[Inflammatory response in acute myocardial infarction. Predictive values]. / Respuesta inflamatoria en el infarto agudo de miocardio. Valores predictivos.

INTRODUCTION AND OBJECTIVES: Our purpose was to investigate the significance of inflammatory acute phase response early after myocardial infarction. We also observed how these indices were influenced by trombolytic therapy. METHOD: We examined the blood samples of 200 non consecutive patients at the first day of acute myocardial infarction (155 [77%] males; mean age 65 +/- 13 years) to characterize the proteins and proinflamatory reactants profile. Results were correlated with hospital mortality. Thrombolytic therapy was administrated to 117 patients on admission and in these patients the samples were taken after the procedure. RESULTS: Overall mortality was 8%. Serum C-reactive protein (69 vs 41 mg/l), haptoglobine (237 vs 190 mg/dl), gammaglobuline (0.93 vs 0.84 g/dl), alpha-1-globuline (0.28 vs 0.23 g/dl) and alpha-2-globuline (0.7 vs 0.6 g/dl) were significantly higher in patients without trombolytic therapy. Conversely, patients who had received lytic therapy, had higher plasma concentrations of interleukin-1 beta (104 vs 40 pg/dl). The only clinical variable which was associated with mortality was a Killip class > or = 2 on admission (mortality = 21%; odds ratio = 5.2; p = 0.02). Other biochemical variables associated with a higher mortality were a white blood cell count > 10/nl (mortality = 12%; odds ratio = 5.4; p = 0.01), increased activated neutrophils > 80% (mortality = 18%; odds ratio = 5.4; p = 0.004) and C-reactive protein > 20 mg/l (mortality = 11%; odds ratio = 6; p = 0.05). Only patients with activated neutrophils > 80% on admission had a higher probability of dying during hospital stay (Exp[B] = 3.6; B = 1.2; r = 0.29; p = 0.001). CONCLUSION: The acute phase reaction in early myocardial infarction is determined by thrombolytic treatment. A high increase of activated neutrophils on patient admission is the only biochemical predictive value for hospital mortality.

[Auricular fibrillation and stroke in patients with sick sinus syndromeusing permanent pacemakers]. / Fibrilación auricular y accidente vascular encefálico en pacientes con enfermedad del nodo sinusal portadores de marcapasos definitivos.

INTRODUCTION AND OBJECTIVES: Since physiological pacing systems have become available, a debate has raged about the merits of atrial versus ventricular pacing in the sick sinus syndrome. The goal of this retrospective report was to study the long term incidence and the independent predictors for atrial fibrillation and stroke in 153 paced patients with sick sinus syndrome, adjusting for differences in baseline clinical variables with multivariate analysis. METHOD AND RESULTS: From 1980 to 1994, we implanted 32 dualchamber, 33 atrial, and 88 ventricular pacemakers to treat patients with sick sinus syndrome. After a maximum follow-up of 177 months (median 30 months for paroxismal atrial fibrillation, 45 months for chronic atrial fibrillation and 43,5 months for stroke) the actuarial incidence of paroximal atrial fibrillation was 7.8% at 1 year, 29% at 5 years and 42% at 10 years. The actuarial incidence of chronic atrial fibrillation was 1.3% at 1 year, 9.8% at 5 years and 22% at 10 years. Independent predictors for paroxismal AF from Cox's model was history of atrial tachyarrhythmias (p < 0.0001), chronic obstructive pulmonary disease (p = 0,006) and age (> 70 years-old) (p = 0.035). Only a history of atrial tachyarrhythmias before pacemaker implant was an independent predictor for chronic atrial fibrillation (p < 0.0001). The odd ratio for paroxismal atrial fibrillation in patients with previous atrial tachyarrhythmias and chronic atrial fibrillation were 6 (2.8-12) and 4 (1.6-9.7) (95% confiance limits). Actuarial incidence of stroke was 3% at 1 year, 10% at 5 years and 14% at 10 years. Independent predictors for stroke were history of peripheral vascular disease (p = 0.033) and hypertensive cardiomyopathy (p = 0.015). Development of paroxysmal and chronic atrial fibrillation during the follow-up were higher in patients with stroke (p < 0.001 and p < 0.05). CONCLUSIONS: Development of atrial fibrillation and stroke in paced patients with sick sinus syndrome are strongly determined by clinical variables. Preimplant paroxysmal atrial tachyarrhythmias is the most important predictor for atrial fibrillation in the follow-up.

[50 hz alternating current as a cause of inhibition of monopolar ventricular pacemakers]. / Corriente alterna de 50 Hz como causa de inhibición de marcapasos ventriculares monopolares.

It is not well established the importance of 50 Hz alternating current (AC) (that supplies most of house appliances) as a source of inappropriate inhibition of today cardiac pacemakers (PM). This problem has been studied in 58 consecutive patients permanently paced (VVI unipolar) for AV block with 27 different PM models from 11 manufacturers. Under ECG monitoring, 50 Hz AC was applied through a pair of electrodes set at both patient's wrists using a battery powered external source, with voltage ranging between 0 and 45 V. Inappropriate inhibition was considered if PM pauses longer than twice the programmed escape interval of the PM were observed during interference. This happened in 46 patients (79.3%), with PM from all 11 manufacturers, with voltages ranging from 3 to 28 V. In each case, inhibition was seen with a narrow voltage window between no interference detection and interference reversion of the PM. Only 3 patients (5.2%) referred perception of electrical current during the study. Three of the patients studied had complained, prior to the study, about dizziness or presyncope related to touching electrical devices and in all of them inappropriate inhibition was observed during interference. We conclude that: 1) it is possible to demonstrate inappropriate inhibition caused by 50 Hz AC galvanic interference in a high percentage of unipolar PM; 2) This inhibition occurs at current levels that in most cases are not sensed by the cutaneous nerves, and 3) although the problem seems to have little clinical significance it should be investigated in paced patients with symptoms attributable to inappropriate inhibition of their PM.

[Late potentials in patients during the hospitalization period following acute myocardial infarction]. / Potenciales tardíos en la fase hospitalaria del infarto agudo de miocardio.

Serial signal-averaged electrocardiograms were recorded every 72 hours in 60 patients admitted to the coronary care unit with acute myocardial infarction. The prevalence of late potentials was 61.6% (37 patients) during hospitalization. Of these 37 patients, late potentials appeared transiently in 20 (54%), while in 9 patients (24%), once late potentials had appeared, they tended to persist. No specific clinical characteristics were related to the development of late potentials (site of infarction, peak creatine kinasa activity, Killip class, thrombolytic therapy). The presence of late potentials did not identify patients who developed clinically significant ventricular tachyarrhythmias (primary ventricular fibrillation, ventricular tachycardia). The abnormal late potentials were modified by the administration of lidocaine. This lack of correlations suggests that the abnormal signal averaged electrocardiogram and complex ventricular arrhythmias during acute myocardial infarction have different electrophysiological bases. Late potentials could be only a bystander electrophysiological phenomenon without clinical correlation in this clinical phase.

[Anatomo-functional substrate of high risk arrhythmia after myocardial infarct]. / Sustrato anatomofuncional de las arritmias de alto riesgo tras el infarto de miocardio.

Ventricular arrhythmias detected in the late-hospital phase of myocardial infarction have been identified as a risk factor for sudden death, being their prognostic value independent of ventricular function. However, relations between both factors are not clarified. In order to study hypothetic associations between ventricular arrhythmias and some clinical, hemodynamic and angiographic variables, 60 patients (52 males, 8 females) underwent 24-hour Holter recordings and cardiac catheterization with left ventricular and coronary angiographies, 3-5 weeks after hospital admission. Past history data, acute phase complications and hemodynamic and angiographic results were compared between patients with and without significant ventricular arrhythmias during Holter monitoring (10 or more PVC's/hour and/or repetitive forms). No significant differences were found between both groups neither in mean age nor in the incidence of previous angina or infarction, cerebral ischemia, diabetes, lipid disorders or subjective feeling of being under psychological stress. Prior history of arterial hypertension was, however, significantly more frequent in patients with ventricular arrhythmias (53.3% vs 17.8%; p = 0.0183). No differences were observed in the localization of the infarct or in the complications during the acute phase (CPK peak, Killip's score, angina after 24 hours of evolution, intraventricular or A-V conduction disorders and supraventricular and ventricular arrhythmias). Among hemodynamic data, only left ventricular and aortic systolic pressures were different in both groups, being significantly higher in patients with ventricular arrhythmias. There were not differences in left ventricular segmentary contraction and in number of coronary vessels involved. To conclude, significant ventricular arrhythmias were recorded in 25% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Syncope: epidemiological characteristics of a hospital series]. / Síncope: características epidemiológicas de una serie hospitalaria.

Three hundred hospital patients with syncope (193 males and 107 females, mean age 61 +/- 17 years) were prospectively evaluated with a standard protocol. Associated diseases were found in 76.7% of cases. The incidence of heart diseases was 50.8% in males vs 32.7% in females (p less than 0.003). The cause of syncope was diagnosed in 250 patients (84%). The diagnosis was made at initial evaluation in 101 patients (group A); in the remaining patients (group B), no diagnosis was made in 25% (16.6% of the overall series) despite a wide array of investigations. Syncope due to arrhythmia was diagnosed in 57.6% (group A: 91.1% group B: 40.7; p less than 0.0001); cardiac syncope not due to arrhythmia was diagnosed in 4%, and other types of syncope in 21.6% (group A; 6.9%; group B: 29.1%; p less than 0.0001). It is concluded that a) the hospital population of patients with syncope represents a subgroup of advanced age and a high incidence of associated diseases; b) one third of patients were diagnosed at the initial evaluation, whereas in 25% of the remaining ones no diagnosis was obtained, and c) in these patients, arrhythmia is the most likely cause of syncope.

[Concealed conduction and fatigue phenomenon in an accessory pathway]. / Conducción oculta y fenómeno de fatiga en una vía accesoria.

We report the appearance of concealed conduction and fatigue phenomenon in the accessory pathway of a patient with WPW syndrome. Both phenomena were demonstrated by the loss of delta wave during and after rapid atrial pacing. The mechanisms involved in these unusual properties of accessory pathways are discussed.

[Atypical bidirectional tachycardias]. / Taquicardias bidireccionales atípicas.

Two cases of bidirectional tachycardia are presented. The ventricular origin of these arrhythmias was assessed by His bundle recordings. Because of the V1 morphology of the ventricular complexes during tachycardia in one case and the unknown etiology in the other, these arrhythmias were considered to be atypical. The involved mechanisms and the causes inducing these tachycardias are discussed. Whatever the involved mechanism, our cases reaffirm the opinion that the terminology bidirectional tachycardia should be used only to describe an electrocardiographic pattern that may be caused by different electrophysiological mechanisms.