RESUMEN
We measured the systolic time intervals (STI) in 14 patients (pts) with intermittent left bundle branch block (LBBB) in order to find correlations and comparisons in their values which might pertain to the individual patients, with (b) and without (a) LBBB. QS2I, PEP and the PEP/LVET ratio increased significantly (b) while the LVET I did not change. STI correlation was significant and improved further when the QS2 (b) was corrected by subtracting from it the QRS prolongation (b) in msec. All 7 pts with a PEP/LVET ratio (b) greater than 0.65 had an (a) ratio greater than 0.42 (normal limits for our laboratory), sensitivity 100%. Six of 7 patients with a PEP/LVET (b) less than 0.65 had an (a) ratio less than 0.42 (specificity 87.5%). For the individual patient with LBBB his STI can be quite accurately assessed by subtracting from his QS2 (b) the prolongation of the QRS (b) greater than 80 msec the length of the normal QRS duration. The above data were prospectively evaluated in 10 pts to whom intermittent right ventricular pacing was applied. We found that the correction of the QS2 interval for QRS prolongation permitted a very reliable calculation of the STI.
Asunto(s)
Bloqueo de Rama/fisiopatología , Estimulación Cardíaca Artificial , Electrocardiografía , Ventrículos Cardíacos/fisiopatología , Contracción Miocárdica , Sístole , Anciano , Anciano de 80 o más Años , Fascículo Atrioventricular/fisiopatología , Bloqueo de Rama/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
A 56 year old man with a large anterior myocardial infarction and diffuse left ventricular hypocontractility and dilatation was found to have narrowing of the distal part of the left anterior descending coronary artery in diastole. This most unusual finding was ascribed to diastolic compression of the vessel by the enlarged left ventricle. Only 3 similar cases have been found in the literature up to now.