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Biomedical subjects

A A de Paola

Publications and source records attributed to A A de Paola.

At least 19 recordsLinked to original sources
PubMed2001

Catecholaminergic polymorphic ventricular tachycardia. An important diagnosis in children with syncope and normal heart.

Syncope in children is primarily related to vagal hyperreactivity, but ventricular tachycardia (VT) way rarely be seen. Catecholaminergic polymorphic VT is a rare entity that can occur in children without heart disease and with a normal QT interval, which may cause syncope and sudden cardiac death. In this report, we describe the clinical features, treatment, and clinical follow-up of three children with syncope associated with physical effort or emotion and catecholaminergic polymorphic VT. Symptoms were controlled with beta-blockers, but one patient died suddenly in the fourth year of follow-up. Despite the rare occurrence, catecholaminergic polymorphic VT is an important cause of syncope and sudden death in children with no identified heart disease and normal QT interval.

Adrenergic beta-Antagonists↗
PubMed2001

Treatment of atrial fibrillation with radiofrequency ablation and simultaneous multipolar mapping of the pulmonary veins.

OBJECTIVE: To demonstrate the feasibility and safety of simultaneous catheterization and mapping of the 4 pulmonary veins for ablation of atrial fibrillation. METHODS: Ten patients, 8 with paroxysmal atrial fibrillation and 2 with persistent atrial fibrillation, refractory to at least 2 antiarrhythmic drugs and without structural cardiopathy, were consecutively studied. Through the transseptal insertion of 2 long sheaths, 4 pulmonary veins were simultaneously catheterized with octapolar microcatheters. After identification of arrhythmogenic foci radiofrequency was applied under angiographic or ultrasonographic control. RESULTS: During 17 procedures, 40 pulmonary veins were mapped, 16 of which had local ectopic activity, related or not with the triggering of atrial fibrillation paroxysms. At the end of each procedure, suppression of arrhythmias was obtained in 8 patients, and elimination of pulmonary vein potentials was accomplished in 4. During the clinical follow-up of 9.6+/-3 months, 7 patients remained in sinus rhythm, 5 of whom were using antiarrhythmic drugs that had previously been ineffective. None of the patients had pulmonary hypertension or evidence of stenosis in the pulmonary veins. CONCLUSION: Selective and simultaneous catheterization of the 4 pulmonary veins with microcatheters for simultaneous recording of their electrical activity is a feasible and safe procedure that may help ablation of atrial fibrillation.

Adult↗
PubMed2001

The impact of syncope during clinical presentation of sustained ventricular tachycardia on total and cardiac mortality in patients with chronic Chagasic heart disease.

OBJECTIVE: To assess the impact of syncope during sustained ventricular tachycardia on total and cardiac mortality in patients with chronic chagasic heart disease. METHODS: We assessed 78 patients with sustained ventricular tachycardia and chronic Chagas' heart disease. The mean age was 53+/-10 years, 45 were males, and the mean ejection fraction was 49.6+/-13%. The patients were divided into 2 groups according to the presence (GI=45) or absence (GII=33) of syncope during sustained ventricular tachycardia. RESULTS: After a mean follow-up of 49 months, total mortality was 35% (28 deaths), 22 deaths having a cardiac cause (78.6%). No difference was observed in total (33.3% x 39.4%) and cardiac (26.7% x 30.3%) mortality, or in nonfatal sustained ventricular tachycardia between GI and GII patients (57.6% x 54.4%, respectively). However, the presence of syncope during recurrences was significantly greater in those patients who had had the symptom from the beginning (65.4% x 18.1%, p<0.01). CONCLUSION: Syncope during the presentation of sustained ventricular tachycardia is not associated with an increase in total or cardiac mortality in patients with chronic Chagas' heart disease. However, syncope during the recurrence ventricular tachycardia is greater in patients experiencing syncope in the first episode, of sustained ventricular tachycardia.

Adult↗
PubMed1999

Efficacy and safety of sotalol versus quinidine for the maintenance of sinus rhythm after conversion of atrial fibrillation. SOCESP Investigators. The Cardiology Society of São Paulo.

To compare the efficacy and safety of sotalol and quinidine after conversion of atrial fibrillation (AF) of <6 months, a prospective multicenter trial enrolled 121 patients who were randomized to receive dl-sotalol (160 to 320 mg/day, 58 patients) or quinidine sulfate (600 to 800 mg/day, 63 patients). Patients with left ventricular ejection fraction of <0.40 or left atrial diameter >5.2 cm were excluded. After 6 months of follow-up, using the Kaplan-Meier method, the probabilities of success were comparable between sotalol (74%) and quinidine (68%), but recurrences occurred later with sotalol than with quinidine (69 vs 10 days, p <0.05). Four patients developed proarrhythmic events, 3 (5%) with sotalol and 1 (2%) with quinidine, which were all associated with diuretic therapy. In patients converted from recent-onset AF (< or = 72 hours), sotalol was more effective than quinidine (93% vs 64%, p = 0.01), whereas in chronic AF (> 72 hours), quinidine was more effective than sotalol (68% vs 33%, p <0.05). During recurrences, the ventricular rate was significantly reduced in patients taking sotalol (98 to 82 beats/min, p <0.05). Independent predictors of therapeutic success were recent-onset AF in the sotalol group (p <0.001) and absence of hypertension in the quinidine group (p <0.05). In conclusion, sotalol and quinidine have comparable efficacy and safety for the maintenance of sinus rhythm in the overall group. In recent-onset AF, sotalol was more effective, whereas in chronic AF, quinidine had a better result. Recurrences occurred later with sotalol when compared with quinidine. Because of proarrhythmia, these drugs should be used judiciously in patients on diuretic therapy.

Adult↗
PubMed1999

Characteristics and identification of sites of chagasic ventricular tachycardia by endocardial mapping.

OBJECTIVE: To study electrophysiological characteristics that enable the identification and ablation of sites of chagasic tachycardia. METHODS: Thirty-one patients with chronic Chagas' heart disease and sustained ventricular tachycardia (SVT) underwent electrophysiological study to map and ablate that arrhythmia. Fifteen patients had hemodynamically stable SVT reproducible by programmed ventricular stimulation, 9 men and 6 women with ages ranging from 37 to 67 years and ejection fraction varying from 0.17 to 0.64. Endocardial mapping was performed during SVT in all patients. Radiofrequency (RF) current was applied to sites of presystolic activity of at least 30 ms. Entrainment was used to identify reentrant circuits. In both successful and unsuccessful sites of RF current application, electrogram and entrainment were analyzed. RESULTS: Entrainment was obtained during all mapped SVT. In 70.5% of the sites we observed concealed entrainment and ventricular tachycardia termination in the first 15 seconds of RF current application. In the unsuccessful sites, significantly earlier electrical activity was seen than in the successful ones. Concealed entrainment was significantly associated with ventricular tachycardia termination. Bystander areas were not observed. CONCLUSION: The reentrant mechanism was responsible for the genesis of all tachycardias. In 70.5% of the studied sites, the endocardial participation of the slow conducting zone of reentrant circuits was shown. Concealed entrainment was the main electrophysiological parameter associated with successful RF current application. There was no electrophysiological evidence of bystander regions in the mapped circuits of SVT.

Adult↗
PubMed1998

Angiographic and electrophysiological substrates for ventricular tachycardia mapping through the coronary veins.

OBJECTIVE: To study the value of epicardial mapping through the coronary venous system in patients with sustained ventricular tachycardia. DESIGN: 20 consecutive patients with sustained ventricular tachycardia who were candidates for radiofrequency ablation. SETTING: Electrophysiological laboratory. INTERVENTIONS: Coronary venous angiography was performed with a catheter, which provided coronary sinus occlusion during injection of contrast media. Multipolar microelectrode catheters were then manoeuvred into the tributaries of coronary sinus, using an over-wire system or an on-wire system. An endocardial ablation catheter was positioned in the left ventricle. Conventional programmed ventricular stimulation was performed for sustained ventricular tachycardia induction. Endocardial radiofrequency ablation was performed using impedance or temperature monitoring. RESULTS: Coronary veins were catheterised in all patients; 20 had induction of sustained ventricular tachycardia, 14 were stable. Presystolic epicardial electrograms were recorded in six patients and concealed entrainment in two, helping as a landmark for endocardial ablation. After simultaneous epicardial and endocardial mapping, successful endocardial radiofrequency ablation was achieved in nine of 14 patients with stable ventricular tachycardia (64%). CONCLUSIONS: Epicardial mapping through the coronary veins in patients with ventricular tachycardia is feasible, safe, and can be a useful landmark for endocardial catheter mapping and ablation.

Adult↗
PubMed1998

[Analysis of atrial fibrillation recurrence during therapy with sotalol or quinidine. Researchers of +SOCESP].

PURPOSE: To analyze the recurrences of atrial fibrillation in patients treated with sotalol or quinidine. METHODS: After conversion to sinus rhythm, 121 patients with paroxysmal atrial fibrillation were randomized to sotalol (58 patients) or quinidine (63 patients) and followed-up during 6 months. Symptoms and ventricular rates on the 12 lead electrocardiogram of the arrhythmic events were compared between the two groups. Clinical and echocardiographic characteristics were analyzed as predictors of atrial fibrillation recurrence. RESULTS: Seventeen (14%) patients relapsed into atrial fibrillation; 7 (12%) were treated with sotalol and 10 (16%) with quinidine. Recurrence occurred later in the sotalol group (median 69 days) in comparison with the quinidine group (median 10 days) (p = 0.04). Symptoms were present in 14 (82%) patients during the initial crisis and in 10 (47%) during recurrence. Recurrence was less symptomatic during antiarrhythmic therapy (p < 0.04), with no statistical differences between the two groups. Only patients treated with sotalol had ventricular rates during the recurrences lower than during initial crisis (p < 0.02). All variables failed to predict recurrence of atrial fibrillation. CONCLUSIONS: It was not possible demonstrate differences between sotalol and quinidine for the prevention of atrial fibrillation. Recurrence was less symptomatic during antiarrhythmic therapy. Patients treated with sotalol relapsed to atrial fibrillation later and had ventricular rates during recurrences significantly lower than during the initial crisis.

Adult↗
PubMed1998

[Angiography of the coronary venous system. Use in clinical electrophysiology].

PURPOSE: To study the angiographic anatomy of human coronary veins and the possibility of epicardial venous mapping through microelectrode catheters. METHODS: We evaluated 30 patients with sustained ventricular tachycardia using a catheter which provided occlusion of the coronary sinus ostium during venous angiography. They were 25 males, 5 females, ages ranging from 24 to 76 years (mean = 52.7). The veins were studied according to their number, caliber and distribution in the anterior and posterior wall of the left ventricle. RESULTS: Coronary sinus was catheterized in all patients. No discomfort or complication were observed. The number of veins from posterior wall of the left ventricle was 3.1 and anterior wall, 1.9, p < 0.05. The caliber of the coronary veins were: anterior interventricular vein (distal segment = 1.19 +/- 0.22 mm, middle segment = 1.65 +/- 0.35 mm), posterior interventricular vein (distal segment = 1.83 +/- 0.47 mm, middle segment = 2.00 +/- 0.52 mm), left posterior vein (distal segment = 1.45 +/- 0.25 mm, middle segment = 2.49 +/- 0.92 mm); p < 0.05. CONCLUSION: The balloon occlusion technique for coronary venous angiography is feasible and safe. The number and the caliber (distal and middle) of the veins from the posterior wall of the left ventricle were significantly greater than those from the anterior wall. Anatomic conditions for venous epicardial mapping are more adequate in the posterior wall of the left ventricle.

Adult↗
PubMed1998

[Catheter ablation of atrial flutter. Electrophysiological characterization of posterior and septal isthmus block].

PURPOSE: Evaluate the different types of conduction blocks obtained between inferior vena cava-tricuspid annulus (posterior isthmus) and between tricuspid annulus-coronary sinus ostium (septal isthmus) after radiofrequency (RF) catheter ablation of atrial flutter (AFL). METHODS: In 16 procedures, 14 patients (pts), 9 male, with type I AFL underwent RF ablation. Atrial activation around tricuspid annulus was performed with a 10-bipole "Halo" catheter (H1-2; H19-20). In sinus rhythm, isthmus conduction was evaluated during proximal coronary sinus (PCS) and low lateral right atrium (H1-2) pacing, before and after linear ablation. According to the wave front of impulse propagation we assessed absence of block (bidirectional conduction); incomplete block (bidirectional conduction with delay in one front of impulse propagation) and complete block (absence of conduction). The PCS/H1-2 interval was measured before and after ablation. RESULTS: Complete isthmus block was achieved in 7 (44%) and incomplete block in 4 (25%) procedures. Conduction block was not achieved in 5 procedures. At a mean follow-up of 12 months, there were no recurrences in the pts with complete block, whereas AFL recurred in the 6 pts with incomplete or no conduction block (p < 0.001). Pts with complete block had delta PCS/H1-2 interval (74.0 +/- 26.0 ms) greater than incomplete (30.5 +/- 7.5 ms) or absent block (p < 0.05). CONCLUSION: The verification of complete isthmus conduction block with atrial multipolar mapping is an effective strategy to assess electrophysiological success and absence of late recurrence in common atrial flutter ablation.

Adolescent↗
PubMed1997

[Athlete's heart in elite disabled athletes].

PURPOSE: To assess the prevalence of the athlete's, heart syndrome in elite disabled Brazilians athletes. METHODS: Seventy-five athletes, age 27.8 +/- 6.7 years, 56 men, with various disabilities (47 physical, 12 visual and 16 cerebral paralysis) underwent clinical, electrocardiographic, vectorcardiographic, ergometric and echocardiographic evaluations. RESULTS: Athlete's heart signs occurred in 33% of the clinical evaluations, in 55% of the electrocardiograms, in 15% of the vectorcardiograms, and in 5% of the echocardiograms. At least one of these signs was presented in 51% of the athletes. There were 2 or more abnormalities in 46% of the athletes and 4 or more signs in 12%. Exercise test was considered not ischemic in 77% of the subjects. There was right bundle branch block in 23% of the tests. CONCLUSION: There were two or more athlete's heart syndrome signs in 46% of Brazilian disabled athletes.

Adult↗
PubMed1996

[Brazilian multicenter study of sotalol effectiveness in ventricular arrhythmias].

PURPOSE: To evaluate the effects of sotalol in patients with nonsustained ventricular tachyarrhythmia (NSVT). METHODS: Ninety patients were enrolled. Patients were submitted to a double-blind crossover randomized study (placebo x 320 ms/po/d/sotalol; 4 weeks, after a wash-out control period. Holter recordings were performed in control (Ct), placebo (Pb) and drug (Dg) periods. Eligible patients had > 50/h isolated ventricular premature beats (VPB), in control, with or without pairs (P) or nonsustained VT (NSVT; > 3 beats, > 100bpm). Drug efficacy criteria were; > or = 75% reduction in isolated VPB, reduction > or = 90% of P and NSVT. The effects of the Dg were evaluated in the global population, in patients with Chagas' disease, idiopathic arrhythmias and ischemic/hypertensive patients. RESULTS: Differences between control and placebo were NS. Isolated VPB; Dg was effective in 42% (38/90 patients) with a mean of Pb and Dg respectively of 11,770 +/- 13,818 and 1,043 +/- 1,554 (p < 0.001). Pairs: drug was effective in 48% (32/67 patients) with a mean of Pb and Dg respectively of 439 +/- 586 and 27 +/- 52 (p < 0.001). NSVT: drug effectiveness was 53% (19/36 patients) with a mean of Pb and Dg respectively of 445 +/- 1,148 and 2.5 +/- 5.8 (p < 0.102). In patients with Chagas' disease, the reduction in VPB was 33% (13/39 patients), in pairs was 42+ (14/34) and in NSVT was 64% (12/22). In idiopathic patients the reduction of VPB was 53% (17/32 patients), in pairs was 50% (10/20) and in NSVT was 36% (4/11). In ischemic and hypertensive patients the reduction of VPB was 47% (7/15 patients) and 73% in pairs (8/11). CONCLUSION: In the present study, sotalol was effective in the control of nonsustained ventricular tachyarrhythmia, with minimal side-effects.

Administration, Oral↗