Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HEART CONDUCTION SYSTEM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30Linked to original sources
PubMed2001

[The analysis of heart rate variability as non-invasive method of cardiovascular system assessment].

Heart rate variability (HRV) is estimated using time and frequency method. This analysis allows a non-invasive assessment of both the heart and autonomic nervous system. The usefulness of HRV estimation has been confirmed in patients not only with diabetic neuropathy, tetraplegia, various heart diseases (after heart transplantation, with heart failure, after myocardial infarction, with hypertrophic and dilated cardiomyopathy, with cardiological syndrome X and with arrhythmia), but also with thyroid gland diseases and in physiological states of human being. The described information indicate a wide range and increasing usefulness of HRV analysis in medical studies.

Autonomic Nervous System↗
PubMedDate not supplied

Cardiac dysautonomia in leprosy.

Responses to various tests of cardiovascular reflexes were studied in 15 patients with leprosy. Heart rate was continuously monitored by electrocardiogram and blood pressure was recorded simultaneously. Three patients showed evidence of cardiac dysautonomia, showing involvement of both the sympathetic and parasympathetic systems. These three patients belonged to the bacilliferous group.

Autonomic Nervous System↗
PubMed1978

Cardiovascular effects of tricyclic and tetracyclic antidepressants.

Cardiovascular effects of therapeutic doses of tricyclic or tetracyclic antidepressants (TCA) were examined in 66 patients. After three weeks of therapy, heart rate and PR interval were increased (P less than .02, P less than .05), while prolongation of the QTc time and the QRS interval did not reach significant levels. We observed significant flattening of T waves (P less than .05), which was not associated with changes in the serum potassium level. These changes were reversible after treatment was discontinued. When therapy was maintained for 13 months, only the heart rate continued to be increased, whereas all other ECG values had returned to normal. The TCA therapy led to a significant prolongation of the preejection period (P less than .01) and slight shortening of the left ventricular ejection time, indicating a decrease in myocardial contractility. There was no difference of effects on the values studied between tricyclic and tetracyclic antidepressants.

Adult↗
PubMed1981

Comparative study of the action of local anesthetics on AV conductivity of dog heart in situ.

Effects of local anesthetics (procaine, lidocaine, prilocaine, mepivacaine and bupivacaine) on AV conductivity were studied using a direct perfusion technique of the canine AV node artery in situ. The agents induced dose-dependent depression of AV conductivity in doses between 100 microgram and 3 mg. The depression was assumed to have resulted from their direct action on the AV node, since it was not affected by prior administration of atropine or tetrodotoxin into the AV node artery. The order of potency to suppress AV nodal conductivity evaluated from ED50 for causing first to third degrees of AV block was bupivacaine greater than mepivacaine = prilocaine = lidocaine greater than procaine with a relative potency ratio of 5 : 2--2.5 : 1.

Acetylcholine↗
PubMed1977

[An experimental study on canine A-V junctional pacemaker--evaluation of the automaticity by overdrive suppression and autonomic blockade by practolol and atropine].

1. The automaticity of the A-V junction was evaluated in 15 awake dogs with experimentally induced A-V junctional rhythm. 2. The spontaneous heart rate of these dogs ranged from 54 to 112 beats a minute, showing about 1.5-2.5 times slower than that of control dogs with sinus rhythm. The duration of asystole after overdrive in these dogs prolonged significantly in accordance with an increase in the frequency of stimulation for overdrive, and its mean +/- SD attained 4.7 +/- 1.1 seconds after overdrive at a rate of 2.5 times the spontaneous heart rate. 3. By administration of atropine (0.04 mg/kg, i.v.) to 8 dogs, the duration of asystole after overdrive, at a rate of 1.5 times the spontaneous heart rate, decreased from 2.6 +/- 0.8 to 1.5 +/- 0.4 seconds. By administration of practolol (0.5 mg/kg, i.v.) to 7 other dogs, the duration of asystole after overdrive increased from 3.0 +/- 1.1 to 6.4 +/- 2.2 seconds. 4. It should be suggested that, (1) about 5 seconds of asystole might physiologically occur before the initiation of the A-V junctional escape beat during the long-standing sinus arrest, and (2) the sympathetic nerve might play a more important role in regulating the automaticity of the A-V junction than the vagus nerve.

Animals↗
PubMed1975

[Effect of sparteine sulfate on the predamaged conduction system of the heart].

Antiarrhythmic drugs are known to cause AV-blockade. In animals and healthy humans the alcaloid of the gorse sparteine sulphate has been reported not to cause those side effects. We have studied in 10 patients with predamaged conduction system the grade of AV-blockade, the AV-interval and the intraventricular excitation spread by e.c.g. after i.v. injection of 200 mg sparteine sulphate (ajmalin, 50 mg i.v. as control). In 6 out of 10 patients no side effects have been observed. In 4 patients both sparteine and ajmalin injection caused higher graded AV-blockade. Our results suggest that sparteine sulphate like other antiarrhythmic drugs should not be administered to patients with a predamaged conduction system.

Ajmaline↗
PubMed1992

[Histochemical findings in the atrioventricular conduction system in congenital heart defects].

The authors examined, using histochemical methods, the AV conduction system in five infants and two children who died unexpectedly with a congenital heart disease. The activity of "glycogen dependent" phosphorylase in the AV conduction system was mostly negative or weak. The probable cause of this finding is hypoxia, although the effect of hypotrophy must be admitted. In groups of cells penetrating into connective septal tissue a decrease of oxidoreductases and hydrolases was found. These findings may be associated with regressive changes in the postnatal reduction of the AV conduction system.

Atrioventricular Node↗