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Biomedical subjects

G Vergara

Publications and source records attributed to G Vergara.

At least 19 recordsLinked to original sources
PubMed1992

Long-term follow-up of patients with inducible supraventricular tachycardia treated with flecainide or propafenone: therapy guided by transesophageal electropharmacologic testing.

We report our experience with flecainide and propafenone therapy for inducible supraventricular tachycardias and paroxysmal supraventricular tachycardias due to atrioventricular (AV) nodal reentry or the Wolff-Parkinson-White syndrome. We performed an electropharmacologic test (ET) that consisted of first inducing a clinical arrhythmia by transesophageal atrial pacing (TAP) protocol. This was followed by intravenous drug administration and TAP reevaluation, either after acute intravenous administration or in oral steady-state. We used ET with flecainide and/or propafenone to study 2 groups of patients at least 3 years before the long-term clinical observation period. The first group was comprised of 58 patients with reciprocating tachycardias--due to AV node reentry in 17 (29.3%) and anomalous pathway in 41 (70.7%). Twelve (29.3%) of the latter had reciprocating tachycardias, 15 (36.6%) had atrial fibrillation, and 14 (34.2%) had both arrhythmias. During ET, flecainide was administered to 42 patients, and the ET was considered positive in 28 (66.7%). Propafenone was administered to 32 patients, with positive results in 15 (46.9%). In 15 patients, both flecainide and propafenone were tested, 8 receiving flecainide after a negative ET with propafenone, and 7 receiving propafenone after a negative ET with flecainide. In the first group, the ET was positive in 7 (87.5%), and in the second group, it was positive in 3 (42.9%). In a follow-up of 40.1 +/- 11 months, 38 (65.5%) patients had positive outcomes, 5 (8.6%) had to stop receiving the drugs because of side effects, 3 (5.2%) stopped because of inefficacy, and 12 (20.7%) dropped out.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Electropharmacological testing by transoesophageal atrial pacing in inducible supraventricular tachyarrhythmias. A good approach for selection of long-term anti-arrhythmic therapy.

Sixty-eight patients with disabling episodes of inducible supraventricular tachyarrhythmia were tested electropharmacologically by transoesophageal atrial pacing. Using this technique we induced clinical arrhythmia in 67 (98.5%); 26 (38.8%) had a reciprocating tachycardia due to AV node reentry and 41 (61.2%) a by-pass tract. In the latter we induced a reciprocating tachycardia in 12 (29.3%), atrial fibrillation in 25 (36.5%) and both in 14 (34.2%). We then performed an anti-arrhythmic drug test and a transoesophageal reevaluation either after acute intravenous drug administration or during oral steady state. Altogether we tested 111 drugs or a combination of drugs before the results were considered positive; all patients tolerated the procedure well and were discharged with the drug or combination of drugs judged effective. At follow-up of 16.6 +/- 8.5 months, 42 patients (62.7%) were symptom-free, 17 (25.3%) had minor and non-disabling relapses, six (9%) stopped the drug because of inefficacy (1-1.5%) or side effects (5-7.5%); two (3%) dropped out. We conclude that electropharmacological testing with transoesophageal pacing constitutes a very good approach for inducible supraventricular tachyarrhythmias: it permits selection of optimal long-term anti-arrhythmic treatment and is well tolerated, only slightly invasive and without adverse effects.

Administration, Oral↗
PubMed1992

Life-threatening tachyarrhythmias in athletes.

The arrhythmias in competitive athletes may be classified as "benign," "paraphysiological" due to prolonged athletic training, or "pathological" due to hemodynamic effects on the athletic performance-risk-arrhythmogenic substratum. Pathological arrhythmias include life-threatening forms that are severe enough to produce symptoms (presyncope, syncope, cardiac arrest) during athletic activity. These forms are in particular rapid VT, VF, torsades de pointes, preexcited atrial fibrillation, sinus atrial and AV block. Our study population includes 766 competitive athletes, mean age 21.1 years (74 top international level), investigated with a cardioarrhythmological work-up for symptoms and for arrhythmias from 1974 to June 30, 1991. Three leading categories, represented by 16 aborted sudden death, 8 sudden death, and 7 induced VF (by EES or TAP) athletes, are described. All athletes with life-threatening arrhythmias, previously as asymptomatic or with minor symptoms had an arrhythmogenic substratum due to underlying silent cardiopathy or primary arrhythmic disorders. Athletic activity can be regarded as a trigger of electrical destabilization.

Adolescent↗
PubMed1992

[Sotalol in the Wolff-Parkinson-White syndrome: an electrophysiological and clinical study].

Distinctly different from the other beta-blocking agents, sotalol prolongs action potential duration in myocardial and Purkinje fibers, and increases atrial as well as ventricular effective refractory periods. Similarly, antegrade and retrograde accessory pathway refractory periods are increased by sotalol. The electrophysiologic and clinical effects of sotalol were studied in 40 patients (31 male and 9 female, mean age 32 +/- 14 years) with Wolff-Parkinson-White Syndrome (WPW). All patients had disabling episodes of supraventricular tachyarrhythmias (ST). Of the 40 patients, 15 (37%) had spontaneous recurrence of paroxysmal supraventricular reciprocating tachycardia (PSRT), 14 (35%) of atrial fibrillation (AF) and 11 (28%) of both PSRT and AF. All of the patients were non responders to serial transesophageal electropharmacological tests using I C class drugs. Sotalol 252 +/- 73 mg daily was administered, and, in steady-state, a new transesophageal study (TS) was performed to observe the re-induction of PSRT and/or AF. 34 patients (85%) were responders to TS (noninducibility of ST, or nonsustained ST or AF inducibility with an increase of 30% in the minimum R-R interval between pre-excitated beats during AF) and the results were confirmed during a follow-up of 17 +/- 9 months. In the non-responder group (5 patients), a I C class drug was associated with sotalol. One patient, who was a "non responder" to sotalol, sotalol + I C class drug, and to amiodarone, underwent surgical therapy. In the 26 patients (65%) who had episodes of PSRT (37%) or episodes of PSRT and AF (28%), it was impossible to reinduce PSRT in 85% of the cases. AF was induced at baseline in all of the studied patients, but after sotalol administration in 15 patients, it was impossible to reinduce AF. The rate of induced AF decreased from 208 +/- 39 beats/min to 156 +/- 36 beats/min (p < 0.001). The mean shortest R-R interval between pre-excitated beats increased from 214 +/- 35 (baseline) to 293 +/- 97 msec (sotalol steady state) (p < 0.001). No side effects were observed. A significant prolongation (p < 0.001) of the QTc interval was observed in all the patients after sotalol administration (from 0.39 +/- 0.2 to 0.42 +/- 0.02 sec.). On the basis of our results, we may conclude that sotalol has a potent effect on the antegrade refractoriness of the anomalous pathway and, in WPW syndrome at risk, is also effective in patients who don't respond to I C class drugs.

Adult↗
PubMed1992

[Vascular lesions in Candida albicans sepsis].

In two premature newborns affected by candida sepsis we observed at ultrasonography alterations of the heart and of the anterior cerebral artery. These alterations suggest a cardiovascular involvement that is rarely reported in the literature as a complication of systemic candidiasis.

Candidiasis↗
PubMed1991

[Supraventricular reentry tachycardia and athletic fitness].

Paroxysmal supraventricular reciprocating tachycardias (PSRT) which are due to a different type of reentry including the atrioventricular reentry circuit of Wolff-Parkinson-White (WPW) syndrome, may disturb the professional career of an athlete. Moreover even severe episodes of preexcited atrial fibrillation of WPW may occur. PSRT in athletes may present various clinical consequences: unimportant symptoms, or severe hemodynamic effects on the athletic performance particularly during sports activity at intrinsic high risk. The athletes are evaluated by clinical protocol which includes Holter monitoring ergometric test, echocardiography study, thyroid check and transesophageal electrophysiologic study at rest and during exercise. The arrhythmological study should be carefully performed in order to exclude an underlying heart disease, to study electrophysiological mechanisms and possible hemodynamic effect sports activity relate of the inducible and clinical tachyarrhythmias. Sometimes, these PSRT may disappear after interruption of athletic activity because of modifications of electrophysiological conditions related to the sports activity.

Electrocardiography, Ambulatory↗
PubMed1991

[Role of antitachycardia pacemakers in the treatment of supraventricular hyperkinetic arrhythmias].

The use of an antitachycardia pacemaker in the treatment of hyperkinetic supraventricular arrhythmias is founded on a reliable electrophysiological ground and on an high technology. Nevertheless the clinical impact of this approach is not considerable since the 5% to 7% of the potential candidates are in effect treated with an antitachycardia device. The success of new therapeutical procedures (i.e. catheter ablation) together with the shifting of the clinical, technical and commercial interest towards the electrical treatment of the malignant ventricular tachyarrhythmias are the main causes of the minor role that now the antitachycardia pacemakers play in the management of the patients with hyperkinetic supraventricular arrhythmias.

Aged↗
PubMed1991

[Usefulness of a complete echographic evaluation of the atrial dimensions for the diagnosis of idiopathic atrial fibrillation].

Left atrial enlargement may occur sometimes through only the increase of the supero-inferior (S-I) diameter, with normality of the antero-posterior (A-P) and latero-medial dimensions. In this study, both the largest dimensions of the left atrium and S-I and transversal dimensions of the left atrium and S-I and transversal dimensions of the right atrium were investigated, among the 98 pts suffering from recurrent paroxysms of atrial fibrillation (FAP). On the basis of the clinical, ECGraphic and echocardiographic data, a subgroup of 78 pts has been found, with FAP reliable to heart disease, which mostly appeared as accompanying a finding of atrial enlargement--left or right or both--. The remaining 20 pts distinguished, by means of the echocardiographic findings, as following: a) "idiopathic" FAP, neither dependent on heart disease nor on atrial enlargement (no. 11 pts); b) FAP dependent on "unexplained" atrial enlargement, i.e. unreliable to definite cardiac pathology (no. 9 pts). Among the b) pts, 7 showed the only, isolated S-I dimension increased. Therefore, the determination of the all largest dimensions of the atria, in pts with recurrent FAP, appeared able to more carefully distinguish the true cases of "idiopathic" FAP.

Adult↗
PubMed1991

[Electropharmacological test with class-I C drugs in paroxysmal supraventricular re-entrant tachycardia: is a negative result with a drug predictive of the ineffectiveness of other drugs of the same class?].

UNLABELLED: Propafenone and flecainide, both I C class drugs, are first choice in the treatment of paroxysmal supraventricular reciprocating tachycardia. The aim of this study was to check whether a negative or paradoxical electropharmacological test with one of the two drugs was predictive of an equally negative or paradoxical test with the other drug. Thirty patients with disabling paroxysmal supraventricular reciprocating tachycardia, 16 M, 14 F, mean age 30.6 +/- 16 years, were studied with serial electropharmacological tests using esophageal approach. The reentry circuit was sustained by an anomalous pathway in 25 patients (83.5%) whereas it was idionodal in the other 5 (16.5%). Propafenone was tested in 13 patients (43.5%, group A) after flecainide had resulted negative or paradoxical in the first test. In 17 patients (56.5%, group B) flecainide was tested after propafenone had resulted negative or paradoxical. The second drug tested was also ineffective in 14 of the 30 patients (group A + group B) while it had positive results in 16 patients. Specifically, propafenone was positive in 6 of the 13 patients (group A) in whom flecainide had been negative, and flecainide was positive in 10 of the 17 patients (group B) with acute negative or paradoxical propafenone test. These "acute" results were confirmed in steady-state with esophageal study and in the follow-up (21.9 +/- 9.3 months). CONCLUSIONS: 53.5% of the patients who are "non responders" to the electropharmacological test with one of the two drugs (propafenone or flecainide) may be "responders" to the other drug. Thus the ineffectiveness of one of the two drugs is not predictive of ineffectiveness of the other.

Adolescent↗
PubMed1990

[Transesophageal electric atrial stimulation as an electro- pharmacological method of treatment of supraventricular tachycardia].

From 1985 to 1988 the authors performed 299 procedures of transesophageal atrial pacing in 162 patients with hyperkinetic supraventricular arrhythmias. The pacing abolition of atrial flutter had been mainly applied with an invasive technique. The employment of transesophageal atrial pacing received its large development, but simplified this, the probability of abolishing supraventricular tachycardia becoming lower.

Adult↗
PubMed1990

[Stable ventricular tachycardia in arrhythmogenic dysplasia of the right ventricle in sportsmen].

Right ventricular arrhythmogenic dysplasia (RVAD) is a typical asymptomatic arrhythmogenic cardiopathy in athletes, which is occasionally concurrent with normal ventricular function and life-threatening arrhythmias. A total of 32 athletes (28 males and 4 females, mean age, 23 years, mean follow-up, 6.7 years) were examined for severe cardiac arrhythmias with left bundle branch block. The conclusive diagnosis of RVAD was established from clinical, echocardio-, and angiographic evidence. The protocol of the examination involved Holter monitoring, loading tests, electrophysiological study, two-dimensional echocardiography, cardiac angiography of the right and left ventricles, coronary angiography. The most severe arrhythmias were observed in athletes whose mean age was 23.4 years, 20 patients had sustained ventricular tachycardia (it occurred only in 19 who were indulging in sports), 6 presented with transient ventricular tachycardia, and 1 had ventricular fibrillation. They all had been considered fit for sports. The disease proceeded severely in 16 of 32 athletes (in 13 of 16 while indulging in sports), the conditions close to syncope were seen in 9 patients (8 had sustained ventricular tachycardias and 1 had transient ventricular tachycardias), syncopes were observed in 5 patients (sustained ventricular tachycardias).

Adult↗