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Biomedical subjects

L M Rodriguez

Publications and source records attributed to L M Rodriguez.

At least 19 recordsLinked to original sources
PubMed1997

Predictors for successful ablation of right- and left-sided idiopathic ventricular tachycardia.

This study reports on predictors for successful radiofrequency (RF) ablation of idiopathic ventricular tachycardia (VT) in 48 patients--35 with right ventricular (RV) outflow tract and 13 with left ventricular VT. In RV outflow tract idiopathic VT, RF ablation was successful in 29 of 35 patients (83%). The following information allowed differentiation between patients with and without a successful RF ablation: > 1 induced VT morphology (O vs 3); presence of delta wave-like beginning of the QRS (2 vs 3) and > or = 11 of 12 leads showing a "match" between the clinical VT and the pacemap (28 vs 1). Endocardial activation times were not different between both groups (-15 +/- 18 vs -4 +/- 5 ms). In left ventricle idiopathic VT, RF ablation was successful in 12 of 13 patients (92%). In patients who underwent successful ablation, 1 VT morphology was induced and no delta wave-like beginning of the QRS was present; a correlation between clinical VT and the pacemap > or = 11 of 12 leads was found and the endocardial activation time preceded the QRS (range of -5 to -58 ms [mean -30 +/- 14]). Purkinje activity was observed in 5 of 7 patients with an idiopathic VT originating from the inferoposterior region but not from the inferoapical region of the left ventricle. Four patients (14%) with RV outflow tract idiopathic VT had recurrence during a mean follow-up of 2 to 50 months (mean 30 +/- 12). Thus, (1) in RV outflow tract idiopathic VT a good pacemap was more important than an early endocardial activation time; (2) an optimal pacemap as well as an early endocardial activation time were important predictors for successful ablation of the left ventricle idiopathic VT; (3) Purkinje activity was recorded in VTs arising in the inferoposterior region of the left ventricle; and (4) factors for unsuccessful ablation for idiopathic VT were > 1 induced VT morphology, a delta wave-like beginning of the QRS, and a VT/pacemap correlation < 11 of 12 leads. Idiopathic VT can be successfully ablated with both immediate and long-term success.

Adolescent↗
PubMed1997

The asymptomatic patient with the Wolff-Parkinson-White electrocardiogram.

Sudden death can be the first manifestation of the Wolff-Parkinson-White (WPW) syndrome. The underlying mechanism being atrial fibrillation with a very high ventricular rate, because of a short anterograde refractory period of the accessory atrioventricular pathway (AP), deteriorating into ventricular fibrillation. Information on the anterograde refractory period of the AP is therefore important to recognize asymptomatic people with the WPW ECG at risk for dying suddenly. Several noninvasive tests are available to identify the low risk patient. Decision making when to interrupt the AP in asymptomatic WPW patients not at low risk requires an invasive study to document the electrophysiological properties of the AP and to determine its exact location.

Adolescent↗
PubMed1997

Radiofrequency catheter ablation of sustained monomorphic ventricular tachycardia in hypertrophic cardiomyopathy.

INTRODUCTION: Incessant monomorphic ventricular tachycardia (VT) with a right bundle branch block morphology and a northwest axis is a rare arrhythmic complication in a patient with hypertrophic cardiomyopathy and apical left ventricular aneurysm. METHODS AND RESULTS: The origin of this VT was localized using the following criteria: the presence of entrainment without fusion, equal intervals from the stimulus to the beginning of the QRS complex and from the electrogram to the QRS complex during VT, and the first postpacing interval identical to the tachycardia cycle length. Radiofrequency energy applied to the septoapical part of the apical left ventricular aneurysm terminated the tachycardia within 2 seconds. CONCLUSION: Using criteria to guide radiofrequency (RF) ablation of VT in patients with coronary artery disease, an incessant monomorphic VT in a patient with hypertrophic cardiomyopathy was successfully ablated.

Aged↗
PubMed1996

Radiofrequency catheter ablation of idiopathic ventricular tachycardia originating in the anterior fascicle of the left bundle branch.

INTRODUCTION: Idiopathic ventricular tachycardia (VT) originating in or close to the anterior fascicle of the left bundle is rare. A patient with no structural heart disease and VT with a right bundle branch block configuration and right-axis deviation underwent an electrophysiologic examination. METHODS AND RESULTS: Both endocardial activation mapping during VT and pacemapping were performed via a transseptal approach to localize the site of origin of the VT. Endocardial recordings of the His bundle and the posterior and anterior fascicles of the left bundle branch revealed an origin of the VT in or close to the anterior fascicle. The Purkinje potential at that site preceded the QRS complex by 20 msec, with pacemapping showing an optimal match between the paced rhythm and the clinical VT. RF energy delivered at this site terminated the VT. A left anterior hemiblock appeared after RF ablation. Ten months later, the patient is free from recurrences of VT. CONCLUSIONS: Idiopathic VT originating in or close to the anterior fascicle was cured by RF ablation. A Purkinje potential preceding the QRS during tachycardia and an optimal pacemap were used to guide RF ablation.

Anti-Arrhythmia Agents↗
PubMed1996

Cure of incessant pacemaker circus movement tachycardia by radiofrequency catheter ablation.

INTRODUCTION: Treatment of pacemaker circus movement tachycardia (PCMT) in patients with very long VA conduction times may present a problem. METHODS AND RESULTS: PCMT occurred in a 46-year-old woman with an uncommon AV nodal reentrant tachycardia who developed 2:1 AV block after fast pathway radiofrequency catheter (RF) ablation performed at another institution. Due to the long VA conduction time, PCMT could not be prevented by reprogramming the pacemaker or by the addition of antiarrhythmic drugs. Cure of the PCMT was obtained after selective RF ablation of the slow AV nodal pathway. CONCLUSION: RF ablation of the retrograde conduction offers another alternative for treatment of PCMT.

Catheter Ablation↗
PubMed1996

Wide complex tachycardia with atrioventricular dissociation and QRS morphology identical to that of sinus rhythm: a manifestation of bundle branch reentry.

OBJECTIVE: To determine the features that distinguish bundle branch reentry (BBR) ventricular tachycardia from a supraventricular tachycardia with aberration on the 12 lead electrocardiogram (ECG). PATIENTS: Three patients in whom premature beats (2 cases) or sustained tachycardia (2 cases) showed a QRS configuration identical to that observed during sinus rhythm. INTERVENTIONS: Programmed electrical stimulation. RESULTS: These arrhythmias were ventricular in origin and caused by a BBR mechanism, as suggested by the following data obtained during electrophysiological study: (a) an H-V interval shorter during tachycardia than during sinus rhythm; (b) A-V dissociation; (c) activation of the right bundle branch before activation of the bundle of His. The ECG of all 3 patients showed right bundle branch block with very prolonged QRS duration (0.16 to 0.20 s). Characteristically, all 3 had prolonged H-V interval during sinus rhythm. All patients had had a previous myocardial infarction and had a dilated left ventricle. CONCLUSION: The presence of (a) wide complex extrasystoles or tachycardia with a QRS morphology identical to that of sinus rhythm; (b) A-V dissociation; and (c) a very prolonged QRS duration (0.16 s or more) is suggestive of ventricular tachycardia caused by bundle branch reentry.

Aged↗
PubMed1995

Aborted sudden death in the Wolff-Parkinson-White syndrome.

In a population of 690 patients with Wolff-Parkinson-White (WPW) syndrome referred to our hospital from January 1979 to February 1995, 15 patients (2.2%) had an aborted sudden death out of the hospital. This retrospective study examines their clinical and electrophysiologic characteristics. Gender, accessory pathway localization, and presence of multiple accessory pathways were compared between patients with and without spontaneous ventricular fibrillation (VF). Whereas gender and the presence of multiple accessory pathways did not significantly differ between both groups, septally located pathways occurred significantly more often in the VF group. In patients with aborted sudden death, spontaneous VF was found significantly more often in men (13 of 15). VF was the first manifestation of the WPW syndrome in 8 patients. The remaining 7 patients had documented episodes of atrial fibrillation, circus movement tachycardia, or both (n = 2). Ten of the 15 patients were exercising or under emotional stress at the time of aborted sudden death. Only 1 patient had 2 accessory pathways. The location of the accessory pathway was septal (midseptal or posteroseptal) in 11 patients, left lateral in 4, and right lateral in 1).

Adolescent↗
PubMed1995

Cure of interfascicular reentrant ventricular tachycardia by ablation of the anterior fascicle of the left bundle branch.

INTRODUCTION: Fascicular reentrant ventricular tachycardia (VT) using the anterior fascicle of the left bundle anterogradely is rare and may produce identical QRS morphology during sinus rhythm and VT. Catheter ablation of this type of VT has not been described in detail. METHODS AND RESULTS: In a postinfarct patient with dilated left ventricle and recurrent VT (showing a QRS configuration of right bundle branch, left posterior fascicular block), endocardial recordings from the His-Purkinje system showed that VT was due to interfascicular reentry. Induction of VT occurred after progressive retrograde conduction delay on increasing the prematurity of the extrastimulus. Anterograde conduction occurred exclusively over the left anterior fascicle, which caused identical QRS morphology during sinus rhythm and VT. During VT, the left posterior fascicle was used retrogradely. The usual target for bundle branch reentry ablation, the right bundle, did not participate in the reentrant circuit. While performing left ventricular endocardial mapping, VT was interrupted when positioning the catheter on the left anterior fascicle, and "reversed" nonsustained bundle branch reentry occurred with anterograde conduction over the posterior fascicle and retrograde conduction over the anterior fascicle. Ablation of conduction in the anterior fascicle led to cure of the VT. CONCLUSION: Interfascicular reentrant VT with right bundle branch block, right-axis QRS configuration can be cured by catheter ablation of anterior fascicle conduction.

Aged↗
PubMed1994

Safety of radiofrequency catheter ablation of accessory atrioventricular pathways.

The acute anatomic and valvular consequences of radiofrequency catheter ablation of accessory pathways were evaluated in 62 patients by means of serial echocardiographic examinations. Semiquantitative assessment of valvular incompetence and classification into one of four grades according to the width and the extension of the jet from the valvular orifice were carried out. Segmental wall motion abnormalities were evaluated semiquantitatively with four grades of severity (normal, hypokinesia, akinesia, or dyskinesia). New echocardiographic abnormalities were observed in five patients. One thrombus on the ventricular aspect of the mitral valve, three hemodynamically insignificant pericardial effusions, and one increase in severity of tricuspid incompetence were found 1 day after radiofrequency catheter ablation. We conclude that echocardiographic changes after radiofrequency ablation of accessory pathways are rare and of minor significance. These findings confirm the safety of the procedure.

Adolescent↗
PubMed1994

Factors influencing changes in the signal-averaged electrocardiogram within the first year after a first myocardial infarction.

One hundred twenty-nine patients were prospectively studied after a first myocardial infarction. A first signal-averaged electrocardiogram (SAECG-1) was performed in the acute phase (within 48 hours after onset of symptoms) and a second one (SAECG-2) in the late phase (6 to 18 months after hospital discharge). We studied the influence of nine parameters on the evolution of the signal-averaged electrocardiogram: age, gender, myocardial infarction location, number of diseased coronary vessels, infarct-related coronary artery patency, use of thrombolytic therapy or percutaneous transluminal coronary angioplasty in the acute phase, left ventricular ejection fraction, and recurrence of ischemic events. No follow-up data were available in 15 patients. Of the remaining 114 patients, an ischemic event occurred in 25 (22%). The signal-averaged electrocardiogram remained unchanged in 97 (85%) (remaining normal in 78 and abnormal in 19). It became abnormal in 13 (11.5%) and became normal in 4 (3.5%). In patients with a normal SAECG-1, two factors were associated with the change to an abnormal SAECG-2: (1) an ischemic event occurred in 11 (85%) of 13 patients whose SAECG-2 was abnormal compared with only 13 (17%) of 78 patients whose SAECG-2 remained normal (p < 0.0001), and (2) 100% of patients with an abnormal SAECG-2 had an inferior myocardial infarction compared with 54% of patients with a normal SAECG-2 (p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Supernormal conduction in the left bundle branch.

This report describes a patient with tachycardia-dependent left bundle branch block (LBBB) and atrial extrasystoles, some of which were followed by an unexpectedly narrow QRS complex. His-bundle recordings and premature atrial stimulation were performed to analyze the mechanism underlying the normalized intraventricular conduction of some of the early atrial impulses. The results suggested the presence of supernormal conduction in the left bundle branch (LBB), because: (1) the HV interval was identical in LBBB complexes and in early narrow QRS complexes; (2) during single test stimulation using different paced atrial cycle lengths, there was a well-defined range of H1H2 intervals resulting in normalization of intraventricular conduction; and (3) atrial pacing with a cycle length of 500 msec resulted in alternation between wide and narrow QRS complexes. These findings rule out alternative mechanisms that could explain the unexpectedly normal intraventricular conduction of early impulses.

Bundle-Branch Block↗
PubMed1994

Recurrence rate after accessory pathway ablation.

OBJECTIVE: To evaluate characteristics of patients and accessory pathways as well as additional technical factors involved in the reappearance of accessory pathway conduction after successful ablation. DESIGN: Analysis of recurrences after radiofrequency ablation. SETTING: 163 consecutive patients with 167 accessory pathways. SUBJECTS: 97 men and 66 women with a mean (SD) age of 36 (14) range (11 to 75) years. RESULTS: After a mean (SD) follow up of 14 (7) range (2 to 27) months, conduction recurred in 13 out of 167 (7.8%) accessory pathways. The initial manifestation of recurrence was circus movement tachycardia in 7 patients and reappearance of delta waves on a 12 lead electrocardiogram in 6 patients. The interval to the return of accessory pathway conduction ranged from 3 hours to 90 days. Age, sex, presence of multiple accessory pathways, criteria to determine the target ablation site, number and duration of radiofrequency applications, and cumulative energy did not significantly differ between the groups with recurrence and without. Recurrence was less common with concealed accessory pathways (2/44) than with overt accessory pathways (11/110). The difference was not significant. The only variable to influence the recurrences in this study group was the location of the accessory pathway. Reappearance of conduction through right sided accessory pathways occurred significantly more often than through left sided ones (8/40 v 5/114, P = 0.01). CONCLUSION: After radiofrequency ablation the recurrence rate of accessory pathways is low and there are no predictors of the risk of reappearance of conduction apart from the right sided location of the accessory pathway.

Adolescent↗
PubMed1993

The 12-lead electrocardiogram in midseptal, anteroseptal, posteroseptal and right free wall accessory pathways.

The 12-lead electrocardiograms of 50 patients with 1 anterogradely conducting accessory pathway were analyzed to obtain characteristics of electrocardiographic findings in the midseptal, anteroseptal, true posteroseptal and right free wall accessory pathway locations. Locations were confirmed by surgery (33 patients) or radiofrequency catheter ablation (17 patients). This study analyzed (1) QRS in the frontal plane, (2) delta wave axis in the frontal plane, (3) the angle between QRS and delta wave axes, (4) the R/S ratio in lead III, (5) negativity of delta wave in inferior leads, and (6) the R/S ratio in precordial leads.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Improvement in left ventricular function by ablation of atrioventricular nodal conduction in selected patients with lone atrial fibrillation.

Left ventricular (LV) function was studied in 30 patients with lone atrial fibrillation (AF) (paroxysmal [n = 27] and persistent [n = 3]) before and after ablation of atrioventricular conduction. In all patients, drug treatment did not control ventricular rate during AF or prevent recurrences of the arrhythmia, or both. LV ejection fraction, and LV end-systolic and end-diastolic, and left atrial dimensions were measured by echocardiography before (mean 7 +/- 10 months, range < 1 to 37) and after (14 +/- 20 months, < 1 to 77) ablation. Before ablation, LV ejection fraction was < or = 50% in 12 patients (group I) and > 50% in 18 (group II). After ablation, LV ejection fraction increased significantly in group I from 43 +/- 8% to 54 +/- 7% (p < 0.0001). There were also significant decreases in LV-end systolic and end-diastolic, and left atrial dimensions. No changes in these parameters were observed in group II. Groups I and II had a significant difference in the duration of AF (group I: mean 11 years, range 8 to 28; and group II: 5 years, 2 to 14) (p < 0.05). No difference was present in age, sex, New York Heart Association functional class for dyspnea, or type of ablation procedure. Thus, some patients with lone AF may show deterioration of LV function, which appears to be related to the duration of the arrhythmia; in these cases, LV function may improve significantly after ventricular rate control is accomplished by ablation of atrioventricular conduction.

Adult↗
PubMed1993

Value of the 12-lead electrocardiogram in arrhythmogenic right ventricular dysplasia, and absence of correlation with echocardiographic findings.

The 12-lead electrocardiogram during sinus rhythm was studied in 20 patients with arrhythmogenic right ventricular (RV) dysplasia with symptomatic ventricular tachycardia. Findings were analyzed, together with echocardiographic evaluation of site, extent and progression of RV wall abnormalities. Electrocardiographic abnormalities were found in 90% of patients. No correlation was found between abnormalities on the initial 12-lead electrocardiogram, and the echocardiographic extent and location of RV involvement. Over time, echocardiographic progression of the disease was observed; RV size increased in 6 of 7 patients from 34 +/- 3 to 39 +/- 3 mm (p = 0.01), and there was progression in the extent of RV wall motion abnormalities in 4 of 7 patients. Analysis of serial electrocardiographic recordings did not reveal changes indicative of progression of the disease during follow-up of 71 +/- 48 months. It is concluded that electrocardiographic abnormalities suggesting arrhythmogenic RV dysplasia are present in 90% of symptomatic patients on the first electrocardiogram recorded during sinus rhythm. However, serial electrocardiographic recordings in these patients do not provide information regarding anatomic progression of the disease.

Adolescent↗
PubMed1993

Effects on the signal-averaged electrocardiogram of opening the coronary artery by thrombolytic therapy or percutaneous transluminal coronary angioplasty during acute myocardial infarction.

One hundred twenty-nine patients were retrospectively analyzed and divided into 3 groups according to (1) the presence of a patent artery obtained either spontaneously or after thrombolytic therapy but without percutaneous transluminal coronary angioplasty (PTCA) (group I, n = 83), (2) the presence of a patent artery after opening by PTCA (group II, n = 29), or (3) absence of reperfusion despite thrombolytic therapy or PTCA (group III, n = 17). Thrombolytic therapy was given within 4 hours after onset of symptoms (mean 2.5 +/- 1.0 hours) and PTCA was performed within 24 hours after the onset of symptoms (mean 6 +/- 6 hours). Signal averaging was performed within 24 hours after cardiac catheterization. An abnormal signal-averaged electrocardiogram was present in 10 of 83 (12%) group I, 9 of 29 (31%) group II and 7 of 17 (41%) group III patients (p < 0.05 group I vs II, p < 0.01 group I vs III, no statistical difference group II vs III). Therefore, in contrast to reperfusion by thrombolytic therapy the incidence of abnormalities on the signal-averaged electrocardiogram early after myocardial infarction is not reduced by an early opening of the culprit vessel by PTCA.

Angioplasty, Balloon, Coronary↗