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M Scanavacca

Publications and source records attributed to M Scanavacca.

35 records · Page 2Linked to original sources
PubMed1994

Clinical and electrophysiologic features of syncope in chronic chagasic heart disease.

INTRODUCTION: Syncope in patients with chronic Chagasic heart disease (CCHD) is a frequent but poorly studied problem. METHODS AND RESULTS: Fifty-three patients with CCHD and recurrent syncope were followed for 2 to 127 months. They were classified into the following groups: G-I (n = 15) without inducible ventricular tachycardia (VT) and normal HV interval; G-II (n = 17) with only inducible VT; G-III (n = 11) with only an abnormal HV interval; and G-IV (n = 10) with both an inducible VT and an abnormal HV interval. Empiric pharmacologic therapy was given in G-I; pharmacologic therapy guided by electrophysiologic study in G-II; atrioventricular pacing in G-III; and empiric pharmacologic with atrioventricular pacing in G-IV. Age and sex were similar among groups; New York Heart Association Functional Class I symptoms were more prevalent (P = 0.0001) in G-I. The ejection fraction by echocardiography was higher in G-I (P = 0.0122). The density of premature ventricular complexes by Holter monitoring was similar among groups. The complexity of premature ventricular complexes by Holter was significantly higher in G-II (P = 0.0270); this variable, analyzed from the exercise electrocardiogram, was not different among groups. All deaths were sudden, prevalence was higher in G-II and absent in G-III, and recurrence of syncope was similar among groups. CONCLUSION: The most probable causes of recurrent syncope were VT (43%) with poor prognosis, and paroxysmal atrioventricular block (21%) with a favorable prognosis. Absence of congestive heart failure, complexity of premature ventricular complexes by Holter, and absence of intraventricular heart block showed statistical correlation with normal electrophysiologic study, inducible VT, and normal HV interval, respectively.

Adult↗
PubMed1994

[Acute atrial fibrillation in the emergency room. Which is the best drug for a rapid sinus rhythm conversion?].

PURPOSE: To evaluate differences between amiodarone, procainamide and quinidine in the time delay necessary to convert acute atrial fibrillation (AF) to sinus rhythm. METHODS: Sixty patients with acute AF were randomized in three groups (G) and treated with: quinidine (QG)-(21 patients) i.v. digital + quinidine up to 600 mg; procainamide (PG)-(23 patients) i.v. digital + i.v. procainamide, 10 mg/kg; amiodarone (AG)-(16 patients) i.v. amiodarone, 5 mg/kg. To evaluate time delay to conversion, all patients have their rhythm recorded by Holter system during four hours. Statistics were done with x2, considering significant a p < 0.05. RESULTS: There were no differences between groups regarding to age, gender and delay from symptoms initiation and medical assistance. Conversion to sinus rhythm occurred, in QG-71.4% cases; PG-47.8% and AG-50% (p > 0.05). Time delay in minutes to conversion were, respectively (media +/- SD): QG-112 +/- 43; PG-44.1 +/- 28; AG-20 +/- 13, significantly lower in PG and AG related to QG (p = 0.001). Although not significant, side effects were observed mostly in PG. CONCLUSION: Amiodarone is a good choice to convert, very quickly, acute AF. Otherwise, quinidine has the best rate of conversion but with a longer time delay.

Acute Disease↗
PubMed1994

[The pseudo-pacemaker syndrome].

We describe three cases of the pseudo-pacemaker syndrome. One of them due to selective fast pathway fulguration of atrioventricular nodal reentrant tachycardia and two others have occurred in spontaneous form. All cases were related with the presence of first-degree atrioventricular block and sinus node tachycardia. The treatment was done with complete atrioventricular block induction catheter ablation and permanent pacemaker implantation in two patients. In conclusion, the procedure of radiofrequency ablation to control AV nodal reentry tachycardia must preserve the fast nodal pathway in order to avoid the pseudo-pacemaker syndrome and this syndrome can spontaneously occur and must be considered during investigation of etiology of syncope.

Adult↗
PubMed1994

[Reproducibility of head-up tilt test in patients with neurocardiogenic syncope].

PURPOSE: In order to identify the reproducibility of head-up tilt test, a second test one week later in 22 patients with a positive first test, was performed. METHODS: The test was performed in a fasting state during the morning. The heart rate and blood pressure were monitored during 20 minutes in the supine position and then at 60 degrees for up to 40 minutes. The test were considered positive if the patient experienced syncope or pre-syncope with fall in systolic blood pressure > 30mmHg. The following aspects were evaluated: reproducibility of the positive response; the type of response (hypotension, asystole or hypotension plus bradycardia) and the time interval between tilt and the beginning of symptoms. RESULTS: Eighteen (82%) patients had a second positive response; 14 (77.8%) of then had the same type of response; and 17 (94%) had syncope in similar time interval after tilt. CONCLUSION: The head-up tilt testing has good reproducibility, although its use in the therapeutic management needs a longer period of evaluation.

Adolescent↗
PubMed1994

[Diagnostic value of the tilt test in the evaluation of syncope of unknown origin. Preliminary results].

PURPOSE: In order to identify neurally mediated syncope, head-up tilt testing was performed in patients with recurrent unexplained syncope. METHODS: The tests were performed in 125 patients in the fasting state, between 8:30 and 11:30 a.m. The blood pressure and heart rate were continuously monitored during 20 minutes in the resting state, and then, positioned at 60 degrees angle, for up to 40 minutes. A group of 20 patients with first negative test was submitted to intravenous isoproterenol in bolus of 2 micrograms every 2 minutes until symptoms occur or at a total dose of 8 micrograms. The test was considered positive when systolic blood pressure decreased at least 30 mmHg and the patient experimented syncope or pre-syncope. RESULTS: In 52 patients the test was positive (41.6%), 63.5% of which had hypotension exclusively; 7.7% asystole; and 28.8% had hypotension and bradycardia. Nine of the 20 patients submitted to isoproterenol test were positive (45%). All patients recovered spontaneously after returning to supine position. CONCLUSION: Head-up tilt testing is a safe and effective method for the identification of neurally mediated syncope.

Adolescent↗
PubMed1993

[Catheter ablation of accessory pathways with low energy. Results in 40 consecutive patients].

PURPOSE: To evaluate the results of direct current catheter ablation of accessory pathways by mean of a new low energy power source. METHODS: Catheter ablation was performed in 40 consecutive patients (23 male, mean age 31 +/- 11 years) with accessory atrioventricular pathways (AP) using a low energy DC power source. The electrophysiologic study and AP ablation were performed in the same procedure by endocardial approach using non-deflectable 6F bi, tri, or quadripolar electrodes. RESULTS: AP was located at left free wall (LFW) in 22 patients (55%), posteroseptal (PS) in 11 patients (27.5%), anteroseptal (AS) in 5 patients (12.5%) and right lateral (RL) in 2 patients (5.0%). A mean of 7.7 +/- 7 catodal shocks of 5-75 (20) joules (J) was delivered in 1.45 +/- 7 sessions, with a mean cumulative energy of 178 +/- 213J per patient. The mean values of number of shocks, number of sessions and cumulative energy per patient were lower in LFW AP ablation than in other positions (5 +/- 4 x 11 +/- 8 - p = 0.008; 1.1 +/- 0.3 x 1.8 +/- 0.9 - p = 0.008 and 118 +/- 150 x 260 +/- 245 - p = 0.03). The mean CK-MB rise was 18.5 +/- 7.8U/1. Three patients (7.5%) presented hemopericardium after PS AP ablation and in 1 patient (2.5%), a PS AP (paranodal pathway) ablation resulted in total atrioventricular block. During a follow-up of 9.5 +/- 4 months AP was absent in 28 (70%) patients; 18/22 (82%) with LFW AP, 6/11 (54%) with PS AP, 3/5 (60%) with AS AP and 1/2 (50%) with RL-AP, (p = 0.10). CONCLUSION: Low energy DC ablation is effective for AP ablation. The results are related with AP position.

Adolescent↗
PubMed1992

[The late results of fulguration of the atrioventricular node using high-energy shocks in patients with supraventricular tachycardias].

PURPOSE: To evaluate the long-term efficacy and safety at long term after atrioventricular junction fulguration (complete AV block induction, using high energy shocks, to control drug-resistant supraventricular tachyarrhythmias. METHODS: Twenty-eight patients, 17 (60.7%) men, with mean age 48.1 years, were submitted to one up to six ablation sessions with high energy shocks. The total delivered energy per patient was 1304 +/- 868 J. Each shock ranged from 100 to 400 J. RESULTS: After 12 months, at least, 60.6% of patients were in complete atrioventricular block; three (10.8%) were asymptomatic without complete AV block, and in five (17.8%) the ablation was unsuccessful. CONCLUSION: AV junction ablation with high energy shocks is safe and efficient in long-term follow-up.

Adult↗
PubMed1992

Recurrent ventricular tachycardia associated with postinfarction aneurysm. Results of left ventricular reconstruction.

Left ventricular reconstruction was used to control recurrent ventricular tachycardia in 19 patients (16 male), mean age of 56 years, with postinfarction anteroseptal aneurysms. The "origin" of recurrent ventricular tachycardia was not determined because the ventricular tachycardia induced by programmed stimulation produced hemodynamic deterioration in all patients. The average ejection fraction was 30.7% +/- 10.1%. In the left ventricular reconstruction technique, the plication of the aneurysmal septum and the reduction of the orifice of the left ventricular cavity after aneurysmal resection with a purse-string suture appear important to prevent the functioning of the reentry circuits. There was one death in the immediate postoperative period. The mean ejection fraction was 47.8% +/- 8.1% (p less than 0.001). The postoperative programmed stimulation induced ventricular tachycardia in only one patient. There were two late deaths. The other 16 patients are asymptomatic (five with antiarrhythmic drugs) in functional class I and without recurrence of ventricular tachycardia. Left ventricular reconstruction is an acceptable technique that changes the spatial orientation in eventual tachycardia circuits. Hence this technique is an alternative for long-term control of the right ventricular tachycardia associated with postinfarction anteroseptal aneurysm without previous electrophysiologic mapping.

Bundle-Branch Block↗
PubMed1991

Incessant ectopic atrial tachycardia and sudden death.

A patient with refractory and incessant ectopic atrial tachycardia (IEAT) is reported in whom it was possible to document, during ECG (Holter) the occurrence of aborted sudden death by spontaneous ventricular fibrillation (VF). Following the second of two attempts at surgical ablation of the origin of the IEAT, the patient has been asymptomatic without antiarrhythmic drugs and in sustained sinus rhythm for 24 months. Although we cannot exclude the residual action of amiodarone and flecainide (proarrhythmia) or the residual peripartum cardiomyopathy it is probable that the observed VF was a true complication of a cardiomyopathy induced by a chronically increased heart rate (HR). Although unclear, this VF might be considered as a form of adrenergic-dependent long QT syndrome due to early afterdepolarization in the presence of predisposing myocardial conditions.

Adult↗
PubMed1990

[Pacemaker with mechanical sensors. Accumulated experience in long-term follow-up].

PURPOSE: To evaluate the behavior of single chamber stimulation system, rate responsive with vibration sensing, taking into consideration the results of long term clinical follow-up. PATIENTS AND METHODS: From september 1986 to april 1989, 70 patients received pacemakers with vibration sensing. Sixty four patients (91.9%) implanted Activitrax I model and six (8.1%) Activitrax II. Thirty-one (44.3%) were men and the mean age was 51.2 years. Fifty-one patients (72.9%) had complete atrioventricular block, 11 (15.7%) sinus node dysfunction, one (1.4%) sinus node and atrioventricular disease, and one (1.4%) for therapeutic support of arrhythmia. The etiology of these dysfunctions were Chagas' disease in 31.4%, myocardiosclerosis in 35.7%, post-operative in 15.6%, post-av node fulguration in 5.8% and idiopathic in 11.5%. The group was submitted to clinic and electronic evaluation and laboratory examinations: echocardiogram, dynamic ECG, stress test and ergoespirometric test. The mean follow-up as 19.6 months. RESULTS: Clinic evaluations: decrease in congestive heart failure functional class in 86% of the patients. No recurrence of syncopes and no cardiac deaths. Echocardiogram: increase in ejection fraction in 42% of patients. Dynamic ECG: appropriate rate response in 94.3% of patients (good cronotropic response). Ergoespirometry: increase in oxygen consumption in 75% of studied cases, Electronic evaluation: absence of generator dysfunction; complications in 18% of cases, all corrected by reprogramation. CONCLUSION: The single chamber cardiac stimulation system with vibration sensing showed safety, efficacy and low rate of complications.

Adolescent↗
PubMed1989

[The quality of life of patients with cardiac arrhythmia undergoing surgical treatment].

The handling of patients with malign ventricular arrhythmia, since 1979, can count on intracardiac electrophysiological studies, cardiac mapping and unconventional cardiac surgery. Such service, which requires the use of sophisticated equipment and specialized professionals, is being provided to patients from all over the country and from all social strata. The Hospital, which maintains the costly, infrastructure required to provide such service, is interested in knowing the reach of the therapeutic action, going beyond the mere knowledge of the success in the immediate treatment. In order to situate the patient as well as his family and social relations, a Social Service professional has been appointed, and same, from a group of 37 patients under treatment (there were 15 deaths), has selected for the survey 17 residents in the metroplitan region of São Paulo, because of contact with them was easier. Evaluation of the changes in the quality of life of the patients that have undergone surgery has been structured in such a way to detail the research procedure, treatment of the data and discussion of the results. Thus, an attempt has been made to characterize the extent of the benefits obtained in the surgeries, at the individual, familiar and social level. Basicaly, in the group of patients surveyed, 70% have been identified as males, 70% as married, 65% older than 50 years, 76% associated to the social security system, 70% with primary level schooling and thus a low family income (1.6 minimum wages per capita).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Myocardial dysfunction secondary to persistent tachycardia].

This study demonstrates the presence of variable degrees of reversible ventricular dysfunction in five patients with incessant atrioventricular tachycardia (IAVT) submitted to surgical ablation of the anomalous pathway. The patients were three females and two males, with age ranging from four to 39 years (mean 15.2). Preoperative EKG presented persistent tachycardia with narrow QRS and RP greater than PR in every case. The P wave was negative in leads D2, D3, AVF from V2 to V6. The 24 hours Holter monitoring demonstrated IAVT rhythm with few sinus beats. The heart rate variated from 140 to 190 bpm (mean 158 bpm). The echocardiogram ejection fraction ranged from 33% to 59% (mean 49.6%). The left ventricular diastolic diameter varied from 47 to 66 mm (mean 53.8). The chest X-ray showed moderate heart enlargement in two patients and mild enlargement in one. All the patients were refractory to isolated or associated antiarrhythmic drugs. Postero-septal anomalous A-V pathway (with exclusively slow retrograde conduction, was demonstrated by electrophysiologic study. After surgery every patient was asymptomatic without medication. Permanent sinus rhythm with heart rate of 62 to 100 bpm (mean 78.4 bpm) in a four months to two years follow-up. The postoperative echocardiogram ejection fraction ranged from 63% to 81% (mean 71.6%) and the left ventricular diastolic diameter was 42 to 57 mm (mean 48.2 mm). The heart area was normal in four patients and mildly increased in one patient. Thus, persistent increase in heart rate induces variable degrees of reversible myocardial dysfunction.

Adult↗
PubMedDate not supplied

Electrophysiologic study in chronic Chagas' heart disease.

Cardiac arrhythmias are common in chagasic patients. Electrophysiologic study is an invasive procedure for the investigation of sinus node function, atrioventricular node conduction and intraventricular (His-Purkinje) conduction and the mechanism of tachycardias. It is useful in elucidating syncope, dizziness and tachycardiac palpitations that remain unexplained by non-invasive diagnostic methods. It is fundamental in directing non-pharmacological therapy, especially in "sudden death" survivors. Chagasic patients may benefit from electrophysiologic study after a critical clinical evaluation.

Arrhythmias, Cardiac↗