[Antitachycardia pacing in patients with left ventricular dysfunction and hemodynamically unstable arrhythmias]. / Pacing antitaquicardia em doentes com disfunção ventricular esquerda e arritmias com instabilidade hemodinâmica.

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.

[Isolated left anterior artery disease: angiographic features and clinical evolution of patients submitted to surgical myocardial revascularization or angioplasty]. / Doença isolada da artéria descendente anterior: características angiográficas e evolução clínica de doentes submetidos a revascularização miocárdica cirúrgica ou angioplastia.

The option for revascularization and the choice of intervention in isolated left anterior descending artery disease may be controversial. We decided to study retrospectively a group of revascularized patients (PTCA or surgery), with previous isolated LAD disease, to evaluate the angiographic features of LAD lesion, its contribution to the persistence of symptoms after revascularization and also to compare the occurrence of cardiac events in the two subgroups (PTCA and surgery). We studied 87 patients (mean age 57 +/- 10 years) submitted to myocardial revascularization (68 PTCA; 19 surgery), whose clinical evolution was followed for a mean period of 49 +/- 10 months (cardiac events: death, myocardial infarction, angina, heart failure, PTCA, surgery). We evaluated in cineangiography angiographic features of LAD lesions (degree of stenosis, lesion length and diameter, ectasia, luminal irregularity, ulcerated plaque, eccentricity, thrombus, calcification, type of lesion). On comparing angiographic features, we noted coronary lesions were longer in operated patients (p < 0.05) and a tendency for more complex lesions in this group (p = 0.08). After revascularization, 65% of PTCA patients and 26% of operated patients maintained angina (p < 0.01). The frequency of events was significantly higher in patients submitted to PTCA (84%) due to the greater occurrence of angina (65%). Sixteen percent PTCA were redilated and 6% operated whereas 11% of the surgical group were reoperated, without statistical difference regarding reintervention between the two groups. In the PTCA group, the greater frequency of angina and the necessity of a new PTCA could reflect restenosis. The disappearance of angina in operated patients may reflect probable patency of coronary bypass.

[Comparative study of Toronto SPV prosthesis and bileaflet mechanical aortic prosthesis with 2D-Doppler echocardiography]. / Estudo comparativo entre próteses toronto SPV e próteses mecânicas bidisco em posição aórtica por ecocardiografia 2D-Doppler.

AIM: The aim of this study was to make a noninvasive comparison, by means of Doppler echocardiography, of the hemodynamic performance of biological stentless xenografts and mechanical bileaflet (MB) prostheses (P) in aortic position. METHODS: We studied 20 patients (pts) with normofunctional (nf) aortic Toronto (T) Stentless Porcine valves (SPV)--Group I--8 males, aged 69 +/- 12 years, 32 +/- 9 months after surgery, and 30 pts with nf MB aortic P (Carbomedics or St. Jude Medical)--Group II--17 males (p = NS vs G I), aged 61 +/- 12 years (p < 0.01 vs G I), 30 +/- 12 months after implantation (p = NS vs G I). Both groups were comparable with regard to body surface area and surgical indication. P diameters ranged from 21 to 25 mm (G I: 22.9 +/- 1.7; G II: 22.8 +/- 1.7 - p = NS), the number of pts with the same P diameter in each group being similar. We analysed, at rest: aortic orifice diameter (AoOd - cm), maximal (GMax) and mean (GMean) transprosthesic pressure gradients, P functional area (PFA) and P resistance (PRes). Gradients (mm Hg) were calculated by means of the Bernoulli equation, PFA (cm2) by means of the continuity equation and PRes (dynes.s.cm-5) as 1333 x Gmean x SEP/SV (SEP = systolic ejection period; SV = stroke volume). RESULTS: AoOd (G I vs G II): P 21--1.78 +/- 0.04 vs 2.00 +/- 0.10 (p < 0.001); P 23--1.91 +/- 0.10 vs 2.19 +/- 0.10 (p = 0.01); P 25--2.22 +/- 0.24 vs 2.29 +/- 0.19 (NS). Doppler parameters: [table: see text] CONCLUSIONS: P T SPV show better hemodynamic performance when compared to P MB with the same diameter, in aortic position. In addition, our results suggest that P T SPV allow the use of larger valve sizes for the same aortic orifice diameter.

[Biological prostheses in the tricuspid position. The immediate and follow-up results]. / Próteses biológicas em posição tricúspide: resultados imediatos e no follow-up.

The results of bioprostheses in the tricuspid position were analysed in 42 patients. 79% were in NYHA class III-IV and 43% had previous cardiac surgery. Concomitant surgical procedures were performed in 86% of the cases. Surgical mortality was 14.3%. Mean follow-up was 54 +/- 31 months. Eight patients were reoperated (5.1%/patient/year), but only 3 for the tricuspid prosthesis. Four patients, with left-sided mechanical prostheses, had systemic thromboembolic events (3.8%/patient/year) and 3 on oral anticoagulation had major haemorrhage (2.8%/patient/year). Primary tricuspid valve dysfunction occurred in two patients (1.2%/patient/year). There were no cases of tricuspid valve thrombosis. For hospital survivors, 5 and 8 years survival was 91.4 +/- 10.3% and 76.2 +/- 10.4%, respectively. The only preoperative predictor of decreased survival was pulmonary artery systolic pressure > or = 50 mmHg. Tricuspid valve replacement with a bioprosthesis was usually performed in the set of multiple-valve operation, with previous cardiac surgery in a high percentage of patients, carrying a significant surgical mortality. However, the long-term survival and the low rate of events related to the tricuspid bioprosthesis favours its use, when conservative surgery is not feasible.

[Therapeutic exhaustion in patients with an implantable cardioverter-defibrillator. Are there predisposing factors?]. / Exaustão terapêutica em doentes com cardioversor-desfibrilhador implantável. Há factores predisponentes?

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.

[Significance of the exercise test in the assessment of graft patency after myocardial revascularization with arteries only]. / Importância da prova de esforço na avaliação da permeabilidade dos enxertos após revascularização miocárdica com utilização exclusiva de artérias.

UNLABELLED: Although treadmill exercise testing (TET) has been used to identify ischaemia and determine clinical prognosis after myocardial revascularization, considerable controversy remains on its role in the detection of obstructive lesions of the arterial grafts. AIM: To assess the value of TET in determining the patency of arterial conduits after coronary bypass surgery with complete revascularization. METHODS: Twenty five patients - 21 men and 4 women; age 53.7 +/- 8.7 years - submitted to complete myocardial revascularization exclusively with arterial conduits (CABG-A), undergoing coronary angiography and a symptomlimited TET (Bruce protocol) within 9 months after CABG-A. Angiograms were visually classified in 2 groups (Group I - conduits without lesions, n = 14; Group II > 50% stenosis or occlusion of > or = 1 conduit, n = 11). Clinical characteristics and the following parameters of the TET were compared: total exercise time (ETime); metabolic equivalents (METS); % of predicted maximal heart rate (% MHR); exercise-induced ST depression (decreases ST); and occurrence of angina. The arterial conduits used were: left internal mammary artery -24-; right internal mammary artery -11-; gastroepiploic artery -14-. RESULTS: There were no differences in age, gender, left ventricular systolic function, severity of coronary artery disease, and number of conduits per patient. Group I attained superior values for the following parameters: ETime (p < 0.01) and METS (p < 0.01). Among Group II there were more patients with angina (p = 0.03). Fourteen patients exceeded 8 METS (11 from Group I and 3 from Group II - p = 0.002-). There was no statistical difference among the number of patients with ST depression during exercise. CONCLUSIONS: After CABG-A the exercise tolerance seems to be related with the patency of the conduits and may play an important role in the detection of graft abnormalies. On the contrary, exercise-induced ST depression had low specificity in detecting obstructive lesions of the conduits.

[Experience of the exclusive use of arteries in myocardial revascularization]. / Experiência na utilização exclusiva de artérias em revascularização miocárdica.

OBJECTIVES: To present the initial experience of a surgical team from Santa Marta Hospital using exclusive arterial grafts on coronary bypass surgery. SETTING: Cardiology and Cardiothoracic Departments. POPULATION AND METHODS: From November 1987 to May 1994, 176 consecutive patients were submitted to surgical myocardial revascularization with the exclusive use of arterial grafts. The patients were operated by one cardiothoracic surgical team. A revision of clinical and angiographic characteristics of the patients was done along with the surgical procedure and intrahospital morbidity. After hospital discharge, follow-up was done by direct evaluation and/or by a questionnaire made using phone or letter on a periodical basis. RESULTS: The medium number of coronary bypasses performed were 2.07 +/- 0.8. The left internal mammary artery was the vessel more frequently used, specially to the myocardial area supplied by the left coronary descending artery. The right internal mammary artery was the second arterial graft more currently used. Gastroepiploic artery was utilized preferentially to coronary arteries supplying the inferior wall of the heart. Hospital mortality was 3.4%-6 patients. One hundred twenty patients have a normal life, without physical restrictions, 25% of the patients have symptoms of angina that is severe in 9. Mean follow-up time was 34 +/- 10 months. IN CONCLUSION: Coronary artery bypass surgery with exclusive use of arterial grafts can be executed with an acceptable mortality and low morbidity rates, even in urgent cases, with relieve of cardiac symptoms and good quality of life.

[Acute aortic dissection. Therapeutic strategies and results]. / Dissecção aguda da aorta. Estratégias terapêuticas e resultados.

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.

[Hemolytic anemia in the malfunction of a mitral bioprosthesis]. / Anemia hemolítica em disfunção de bioprótese mitral.

Valvular cardiac prosthesis have dramatically altered the prognosis of patients with valvular cardiac disease; however, they are not free of complications. Prosthesis disfunction and problems related to anticoagulation are the more common, but hemolytic anemia should also be considered. In this case, hemolytic anemia appears as the major complication of a mitral bioprosthesis; the decision concerning the presentation of this case report rests upon its rarity and peculiar circumstances of appearance. A brief revision of the diagnostic work-up is also made.

[The assessment of the histomorphological characteristics of the arteria gastroepiploica dextra and its potential as an artery for myocardial revascularization]. / Avaliação das características histomorfológicas da artéria gastroepiplóica direita e do seu potencial como artéria para revascularização miocárdica.

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.

[Successful operation of aortic abscess ruptured into left atrium. Diagnostic importance of color coded Doppler echocardiography]. / Abcesso aórtico com rotura para a aurícula esquerda, operado com sucesso. Importância diagnóstica do eco-Doppler codificado a cor.

Myocardial abscesses are a serious complication of infectious endocarditis. A 60 years old male patient with subaortic ring abscess is reported. A fistula developed between the left ventricular outflow tract and the left atrium. Doppler echocardiography was of outmost importance for diagnosis. Surgery was successfully performed.

[Annuloaortic ectasia: report of a case]. / Ectasia anulo aórtica: a propósito de um caso.

The authors describe a case of a patient with annuloaortic ectasia (AAE) and severe aortic regurgitation. The diagnostic was made by angiography. He was submitted to a Bentall's procedure; replacement of the ascending aorta by a conduit and of aortic valve by a mechanical prosthesis with reimplantation of coronary arteries into the conduit. The only complication was atrial fibrillation with fast ventricular response. Nowadays he is clinically well, in NYHA class I. The authors make some considerations about AAE, its surgical treatment and its results.

[Brain stem auditory evoked potentials in rabbits with hereditary glaucoma associated with hearing loss: morphofunctional correlations]. / Potenciales evocados auditivos del tronco cerebral en el conejo con glaucoma hereditario asociado a hipoacusia: correlación morfofuncional.

32 rabbits suffering from simple hereditary glaucoma were studied from the ophthalmological, otological and histopathological point of view. Gonioscopy, tonometry, ophthalmo- and retinography, otoscopy, tympanometry, ABR and the corresponding histopathological studies of the eye and of the cochlea were performed. The simple hereditary glaucoma seems to be causally related with concomitant hearing loss due to congenital endolymphatic hydrops. Further studies are planed.