RESUMEN
BACKGROUND: The terms counterclockwise (CC) and clockwise (C) atrial flutter (Afl) are used to describe right atrial activation around the tricuspid valve in the left anterior oblique view. The manner in which the left atrium is activated, as reflected by coronary sinus (CS) recordings, has not been systematically evaluated. METHODS AND RESULTS: Nine patients with both CC and C Afl underwent electrophysiological study with CS recordings during both rhythms with the use of a decapolar catheter with the tip placed in the distal CS. Patterns of CS activation during each type of Afl as well as during during sinus rhythm were categorized into 1 of 3 patterns: sequential proximal-to-distal, sequential distal-to-proximal, and fused, indicating activation from different directions. In 7 of 9 patients, the pattern of CS activation in CC Afl and C Afl differed, with a proximal-to-distal pattern in CC Afl and a fused pattern in C Afl. In 2 patients, pacing the high right atrial septum near the presumed site of Bachmann's bundle in sinus rhythm showed a similar fused pattern of CS activation. CONCLUSIONS: These results demonstrate different patterns of CS activation in CC Afl and C Afl in the majority of patients and are consistent with a model in which the left atrium is activated predominantly over Bachmann's bundle during C Afl and over the CS os in CC Afl. These findings may have implications for maintenance of Afl, interpretation of flutter wave morphology on surface ECG, and left atrial mechanical function in Afl.
Asunto(s)
Aleteo Atrial/fisiopatología , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Anciano , Anciano de 80 o más Años , Estimulación Cardíaca Artificial , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Femenino , Tabiques Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Two patients with massive pulmonary embolism (PE) presented with generalized seizures. Pathophysiologic abnormalities that explain this clinical syndrome include respiratory acidosis, hypoxemia, and cerebral hypoperfusion due to decreased cardiac output. PE should be considered in the differential diagnosis of new-onset and otherwise unexplained seizures.
Asunto(s)
Epilepsia Generalizada/diagnóstico , Embolia Pulmonar/diagnóstico , Acidosis Respiratoria/etiología , Adulto , Isquemia Encefálica/etiología , Gasto Cardíaco Bajo/etiología , Circulación Cerebrovascular , Diagnóstico Diferencial , Epilepsia Generalizada/etiología , Femenino , Humanos , Hipoxia/etiología , Masculino , Embolia Pulmonar/complicaciones , Embolia Pulmonar/tratamiento farmacológico , Embolia Pulmonar/fisiopatología , Terapia TrombolíticaRESUMEN
Because of constraints on the costs of providing medical care, cardiologists in the future will find themselves challenged to provide care for their patients in the most cost-effective manner possible. Although stress-echocardiography has been shown to compare favorably with other tests in diagnostic accuracy, data on cost-effectiveness are scarce. In this article, general concepts of cost-effectiveness as they relate to stress-echocardiography are reviewed and the available literature is summarized. Although definitive data are lacking, there is evidence to suggest that stress-echocardiography may prove to be cost-effective in several clinical situations.