RESUMEN
The 12-lead electrocardiography (ECG) is the gold standard for diagnosis of abnormalities of the heart. However, the ECG is susceptible to artifacts, which may lead to wrong diagnosis and thus mistreatment. It is a clinical challenge of great significance differentiating ECG artifacts from patterns of diseases. We propose a computational framework, called the matrix of regularity, to evaluate the quality of ECGs. The matrix of regularity is a novel mechanism to fuse results from multiple tests of signal quality. Moreover, this method can produce a continuous grade, which can more accurately represent the quality of an ECG. When tested on a dataset from the Computing in Cardiology/PhysioNet Challenge 2011, the algorithm achieves up to 95% accuracy. The area under the receiver operating characteristic curve is 0.97. The developed framework and computer program have the potential to improve the quality of ECGs collected using conventional and portable devices.
Asunto(s)
Electrocardiografía/métodos , Algoritmos , Artefactos , Electrocardiografía/normas , Humanos , Control de CalidadRESUMEN
We report a 48-year-old male with a rare complication of pacemaker revision-fracture, migration, and secondary endocarditis due to a venous introducer sheath. We illustrate the possible mechanism of injury and discuss approaches to management.
Asunto(s)
Bradicardia/terapia , Endocarditis/etiología , Marcapaso Artificial/efectos adversos , Remoción de Dispositivos/métodos , Ecocardiografía Transesofágica , Electrocardiografía , Endocarditis/diagnóstico , Endocarditis/cirugía , Falla de Equipo , Fluoroscopía , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana EdadRESUMEN
INTRODUCTION: This review focuses on the role of the fixed-dose combination (FDC) drug valsartan/hydrochlorothiazide (HCTZ) in the treatment of hypertension. Effective blood pressure control often is not achieved with monotherapy and, instead, requires combinations of drugs with different mechanisms of action to produce additive or synergistic effects. AREAS COVERED: FDC valsartan/HCTZ enhances not only efficacy for blood pressure control but also provides beneficial effects on target organs beyond that expected from arterial pressure reduction alone. Data describe key clinical trial experiences with the FDC, with particular attention to efficacy and tolerability. Literature searches of these various topics were conducted in January 2011. There is evidence of potential benefits with this combination associated with left ventricular hypertrophy, left ventricular dysfunction and renal disease. The FDC is an effective treatment for patients with hypertension and is superior to monotherapy than either drug alone. EXPERT OPINION: In addition to the benefits of each drug, valsartan/HCTZ's metabolic interactions reduce some of the negative effects of both compounds. With its increased simplicity, minimal side-effect profile and efficacy without a significant cost penalty, valsartan/HCTZ represents an excellent choice for antihypertensive therapy.
Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Antihipertensivos/uso terapéutico , Diuréticos/uso terapéutico , Hidroclorotiazida/uso terapéutico , Hipertensión/tratamiento farmacológico , Tetrazoles/uso terapéutico , Valina/análogos & derivados , Bloqueadores del Receptor Tipo 1 de Angiotensina II/administración & dosificación , Bloqueadores del Receptor Tipo 1 de Angiotensina II/efectos adversos , Bloqueadores del Receptor Tipo 1 de Angiotensina II/economía , Animales , Antihipertensivos/administración & dosificación , Antihipertensivos/efectos adversos , Antihipertensivos/economía , Diuréticos/administración & dosificación , Diuréticos/efectos adversos , Combinación de Medicamentos , Costos de los Medicamentos , Sinergismo Farmacológico , Humanos , Hidroclorotiazida/administración & dosificación , Hidroclorotiazida/efectos adversos , Hidroclorotiazida/economía , Hipertensión/economía , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/prevención & control , Insuficiencia Renal/prevención & control , Tetrazoles/administración & dosificación , Tetrazoles/efectos adversos , Tetrazoles/economía , Valina/administración & dosificación , Valina/efectos adversos , Valina/economía , Valina/uso terapéutico , Valsartán , Disfunción Ventricular Izquierda/prevención & controlRESUMEN
Sudden cardiac arrest (SCA) due to fatal cardiac arrhythmias such as ventricular fibrillation is the leading cause of death in the United States, killing 350,000 Americans each year. Thus, it is of great importance to investigate the mechanisms that can suppress abnormal heart rhythms. In this work, we study the effects of drugs such as channel blockers through mathematical modeling of cardiac electrophysiological phenomena. In particular, we carry out multi-level simulations to study how channel blockers affect arrhythmias at cellular, fiber, and tissue levels. Numerical simulations show that the drugs have different effects at different scales (cellular versus fiber or tissue). Moreover, the drugs may appear to be arrhythmic in one model but antiarrhythmic in another. These observations indicate that analysis and simulation based on multiple scales and multiple models are crucial to fully understand the properties of drugs in treating arrhythmias.