Biomedical subjects

G Braito

Publications and source records attributed to G Braito.

3 recordsLinked to original sources

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↗

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↗

PubMed1989

[Arrhythmogenic implications of non-iatrogenic thyroid dysfunction].

We studied all patients with hyperkinetic and hypokinetic arrhythmias, who were recovered in the Cardiology Department and Arrhythmologic Centre of S. Chiara Hospital in Trento between 1983 and 1987. From these we selected all the patients who, on admission, had clinical and biochemical symptoms of dysthyroidism. Of the 2465 patients with cardiac arrhythmias, 93 (3.8%) had an evident thyroid pathology which was due to chronic amiodarone treatment in 42 (44.6%) and was primary and non-iatrogenic in 51 (55.4%). In the latter the thyroid pathology consisted of hyperthyroidism in 43 cases (toxic nodular goitre or Graves' disease), and of hypothyroidism in 8. As regard the types of arrhythmias, hyperthyroidism is predominant in patients with atrial fibrillation (70%) and in those with paroxysmal supra-ventricular reciprocating tachycardia (11.5%), but it is also present in patients with hyperkinetic ventricular arrhythmias (14%). Hypothyroidism is found in patients with hyperkinetic ventricular arrhythmias (25%), atrial fibrillation (37.5%) and atrio-ventricular block (37.5%). The average age of the hyperthyroid population with atrial fibrillation is higher than that of patients with paroxysmal supraventricular reciprocating tachycardia. The control of the thyroid pattern, especially as regards atrial fibrillation and paroxysmal supraventricular reciprocating tachycardia results in absence of arrhythmic episodes even without treatment in 40% of cases, and in an easier drug control in the other cases. Our study indicates that it is necessary to carry out systematic research of a thyroid dysfunction in all patients with cardiac arrhythmias, especially as regards women, atrial fibrillation and paroxysmal supraventricular reciprocating tachycardia. It is also evident that in order to achieve long-term control over hyperkinetic arrhythmia it is very important to overcome hyperthyroidism.

Adolescent↗