Country cardiograms case 57.

Country cardiograms case 54: Answer.

Country cardiograms case 49.

Electrocardiographic changes at high attitude.

SUBJECTS AND METHODS Fifteen subjects had cardiograms recorded. Of these, four were Sherpas, on whom only single records were taken at the winter station. For reasons of clarity, the quantitative results reported are from six subjects on whom most work was done. Their age and weight are shown in Table I; they all acclimatized well by normal climbing criteria. The cardiograms of the other subjec...

Large-scale ensemble averaging of ambulatory impedance cardiograms.

Impedance cardiography has been used increasingly to measure human physiological responses to emotional and mentally engaging stimuli. The validity of large-scale ensemble averaging of ambulatory impedance cardiograms was evaluated for preejection period (PEP), interbeat interval, and dZ/dt(min) amplitude. We tested whether the average of "classical" 60-sec ensemble averages across periods with...

The first derivative thoracic impedance cardiogram.

When an alternating current of high frequency is applied to the thorax, the first derivative of the impedance to this current is affected by the cardiac cycle resulting in a characteristic wave form. Phonocardiograms, electrocardiograms, and first derivative thoracic impedance cardiograms were recorded simultaneously in 91 subjects. The first derivative thoracic impedance cardiograms were found...