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Biomedical subjects

N da Silva

Publications and source records attributed to N da Silva.

At least 19 recordsLinked to original sources
PubMed1999

[Antitachycardia pacing in patients with left ventricular dysfunction and hemodynamically unstable arrhythmias].

UNLABELLED: The use of antitachycardia pacing (ATP) has shown itself to be an effective therapeutic option in the treatment of ventricular tachycardia (VT) in carriers of implantable cardioverter defibrillators (ICD). OBJECTIVE: To assess the safety and efficacy of ATP in ICD carriers with ischemic cardiopathy and systolic dysfunction of the left ventricle (LV) presenting VT badly tolerated hemodynamically. METHODS: We studied five patients (four male and one female), survivors of acute myocardial infarction, mean age 56.4 +/- 15.7 years and an ejection fraction < 35%, submitted to ICD implantation by VT inducible in the electrophysiological study (EPS) and refractory to pharmacologic therapy. In three cases the arrhythmia was syncopal and in two the patients felt palpitations and dizziness (systolic blood pressure < 90 mmHg during VT). The ICDs were implanted between March 1996 and October 1997 by transvenous approach in pectoral position. ATP was used as an initial therapeutic alternative (VT zone with a detection frequency of 160-220/min) according to an empirical programme (n = 3) or, whenever feasible, in accordance with the type of VT interruption during EPS (n = 2). During the follow-up of 11 +/- 6 months (2-18), a periodic assessment of the symptomatology and a detailed analysis of episodes of ventricular arrhythmia detected by ICD were made. RESULTS: Two hundred and fourteen episodes of VT were recorded with a post detection duration of > 2.5 sec treated by ICD. The ATP rate of efficacy was 93%. In 3% of the episodes the ATP did not alter VT; in 2% the rate of VT increased (reduction of the VT cycle > 20%) and in 2% therapeutic exhaustion was observed (after the application of ATP and the maximum number of shocks per episode). In 14 episodes with ATP inefficiency, two syncopes occurred (1% of the total number of episodes treated). CONCLUSION: In this study antitachycardia pacing has proven to be a therapeutic option with high rates of efficacy and safety despite its use in survivors of myocardial infarction with moderate to severe compromise of systolic function of the left ventricle and ventricular arrhythmias with hemodynamic instability.

Aged↗
PubMed1999

[The nonpharmacological treatment of atrial fibrillation].

The authors describe the main forms of nonpharmacological treatment of atrial fibrillation considering catheter ablation and surgical therapy. A new methodology to modify atrioventricular conduction is discussed as well its long-term results. All studies are non-randomised with selected patients, which makes the development of a therapeutical algorithm difficult. However, the results have shown that it is possible to recover sinus rhythm through surgery or catheter ablation and to control the ventricular rate either by His ablation or modification of atrioventricular conduction.

Aged↗
PubMed1999

[Should all patients with ventricular pre-excitation of the Wolff-Parkinson-White syndrome type undergo catheter ablation?].

The authors make a concise review concerning clinical, electrocardiographic and electrophysiologic risk stratification in Wolff-Parkinson-White syndrome and present the results of radiofrequency catheter ablation of atrioventricular accessory pathways. The low sensitivity of electrophysiologic criteria for the identification of a high risk profile limits their use in asymptomatic patients with a low incidence of sudden death. The greater risk of ventricular fibrillation in symptomatic patients makes radiofrequency catheter ablation the treatment of choice for these patients. Therefore, the authors do not recommend an electrophysiologic risk stratification in Wolff-Parkinson-White syndrome, but emphasize that catheter ablation should be performed in all symptomatic patients.

Adolescent↗
PubMed1999

[Atrial fibrillation in Wolff-Parkinson-White syndrome].

The authors describe the main etiopathogenic factors and clinical importance of atrial fibrillation and analyse the results of catheter ablation of atrioventricular accessory pathways in Wolff-Parkinson-White syndrome. Atrial vulnerability is the principal mechanism and radiofrequency catheter ablation of atrioventricular accessory pathways seems to be useless to prevent atrial fibrillation.

Atrial Fibrillation↗
PubMed1998

[Therapeutic exhaustion in patients with an implantable cardioverter-defibrillator. Are there predisposing factors?].

UNLABELLED: In patients (pts) with implantable cardioverter-defibrillators (ICD), antitachycardia pacing (ATP) schemes may be used followed by a limited number of endocavitary shocks in the same episode of ventricular tachycardia (VT) with the potential risk of therapeutic exhaustion. OBJECTIVE: To assess the incidence of episodes of therapeutic exhaustion in a population of ICD carriers with ATP programmes and to attempt to determine their correlation with clinical variables. METHODS: Study of the episodes of VT treated by ICD in 8 patients (6 male; 2 female) with an average age of 56 +/- 17 years with a follow-up > 6 months. The underlying pathology was: ischemic heart disease-5 patients; arrhythmogenic dysplasia of the right ventricle-1 patient; hypertrophic cardiomyopathy-1 patient; and operated pulmonary valve stenosis-1 patient. The authors considered therapeutic exhaustion to be the occurrence of episodes in which VT persisted after the application of ATP and the maximum number of shocks. The patients with episodes of therapeutic exhaustion (group A-3 patients) were compared with the remaining patients (group B-5 patients) with regard to the following parameters: age; ejection fraction; previous myocardial infarction (pMI; cardiac frequency during VT (cfVT); number of episodes of non-maintained VT (NMVT) without therapeutic intervention; > 20% reduction of the VT cycle after ATP (VTATP); intensity of programmable shocks (Icho); and medication with anti-arrhythmia drugs (AA). RESULTS: In a total of 262 VT records (duration > 2.5 sec. after detection) with treatment by ICD during an average follow-up of 11 months, 6 episodes (2.3%) of therapeutic exhaustion were detected in 3 patients. Four of the episodes occurred in the same patient in a period of 4 hours, hospitalisation being necessary following syncope. In the other two cases, there were complaints of dizziness which subsided spontaneously a short time after the application of the last shock by the ICD. [table: see text] CONCLUSION: Therapeutic exhaustion occurred in about 2% of the VT treated with this population. The possibility of a high number of non maintained VT episodes being associated to a greater possibility of therapeutic exhaustion may have implications on ICD programming.

Adult↗
PubMed1997

[Guided anti-arrhythmia therapy by programmed ventricular stimulation. A case of arrhythmogenic dysplasia of the right ventricle].

Right ventricle dysplasia (RVD) is a rare clinical entity, described in young people, and a known cause of ventricular arrhythmias and sudden death. A genetic transmission has been suggested from the study of familial cases. The disease is characterized by a dilated right ventricle, cardiac infiltration with fatty tissue and focal fibrosis. Lymphoplasmocyte infiltrates are documented. The diagnosis is based on electrocardiography, echocardiography, magnetic resonance imaging and right ventricular endomyocardial biopsy. The authors report a case of a young woman with symptomatic ventricular tachycardia (VT) in whom the diagnosis of RVD was established. Programmed ventricular stimulation was used to reproduce the clinical VT and to test the efficacy of the anti-arrhythmic drug therapy. The diagnosis criteria and therapeutic options are discussed.

Adult↗
PubMed1997

[The implantable cardioverter-defibrillator: the Portuguese experience].

OBJECTIVE: The aim of this study was to review the Portuguese experience with implantable cardioverter-defibrillator therapy (ICD), in order to evaluate the increase in the number of ICD implanted, the main indications for this kind of therapy, the technical evolution of the procedure and the results of the follow-up of these patients during the last five years. PATIENT SELECTION: The study group consists of 58 patients, 53 male and 5 female, mean age 54 +/- 14 years with ICD implanted in our country since 1992. The ICDs were implanted in 4 Hospitals, namely, Santa Cruz Hospital with 36 patients, Santa Maria Hospital with 11, Santa Marta Hospital with 8 and Coimbra University Hospital with 3 patients. Twenty six patients were resuscitated from cardiac arrest and the other 32 had ventricular tachycardia (VT) not tolerated haemodynamically and refractory to therapy. The diagnosis was coronary artery disease in 31 patients, dilated cardiomyopathy in 8, valvular disease in 4, congenital cardiopathy in 3, right ventricular dysplasia in 2, congenital long QT syndrome in 1, hypertrophic cardiomyopathy in one. Seven patients had idiopathic ventricular fibrillation without structural heart disease and one patient had isolated right ventricular dilatation. METHODS: All patients underwent electrophysiological study before ICD implantation. In 2 patients epicardial leads were used and in the remaining 56 patients a transvenous approach was used. The device was implanted in an abdominal position in 36 patients and in a pectoral position in 22. Defibrillation and pacing thresholds were measured during the implantation procedure and whenever necessary. Patients were followed up on an outpatient basis with evaluation of the number of arrhythmic episodes, therapy efficacy with reprogramming of the device when required. RESULTS: The number of implantations has increased, from 4 devices implanted in 1992, to 32 in 1996. The implantation was successful and without mortality or complications in all patients. Defibrillation threshold was 16 +/- 3 J, with an electrode impedance of 48 +/- 9 Ohms. During a mean follow-up time of 18 +/- 15 months (1 to 56) 5 patients died, one of sudden death and 4 of non cardiac deaths, 15 patients were re-admitted to hospital and in 8 patients the device was replaced due to exhaustion. In this period, 37 patients (64%) had arrhythmic episodes detected by the device, 32 patients (55%) had shocks and 9 (16%) were treated with anti-tachycardia pacing. Inappropriate shocks were observed in 10 patients (17%). The ICD were reprogrammed in 11 patients. CONCLUSIONS: Portuguese experience with IC implantation is increasing and has shown to be a safe procedure with no operative mortality or morbidity. The incidence of appropriate shocks was high with a good efficacy in sudden death reduction.

Adult↗
PubMed1995

[Acute aortic dissection. Therapeutic strategies and results].

OBJECTIVE: To analyse early and medium-term results of patients (pts) with acute aortic dissection (DAO) regarding the importance of the different therapeutic modalities adopted. DESIGN: Retrospective study of the cases with DAO admitted in the cardiology intensive care unit of Santa Marta Hospital. POPULATION: 46 pts (aged 25 to 80 years) with the diagnosis of DAO from January/1989 throughout December/1993. RESULTS: early mortality rate (30 days) was 36%. DAO type A Two cases were treated only with medical therapy for they suffer from severe associated pathology. Twenty eight pts were treated surgically. In this group mortality concerning time passed from the beginning of the symptoms throughout the surgery was: < 24 h-31%, 24-72 h-40%, > 72 h-63%. Among 17 discharged pts mortality occurred in 7% during the first year. DAO type B In pts with uncomplicated Stanford type B DAO survival was 90%. Emergency surgery was performed in pts who developed complications such as rupture of the aorta, occlusion of major arteries or extension of dissection. In this particular group mortality was 66%. Among 11 discharged pts with type B DAO 9% died within one year. During the follow-up period of 17.4 +/- 14.8 months one third of the pts discharged from hospital had clinical events. CONCLUSION: despite new advances in diagnostic and therapeutic approaches, DAO still's reported as a relatively high hospital mortality situation. Remove pts to an institution with ability to perform quickly the correct diagnosis and treatment becomes essential. Clinical presentation, type of DAO, surgery timing when indicated and major complications were of particular importance in the prognosis of pts with DAO. The frequency of cardiovascular events in pts who left the hospital alive emphasized the need to maintain blood pressure within normal limits.

Acute Disease↗
PubMed1994

[Holt-Oram syndrome. Review and report of 2 familial cases].

In 1960 Holt and Oram reported a family in which upper extremity malformations were associated with a secundum atrial septal defect. Since then, more than 200 cases have been reported with a wide spectrum of phenotypes. The authors present the cases of one mother and daughter with Holt-Oram Syndrome (SHO).

Adult↗
PubMed1994

[Acute myocardial infarct: the prognostic significance of complex coronary lesions].

OBJECTIVE: The aim of our study was to analyze the possible influence of coronary lesion morphology on the prognosis of patients (pts) with Acute Myocardial Infarction (AMI) evaluated by coronary angiography before hospital discharge. DESIGN: Retrospective study. SETTING: Study performed at the Cardiology Department of a Central Hospital. MATERIAL AND METHODS: 141 consecutive pts admitted because of AMI were evaluated, with an age average of 53.4 +/- 9.6 years, who had hospital discharge. All pts were submitted to angiography between the 2nd and 3rd week after AMI. The ventriculography was evaluated to determine the ventricular function score, as defined by the CASS protocol. The coronarography was performed to access the number of diseased vessels and to analyze their lesion morphology. Complexity was defined by the presence of one of the following characteristics: irregularity, shoulder, ulcers, filling defects, contrast retention and ecstasy. TWO GROUPS OF PTS WERE CONSIDERED: Group I--n = 64 pts, with complex lesions, and Group II--n = 69 pts with non complex lesions. Seven pts were excluded from the study because they had no significant coronary disease. Mean time of the follow up was 21.4 +/- 8.5 months and was similar in the two groups. The cardiac events considered were angina after AMI; reinfarction; heart failure; new hospital admission, percutaneous transluminal coronary angioplasty; coronary artery bypass grafting and death. RESULTS: In relation to both groups no statistically significant difference was found concerning sex, age, left ventricular function score and number of diseased vessels. In group I a higher incidence was found for cardiac events (p 0.006) and for the occurrence of angina after AMI (p < 0.02). In this group the number of pts with cardiac events was also higher (p < 0.01). No difference was found in relation to each of the morphologic characteristics and a high risk profile could not be found. CONCLUSIONS: Besides left ventricular function and the number of diseased vessels, the analysis of coronary lesion morphology, evaluated 2 to 3 weeks after AMI, could be useful in risk stratification after AMI.

Adult↗
PubMed1993

[Atrial fibrillation and coronary disease].

OBJECTIVE: To study the incidence of atrial fibrillation in patients (pts) with angiographic coronary artery disease and its relation with clinical and angiographic parameters. DESIGN: Retrospective study. SETTING: Six hundreds consecutive pts, submitted to diagnostic coronary angiography, performed in Hemodynamic Laboratory of Santa Marta Hospital (from 88/04/03 to 90/05/04). MATERIAL AND METHODS: From six hundreds pts were excluded 43 because they had also valvular heart disease and/or minimal coronary artery lesions. Two groups were considered: Group I-pts with atrial fibrillation (n = 7) and Group II-pts in sinus rhythm (n = 549). We evaluated the following parameters: age, sex, clinical history, basal ECG, cardiac enlargement in chest X-ray, angiographic score of LVF, left ventricular diastolic pressure (LVDP), ventricular aneurysm, mitral regurgitation and number of vessels disease. RESULTS: We only found significant statistically differences between the two groups concerning the following parameters: a) age-mean age was superior in group I (Group I-64.2 +/- 8.2 versus 56.3 +/- 9.6), the number of pts older than 60 years in group I was 75% vs 33.8% in group II (p < 0.02); b) heart failure-the incidence was superior in group I, 37.5% vs 9% in group II (p < 0.03); c) cardiac enlargement in chest X-ray-75% pts of group I vs 22% of group II (p < 0.002); d) moderate to severe mitral regurgitation-25% of pts in group I vs 5% of pts of group II (p < 0.05). CONCLUSIONS: Atrial fibrillation is an unusual rhythm in pts with angiographic coronary artery disease. Its presence is related with age, clinical evidence of heart failure, cardiac enlargement and moderate to severe mitral regurgitation.

Age Distribution↗
PubMed1993

[The assessment of the histomorphological characteristics of the arteria gastroepiploica dextra and its potential as an artery for myocardial revascularization].

OBJECTIVE: Comparative analysis of the histomorphological characteristics of left (LIMA) and right (RIMA) internal mammary arteries, right gastroepiploic (RGEA) and anterior descending artery (ADA) with evaluation of the respective prevalence of atherosclerotic changes. SETTINGS: Laboratory of Anatomo-Pathology of a Central Hospital with necropsy material obtained from consecutive individuals, deceased of a non-cardiac cause and older than 60 years. MATERIAL AND METHODS: In 31 cadaver fragments of the RIMA, LIMA, GEA and ADA, were obtain, subsequently fixed and stained in order to become evident the structure of the medial layer, and the presence of possible atherosclerotic changes (intimal Hyperplasia, cholesterol clefts, foam-cells, inflammatory cells infiltrate, rupture of the internal elastic lamina, medial fibroses and calcifications). RESULTS: 1--The RGEA has the structure of a muscular artery as the ADA, opposed to the LIMA and RIMA that are elastic arteries. 2--The atherosclerotic changes were predominantly found in the ADA with no significative differences in there prevalence in the RIMA, LIMA or RGEA. CONCLUSIONS: The RGEA despite having histological characteristics diverse than the LIMA and RIMA, has a similar prevalence of atherosclerotic changes and intimal hyperplasia; those allow us to predict a behaviour and a long-term patency comparable, when used as bypass graft for myocardial revascularization.

Abdomen↗
PubMed1993

Effects of diltiazem on myocardial ischemia in patients with coronary artery disease.

OBJECTIVES: To evaluate the effect of diltiazem on the characteristics of ischemic episodes detected by Holter monitoring in a group of patients with proven coronary artery disease. SETTING: Department of Cardiology, Santa Marta Hospital, Lisbon. METHODS: Eleven selected out-patients, aged 48 to 79 years, with transient ST-segmental depression on Holter monitoring and proven coronary artery disease, were submitted to a double-blind crossover placebo controlled study, during hospitalization. The total ischemic burden of each patient and an analysis of ischemic episodes were evaluated before and during the drug/placebo phase trial. Three groups of ischemic episodes were considered: group I constituted by 66 episodes found on basal Holter recording; group II by 28 episodes detected during placebo trial and group III by 12 episodes detected during diltiazem trial. RESULTS: A reduction of the number of ischemic episodes was predominantly observed with the diltiazem administration. Statistically significant differences were observed between basal and placebo groups and especially between basal and diltiazem groups concerning the mean maximum ST-segment depression (2.17 vs 1.80; p = 0.030 and 2.17 vs 1.54; p = 0.0091). Significant differences were also obtained between the above mentioned groups concerning the heart rate variation from the onset of ST-segment depression to its maximum depression (13.5 vs 9.69; p = 0.023 and 13.5 vs 2.91; p = 0.01) and from two minutes before the onset of ST-segment depression to its maximum depression (21.2 vs 12.67; p = 0.012 and 21.2 vs 8.75 p = 0.016). CONCLUSIONS: Diltiazem seems to reduce the number of ischemic episodes in patients with coronary artery disease, during hospitalization. The study of its effects on the characteristics of ischemia requires further investigation with a greater number of patients. The limitations of the present study, described in the discussion, must be taken into account in future pharmacological investigations with Holter monitoring.

Aged↗
PubMed1993

Clinical and electrophysiologic characteristics in patients with Wolff-Parkinson-White pattern.

OBJECTIVES: (1) To obtain a relation between clinical and electrophysiologic characteristics in patients with Wolff-Parkinson-White pattern. To evaluate the atrial vulnerability for inducing atrial fibrillation and its relation to the electrophysiologic protocol phase. (3) To study the effects of flecainide on the treatment of induced sustained supraventricular arrhythmias. SETTING: Department of Cardiology at Santa Marta Hospital. METHODS: An electrophysiologic testing was performed in twenty-three consecutive patients aged from 14 to 55 years, with Wolff-Parkinson-White (WPW) pattern on ECG. Two groups of patients were considered: group I with 12 asymptomatic or nearly asymptomatic patients; group II with 11 symptomatic patients. The parameters studied were the anterograde effective refractory period of the accessory pathway, the number of patients with different types of supraventricular tachycardias (SVT), the relation between the stimulation protocol phase (scanning/DDT/burst) and the occurrence of atrial fibrillation, and the effects of the flecainide on the treatment of induced sustained supraventricular arrhythmias. RESULTS: Statistically significant differences were obtained between group I and II concerning the number of patients in whom induced atrial fibrillation with conduction by the accessory pathway and RR < or = 250 msec was found (0 vs 6, p = 0.0045). No differences were obtained among the anterograde refractory period, the induction of atrial fibrillation independently of the type of atrioventricular conduction, and the induction of atrioventricular reentrant tachycardia and or atrial flutter. The induction of atrial fibrillation was attained during the Scanning/DDT protocol phase in 7 patients in whom this arrhythmia was found with conduction by the accessory pathway and in 2 without preexcitation. All the induced sustained supraventricular arrhythmias were converted by intravenous flecainide. CONCLUSIONS: (1) Only the symptomatic patients have a high risk profile which suggest that electrophysiologic testing do not need to be performed in those with no symptoms. (2) As atrial vulnerability is higher in patients with induced atrial fibrillation and conduction by the accessory pathway, a more intensive ambulatory control seems to be necessary. (3) The results of intravenous flecainide administration on the treatment of sustained induced supraventricular arrhythmias, advocate its use during the electrophysiologic procedures in patients with ventricular preexcitation and WPW pattern.

Adolescent↗
PubMed1992

Functional significance of premature ventricular complex morphology evaluated during treadmill exercise stress test in patients with coronary artery disease.

OBJECTIVES: To evaluate the relation between premature ventricular complexes morphology and left ventricular myocardial systolic function in patients with proved coronary artery disease. SETTING: Department of Cardiology at General Hospital. METHODS: From 112 patients (pts) with proved coronary artery disease, thirty-three pts with premature ventricular complexes (PVC) detected during treadmill exercise stress test were selected. Two groups of pts were considered: group I-20 pts with regular contour or with a narrow notching (< 40 ms; type I PVC) and group II-13 patients with wide notching (> 40 ms; type II PVC). In each group the following parameters were studied: ejection fraction, QRS duration, duration of exercise, number of metabolic units and the prevalence of ventricular aneurysm and mitral regurgitation. RESULTS: Statistical significant differences were found between group I and II concerning the mean ejection fraction (59.2% vs 48.6%; p < 0.05). The prevalence of ventricular aneurysm and mitral regurgitation was higher in patients with type II ventricular premature complexes (10% vs 30%). CONCLUSION: Particular characteristics of premature ventricular complexes detected during treadmill exercise stress test, in patients with proved coronary artery disease, suggest the presence of left ventricular myocardial systolic dysfunction.

Coronary Disease↗