In contrast to the usual occurrence of tachycardia during epileptic seizures, a 23-year-old man had episodic prolonged sinus arrest that lasted up to 9 seconds at the time of clinically observed seizures. There was no demonstrable cardiac disease.
Some cardiac pacemakers maintain constant energy per stimulus by automatically increasing the stimulus duration as battery depletion causes the stimulus amplitude to decline. This feature does not guarantee an invariant capture safety margin, however, because the stimulus energy at threshold increases for stimulus durations exceeding the geometric mean of… (More)
A dvances in implantable device technology over the past few years can be seen in these illustrations. The photograph on the left shows a 1997-model implantable cardioverter-defibrillator (ICD) in front of an older version. Beside it is a modern single-chamber pacemaker in front of an older mercury-zinc– cell model. The Table shows their relative weights.… (More)
Relation of transmitral flow velocity patterns to left ventricular diastolic function: new insights from a combined hemodynamic and Doppler echocardiographic study.  The DEFIANT research group. Improved diastolic function with the calcium antagonist nisoldipine (coat-core) in patients post-myocardial infarction: results of the DEFIANT study. Analysis of… (More)