Analysis of heart rate turbulence in advanced heart failure and heart transplantation patients.

OBJECTIVE: The objective of this study was to describe heart rate turbulence (HRT) in advanced heart failure (HF) patients and in a group of patients who underwent heart transplantation (HT). MATERIALS AND METHODS: We performed 24-hour Holter recordings in 20 patients with advanced HF referred to our hospital for HT, including 16 males of overall mean age of 44 +/- 13 years and with a mean ejection fraction (EF) 21 +/- 7%. An additional set of recordings was obtained in a second group of 27 patients who had already undergone HT, including of 21 males of overall mean age of 47 +/- 14 years. We recorded the number of premature ventricular contractions (PVCs), mean heart rate (MHR), and 2 parameters of HRT-turbulence onset (TO) and turbulence slope (TS). RESULTS: Patients with HT showed a low density of premature ventricular complexes, in contrast to patients in the advanced HF group. For this reason, HRT could only be analyzed in 15 of the patients with advanced HF (66%) and in 10 of the patients who underwent HT (37%). MHR was 77 +/- 10 bpm in the advanced HF group and 90 +/- 10 bpm in the HT group. In both groups, TO and TS showed highly attenuated values. CONCLUSIONS: Patients with advanced HF showed a high number of PVCs with attenuated HRT parameters, reflecting increased circulating catecholamine levels and decreased response of the autonomic nervous system. Patients who underwent HT showed elevated MHRs, a small number of PVCs, and attenuated HRT values, as corresponds to a denervated heart.

Acute, short- and long-term efficacy of oral bevantolol in patients with coronary artery disease: a placebo-controlled, randomized, double-blind study.

The efficacy and safety of bevantolol (new cardioselective beta-blocking agent without intrinsic sympathetic activity) were evaluated in chronic stable angina pectoris. Acute effects on heart rate (HR) and pulmonary function (forced expiratory volume in the first second, FEV1, and vital capacity, VC) (double-blind placebo, propranolol, 80 mg, and bevantolol, 150 mg) and the antianginal efficacy during early (double-blind placebo period) and chronic bevantolol therapy (long-term follow-up for 52 weeks) were studied. Bevantolol reduces HR in the same way as propranolol (both p less than 0.01). Pulmonary function is modified significantly only by propranolol (decreasing FEV1, p less than 0.05). Bevantolol reduces antianginal attacks and nitroglycerin consumption (p less than 0.01) and improves exercise tolerance (p less than 0.01) during early and chronic therapy.

[Hemodynamic benefits of AV interval adjustment and heart rate increase during exercise in dual-chamber pacing as determined by Doppler]. / Determinación por técnica de Doppler de la importancia hemodinámica del ajuste de sincronía auriculoventricular y del incremento de la frecuencia cardíaca durante el ejercicio en la estimulación bicameral.

In order to determine the relative significance of ventricular rate increase and AV delay on exercise cardiac output, we have studied 10 patients (8 male and 2 female, 16-59 years) with complete chronic heart block treated with AV sequential pacing. Cardiac output variations (delta CO) were estimated by pulsed Doppler comparisons of the aortic flow velocity in the supine position, at rest and during bicycle exercise. The following pacing programs were tested: DDD with AV intervals of 50, 100 and 150 ms (DDD50 o DDDD100, DDD150), VVI at 70 ppm (VVI70), and VVI at the maximal available rate in this pacing mode-113 or 130 ppm depending on the PM type (VVIM). Exercise measurements in DDD mode were taken when that rate was reached. The delta CO was calculated as a percent change of the product flow velocity integral x heart rate, from that obtained with VVI70 mode at rest. At rest, the delta CO obtained with DDD pacing was 20.4 +/- 14.7% and the optimal AV delay was 50 ms in 1 patient, 100 ms in 3 patients and 150 ms in six. During exercise, the delta CO was higher in DDD and VVIM modes (82.0 +/- 30.8% and 56.2 +/- 37.6%, respectively; p less than 0.01) than in VVI70 mode (20.4 +/- 10.4%; p less than 0.005), the greatest delta CO was reached at DDD mode in 8 out of 10 patients (p less than 0.03). The optimal AV delays were 50 ms in 5 patients, 100 ms in 4 patients and 150 ms in one. Thus, DDD pacing with the optimal AV delay seems to obtain greater haemodynamic benefits during exercise than does rate-responsive pacing; the optimal exercise AV delay varies from patient to patient and is usually less than 150 ms.

General Linear Models for Pain Prediction in Knee Osteoarthritis: Data from the Osteoarthritis Initiative / Modelos Lineales Generales para Predecir Dolor en Osteoartritis de Rodilla: Datos de la "Osteoarthritis Initiative"

Abstract: Knee pain is the most common and disabling symptom in Osteoarthritis (OA). Joint pain is a late manifestation of the OA. In earlier stages of the disease changes in joint structures are shown. Also, formation of bony osteophytes, cartilage degradation, and joint space reduction which are some of the most common, among others. The main goal of this study is to associate radiological features with the joint pain symptom. Univariate and multivariate studies were performed using Bioinformatics tools to determine the relationship of future pain with early radiological evidence of the disease. All data was retrieved from the Osteoarthritis Initiative repository (OAI). A case-control study was done using available data from participants in OAI database. Radiological data was assessed with different OAI radiology groups. We have used quantitative and semi-quantitative scores to measure two different relations between radiological data in three different time points. The goal was to track the appearance and prevalence of pain as a symptom. All predictive models were statistically significant (P ≤ 0,05), obtaining the receiving operating characteristic (ROC) curves with their respective area under the curves (AUC) of 0.6516, 0.6174, and 0.6737 for T-0, T-1 and T-2 in quantitative analysis. For semi-quantitative an AU C of 0.6865, 0.6486, and 0.6406 for T-0, T-1 and T-2. The models obtained in the Bioinformatics study suggest that early joint structure changes can be associated with future joint pain. An image-based biomarker that could predict future pain, measured in early OA stages, could become a useful tool to improve the quality of life of people dealing OA.

Resumen: El dolor de rodilla es el síntoma más común y limitante de la Osteoartritis (OA), además de presentarse como una manifestación tardía de la enfermedad. Los cambios que ocurren en las estructuras de las articulaciones se presentan en las primeras etapas de la OA. Algunos de los cambios más comunes son la formación de osteofitos óseos, degradación del cartílago, y la reducción del espacio en la articulación, entre otros. El principal objetivo de este estudio es la asociación de características radiológicas con el síntoma de dolor de las articulaciones, para lo que fueron realizados dos estudios: univariado y multivariado, usando herramientas bioinformáticas para determinar la relación de futuro dolor con la evidencia radiológica temprana de la enfermedad. Todos los datos fueron recuperados de la Osteoarthritis Initiative repository (OAI). Este estudio de caso-control se llevó a cabo utilizando los datos disponibles de los participantes de la base de datos de la OAI. Los datos radiológicos fueron evaluados con diferentes grupos de radiología de la OAI. Fueron usadas puntuaciones cuantitativas y semi- cuantitativas para medir las dos diferentes relaciones entre los datos radiológicos en tres diferentes puntos de tiempo. El objetivo fue seguir la trayectoria de la aparición y prevalencia del dolor como síntoma. Todos los modelos predictivos fueron estadísticamente significativos (P ≤ 0,05). Para el análisis cuantitativo se calcularon las áreas bajo la curva (AUC): 0.6516, 0.6174, y 0.6737 para T-0, T-1 y T-2, y para el análisis semi-cuantitativo se calcularon las AU C: 0.6865, 0.6486, y 0.6406 para T-0, T-1 y T-2. Los modelos obtenidos en el estudio bioinformático sugieren que los cambios tempranos en la estructura de las articulaciones pueden estar asociados con el futuro dolor de rodilla. Un biomarcador basado en imágenes que pueda predecir el futuro dolor, medido en las primeras etapas de OA, podría convertirse en una herramienta útil para mejorar la calidad de vida de la gente que padece OA.

Sick sinus syndrome: strategies for reducing mortality.

The evolution of sick sinus syndrome is slow, and its clinical and electrocardiographic manifestations are intermittent. A-V and I-V conduction disturbances often arise, but incidence of defects with clinical consequences is too low. Death rate, when large groups are considered, is slightly higher than that of the general population of the same age and with similar pathologies. Mortality depends on concomitant pathologies, on the development of congestive heart failure, on the arterial thromboembolism and on the type of sinus disease. The use of ventricular pacemakers (VVI) did not reduce mortality. Atrial pacing (AAI) gives the auricles electrical stability preventing fibrillation and systemic embolism. The hemodynamic role of the auricles is also preserved. As a consequence, death rate is reduced when AAI is used. In cases with a-v conduction disturbances or with paroxysmal atrial fibrillation, dual chamber pacing (DDD) is preferable because it permits ventricular pacing to be continued even if a-v block or paroxysmal or chronic atrial fibrillation appears. When using ventricular pacing and in cases in which pacing is not considered, warfarin or aspirin can prevent strokes and systemic embolism. In bradycardia-tachycardia syndrome requiring treatment of arrhythmias dual chamber pacemaker must be implanted.

A prospective multicenter study on the safety of a pacemaker with automatic energy control: influence of the electrical factor on chronic stimulation threshold. PEACE Investigators.

The effectiveness and safety of a pacemaker with automatic control of capture was evaluated in 162 patients followed at 27 Spanish centers. The aim of our prospective, multicenter, and randomized trial was to determine the relationship between the voltage output of the pulse generator and the stimulation threshold. We randomized 162 patients (107 men, mean age 75 +/- 12 years). We implanted a ventricular pacemaker model Regency SR+ or SC+ with Pacesetter's low polarization bipolar leads Membrane E 1450. The patients were randomized to receive Autocapture or not; group I (81 patients) Autocapture On, pulse output automatically adjusted and group II (81 patients) Autocapture Off, fixed output parameters (3.9 V, 0.37 ms). We performed a 6-month follow-up measuring stimulation threshold by means of the VARIO test and Autocapture test, evoked response signal, and R wave signal. The mean R wave was 15.77 +/- 3.5 mV at the end of the follow-up for group I, and 14.91 +/- 6.8 mV for group II (P = NS). The measured evoked response at the end of the follow-up was 9.25 mV in Group I and 8.48 mV in Group II (P = NS). The stimulation threshold was not different between groups. The current density created with the voltage and pulse width used in this study (< or = 3.9 V and 0.37 ms) at the tip of this electrode during the maturation process had no influence on the development of the chronic detection and stimulation thresholds.