[Ventricular arrhythmias induced by appropriate antibradycardia pacing in patients with implantable defibrillators]. / Inducción de arritmias ventriculares por estimulación antibradicardia apropiada en pacientes portadores de desfibrilador automático.

INTRODUCTION AND OBJECTIVES: The induction of ventricular arrhythmias by appropriate antibradycardia ventricular pacing in patients with implantable cardioverter defibrillators has been reported in only a few cases. The aim of this study was to assess the incidence, characteristics and management of these episodes. METHODS: The follow-up records of 180 patients with implantable cardioverter defibrillators with intracardiac electrogram storage were reviewed. Pacing induced episodes were defined as those occurring immediately after an appropriate paced stimulus in a patient with sporadic paced beats. We assessed the number and type of episodes, mode of onset, therapy administered and the efficacy of different prevention measures. RESULTS: Pacing induced episodes were found in 9 patients (5%). Seven received device administered therapy which was effective in all cases. One to 95 episodes were observed per patient, of which 138 were monomorphic ventricular tachycardias and 20 polymorphic ventricular tachycardia/ventricular fibrillation episodes. All were induced by a paced ventricular beat after a post-extrasystolic pause or after long RR intervals during atrial fibrillation. Pacing induced arrhythmias were prevented by changing the pacing rate or hysteresis in 3 out of 6 patients and by decreasing the stimulus energy in 3 out of 3. Antibradycardia pacing function was disabled in 4 patients. CONCLUSIONS: Ventricular arrhythmias induced by appropriate antibradycardia ventricular pacing are relatively common in patients with implantable cardioverter defibrillators. Effective prevention can be achieved in most cases by changing the pacing rate or the pacing stimulus energy, however in selected cases the antibradycardia function may be disabled.

[Usefulness of predictors of angiographic restenosis to predict clinical restenosis after coronary stent placement]. / Utilidad de los predictores de reestenosis angiográfica en la predicción de reestenosis clínica de stents intracoronarios.

INTRODUCTION: After coronary stenting, several predictors of angiographic in-stent restenosis have been identified in different studies, however, little is known about predictors of clinical restenosis, a more functional aspect of coronary restenosis. AIM: To assess whether risk factors for angiographic restenosis previously described, are able to predict clinical restenosis and at what rate in current practice. PATIENTS AND METHODS: 216 consecutive patients (271 stents in 256 lesions) with procedural success were followed-up for 17.6 +/-10 months during periodic visits. Clinical restenosis was defined as the presence of symptoms or signs of myocardial ischemia, associated with >= 50% diameter stenosis on the angiogram. RESULTS: Clinical restenosis occurred in 33 lesions (13%), which were revascularized with 34 stents associated with unstable angina in 29, acute myocardial infarction in three and death in one case. Multivariate analysis identified as independent predictors of clinical restenosis, a vessel diameter less than 3 mm (p < 0.001, OR 4.5), a restenotic lesion (p = 0.01, OR 2.9) and the presence of residual stenosis by visual estimate (> 0%) after implantation (p = 0. 02, OR 2.5). These three risk factors explained most clinical restenosis (73%), with rates of 22% when at least one was present and 4% in absence of all these. The presence of diabetes mellitus, the location in the anterior descending coronary artery or at coronary ostium, and the number or total length of stents per lesion did not achieve an independent, significant association as predictors of clinical restenosis. CONCLUSIONS: Most clinical restenosis after coronary stenting can be predicted by the restenotic character of the revascularized lesion, the diameter of the vessel being less than 3 mm and the presence of residual stenosis by visual estimate at the end of procedure.

[The long-term clinical results of the implanting of intracoronary stents in current practice]. / Resultados clínicos a largo plazo del implante de stents intracoronarios en la práctica actual.

INTRODUCTION: Published Stress and Benestent studies, obtained in selected populations under technical conditions that do not reflect present practice with intercoronary stenting showed a clinical benefit of coronary stenting. OBJECTIVE: To assess clinical longterm outcome of coronary stenting in current practice and to compare coronary lesions with and without Stress/Benestent criteria. METHODS: 216 consecutive patients with successful placement of 279 stents in 256 lesions and no major in-hospital events. Mean clinical follow-up was 16.7 +/- 10.4 months. Standard technique included seven types, high pressure balloon inflation (15.6 +/- 2.2 atm) and post-stenting treatment of four weeks with aspirin and ticlopidine. RESULTS: Cumulative rates of target lesion revascularization were 9.7% at 6 months, 13.5% at 12 months and 15.1% at 18, 24 and 36 months. Cumulative rates of combined clinical end-point (death, myocardial infarction and target lesion revascularization) were 11.3%, at 6 months, 13.9% at 1 year, 19.3% at 2 years and 21.1% at 3 years. No Stress/Benestent lesions were 193; 75%, and had a higher incidence of target lesion revascularization (17.9 vs 7.5%, Log Rank = 0.015) and combined clinical end-point (22.4 vs 10%, Log Rank = 0.025), than Stress/Benestent lesions. CONCLUSION: Coronary stenting of no Stress/Benestent lesions have a less favourable clinical longterm outcome. However, clinical outcome in a nonselected population at the present time is similar to the old Stress/Benestent studies, probably because of technical improvements.

[Role of adenosine triphosphate (ATP) in head-up tilt-induced syncope]. / Papel del adenosín trifosfato (ATP) en la inducción de síncope mediante test de basculación.

INTRODUCTION AND OBJECTIVES: Recent studies have demonstrated that adenosine is an endogenous modulator of the cardiac excitatory afferent nerves, and could provoke a vasovagal response during head-up tilt test. Isoproterenol has been the drug of choice to increase the sensitivity of this testing. The aim of the present study was to analyze the role of adenosine in head-up tilt-induced syncope in susceptible patients, and to compare the relative sensitivities of adenosine and isoproterenol. METHODS: Thirty patients with unexplained syncope (16 female and 14 male, mean age 37.1 +/- 18 years), no heart disease and negative baseline head-up tilt test were studied. After the baseline test, patients were randomized to receive adenosine triphosphate (bolus injections of 3, 6 and 9 mg/ 5 min) or isoproterenol (bolus injections of 2, 4 and 6 micrograms/5 min) and underwent a second tilt test. After 15 min at rest, patients received the alternative drug and a third test was performed. Eleven normal control subjects were tested with adenosine in the upright position to determine its effects. RESULTS: A vasovagal response was induced in 7 patients (23.3%) after ATP administration. Nine patients (30%) showed a positive response with isoproterenol. Only 2 patients (6.6%) showed a positive response with both drugs. Of the control subjects, one (9%) had a vasovagal response after ATP administration. CONCLUSIONS: We conclude that adenosine triphosphate seems to be a useful tool to provoke vasovagal reaction in susceptible patients during head-up tilt test.

[Epidemiological changes in infectious endocarditis. A prospective study, 1992-96]. / Cambios epidemiológicos en la endocarditis infecciosa. Estudio prospectivo 1992-96.

BACKGROUND: To know the present epidemiological situation of the infective endocarditis in our environment and its evolution in the last few years. RESULTS: The incidence of infective endocarditis was 0.85 per thousand patients admitted to hospital, with a mean age of 43 years. The predisposed factors more frequently found were: drug addiction (32%) and cardiac prosthetic valves (23%). In the greatest number of our patients the cardiac valves involved were: tricuspid (28%), mitral (27%) and prosthetic valves (23%). The causative organism were: S. aureus (19 cases), Streptococcus (15 cases) and S. epidermidis (11 cases). The echocardiography study resulted diagnostic in 90% of the patients, valve replacements were performed in 22% of the cases. The overall mortality rate was 10%. CONCLUSIONS: The current profile of infective endocarditis is characterized by a high incidence of parenterally drug addict patients or prosthetic valves carriers. Increase of the infections of S aureus and a decrease of Streptococcus infections, as well as a less overall mortality.

Role of endogenous opioids in syncope induced by head-up tilt test and its relationship with isoproterenol-dependent and isoproterenol-independent neurally-mediated syncope.

This study was designed to evaluate the role of endogenous opioids in neurally-mediated syncope. Head-up tilt test was performed on 35 patients with syncope of unknown origin. Plasma beta-endorphin was measured (1) at baseline, (2) at the end of tilt test or at time of syncope, (3) 15 min before isoproterenol-test, (4) at the end of the isoproterenol-test or at time of syncope. Subjects with a positive tilt testing showed a larger rise in plasma beta-endorphin concentrations at time of syncope (baseline 13.7+/-8.0 vs. syncope 41.4+/-26.4 pmol l(-1); P<0.01). On the contrary, patients with a positive isoproterenol-test showed no rise in plasma beta-endorphin levels (baseline 7.9+/-3.6 vs. syncope 7.4+/-2.7 pmol l(-1); P=ns). Patients with a passive negative tilt test (baseline 6.7+/-2.8 vs. end of test 7.0+/-3.3 pmol l(-1); P=ns) and negative isoproterenol tilt test (baseline 7.4+/-3.8 vs. end of test 8.1+/-3.4 pmol l(-1); P=ns) showed no changes in beta-endorphin concentrations. To further examine the efficacy of i.v. naloxone to prevent syncope, 10 patients were randomized to naloxone (0.02 mg/kg) or placebo. Second head-up tilt testing was negative in 1/5 patients with naloxone and in 2/5 patients with placebo. We conclude that, (1) endogenous opioids seem to be involved in vasovagal syncope induced by baseline head-up tilt test, (2) changes in plasma beta-endorphin concentrations show significant differences between patients who have isoproterenol-dependent and isoproterenol-independent syncope, this finding might occur in the setting of different pathophysiologic mechanisms, and (3) intravenous naloxone at a dose of 0.02 mg/kg was not superior to placebo in order to prevent positive responses to baseline tilt test.

[Long-term prognosis of patients with syncope of unknown origin in prolonged asystole induced by the head-up tilt test]. / Pronóstico a largo plazo de pacientes con síncope de origen desconocido y asistolia prolongada inducida mediante test de basculación.

INTRODUCTION AND OBJECTIVES: Prognosis and therapeutic assessment of patients with syncope and prolonged asystole during head-up tilt test remain unclear. The aim of the present study was to analyze the clinical evolution of patients with syncope of unknown origin, no heart disease and severe cardioinhibitory response induced by head-up tilt. METHODS: A prospective follow-up study was performed in 12 patients (6 male and 6 female, mean age 31 +/- 20 years) with recurrent syncope, no heart disease and affected by severe cardioinhibitory syncope induced by head-up tilt test. This was defined as syncope or near-syncope induced by baseline or isoproterenol tilt with asystole of > or = 3 seconds. All patients were re-tilted twice: with salt and fluid and with metoprolol (25 mg/b.i.d). According to the results of these tests, 5 patients were discharged with dietetic measures (salt & fluid) and 5 with metoprolol. In 2 patients who showed recurrent prolonged asystole a DDD pacemaker was implanted. RESULTS: After follow-up of 34 +/- 20 months all patients ae alive. The number of recurrences was small (2 syncopes and 2 near-syncopes). No relationship was observed between the number of syncopal recurrences and the applied treatment. CONCLUSIONS: We conclude that prolonged asystole induced by head-up tilt test does not confer an adverse prognosis in patients with syncope of unknown origin and no heart disease, thus, the clinical evolution of these patients is benign.

[Usefulness of early exercise test after anterior infarction in the diagnosis of multivessel disease]. / Utilidad de la prueba de esfuerzo precoz postinfarto anterior para detectar enfermedad multivaso.

OBJECTIVE: The aim of the present study was to determine the reliability of early exercise test to detect multivessel disease in survivors of an uncomplicated first anterior Q-wave myocardial infarction. METHODS: Among 100 consecutive patients 64 (aged 55 +/- 10 years) were included in the study. Thirty-four patients (53.1%) received thrombolytic therapy and this was considered successful, by means of non-invasive criteria, in 24 patients (37.5%). A standard symptom-limited exercise test, 11-15 days after myocardial infarction, and coronary arteriography, < 72 hours later, were performed in all patients. RESULTS: On exercise test 6 (9.3%) patients developed significant ST segment depression, 48 (75%) significant ST segment elevation, 5 (7.8%) ST depression in inferior leads together with ST elevation in anterior leads and 3 (4.6%) angina. Of the 18 patients with multivessel disease 5 (27.8%) developed ST depression, 10 (55.5%) ST elevation, 1 (5.5%) ST depression in inferior leads together with ST elevation in anterior leads and 1 (5.5%) angina. CONCLUSIONS: Our study indicates that ST depression in a symptom-limited exercise test performed early after an anterior Q-wave acute myocardial infarction is unusual and has low sensitivity (27.8%) to detect multivessel disease. ST elevation is the more common finding in this test (75%) and has no relation with the severity of CAD.

[Use of transdermal scopolamine in the prevention of neuro-cardiogenic syncope induced by the tilt test]. / Uso de la escopolamina transdérmica en la prevención del síncope neurocardiogénico inducido mediante test de basculación.

INTRODUCTION AND OBJECTIVES: The underlying mechanism of syncope induced by head-up tilt test is still incompletely understood. It has been proposed a sudden increase in parasympathetic's activity induced by the excessive activation of the cardiac mechanoreceptors. The aim of our study was to evaluate the clinical, electrocardiographic and hemodynamic responses to head-up tilt test before and after treatment with transdermal Scopolamine (anticholinergic agent). METHODS: We studied 17 patients (8 females, 9 males; mean age 43 +/- 19 years) with > or = 2 syncopal episodes of unknown origin and a positive tilt test (a positive response to tilt testing alone or in conjunction with an infusion of isoproterenol was defined as the appearance of syncope or presyncope associated to hypotension and/or bradycardia). Symptoms developed in 12 patients during the baseline tilt (Group I) and in 5 patients after infusion of isoproterenol (Group II). Mean time to symptoms was 8.5 +/- 7.9 minutes in group I. All patients were them treated with transdermal Scopolamine (1.5 mg/24 hours) and 48 hours later tilt test was repeated. RESULTS: In group I, 8 patients (66.6%) became tilt test negative and in the remaining 4 patients mean time before the appearance of symptoms was increased (8.5 +/- 7.9 vs 16.2 +/- 2.5 minutes; p < 0.05). In group II, 3 patients (60%) became tilt test negative and in the remaining 2 patients symptoms developed after an infusion of higher doses of isoproterenol than in the first study. So, with transdermal scopolamine 11 out of 17 patients became tilt test negative and time to symptoms was increased in all of the remaining 6 patients. CONCLUSIONS: Our study suggest that transdermal scopolamine is an usefull treatment in the prevention of neuro-cardiogenic syncope induced by head-up tilt test.

[Long-term follow up of Doppler parameters of ventricular diastolic function after myocardial infarct]. / Evolución a largo plazo de los parámetros Doppler de función diastólica ventricular tras un infarto del miocardio.

Forty-two survivors of a first transmural, noncomplicated myocardial infarction underwent mitral flow pulsed-Doppler studies both at predischarge time and 1 year later, in order to assess the long-term evolution of diastolic parameters in the absence of reinfarction or revascularization procedures. Results showed a decrease of mean value of E wave peak velocity (59.6 +/- 14 cm/sec vs 46.8 +/- 13 cm/sec, p < 0.001). Mean value of A wave peak velocity remained stable (59.4 +/- 16 cm/sec vs 58.8 +/- 13 cm/sec, p = 0.86). The mean value of the E/A ratio showed a significant decrease during follow-up from an initial value > or = 1 to a final value < 1 (1.08 +/- 0.4 vs 0.82 +/- 0.2, p < 0.01). From the point of view of individual results, only 8 of 22 patients with an E/A ratio > or = 1 before discharge presented the same ratio value 1 year later, whereas only 1 patient with a E/A ratio < 1 before discharge presented a > 1 value of this ratio in the late study. It is concluded that during the first year of evolution after transmural, nonrevascularized, noncomplicated infarction, the left ventricle filling pattern displays a significant change from predischarge phase (mainly protodiastolic with predominant E wave) to late follow-up (mainly telediastolic with predominant A wave). Different hypotheses to explain these results are discussed.

[Echocardiography during transesophageal atrial pacing. Its applicability and diagnostic value]. / Ecocardiografía durante la estimulación auricular transesofágica. Aplicabilidad y valor diagnóstico.

INTRODUCTION AND OBJECTIVES: Atrial pacing has been proposed as an alternative method to the isotonic exercise, to induce ischemia, and, joined to two-dimensional echocardiography, as one of the main modalities in stress echo. In order to analyse its applicability and diagnostic value in assessing coronary artery disease this study was undertaken. PATIENTS AND METHODS: 52 patients referred to coronarography for suspicion or evaluation of ischemic disease, were submitted to this technique. RESULTS: The study was completed in 44 patients (applicability rate of 84,7%). The results obtained showed a sensitivity, specificity and diagnostic accuracy for the regional wall motion abnormalities echocardiographically detected, of 88%, 68% and 79%, respectively. When electrocardiographic changes or presence of angina during atrial pacing were added to echocardiographic data, sensitivity increased to 96%. In 41 patients in which a conventional stress test was available, sensitivity was 55% electrocardiographically, 33% clinically and 68% globally. CONCLUSIONS: It is concluded that transthoracic two-dimensional echocardiography during atrial pacing is a safe, highly sensitive method for coronary artery disease detection. The limitations of the method for its routine clinical application are also analysed.

Effects of early use of captopril on haemodynamics and short-term ventricular remodelling in acute anterior myocardial infarction.

To determine whether ventricular short-term enlargement following acute myocardial infarction is related to increased left filling pressures and whether early treatment with captopril alters this process we studied 68 patients with a first acute myocardial infarction. Forty patients with a pulmonary capillary pressure equal or above 17 mmHg were randomized to treatment with conventional therapy plus captopril (n 20) or placebo (n 20), in a double blind fashion. The remaining 28 patients (non-dysfunction group) were treated conventionally. During the first 72 h, afterload showed a prompt decrease in the captopril group as compared to placebo. Changes from baseline to 14 days in end-diastolic and end-systolic left ventricular volume indexes determined by radionuclide ventriculography were: non-dysfunction, 85.6 (+/- 21) vs 88 (+/- 20) and 44 (+/- 17) vs 44 (+/- 17) ml.m-2; captopril (n 20), 96.6 (+/- 18) vs 99 (+/- 19) and 66 (+/- 22) vs 65 (+/- 22) ml.m-2; placebo (n 20), 96 (+/- 25) vs 113 (+/- 19) (P < 0.001) and 63 (+/- 18) vs 74 (+/- 22) ml.m-2 (P < 0.01). This study indicates that short-term ventricular enlargement is related to the degree of ventricular dysfunction and that captopril may improve this process.

Transdermal scopolamine as treatment of bradyarrhythmias.

Fifteen patients with different degrees of chronic bradyarrhythmias of supraventricular origin were studied with Holter monitoring before and during application of a transdermal patch of scopolamine. No changes were found in the mean or minimal heart rates, standard deviation of the RR interval, or the degree of bradyarrhythmia. It is concluded that transdermal scopolamine is not an adequate treatment of chronic symptomatic bradyarrhythmias.

[Hypertrophic myocardiopathy (II). 24-hour electrocardiographic monitoring and its relation to the echocardiographic characteristics]. / Miocardiopatía hipertrófica (II). Monitorización electrocardiográfica de 24 horas y su relación con las características ecocardiográficas.

Seventy-two patients with hypertrophic cardiomyopathy were evaluated by 24 hours of electrocardiographic ambulatory monitoring. The results were related to echocardiographic extent of hypertrophy, left ventricular outflow obstruction at rest, and transmitral flow parameters. Also, the symptoms and functional classification of NYHA were related to ventricular arrhythmias. Ventricular arrhythmias were detected in 68% of our patients: high degree of ventricular ectopia in 26 (36.1%), and ventricular tachycardia in 14 (19.4%). Most important supraventricular arrhythmias were: atrial fibrillation in 7 patients, atrial flutter in one, and supraventricular tachycardia in five. Asymmetric hypertrophy type I of Maron classification showed the lower number of ventricular arrhythmias. High degree of ventricular arrhythmias were more frequent in patients with: apical hypertrophy, worse functional classification of NYHA (I: 20%; II: 50%; III: 80%), and in patients with impaired distensibility detected by Doppler (80.7% vs 56.7%; p less than 0.05). There was no relationship between left ventricular outflow obstruction at rest and ventricular arrhythmias.

[Intravenous verapamil in hypertrophic myocardiopathy. A study using Doppler ultrasound]. / Verapamil intravenoso en la miocardiopatía hipertrófica. Estudio mediante ultrasonidos-Doppler.

The effect of one intravenous dose of verapamil on left ventricular diastolic and systolic flow was studied by Doppler-echocardiography in 31 patients with hypertrophic cardiomyopathy. On diastolic flow, verapamil induced a decrease in "a" wave velocity (1.02 + 0.37 vs 0.91 + 0.29 m/seg, p less than 0.01), and in its relation with maximal protodiastolic velocity (1.08 + 0.56 vs 0.89 + 0.37, p less than 0.01), and a shortening in the isovolumic relaxation period (0.076 + 0.031 vs 0.068 + 0.02, p less than 0.05). On the ejection flow, verapamil decreased the peak velocity (2.82 + 1.28 vs 2.42 + 1.18 m/seg, p less than 0.001). Nor age, sex, ventricular mass, gradient, neither hypertrophic cardiomyopathy's classification relates with changes after intravenous verapamil. There were no adverse effects. This study by Doppler-echocardiography confirms the beneficial ++ effect of intravenous verapamil in patients with hypertrophic cardiomyopathy not only on gradient reduction but also in the improvement on left ventricular diastolic function.

[Ambulatory cardiology]. / Cardiología ambulatoria.

In order to assess the reality of the ambulatory cardiology care in our region, we have studied prospectively the number and type of patients assisted daily in five outpatient clinics of Virgen del Rosell, Cartagena. 26.3% of the 9,312 studied patients were first visit. 51.1% were cardiologic patients, 35.7% pneumonic and 13.2% non cardiologic neither pneumonic patients. Coronary heart disease was the main pathology. An average of 21.4 +/- 4.7 patients were assisted daily, and time per patient was 7 minutes and 30 seconds. In January and February the affluence of patients to the outpatient clinics increased, and in three of this clinics, the time per patient was less than 6 minutes. We stress the need for Heart and Lung medical specialties separation, the need for number of patients limitation, and the need for technics material dotation for ambulatory cardiology.

[Atypical chest pain with normal coronary vessels: clinical study and follow-up of 22 patients]. / Dolor torácico atípico con coronarias normales: estudio clínico y seguimiento de 22 pacientes.

22 patients with normal coronarography but with angina pectoris or angina-like chest pain without evidence of coronary spasms are reviewed. We studied clinical characteristics, basal and exercise electrocardiography and other tests used to obtain a diagnosis, although only in one patient were we able to find an esophageal pathology which caused the clinical picture. After 20.7 +/- 14.4 months follow-up no patients had myocardial infarction or acute coronary events. Most of them still experience chest pain, are physically limited and use antianginal drugs. The fact that their coronarograms were normal decreased significantly the number of admissions to hospital (2.4 +/- 3.3 vs 0.26 +/- 0.95, P less than 0.02) and the amount of drugs prescribed. The lack of improvement of most of them seems to justify the need for other studies looking for a positive diagnosis and other types of treatment.

Estudio hemodinámico comparado de la estimulación ventricular y secuencial / Comparative hemodinamic study of ventricular and sequential stimulation

Con el fin de comparar los efectos hemodinámicos de las estimulaciones ventricular y secuencial hemos practicado cateterismo cardíaco en 10 pacientes, midiendo las presiones y el gasto cardíaco con ambos tipos de marcapasos. Obtenemos un aumento del 16.4% en el gasto cardíaco durante la estimulación secuencial aumentando igualmente las presiones aórticas y disminuyendo las pulmonares. La mejoría de los parámetros hemodinámicos al comparar con al estimulación ventricular es estadísticamente significativa