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Stents are being used with increasing frequency in percutaneous transluminal coronary angioplasty (PTCA) but their use in small vessels is still controversial, due to the possibility of excessively high rates of adverse events and restenosis.To assess the safety and clinical efficacy of ACS RX Multi-Link (ML) 2.5 mm stents, in "de novo" coronary stenosis.Prospective Registry, with 6 months clinical follow-up, involving all Portuguese centers of Interventional Cardiology.Between April 7 and November 20 1998, 102 patients were enrolled, 82 male and with ages ranging from 30 to 86 years (average 58 +/- 11). Clinical presentation for PTCA was stable angina in 53%, unstable angina in 36% and silent ischemia in 11%. There was a history of previous myocardial infarction in 29% of patients. The main risk factors were hypertension (58%), hyperlipidemia (57%), smoking (25%) and diabetes (20%). Multivessel coronary artery disease was present in 46% of patients and left ventricular function was normal in 89%. Of the 217 existing lesions, 188 (87%) were treated: 35 with balloon angioplasty and 153 with stent implantation, 114 of which were ML 2.5 mm: 79 of 15 mm in length and 35 of 25 mm.Angiographic success with ML stent implantation and major adverse cardiac events (MACE)--myocardial infarction (MI), coronary artery bypass graft (CABG), new target vessel revascularizations and death--were evaluated during hospital stay, and at 1 and 6 months clinical follow-up.Angiographic success was 97.4%. In one patient it was not possible to cross the lesion, in another there was stent migration and in a third distal coronary flow after stenting was TIMI grade 1. Clinical success was 96.1% and there were no cases of death, Q-wave MI or urgent CABG. Two patients had non-Q wave MI and two required urgent repeat angioplasty. Subacute stent thrombosis occurred in 1 patient. There were no additional MACE at 1 month follow-up. At 6-month follow-up (in 97% of patients) MACE had occurred in 14.1%: 2 deaths (one non-cardiac), 3 MI (one non-Q) and 14 new PTCA (one in a non-ML stent). There was no need for CABG in any patient. Six-month survival rate was 97.9%, 94.9% were free of infarction and 84.8% were free of infarction and new revascularization.Multi-Link 2.5 mm stent implantation appears to be safe and efficient with a low incidence of immediate and 6-month adverse events in the range of centers and operators of the Registry.

After ST elevation myocardial infarction, ST segment and T wave changes generally resolve, but in some patients T waves keep their negative components for a long time. The aim of this study is to evaluate the pathophysiological implications of persistent negative T waves and restored positive T waves in the chronic stage of Q wave myocardial infarction.We studied 30 patients with a previous anterior wall ST elevation myocardial infarction (more than one year follow-up) and presenting Q waves in at least three consecutive precordial leads in the standard 12-lead electrocardiogram at rest. Patients were divided into two groups according to the T wave pattern in leads with Q waves: positive T group consisting of patients in whom all T wave components showed an upright configuration; and a negative T group consisting of patients in whom T waves were are least partly inverted. We used echocardiography to measure systolic thickening of the interventricular septum within the infarction area. Systolic thickening was considered significant when end-systolic thickness was greater than end-diastolic thickness by25% in proportion and1 mm in absolute value.Significant systolic thickening was demonstrated in 14 (74%) of the 19 positive T patients and in one (9%) of the 11 negative T patients (odds ratio 8.1; 95% CI, 1.2 to 53.5; p = 0.002).In the chronic stage of a myocardial infarction, restored T wave positivity predicts preserved systolic thickening, suggesting the presence of viable and normally contracting myocytes within the infarction area. Further studies are needed to establish the prognostic value of T wave characteristics in patients with a past history of myocardial infarction.

Coronary angioplasty (PCI) of chronic total occlusions (CTO), even when successful, are associated to less favourable long term results. The recent use of coronary stents has improved the long term outcome of those interventions.To evaluate the short term results and long term occurrence of major adverse coronary events (MACE): death, MI, urgent revascularization and the need for a new target vessel revascularization (TVR) in patients with CTO who had previously been submitted to a PCI with excimer laser for plaque debulking followed by a provisional stent.From our database, we selected 19 patients with a mean age of 51 +/- 13 years (18 male) submitted to PCI between 1994 and 1998. Of those patients, 10 had had of a previous MI. Hypertension, smoking habits and hypercholesterolemia were present in 9 patients (42%). Two patients had diabetes. The main reason for PCI was stable angina in 16 patients (84%) and unstable in 3 patients (16%). Single-vessel disease was present in 18 patients (94%) and multiple-vessel in 1 patient (6%); left ventricular ejection fraction was preserved in 18 patients (94%). Single vessel PCI was performed in 16 patients (84%) and double vessel in 3 patients. Plaque debulking with excimer laser was performed in all patients, followed by 23 stents (Multilink--8; Gianturco Roubin--5; Palmaz Schatz--4; others--6). The mean clinical follow-up was 19 months.There were no major short-term clinical events (death, MI or urgent revascularization). During follow-up, TVR was only required in 5 patients (26%), all of them in the first 7 months after PCI.In the highly selected population, PCI for chronic total occlusion, with excimer laser plaque debulking followed by provisional stents, was a safe procedure with a very acceptable rate of new target vessel revascularization in the follow-up period.

To evaluate the influence of right ventricular (RV) function, determined by RV ejection fraction, on the clinical status of patients with ischemic heart disease and left ventricular (LV) EF under 40%.The role of RV function as a marker of prognosis in heart failure has been debated. We hypothesized that the degree of RV dysfunction is a determinant of the clinical status and outcome of patients with LV dysfunction after myocardial infarction.30 patients, 25 male, with previous myocardial infarction, more than 6 months age, were studied by equilibrium radionuclide angiography. Functional capacity was evaluated by cardiopulmonary exercise test with Naughton protocol. Patients were followed during a 12 month period for major clinical events: death or hospitalisation for congestive heart failure. Two groups of patients were considered according the value of RVEF (or = 30% and30%).The values of EF were: LV = 25 +/- 7% and RV = 35 +/- 9%. Maximum oxygen consumption correlated with RVEF (r = 0.78, p0.001) but not with LVEF (r = 0.12, NS). The group of patients with RVEF30% had a greater exercise time (712 +/- 229 versus 441 +/- 208 seconds, p = 0.003), higher oxygen consumption (19.8 +/- 5.3 versus 13.5 +/- 3.3 ml/kg/min, p = 0.001) and oxygen consumption in relation to the maximum predicted for age and sex (71 +/- 19 versus 50 +/- 13%, p = 0.002). Cumulative frequency of major clinical events was greater in the group with RVEFor = 30% (58% vs 6%, relative risk 3.14, 95% CI 1.23 to 5.05). There was no correlation between the values of LVEF and outcome.In this setting of ischemic LV dysfunction, the RVEF correlates with functional capacity in cardio-pulmonary exercise test and the presence of RV dysfunction is associated to a higher incidence of clinical events.

Syncope is a syndrome caused by a reversible reduction of blood to the brain. Three hemodynamic abnormalities can cause syncope: an acute decrease in cardiac output, an acute increase in cerebrovascular resistance and a fall in systemic blood pressure due to ineffective control of peripheral vascular resistance. We made a retrospective study of 121 patients with syncope history, 67 males, and 57 females, with mean age 48 +/- 14 years, and at least six months of clinical follow-up. Twelve patients had valvular disease, two patients had hypertrophic cardiomyopathy, eight patients had dilated cardiomyopathy, 14 patients had ischemic disease, three patients had congenital disease; 82 patients did not have cardiac disease. Syncope etiology was arrhythmic in 69 patients: 47 patients had tachyarrhythmia (supraventricular--in 27 patients and ventricular in 20 patients) and 15 patients had bradyarrhythmia (seven patients had sinus node disease and eight patients had atrioventricular block). Non arrhythmic etiology of syncope was identified in 29 patients (neurologic disease--ten patients, metabolic disease--one patient and iatrogenic--two patients; vasodepressor syncope--14 patients, and hypertrophic cardiomyopathy--two patients). It was not possible to determine the syncope etiology in 30 patients. The assessment of patients who present syncope depends on establishing the basis for the symptoms. The initial step is differentiating patients with normal cardiovascular systems from those with heart disease. In the former, tilt-table testing proved to be the most productive from a diagnostic perspective; in the latter group, electrophysiologic evaluation was the most elucidative from a diagnostic perspective. The ultimate goal is to obtain a sufficiently strong correlation between syncopal symptoms and detected abnormalities to permit an accurate assessment of prognosis and to develop an effective treatment plan.It is very important to establish the etiology of syncope for optimal management of patients and it is therefore possible to control the symptoms in the majority of them. The patients who present syncope require a complete history and a physical examination for an appropriate workup to be initiated. Tilt-table testing was the most accurate for the diagnosis of vasodepressor syncope while electrophysiologic testing provides an accurate method for assessing the etiology of tachyarrhythmic syncope.

Endocarditis is a rare, but some times fatal, complication of Q fever. Its diagnosis is difficult and it is based on non-specific cardiac findings and a high title of phase I antibodies. The treatment is based on tetracyclines alone or in combination with cotrimoxazole, for long periods of time. The therapeutic efficacy is evaluated by the measurement of phase I antibodies, every three months. The relapses are frequent despite the long period of antibiotic therapy. We report what is probably the first case of Q fever prosthesis endocarditis in Portugal, as a complication following an acute episode of Q fever.

The goal of this study was to evaluate the clinical and echocardiographic results of a cohort of patients subjected to aortic valve replacement with pulmonary autograft (Ross procedure).We studied prospectively with clinical and echocardiographic evaluation all patients subjected to this type of aortic valve surgery, before operation, intraoperatively, before hospital discharge and at the end of this study in September 1994 and we analysed the evolution of the results during the follow-up period.22 consecutive patients 12 men and 10 women mean age 48 +/- 14 years subjected to Ross operation between April 1992 and June 1994.Patients were studied with transesophageal echocardiography intraoperatively and transthoracic echocardiography. Two-dimensional and M-mode evaluation, continuous and pulsed wave Doppler and color coded Doppler were performed, with assessment of the morphology and Doppler profile of both the autograft and the homograft in pulmonary position.No early or late mortality was registered, and apart two patients who were reoperated, all patients were asymptomatic in the last medical visit. There was no incidence of thromboembolic events even though no anticoagulation has been used. Aortic regurgitation was present in 14 patients, grade 1 in 11 patients and grade 2 in three. In the last echocardiogram performed the analysis of aortic flow, demonstrated absence of significant transvalvular gradient (maximal aortic gradient of 5.6 +/- 0.4 mmHg and mean aortic gradient of 1.8 +/- 0.08 mmHg). Pulmonary regurgitation was absent in nine patients, and present in 13, considered trivial in all cases.These data suggest that this type of surgery has a low operative risk, with absence of thromboembolic complications and excellent clinical and echocardiographic results.

To assess the 3-year prognosis of patients with suspected coronary artery disease and a normal dipyridamole-thallium scintigram.43 patients, 16 male and 27 female, mean age 55.8 +/- 9.2 years with suspected coronary artery disease. Forty-two patients had anginal complaints. There was a previous positive treadmill exercise test in 14 patients. All the patients had a normal dipyridamole-thallium SPECT.Dipyridamole was infused at a rate of 0.56 mg/kg in 4 minutes followed by 3 minutes of low-level cycloergometer exercise. Two mCi of thallium-201 were injected 3 minutes after the end of dipyridamole infusion. Stress and redistribution SPECT acquisitions were performed respectively 5-10 minutes and 4 hours after thallium-201 injection. The cardiac events during a 3-year follow-up were analysed.No patient had unstable angina, PTCA, CABG or death. One patient suffered an inferior myocardial infarction 28 months after the scintigraphy. The event rate was 0.78% per patient per year.Three-year prognosis in patients with suspected coronary artery disease after a normal dipyridamole thallium SPECT is excellent approaching that of the general population.

The aim of this study was to evaluate our results of radiofrequency catheter ablation (RFCA) of concealed accessory atrioventricular pathways (CP).We treated with RFCA 19 patients, with 21 CP, 10 men and 9 women, mean age 37 +/- 16 years, with supraventricular tachycardia (SVT) and absence of ventricular pre-excitation in the electrocardiogram (ECG). These patients comprised 50% of the patients who underwent RFCA for SVT and had no ventricular pre-excitation in the ECG. The diagnosis of CP was made by electrophysiologic study, based on the demonstration of a pathway capable of retrograde conduction only.The RFCA was performed without antiarrhythmic drugs in the same session of the electrophysiologic diagnosis. The location of the CP site was obtained by catheter mapping, looking for the earliest atrial retrograde activation during tachycardia or ventricular pacing.The CP had a right-sided location in only 2 patients who had an incessant form of SVT, the CP in these patients exhibit decremental conduction--permanent junctional reciprocating tachycardia. In the other patients the CP was left-sided, lateral in 11 patients, posterior in 3, postero-septal in 3 and medial septal in one patient. In 9 patients there was a simultaneous ventricular activation in the his bundle electrogram and in the electrogram of the ablation site, suggesting partial anterograde penetration of the stimuli on the accessory pathway. Success criteria were achieved in 18 patients (95%) corresponding to 20 CP.The prevalence of CP in the presence of SVT without ventricular pre-excitation is high, almost all left-sided. The CP displays eccentric atrial activation during SVT. It is possible that CP are capable of partial anterograde conduction as well. The success rate of RFCA is high.

First results of tachyarrhythmia's direct current (DC) and radiofrequency (RF) catheter ablation in Portugal (St. Cruz Hospital, Carnaxide).Retrospective analysis of the first 20 patients (P) submitted to catheter ablation in our Center: 11 males and 9 females, aging 36 years (SD 14), with drug-refractory symptomatic tachyarrhythmias. DC ablation was used in the first case and RF current in the nineteen subsequent P.Accessory pathway RF ablation: 92% successful rate (12/13 P); AV nodal modification: fast pathway--1 P (DC ablation), slow pathway--3 P (RF ablation) with one case of late clinical recurrence; two successful His bundle ablation (in paroxysmal atrial flutter/fibrillation) one standard right side and other from left ventricle outflow; one successful RF ablation of a verapamil-sensitive ventricular tachycardia. The mean follow-up was 3.5 months (1 to 7 months for RF and 20 months for DC ablation).Catheter ablation (mainly RF current) is highly effective in tachyarrhythmia's suppression, with 90% global success in our experience without morbidity.

To compare clinical and electrocardiographic characteristics of Nonsustained Ventricular Tachycardia (NSVT) and Idioventricular Accelerated Rhythm (IVAR).We studied 155 patients, 113 men and 42 women, with mean age 54 +/- 14 retrospectively, of these, 108 had NSVT and 47 IVAR. The arrhythmias were defined as follows: NSVT-more than 3 ventricular consecutive beats with an heart rate superior to 110 b/m and lasting less than 30 s.; IVAR-3 or more ventricular consecutive beats with an heart rate equal or superior to 50 and lower than 110 b/m, lasting less than 30 s. We evaluated clinical data (symptoms, functional class and anti-arrhythmic therapy), electrocardiographic data (rhythm, changes in conduction and repolarization) and ventricular function (with ECO, Radionuclide Angiography or Ventriculography). In the Holter recording (ECG-H), we analysed the presence of associated ventricular arrhythmias, their electrocardiographic characteristics (number of episodes, number of beats per episode, previous arrhythmia rate, morfology, regularity) and the relations of the arrhythmia with symptoms.Analysis of underlying pathology showed in both groups, the importance of coronary artery disease (44.5% vs 40%) followed by valvular heart disease (24% vs 27.6%) and cardiomyopathy (22.2% vs 17%) respectively to NSVT and IVAR. Only in the NSVT group there were patients without cardiac pathology (3.6%). Comparing with one control group of our department, this distribution was substantially different (p less than 0.0001). All IVAR episodes were assympthomatic compared with 90% of NSVT. Ventricular premature beats were found in all NSVT patients and in 90% of IVAR patients, and were frequent (greater than 10/h) in 79% and 60%, couplets in 84% and 53% respectively (ns). The previous rate of the arrhythmia was 85.3 +/- 20 b/m in NSVT against 68.7 +/- 14 in IVAR (p less than 0.0001). We found left ventricular disfunction in 60% of NSVT patients and in 63.7% in IVAR patients, being serious in 35% and 39% respectively. The follow-up was of 18.5 months (1-72) and posterior evolution showed 14.8% and 17% of deaths with no relation to the arrhythmia, although in NSVT the number of complexes and episodes were related with the ventricular disfunction (p = 0.02 and p = 0.05).Both arrhythmias appeared in patients with similar clinical and arrhythmic setting and identified a population with structural cardiopathy, bad function and poor outcome.