Variance of opinion among authors regarding the cause and duration of each succeeding portion of the P-R interval points out that knowledge regarding the physiologic basis for these waves is incomplete. Data regarding the P-R segment are scant in electro-cardiographic literature. The necessity for precision in measurement and the need for better visualization of electrocardiographic waves to en...

The different electrocardiographic patterns that are associated with infarction of various parts of the heart are widely recognized today. This knowledge has been acquired from numerous studies correlating the electrocardiograms recorded during life with the position of the pathological changes found in the heart at necropsy. In general the management and prognosis of cardiac infarction depends...

The present study was conducted to obtain electrocardiographic data regarding the values of ST-segment morphology and duration from 84 apparently healthy Holstein cattle in fourteen different age groups from newborn to 7 years old. We recorded electrocardiograms in standard base apex lead system with the paper speed 25 mm/sec. and calibration of 10 mm equal to 1 mV. The morphologic assessments ...

Sixteen thousand resting electrocardiograms were performed on 14000 United Kingdom professional aircrew and air traffic control officers over a two-year period; 103 asymptomatic men with minor ST segment and T wave changes at rest were assessed by exercise electrocardiography and 19 responded abnormally. Five subjects had proven coronary artery disease, one hypertrophic obstructive cardiomyopat...

The success of surgery for supraventricular tachycardia (SVT) is evaluated by a variety of methods in different hospitals. Unfortunately, the predictive values of these methods are not known. We therefore compared the various methods in 261 patients undergoing surgery for SVT at Westmead Hospital since 1981. Surgical outcome was assessed by early tests during the first week after surgery (seria...