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Biomedical subjects

S Kershenovich

Publications and source records attributed to S Kershenovich.

At least 19 recordsLinked to original sources
PubMed1999

Successful radiofrequency ablation of an accessory pathway during pregnancy.

The preexcitation syndrome is a rare entity during pregnancy. We present a 20-week pregnant patient with Wolff-Parkinson-White syndrome and recurrent episodes of tachycardia with hemodynamic compromise refractory to medical treatment that required electrical cardioversion several times. Due to the poor evolution we performed a successful radiofrequency ablation of a right posteroseptal accessory pathway using 70 seconds of total fluoroscopy time without complications. We consider this is an alternative and safer treatment in those cases in which the tachyarrhythmias compromise the hemodynamic state during pregnancy.

Adult↗
PubMed1996

A new ECG algorithm for the localization of accessory pathways using only the polarity of the QRS complex.

A new algorithm is proposed for localization of accessory atrioventricular pathways by use of a 12-lead electrocardiogram (ECG). The polarity of the QRS complex in leads III, V1, and V2 from 102 patients with Wolff-Parkinson-White syndrome with manifested preexcitation who underwent successful radiofrequency catheter ablation was analyzed. Accessory pathways on the right side of the heart were localized to three regions around the tricuspid annulus, and left-sided pathways were localized to two regions around the mitral valve annulus. In 42 of 46 patients (91%) with left posterolateral accessory pathways, a common characteristic of the ECG was a positive QRS complex in leads III and V1 (sensitivity 91%, specificity 95%). Of 19 patients with left inferior paraseptal or inferior accessory pathways, 16 (84%) had a negative QRS complex in lead III and a positive QRS complex in lead V1 (sensitivity 84%, specificity 98%). All six patients with right anterosuperior paraseptal accessory pathways had a positive QRS complex in lead III but a negative QRS complex in lead V1 (sensitivity 100%, specificity 97%). The 25 patients with right inferior paraseptal or inferior accessory pathways had a negative or isodiphasic QRS complex in leads III and V1, but the QRS complex was positive in lead V2 in 21 (84%) of these patients (sensitivity 84%, specificity 100%). Finally, five of the six patients (83%) with right anterior accessory pathways had a negative QRS complex in leads III, V1, and V2 (sensitivity 83%, specificity 96%). With the algorithm, the localization of accessory pathways was thus identified in 90 of the 102 patients (88%).

Adolescent↗
PubMed1993

[Influence of the permeability of the artery responsible for the infarction on the variability of heart rate and late potentials. Its importance in the risk stratification after myocardial infarction].

The use of the heart rate variability for the study of the Autonomic nervous system has been well established. We analyzed late potentials and heart rate variability in 29 control patients and in 102 consecutive patients with a first myocardial infarction. The data obtained were analyzed with both, the medical treatment (thrombolysis and beta-blockers) and the patency of the infarct related vessel. Patients with an infarct had diminished vagal tone as compared with the control group. Those patients with occluded related arteries showed higher incidence of late potentials; interestingly patients with late potentials also had diminished vagal tone. Without looking at the patency of the infarct related artery, thrombolitic and betablocker therapy did not have any effect on vagal tone. All the variables were correlated with the patency of the infarct related artery. Those patients with patent arteries had a preservation of the vagal tone; this was independent of the treatment received and the presence of late potentials. We concluded that the patency of the infarct related artery determines the absence of late potentials and preservation of the vagal tone. This might be one of the mechanisms of how thrombolitic therapy decreases the incidence of cardiac death.

Action Potentials↗
PubMedDate not supplied

[The usefulness of electrophysiology in a patient undergoing cardiomyoplasty].

The cardiomyoplasty is a new surgical procedure that uses a skeletal muscle electrostimulated in order to reinforce or even substitute partially the cardiac muscle. We present the electrophysiology aspects in a patient with dilated cardiomyopathy that underwent cardiomyoplasty. First the latissimus dorsi muscle was prepared with a neurostimulant ITREL II. During the surgical procedure a dual-chamber pacemaker mode DDD brand CPI was placed. After three months, ablation radiofrequency of the AV node was performed in order to control the atrial fibrillation that caused heart failure. By means of the AV block we obtained synchrony between the ventricular stimulation and the latissimus dorsi muscle, and by this the patient improved. Using the modern pacemakers and radiofrequency we can control the bradyarrhythmias as well as the tachyarrhythmias frequent in patients with dilated cardiomyopathy, increasing the success rate of cardiomyoplasty.

Adult↗
PubMedDate not supplied

[Changes in auriculoventricular conduction due to the effect of ethanol].

Transcoronary ablation of atrioventricular conduction by dehydrated alcohol was attempted in one patient with refractory ectopic atrial tachycardia. Ethanol (1.5 ml) was delivered after selective catheterization of the atrioventricular nodal artery in a patient in whom the artery could be identified by cineangiography. The mean creatine kinase (MB fraction) at four hour to six hour after ablation was 40 U. No electrocardiographic QRS changes was seen. The procedure was successful. The patient is asymptomatic 3 months after procedure. Transcoronary alcohol ablation of atrioventricular conduction should be considered in patients in whom electrical techniques have been unsuccessful.

Adult↗
PubMedDate not supplied

[Surgical resection of a focus of ventricular tachycardia guided by endocardial and epicardial mapping].

We describe a case of a 46 years old female with chagasic heart disease. In one year she presented six episodes of sustained ventricular tachycardia, heart rate 230 beats per minute, morphology of RBBB AQRS -60 degrees, with hemodynamic deterioration that needed electrical cardioversion. She was treated with several antiarrhythmic drugs but not good response was obtained. Programmed electrical stimulation was done and it show three different types of ventricular tachycardia, trough pace-mapping the site of the clinical tachycardia was located in the portion inferior and inferior-posterior of the left ventricle that was confirmed by entrainment. Epicardial mapping was performed in 38 ventricular sites following the modified Harken sketch and the location of the site of outlet was confirmed in the posterior base of the left ventricle, at this point the surgical resection was done with no complication. The results were satisfactory. Eight days later programmed electrical stimulation was done and the ventricular tachycardia could not be induced. Six months afterwards the patient is asymptomatic without medical treatment.

Cardiac Pacing, Artificial↗
PubMedDate not supplied

[The clinical and electrophysiological characteristics of patients with idiopathic ventricular tachycardia].

Clinical and electrophysiological characteristics in 20 patients with clinical ventricular tachycardia and normal hearts documented by physical examination, echocardiography, and angiocardiography were analysed. There were 11 males and 9 females. All patients had sustained ventricular tachycardia without hemodynamic instability during tachycardia. A right bundle branch block morphology of ventricular tachycardia was present in 14 patients and left bundle branch block morphology in six patients. During electrophysiologic studies, ventricular tachycardia was induced in 10/15 (66%) patients. Intravenous verapamil terminated the ventricular tachycardia in 9/10 (90%) of cases. However oral verapamil not prevented recurrences. Among 14 patients on whom exercise tests were performed, only two had exercise-induced ventricular/tachycardia. Late potentials were positive in 3/14 (21%) cases and one patient died suddenly during exercise without antiarrhythmic drugs.

Adolescent↗
PubMedDate not supplied

[Atrioventricular and ventriculoatrial conduction in patients operated on for the Wolff-Parkinson-White syndrome].

Over the last decade the surgical treatment of the Wolff-Parkinson-White syndrome has been well accepted. It is important to make an early diagnosis for surgical success. For this purpose we utilized programmed electrical stimulation to assess the functional characteristics of atrioventricular and ventriculoatrial conduction in our post-operative patients. In 55% of the cases we found accelerated nodal conduction. Programmed electrical stimulation correctly identified 90% of successfully treated patients. We did not found any false positive curve, therefore, this method has a high specificity. We concluded that in post-operative patients with the Wolff-Parkinson-White syndrome: 1- There is a high incidence of accelerated nodal conduction and 2- programmed electrical stimulation can correctly identify most of the patients who were successfully treated.

Adolescent↗
PubMedDate not supplied

[Transtelephonic electrocardiography in Mexico. A report of the first 3434 cases].

The transtelephonic electrocardiographic system started in the 70's and it was used mainly in the study of heart disease, cardiac arrhythmias, syncope and sudden death. This report, include 3434 electrocardiogram (ECG) of patients whom visit the emergency room at the General Hospital and private clinic, using three different forms of transtelephonic monitors. The total population were 1715 males and 1719 females with average age of 52.2 +/- 28.8 years. 26.9% had was present in history of systemic hypertension, non-insulin dependent diabetes 12.3% and myocardial ischemic disease in 5.3%. The main ECG indications were chest pain 38.7%, most of them atypical angina, palpitations in 6.9% and dyspnea in 6.5%. 50.1% of the ECG were abnormal. The most important diagnosis were: tachyarrhythmias (25.2%), intraventricular conduction abnormalities (17.7%), myocardial ischemic disease (16%), and premature ventricular and supraventricular beats (11.6%). We concluded that the transtelephonic electrocardiographic system is a very useful method, and available now in Mexico. We detected a high percentage of electrocardiographic abnormalities, it was possible to give the right diagnosis of arrhythmias, acute myocardial infarction, old infarction, and to evaluate the pacemaker functionality. Finally, it helped to get in brief time the diagnosis and treatment in cases of acute myocardial infarction or severe arrhythmias.

Adult↗
PubMedDate not supplied

[Auricular flutter associated with an interatrial septal aneurysm submitted to radiofrequency ablation].

We present the case of a young man who began with type I atrial flutter, he had no response to antiarrhythmic drugs. The echocardiogram showed an atrial septal aneurysm in the region of the fossa ovalis. We performed an electrophysiologic study which showed an atrial flutter with atrial rate of 257 bpm, and 2:1/3:1 AV conduction. The flutter waves were negatives in leads II, III and a VF (type I atrial flutter). An endocardial mapping was obtained in order to localize the area of slow conduction. It was located in the isthmus of atrial tissue bounded by the inferior vena cava and the tricuspid valve annulus in the low posterior septal right atrium. In this area we applied radiofrequency energy in 10 occasions but the arrhythmia was not suppressed. With atrial pacing we achieve a concealed entrainment and then resumption of atrial flutter after cessation of pacing. After another 6 applications of radiofrequency in this same area in sinus rhythm, we paced the atrium without inducing any form of arrhythmia. He was asymptomatic 15 days later, but one month after the ablation, the flutter reappeared, we performed a second successful radiofrequency ablation. In this time he was asymptomatic.

Adult↗
PubMedDate not supplied

[A new electrocardiographic algorithm for localizing accessory pathways using only the polarity of the QRS complex].

From 250 consecutive patients who underwent radiofrequency ablation of accessory pathways, we studied 102 patients with successful ablation of a single overt accessory pathway. All patients had manifested preexcitation on a baseline 12 lead electrocardiogram. None of this patients had additional congenital or acquired cardiac abnormalities which could have affected the QRS morphology. A new algorithm for localizing the AP site was developed, based only on the polarity of the QRS complexes in DIII, V1 and V2, without analysis of the delta wave. We could localize the accessory pathway in five sites with 88% of probability of success. This simplify the electrocardiographic analysis of Wolff Parkinson White and improvement the results of radiofrequency ablation.

Adolescent↗
PubMedDate not supplied

[The DDD pacemaker implanted intravenously].

Retrospectively, we studied 66 consecutive patients in whom we implanted an intravenous DDD pacemaker. The indications were: AV block in 52 patients (79%), sick sinus syndrome in 5 patients (7.5%), both AV block and sick sinus syndrome in 4 patients (6%), and other causes in 5 (7.5%). The venous access route was by subclavian punction in 38 cases (57.5%) and by cephalic vein dissection in 28 (42.5%). With a mean follow-up of 16 months, there were complications in 11 patients (17%), in 9 of them, it was necessary a change in pacing mode different to DDD, and was possible to maintain a DDD pacing mode in 2 patients with a minimal reprogramming. The complications were: A) lost of sense and/or atrial capture in 10 patients (3 of them, had also loss of ventricular capture, one had pacemaker-mediated tachycardia, other had diaphragmatic stimulation and other had a severe infection of the pocket), B) atrial fibrillation appeared in another patient. At the implantation time there were significant differences between patients with and without complications on follow-up, the P wave amplitude was 1.86 +/- 0.75 mV in the first group vs. 3.06 +/- 1.52 mV in the latter group, p < 0.005, and the atrial pacing threshold was 1.10 +/- 1.17 microJ in the first group vs. 0.65 +/- 0.66 microJ in the latter group, p < 0.005. We consider that dual chamber stimulation is a well established form of therapy, although, it requires a more laborious implantation and specialized personal for its follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Radiofrequency ablation in tachycardias due to accessory pathways in a pediatric population].

Catheter ablation of accessory atrioventricular pathways using radiofrequency current was attempted in 61 children and young adolescents less than 18 years of age who were referred for treatment of symptomatic supraventricular tachycardia. Thirty-three children had the Wolff-Parkinson-White syndrome and 30 tachyarrhythmias related to an accessory pathway conducting only in retrograde fashion. Ablation of left sided accessory pathways was usually attempted utilizing an arterial approach to the annulus of the mitral valve, only in one case we used the transseptal approach, while the venous route to the atrial aspect of the tricuspid valvular annulus was chosen for right sided accessory connections. Ablation of 55 of 63 accessory connections was achieved (87% success) with a range of 1 to 42 applications of radiofrequency current. The sessions were completed within 19 to 180 minutes, and we used within 16 to 45 watts of radiofrequency current. Two patients had complications as a result of their ablation procedure. One patient had complete heart block but did not require pacemaker implantation, and other one had mitral regurgitation. A second session was necessary in three patients, two of three accessory pathways were ablated, giving a success rate of 90%. During a one year period of follow-up, we had 4 recurrences (7.2%). Catheter ablation using radiofrequency current is a highly effective and safe curative approach for treating young patients with supraventricular tachycardia mediated by accessory pathways.

Adolescent↗
PubMedDate not supplied

[The response of ventricular tachycardia to adenosine administration].

Ten patients with ventricular tachycardia were studied. Two groups were formed. Group A included 5 patients with idiopathic ventricular tachycardia and group B included 5 patients with coronary heart disease. In all patients an electrophysiologic study was performed and monomorphic sustained ventricular tachycardia was induced through programmed stimulation. All patients received 12 mg of intravenous adenosine. The response was satisfactory in 3 of 5 patients in group A, with the presence of sinus rhythm. No response was seen in the other 2 patients. None of the patients in group B responded to the administration of intravenous adenosine. We concluded that adenosine may be useful in patients with cyclic AMP-mediated triggered activity ventricular tachycardia, in contrast to the coronary heart disease patients in which the mechanism is reentry. This interpretation is supported by results obtained in 15 experiments in canine heart.

Adenosine↗
PubMedDate not supplied

[Radiofrequency ablation in idiopathic ventricular tachycardia originating in the right ventricle].

We present the case of a 10-year-old boy, with structurally normal heart who began two years before admission, with sustained monomorphic ventricular tachycardia with heart rate of 280 bpm and LBBB morphology, AQRS + 60 degrees, with pallor and diaphoresis. The tachycardia was treated with xylocain. He was also treated with propaphenone, verapamil, and amiodarona, in spite of these, he continued with this type of arrhythmia 2 or 3 times a month. We performed an electrophysiologic study which showed ventricular tachycardia originated in the right ventricle infundibulum. We took an endomyocardial biopsy, which was normal. He was scheduled for percutaneous catheter ablation of the tachycardia by radiofrequency energy. During the procedure the ventricular tachycardia appeared spontaneously, we mapped the most early ventricular activation and then in sinus rhythm, this site was pace mapped and resulted in similar pattern of clinical ventricular tachycardia. We identified the site of origin of the ventricular tachycardia in the posterior region of the right ventricle infundibulum, delivering radiofrequency, changing to sinus rhythm. Then we paced the apex of the right ventricle without inducing any form of arrhythmia. He is asymptomatic four months later.

Cardiac Pacing, Artificial↗
PubMedDate not supplied

[Radiofrequency ablation of an accessory left lateral pathway in an infant, using a transeptal approach].

We describe the case of a 4 month old child with supraventricular tachycardia detected on his second day of life, refractory to medical treatment, who was treated with radiofrequency catheter ablation of an accessory auriculoventricular pathway located on the left lateral wall. A venous femoral approach was used and the left atrium was entered through a patent foramen ovale, avoiding the risks of the arterial puncture and allowing us to administrate the radiofrequency current on the proper site. We discuss the potential risks of the therapeutic procedure in children and the benefits of the transeptal over the retrograde approaches for the treatment of left sided accessory pathways. Our conclusion is that catheter radiofrequency ablation of accessory pathways in children is possible with low risk, which can be diminished with the use of the transseptal approach when indicated.

Catheter Ablation↗
PubMedDate not supplied

[Identification of patients at risk of malignant arrhythmia in the 1st year after myocardial infarction].

Two hundred twenty two consecutive patients with acute myocardial infarction were followed for one year. We evaluated the usefulness of late potentials, the spectral analysis, heart rate variability, infarct-related coronary artery, ejection fraction, arrhythmias during Holter monitoring and other clinical variables as risk markers for developing of ventricular arrhythmias and/or sudden death. Twenty four patients (10.8%) had late arrhythmic events: sudden death in 7, sustained ventricular tachycardia in 15 and unexplained syncope in 2. Late potentials had high sensitivity (94%) and negative predictive value (99%), followed by an occluded related-infarct coronary artery (75% sensitivity and 96% negative predictive value). Complex ventricular arrhythmias during Holter monitoring was the test with the highest specificity (92%). A combination of late potentials plus an occluded infarct-related coronary artery or late potentials plus ejection fraction showed 100% sensitivity with 100% negative predictive value. Of the 16 studied variables, 5 had independent and significative value as a predictor of arrhythmic events, these are, according to the relative risk: late potentials (20.2), ejection fraction less than 40% (12.1), complex arrhythmias during Holter monitoring (7.5), the presence of an occluded infarct-related coronary artery (6.4) and anterior myocardial infarction localization (4.5). We consider, that with a combination of simple methods of assessment, we can select a subgroup of survivors of an acute myocardial infarction at high risk of developing ventricular arrhythmias and sudden death, which also identifies patients with low risk for these complications.

Aged↗