The LD-PACE II was designed for use in cardiomyoplasty, aortomyoplasty, and skeletal muscle ventricles. All parameters specified as programmable can be changed in a noninvasive manner (using a programming interface wand connected to a computer using the Windows 95/98 environment). Two new functions may be very useful clinically, based on experimental research. 1. Work-rest regimen. The LD-PACE II is able to deliver alternating periods of muscle contractions and rest. Work and rest periods may be programmed independently between 1 and 120 minutes in increments of 1 minute. The work-rest regimen may be useful clinically if muscle contractions are needed for cardiac assist postoperatively. 2. Night/day regimen. This feature allows for a change in the ratio of muscle contractions according to a patient's activity level. During the day the cardiosynchronization ratio may be set from 1:1 to 1:4, and during the night it may be set for 1:8 to 1:16. This allows the muscle to have a long rest period, prevents overuse, and prolongs battery life. These two new features make this cardiomyostimulator very attractive for cardiomyoplasty in particular. The addition of the work-rest and night-day regimens allow the muscle to rest for periods during the day to prevent overuse, subsequent damage, and potential atrophy.

Cardiomyoplasty↗

PubMedDate not supplied

Human intramyocardial oxygen detected through chronic polarographic electrodes.

The intramyocardial PO2 was studied in 7 patients after cardiac surgery, by means of a long-term electrode implanted subepicardically in the free wall of the left or the right ventricle, utilizing the polarographic method. Inhalation of 100% O2 or 5% CO2 +95% O2 provoked maximal increases in the myocardial PO2. In most cases intense exercise, and the Valsalva manoeuvre caused a decrease in the PO2. Intravenous propranolol slightly increased the PO2 in one case. Other drugs used in coronary patients caused inconstant effects. Sleeping decreased the heart PO2 in one case. This technique appears to be a useful tool for studying the human intramyocardial PO2 during a period of several weeks.

Adolescent↗

PubMedDate not supplied

[Temporary changes of ventricular repolarization after a crisis of paroxysmal tachycardia (post-tachycardial electrocardiographic syndrome)].

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Adolescent↗