Biomedical subjects

J A González Hermosillo

Publications and source records attributed to J A González Hermosillo.

At least 19 recordsLinked to original sources

PubMedDate not supplied

[Late thrombolysis and electrical stability in acute myocardial infarction. Role of the collateral flow].

We evaluated 249 patients (pts) with first acute myocardial infarction: 1. Pts without thrombolysis, n = 119, 2. Pts treated with thrombolysis within 6 hours following MI, n = 80 and 3. Pts treated with thrombolysis between 6-12 hours after MI. Arrhythmic events were evaluated during follow up. All underwent heart rate variability studies and coronary angiogram where anterograde flow (TIMI) and collateral flow (Rentrop scale 0-2 = poor collateral flow and 3 = good collateral flow) were determined. Pts in group 2 and 3 showed a better anterograde and collateral flow than group 1 (p < 0.001). A lower spectral power in the high frequency band and a higher ratio low/high frequency band were observed in group 1 (p < 0.05). Conjunctive consolidation analysis showed more malignant arrhythmias in TIMI 0-2 with poor collateral flow than TIMI 0-2 with good collateral flow (17/138-12.3% vs 0/14-0%). Kaplan Meier analysis was able to demonstrate more cardiac sudden death events in TIMI 0-2 with poor collateral flow than TIMI 0-2 with good collateral flow or TIMI 3 (x2 = 7.22, p = 0.028), independently of thrombolytic treatment.

Arrhythmias, Cardiac↗

PubMedDate not supplied

[The familial incidence of accessory atrioventricular pathways (the pre-excitation syndrome)].

Cases of familial preexcitation syndrome represent a specific subgroup of patients that may result from diverse mechanisms: failure in development and genetic predisposition are the main mechanism involved. We determined the prevalence of this syndrome in first degree relatives of patients with proved accessory pathways by electrophysiologic study and compared such prevalence with the general population (0.15%). In five out of 469 patients (1.06%) we found an accessory pathway in one or more member of their family. Only 6 out of 3752 had preexcitation (0.15%); this prevalence was similar to the general population (P = NS). The identification of family members with this syndrome may be incomplete because we only chose for the study symptomatic patients. We did not observed multiple pathways and in one case we found atrial septal defect. Our data demonstrated familial preexcitation in five families suggesting hereditary predisposition.

Adolescent↗

PubMedDate not supplied

[Complete congenital heart block. Its natural history and evolution].

This study describes the natural history and evolution of 67 patients with congenital auriculoventricular heart block admitted in the Instituto Nacional de Cardiología "Ignacio Chávez", Mexico, D.F. from 1944 to 1998. There were 35 (52%) females and 32 (47%) males, with mean follow up period of 93.7 +/- 104 months. Most of the patients were without structural cardiovascular disease (90%). The most frequent symptoms were dyspnea and syncope. Electrocardiograms showed a ventricular heart rate of 42.2 +/- 9 beats/minute. 85.7% of patients had a supra-Hisian complete heart block. In 31% of patients a pacemaker was implanted because syncope. Overall mortality was 4.4% and malignant ventricular arrhythmias were the principal contributors. Risk factors for mortality identified in this study were junctional escape rhythm lower than 50 beats/minute, inappropriate chronotropic response during exercise, R-R interval prolongation at night, enlargement of cardiac chambers, depressed left ventricular ejection fraction and prolonged QT interval. In all of these conditions we recommend permanent pacemaker implantation.

Adolescent↗

PubMedDate not supplied

[A complete atrioventricular block during exertion].

Exercise-induced atrioventricular (AV) block in patients with normal electrocardiogram at rest is uncommon. We report the clinical features of two patients with AV block during treadmill test. The first patient was a woman of 54 years of age with presyncope on exercise. She developed complete AV block during exercise testing without evidence of ischemic myocardial disease. Electrophysiologic study documented distal AV block. The second patient was a man 31 years old who developed angina and third-degree AV block with depression of ST segment during treadmill test. Myocardial perfusion study suggested ischemic heart disease. He received anti-ischemic drugs with improvement of symptoms. A control exercise testing demonstrated normal AV conduction and electrophysiologic study was normal. In the first case, exercise AV block was probably due to abnormal His Purkinje conduction system refractoriness to autonomic modulation, while in second case AV block was secondary to ischemic heart disease. Third-degree AV block at exercise can be present in patients without conduction system abnormalities at rest. Exercise-induced infra-Hisian AV block must be treated with pacing until ischemic heart disease has been ruled out.

Adult↗

PubMedDate not supplied

[Double tachyarrhythmia: left anterior fascicular ventricular tachycardia associated with atrial flutter and fibrillation. Report of a case].

A patient with episodes of palpitation in whom the electrocardiogram showed a right bundle branch (RBBB) configuration and right axis deviation underwent electrophysiologic study and radiofrequency ablation. Left ventricular endocardial mapping during ventricular tachycardia (VT) identified the earliest ventricular activation in the anterolateral wall of the left ventricle. The fused Purkinje potential was recorded at that site, and preceded the QRS complex by 47 mseg, with pace mapping showing an optimal match between the paced rhythm and the clinical VT. The stimulus to QRS time was equal to the Purkinje potential-QRS time. Several radiofrequency lesions were applied in this region, one of them resulted with termination of the tachycardia. Following delivery of this lesion the ventricular tachycardia couldn't be induced either at baseline or during isoproterenol infusion. During VT, atrial fibrillation and atrial flutter were observed, cardioversion was performed reverting to sinus rhythm.

Atrial Flutter↗

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

[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

[Electrophysiologic effect of intravenous propafenone in supraventricular tachycardia].

The electrophysiologic effects of intravenous propafenone were studied in twenty six patients with supraventricular tachycardias. Ten patients (38%) with intranodal reentrance tachycardia common type, and sixteen patients (62%) atrioventricular orthodromic reentrance tachycardia. Propafenone (2 mg/kg intravenously) given over ten minutes period caused termination of the intranodal reentrance tachycardia in 60% of the cases and 50% to the patients with atrioventricular reentrance tachycardia. The antiarrhythmic effects observed are related to the slowing of the conduction velocity and to the prolongation of the refractoriness in the AV node and accessory pathways preventing the reentrance mechanism. The reinduction of the tachycardia was possible in 46% of the patients. This effects was more significative in the group with accessory pathways (50%), and 40% of the patients with intranodal reentrance. The supraventricular tachycardia was inducible by programmed electrical stimulation in 46% of the patients. None of the patients developed side effects to the administration of the propafenone.

Adolescent↗

PubMedDate not supplied

[Exercise test in patients with permanent pacemakers].

From June 1988 to June 1990 we studied fifty patients who had implantation of a pacemaker. (31 females and 19 males). All of them underwent stress test with Bruce's protocol. Patients were divided in two groups; pacemaker-independent (PI) and pacemaker-dependent (PD). Over 50% of the patients inhibited the pacemaker with their own rhythm, most of them had sinus dysfunction. Complete A-V block was predominant in PD. The group of PI achieved more mets and had more oxygen consumption. Blood pressure response was similar in both groups.

Adult↗

PubMedDate not supplied

[Surgical treatment of supraventricular tachycardias (Wolff Parkinson White and Occult Kent). Experience at the "Ignacio Chávez" National Institute of cardiology].

We report our initial experience in the surgical section of the accessory pathway in thirteen patients: eight patients with Wolff Parkinson White syndrome and five with accessory pathway functioning only in direction ventricle to atrium (Kent concealed), with recurrent episodes of paroxysmal supraventricular tachycardia with no response to medical treatment. Three of these patients had episodes of auricular fibrillation with interval RR lower than 250 msec and one patient presented syncope. A total of fifteen accessory pathways were sectioned: 7 left lateral, 5 left posterior, one left posterolateral, one right lateral, and another one right anteroseptal. In the same procedure two patients had correction of another heart malformation: one with patent ductus arteriosus and another with and another with atrial septal defect. All patients had successful outcome, one of them needed a second surgery for persistent accessory pathway. We had two post-operatory complications: one mediastinitis and one patient with ectopic auricular tachycardia.

Adolescent↗

PubMedDate not supplied

[A retrospective study for the analysis of collateral effects of amiodarone].

UNLABELLED: We analyzed retrospectively 130 patients treated with amiodarone. They were seen at the Arrhythmias Clinic of this Institute from march 1981 until may 1988 with the purpose of evaluate the frequency of the side effects of the drug. The group of patients consisted of 67 men and 63 women, the mean age was 32 years and they were followed for about 32 months. The average dose of the drug was 1.069 gr per week. All of them had a physical and radiological examination, an ECG and laboratory tests. Besides, 86 patients went through an electrophysiological study at least once. One hundred and eighteen patients had periodical tests for thyroid function. All of the patients had a check up every 3 or 6 months. RESULTS: the response to the drug was good or even excellent in 83% of patients. They did not show electrocardiographic changes of statistic significance (duration of the PR, QRS or QT). The ophthalmologic examination showed corneal deposits in 48% of patients, but in no case there was indication to stop the treatment. Ten patients had a spontaneous regression of these deposits. Alterations of the thyroid function were seen in 33.8% of patients, 14 had hypothyroidism and seven hyperthyroidism, the others simple goitre. In four of these cases the drug was discontinued. Dermatologic lesions were seen in only 4% of patients. Despite the high frequency of side effects the need for stopping the treatment was low, with a high percentage of drug efficacy.

Adult↗

PubMedDate not supplied

[Electrofulguration of refractory supraventricular paroxysmal tachycardias. (Experiences of the "Ignacio Cháves" National Institute of Cardiology].

The purpose of this paper is to report our experience with endocardial catheter ablation in the recurrent episodes of paroxysmal supraventricular tachycardia in ten patients. All cases were referred because previous drug trials had failed to control arrhythmia. In four patients with Wolff Parkinson White syndrome, the ablation was used in the accessory pathway, in five patients in the his bundle region, and one patient in the AV perinodal region. The follow-up ranges from 4 to 15 months. We had a complete success rate of 40% and a partial success in other 40%. We did not have any complications during the procedures.

Adolescent↗

PubMedDate not supplied

[Permanent pacemaker implantation. Indications and results].

Clinical, laboratory and electrocardiographic data from 608 patients with permanent pacemakers implanted over a period of 8 years, were evaluated retrospectively. The number of implants was greater in males (56.5%) and in patients over 60 years of age (77.5%). Atherosclerosis was the most common disease found in this group (50%). Syncope occurred in 96.2% of the cases; and complete AV block was the most common electrocardiographic alteration (50.5%). Electrode displacement occurred in 32 patients (5.2%) and was the most commonly found early complication. Among the late complications, 10.3% of the patients had infections in the area of the generator. The total mortality was 7.7% due to the heart disease rather than pacemaker-related complication.

Adult↗

PubMedDate not supplied

[Usefulness of the pre-excitation index to determine the mechanism of supraventricular paroxysmal tachycardia and the location of the anomalous pathway].

To evaluate the preexcitation index in determinate the mechanism of paroxysmal supraventricular tachycardia and localize accessory pathway, fifty nine patients with clinical and electrocardiographic supraventricular tachycardia were analyzed. There were thirty eight patients (64.4%) with orthodromic AV reentry using an accessory pathway for retrograde conduction and 21 patients (35.6%) with typical AV nodal reentrant tachycardia. Preexcitation of the atrium during tachycardia by premature ventricular complex at a time when anterograde His bundle activation was present in 30 o 38 (79%) patients with AV reentry while only 8 of 21 (38%) patients with AV nodal reentry demonstrated preexcitation during tachycardia. There was no significant difference between left and right accessory pathways and in mean tachycardia cycle length between the two groups. However, atrioventricular reentry demonstrated atrial preexcitation during tachycardia more frequently than AV nodal reentry. In conclusion, our findings show that the preexcitation index is a useful method for determinate the mechanism of supraventricular tachycardia and to localize accessory pathways.

Adolescent↗

PubMedDate not supplied

[Wolff-Parkinson-White syndrome with orthodromic supraventricular tachycardia associated with a "hyper-conductor" atrio-ventricular node. A therapeutic challenge].

One case of Wolff-Parkinson-White Syndrome with paroxysmal supraventricular tachycardia related to orthodromic atrioventricular reentry using an accessory pathway for retrograde conduction an a rapidly conducting AV node for anterograde conduction is present. The pharmacological therapy with Digoxin, Propranolol, Quinidine, Disopyramide and Propafenone was not effective. An electrophysiologic study showed a reciprocating tachycardia induced by spontaneous ventricular beats. Both the effective refractory period of the AV node and the anterograde effective refractory period of the accessory pathway were minor or equal to 220 msec which made the control of the arrhythmia difficult. Amiodarone was able to suppress the premature ventricular beats, depress conduction and prolong refractoriness in both, the AV node and accessory pathway to prevent recurrences of atrioventricular reentry. In this patient a false positive test with ajmaline was documented. The electrophysiologic study showed the association of Wolff-Parkinson-White Syndrome with an enhanced atrioventricular nodal-conduction and allowed the selection of an appropriate antiarrhythmic agent.

Adult↗

PubMedDate not supplied

[Electrofulguration of a pre-excitation zone by the bundle of Kent].

The purpose of this presentation is to report the first endocardial catheter ablation in Mexico of a right posteroseptal accessory pathway. The patient, without structural heart disease, had a Wolff Parkinson White syndrome with recurrent episodes of paroxysmal supraventricular tachycardia and atrial fibrillation with a fast ventricular response, through the accessory pathway (Shorter RR interval less than or equal to 190 msec). Previous antiarrhythmic drug therapy had failed to control the tachyarrhythmias. An electrophysiologic study was performed and the right posterior septal accessory pathway was localized by direct mapping of the auriculoventricular junction. Two sessions of electrofulguration with energy shocks ranging from 200 to 250 joules were delivered. There were no complications during the two procedures. Three months afterwards the patient is asymptomatic without tachyarrhythmic episodes, and no drug therapy is necessary. The fulguration prolonged the anterograde accessory pathway conduction. Therefore, the risk of sudden cardiac death due ventricular fibrillation has been reduced.

Adult↗

PubMedDate not supplied

[Usefulness of the thoracic circle in localizing the pre-excitation zone in Wolff-Parkinson-White syndrome].

In this study thoracic circle lead electrocardiogram were recorded during sinus rhythm in 50 patients with Wolff Parkinson White Syndrome. We analyzed: delta wave polarity, QRS axis in the frontal plane, ventricular preexcitation, the pattern of precordial R wave transition and QRS morphology in the unipolar leads, also concordance between electrocardiographic patterns and the site of the accessory pathway determined during electrophysiological study. Electrocardiograms from patients with left lateral sites showed negative delta waves in leads LI or a VL, V7 to V9, positive delta waves in V3R to V9R, a normal QRS axis and early precordial R wave transition (20 of 23 patients). Left posterior sites manifested negative Delta waves in L3, a VF, V7 to V9, V7R to V9R and a prominent R wave in V1 (4 of 5 patients). Left posteroparaseptal sites had the same pattern plus negative delta waves in L2, a superior QRS axis, and RS or Rs morphology in V1 (3 of 3 patients). Right posteroparaseptal sites had negative delta waves in L2, L3, a VF, V3R to V9R, positive delta waves in V7 to V9, a superior QRS axis and an R greater than S in V1 (10 of 11 patients). Right free wall locations manifested negative delta waves in L3, a VR, V3R to V9R, positive delta waves in V7 to V9, a normal QRS axis and R wave transition in V3 to V5 with QS morphology since V3R to V9R (6 of 7 patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

[Myxoma of the right ventricle: report of a clinical case and review of the literature].

We studied a seventeen year old female patient with clinical manifestations of pulmonary embolism. A Two-Dimensional echocardiography showed the presence of a right intraventricular mass. It was surgically removed and the histopathological study showed it to be a myxoma. The recovery of the patient was uneventful. This is the first case of a right ventricular myxoma diagnosed during life in our hospital. The medical literature describing this unusual location is reviewed.

Adolescent↗