Critical observation of the onset and course of transient bundle-branch block after acute myocardial ischaemia in 5 patients showed that the block was initially demonstrated both on increasing heart rate (tachycardia-dependent block) and on slowing (bradycardia-dependent block), with normal intraventricular conduction at intermediate heart rates. In some patients normal conduction disappeared w...

The error resulting from heat conduction i the measurement ofthe ultrasonic absorption coeffcient using the transient thermoelectric method is studied analytically. An expression for the temperature increase in a tissue specimen of finite dimensions, irradiated by a focused ultrasonic transducer, isgiven as a function of spatial coordinates, time, radial and axial beam dimensions, and absorptio...

A-V conduction was analyzed in 75 patients (mean age, 73 years) with sinus bradycardia (SB) by His bundle (BH) recordings. Forty-five of these patients had normal QRS complexes ('-0.10 sec) and 30 had abnormal QRS complexes (_0.12 sec). The conduction times through the atrium (P-A), A-V node (A-H), and His-Purkinje system (H-V) were measured during normal sinus rhythm and transient right atrial...