Changes in the arrhythmic profile of patients treated for heart failure are associated with modifications in their myocardial perfusion conditions

Background: Heart failure (HF) patients can benefit from a proper RS. We had observed that they show an increase in the number of arrhythmias during the first year of pharmacological treatment. Methods: We carried out a prospective observational study in which patients in an HF Clinic were included when they had follow-up Holter monitoring. Patients also had a baseline myocardial perfusion scan (Tc99 sestaMIBI/dypiridamole) and a control scan. Results: We included 90 patients with follow-up Holter and 35 with scintigraphy, for analysis. Fifty-six (62.2%) were men and the average age was 60.8 ± 14.6 years. Follow-up periods were divided by six-month intervals up to 18 months or more, an increase in premature ventricular contractions (PVCs) occurred in the six-month to one-year period (1915.4 ± ± 4686.9 vs. 2959 ± 6248.1, p = 0.09). In the one-year to 18-month control, PVCs went from 781.6 ± 1082.4 to 146.9 ± 184.1, p = 0.05. The increase in PVCs correlated with a reduction in scintigraphy-detected ischemic territories, 5.64 ± 5.9 vs. 3.18 ± 3 (p = 0.1) and a gain in those showing a reverse redistribution pattern (0.18 ± 0.6 vs. 2.09 ± 4.01, p = 0.1). Necrotic territories and time domain heart rate variability did not show significant changes. Conclusions: PVCs increase during the first year of HF treatment, and then they tend to diminish and stabilize. These changes seem to correlate with changes in the perfusion state of the patient. While ischemic territories decrease, reverse redistribution increases, showing that endothelial dysfunction could have a relevant role in arrhythmia generation, possibly because of membrane instability of recovered hibernating myocardium. (Cardiol J 2008; 15: 261-267

Reversible changes of electrocardiographic abnormalities after parathyroidectomy in patients with primary hyperparathyroidism

Background: Several studies have reported that primary hyperparathyroidism is a risk factor of higher cardiovascular mortality, mainly because hyperparathyroidism is related to arterial hypertension, arrhythmias, structural heart abnormalities and activation of the renin–angiotensin– aldosterone system. However, very few studies have shown the electrocardiographic changes that occur after parathyroidectomy. That was the aim of this study. Methods: We studied 57 consecutive patients with primary hyperparathyroidism surgically treated. Electrocardiogram, serum electrolytes, parathyroid hormone, creatinine and albumin measures were obtained before and after surgery and were compared. Results: The most common basal electrocardiographic abnormalities were left ventricular hypertrophy (LVH, 24.6%), conduction disturbances (16.3%), and short QT and QTc intervals. After surgery, a QTc interval lengthening and a tendency of T wave shortening were observed, as well as an inverse association between QTc interval and serum levels of magnesium and corrected calcium. There were no differences in LVH and conduction disturbances after surgery. Conclusions: Primary hyperparathyroidism is an important factor in the development of electrocardiographic abnormalities in this population, some of which are not corrected after parathyroidectomy. Further studies are required to demonstrate what factors are associated with persistence of electrocardiographic disturbances after surgery

Endocarditis infecciosa: una propuesta de tamizaje basada en un perfil de riesgo, en un Hospital de concentración en la Ciudad de México , 1987-2002

Objetivo: Obtener una probabilidad preprueba de endocarditis infecciosa usando el criterio clínico identificadocomo un factor de riesgo independiente de endocarditis para ayudar a tomar la decisión con respecto al usodel ecocardiograma transtorácico en sospecha de endocarditis. Materiales y Métodos: Después de una revisión retrospectiva de las historias del 1 de enero de 1987 al 31 dediciembre del 2002 en el Instituto Nacional de Ciencias Médicas y Nutrición “Salvador Zubirán” (un centroterritorial de referencia), en la Ciudad de México se encontraron 64 pacientes con sospecha o probabilidadde endocarditis infecciosa y estudios completos que fueron incluidos en este estudio y comparados con 39sujetos control; se estableció el diagnóstico definitivo de endocarditis infecciosa de acuerdo a los criteriosde Duke, más un ecocardiograma transtorácico y/o examen citológico obtenido de material de cirugía condeterminadas características clínicas asociadas a este diagnóstico. Resultados: Los factores de riesgo independientes de endocarditis infecciosa fueron valvulopatía previa,nuevo episodio de insuficiencia cardiaca, presencia de nuevo soplo, presencia de bloqueo de rama del hazde His y presencia de embolia séptica.Conclusión: La probabilidad preprueba obtenida en este estudio clínico puede ser usada como una herramientade tamizaje para identificar sujetos con baja probabilidad de endocarditis. PALABRAS CLAVE: Endocarditis, Factores de riesgo, Marcadores Clínicos