogate preexcited SVT (fast paced atrial rhythm with full preexcitation, n = 299) were identified. ECGs were analyzed with the use of wide QRS complex algorithms/criteria to determine specificities of these methods. RESULTS: The Steurer algorithm and VT score (≥3 points), with specificities of 97.6% and 96.1%, respectively, were significantly (p < .01) more specific for the diagnosis of VT than Brugada algorithm, aVR algorithm, and Pava criterion with specificities of 31%, 11.6%, and 57.1%, respectively. The first step of the Brugada algorithm and the first step of the aVR algorithm had also high specificities of 93.3% and 96.0%, respectively. CONCLUSION: There are sufficient electrocardiographical differences between VT and preexcited SVT to allow electrocardiographic differentiation. VT score, Steurer algorithm, and some single criteria do not overdiagnose VT in patients with preexcitation.

Premature ventricular contraction-induced concealed retrograde penetration: Electrocardiographic manifestations on anterograde ventricular preexcitation.

In patients with manifest anterograde ventricular preexcitation, the electrocardiographic manifestation of the anomalous conduction through the simultaneous conduction over the atrioventricular (AV) node and the accessory pathway ("delta wave"); depends on several factors, the most representative being the conduction velocity over one or another connection. Occasionally, ventricular ectopic beats may present with retrograde penetration over one or both conduction pathways (AV node and/or accessory pathway), impacting on the morphology of the next immediate anterogradely conducted QRS. We present a case of a young patient with WPW syndrome and ectopic ventricular beats with different manifestations on the postectopic QRS due to concealed penetration of different conduction pathways.

Respuesta al ECG de octubre de 2017 / Response to ECG, October 2017

No disponible

Cardiac resynchronization therapy by ablation of right-anterolateral accessory pathway.

Ventricular preexcitation caused by right-sided accessory pathways can lead to abnormal septal motion patterns and may be associated with left ventricular (LV) dysfunction and heart failure, despite the lack of a clinical arrhythmia. Hence successful ablation of the accessory pathway abolishes not only preexcitation but also ventricular dyssynchrony in these patients. We describe a case of an asymptomatic 20-year-old male presenting with ventricular Type-B preexcitation combined with LV dysfunction. The individual risk of arrhythmic events was enhanced due to competitive sport activities of the patient and a short antegrade refractory period of the accessory pathway. Hence standard radiofrequency ablation of the right anterolateral accessory pathway was performed, despite no history of tachycardia. After successful accessory pathway ablation, normalization of LV size and function was demonstrated by echocardiography with a long-term follow-up of 4 years.

[Echocardiography with reconstructed M-mode: technical aspects and clinical applications]. / Ecocardiografia con M-mode ricostruito: aspetti tecnici e applicazioni cliniche.

Reconstructed M-mode imaging is a new post-processing technique that permits the reconstruction of any cardiac structure and flow from cine-loops of different sources (tissue, color Doppler and tissue Doppler cine-loops) in M-mode format. This technique can be useful in a number of clinical situations and can facilitate the echocardiographic examination, allowing for correct and easy M-mode analysis to be performed at any time, both at the patient's bedside as well as off-line. In this paper the fundamental technical features and current clinical applications of reconstructed M-mode imaging are illustrated and discussed.

Determinants and prognostic implications of terminal QRS complex distortion in patients treated with primary angioplasty for acute myocardial infarction.

Terminal QRS complex distortion on admission has an impact on a patient's prognosis after primary angioplasty for acute myocardial infarction (AMI). We evaluated the determinants and prognostic significance of terminal QRS complex distortion in 153 consecutive patients with AMI after primary angioplasty. The study population was divided into 2 groups according to the presence (group I, n = 41) or absence (group II, n = 112) of terminal QRS complex distortion. The primary end points were the occurrence, within 6 weeks after AMI, of death, nonfatal reinfarction, or congestive heart failure. Baseline characteristics were similar between the 2 groups. However, patients in group I had higher peak levels of serum creatine kinase than those in group II (5,100 +/- 3,100 vs 3,000 +/- 1,800 U/L, respectively, p <0.01). The rate of angiographic no-reflow (Thrombolysis In Myocardial Infarction flow grade < or =2) was 31.7% in group I and 10.7% in group II (p <0.01). The predischarge left ventricular ejection fraction was 45.0 +/- 12.0% in group I and 54.0 +/- 8.0% in group II (p <0.01). Multivariate analysis identified the pressure-derived fractional collateral flow index and the culprit lesion in the left anterior descending coronary artery as independent determinants of the terminal QRS complex distortion. No patients died during 6 weeks of follow-up. The 2 groups were similar for life-threatening arrhythmia or reinfarction. However, there were more patients in group I than in group II with congestive heart failure (26.8% vs 5.4%, respectively, p <0.01) or who reached the primary end points (29.3% vs 5.4%, respectively, p <0.01). In conclusion, terminal QRS complex distortion on admission is associated with poor clinical outcome after primary angioplasty for AMI, and collateral flow may have a major influence on terminal QRS complex distortion during AMI.

[The echocardiographic assessment of heart activity in paroxysmal tachycardia in children]. / Ekhokardiograficheskaia otsenka deiatel'nosti serdtsa pri paroksizmal'noi takhikardii u detei.

The echocardiograms of 42 children were examined during paroxysmal tachycardia attacks, as well as 15 minutes and 5 days after them. During paroxysms the electrical and mechanical cardiac activity gets dissociated, the end diastolic volume, the stroke index and ejection fraction decrease which is determined by the reduction of the volume load of the left ventricle because of the shortening of the diastolic phase of the cardiac cycle and the lack of the effective systole of the atria. The late diastolic opening of the mitral valve could not be recorded on the echocardiogram. During the interictal period, the most significant disorders of the cardiodynamics and alterations in the anatomical parameters were discovered in senior children suffering from paroxysmal tachycardia for 3 to 5 years and more.

[Significance of isotopes in the study of pre-excitation and ventricular tachycardia]. / Intérêt des isotopes dans l'étude des préexcitations et des tachycardies ventriculaires.

In normal patients, Mac Carthy has demonstrated that there was a very close correlation between the ventricular contractile activity, evaluated by Fourier's isotopic phase analysis, and electrical depolarization, evaluated by endocardial mapping. It has therefore been possible to study asynchronisms or asymmetries of the ventricular contraction-depolarization and particularly the syndromes of ventricular pre-excitation and ventricular tachycardias. In Wolff-Parkinson-White syndromes (WPW), the mapping obtained by heart cavity tomography in addition to dual-plane gamma-angiography, provides most useful informations, due to additional section planes permitting tridimensional location of the earliest site of ventricular activation. It is quite useful to locate the bundle of Kent always difficult on surface electrocardiogram, or when the endocardial exploration does not permit to precisely locate the site of the excentric atrial activation in case of multiple bundles of Kent or without retrograde conduction. When the left bundle of Kent is barely identified, the isotopic image may be improved by oesophageal stimulation. Additional parameters (use of several harmonics, factorial analysis) will permit to improve the localization of accessory pathways, to be destroyed by fulguration or surgery. In case of ventricular tachycardias with limited functional tolerance, only gamma-angiography, lasting only 3 to 5 minutes, may be used. Combined with endocardial tomography or even gamma-angiography performed in sinus rhythm, not only the site of origin of the ventricular ectopy may be localized, but it also can be correlated with ventricular kinetics abnormalities and the cardiopathy in question may be identified. Most authors consider that there is a close relationship between isotopic site, electrocardiographic appearance and the site found by endocardial mapping or "pace-mapping". In patients with ventricular tachycardias of different morphologies, isotopic mapping permits to differentiate those originating from a same lesion (which may be treated by surgery of fulguration) from those originating in remote areas. Therefore, this technique is a non aggressive and rapid method providing accurate informations on severe rhythm disorders currently treated by eradication of their anatomical substratum.

The scintigraphic characteristics of ventricular pre-excitation through Mahaim fibers with the use of phase analysis.

The phase image pattern of blood pool scintigrams was blindly assessed in 11 patients exhibiting conduction through Mahaim pathways, including 6 nodoventricular and 5 fasciculoventricular. These patterns were compared with the phase image findings in normal subjects, patients with left and right bundle branch block in the absence of pre-excitation and patients with pre-excitation through atrioventricular (AV) connections. In all patients with a Mahaim pathway, the site of earliest phase angle was septal or paraseptal. Phase progression was asymmetric and the pre-excited ventricle demonstrated the earliest mean ventricular phase angle in 10 of 11 patients. This pattern, and the associated ventricular phase difference, appeared to vary from that in normal subjects and in those with a septal AV connection, in whom phase progression is generally symmetric. Scintigraphic phase analysis provided localizing information and presented patterns consistent with Mahaim pathways. Although not able to differentiate among Mahaim pathway subtypes, these phase patterns differed from those in normal subjects, those with right and left lateral free wall pathways and most patients with a septal AV pathway. However, the phase pattern of patients with a Mahaim pathway may not differ from that of patients with a septal AV connection displaying an asymmetric pattern of phase progression, or those with left and right bundle branch block in the absence of pre-excitation. Objective, yet imperfect phase measurements supported these differences. Such image findings may complement the often complex electrophysiologic evaluation of patients presenting with pre-excitation.

Massive ST-segment elevation in precordial and inferior leads in right ventricular myocardial infarction.

This report describes a case of right ventricular infarction in which massive ST-segment elevation in the precordial and inferior leads was observed. The maximum magnitude of the ST-segment elevation in the precordial leads was 21 mm in lead V2 and that in the inferior leads was 10 mm in lead II. Angiography revealed a reduction of 90% in the diameter of the right coronary artery in its proximal portion and a normal left coronary system. Recent reports have shown that precordial ST-segment elevation may reflect right ventricular infarction. However, no previously reported instance except our case has shown massive ST-segment elevation in both the precordial and inferior leads. In right ventricular infarction, the current of injury is usually simultaneously present in the right ventricular free wall and left ventricular inferior wall, electrically opposed to each other. Thus, the diffuse and massive ST-segment elevation observed in this study seems to be a rare phenomenon.

Exercise thallium testing in ventricular preexcitation.

Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation.

Phase analysis of gated blood pool scintigraphic images to localize bypass tracts in Wolff-Parkinson-White syndrome.

The ability of radionuclide techniques to localize bypass tracts in patients with Wolff-Parkinson-White syndrome to sites around the atrioventricular (AV) ring using a three view triangulation method was investigated. In 17 patients with Wolff-Parkinson-White syndrome, phase images were generated from gated blood pool scans using the first Fourier harmonic of the time-activity curve of each pixel. In addition, the difference between left and right ventricular mean phase angles was calculated for each patient and for 13 control subjects. Bypass tracts were localized to one or more sites on a 10 site grid schematically superimposed on the AV ring (Duke grid) by electrophysiologic study in all patients and by intraoperative mapping in 7 of the 17 patients. These same 10 anatomic sites were projected onto three scintigraphic views and the site of earliest ventricular phase angle was located in each view. The 10 sites around the AV ring were divided into two anatomic groups: free wall and septal/paraseptal. Phase image locations correlated with electrophysiologic locations within one grid site in 11 of 11 patients with free wall tracts and were confirmed at surgery in 5 of the 11. In five of six patients with septal/paraseptal tracts, electrophysiologic study could not localize the bypass tract to one site, whereas phase images localized two of the five as free wall adjacent to the septum, one as paraseptal and two as true posteroseptal. One posteroseptal site was confirmed at surgery. In one patient, in whom phase image analysis and electrophysiologic study showed different sites, existence of both tracts was confirmed at surgery.(ABSTRACT TRUNCATED AT 250 WORDS)