PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Reflex, Oculocardiac”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 37 records · Page 2Linked to original sources
PubMed1994

Lack of global vagal propensity in patients with oculocardiac reflex.

BACKGROUND: Profound bradycardia during ophthalmic surgery is a rare but potentially serious event. Little is known about the predictability of the oculocardiac reflex. METHODS: Four vagotonic maneuvers were performed on six patients who had profound oculocardiac reflex (3- to 10-second asystole) during eye surgery, the results of which were compared with 30 previously studied control subjects. Electrocardiographs were monitored during the following vagotonic maneuvers: diving response (apneic facial immersion), Valsalva maneuver, ocular compression, and carotid sinus massage. RESULTS: The degree of heart rate slowing as a result of diving response, Valsalva maneuver, and, notably, ocular compression did not differ when these patients were compared with the 30 previously studied control subjects. Carotid sinus massage produced significantly (P = 0.01) more bradycardia in the six patients (mean +/- standard deviation, -24% +/- 6%) than in the 30 control subjects (-12% +/- 7%). The heart rate response to pressure on the eyes did not correlate with prior intraoperative oculocardiac reflex. CONCLUSION: The discrepancy in heart rate sensitivity between surgical extraocular muscle tension and ocular compression may be due to different sensory receptors and brain stem processing for the trigeminally mediated oculocardiac reflex. Carotid sinus massage may help predict low heart rates during eye surgery.

Adult↗
PubMedDate not supplied

Experimental study of oculocardiac reflex (OCR) with graded stimuli.

The present study was conducted to observe the effect of graded mechanical stimuli on occurrence of oculocardiac reflex (OCR). The experiments were carried out in twenty albino rabbits of either sex weighing between 1-2 kg. Changes in heart rate and/or cardiac rhythm (oculocardiac reflex) were studied by applying traction with progressively increasing weights to medial rectus muscle. Mean threshold value of square wave mechanical stimulus just sufficient to produce oculocardiac reflex was found to be 19 +/- 8.52 g. As the traction weights were progressively increased, more and more decrease in heart rate was observed. It was concluded that once the threshold value of stimulus was reached, the oculocardiac reflex showed a graded response with progressively increasing traction weights.

Animals↗
PubMed2003

The effect of induced muscle tension and fatigue on the oculocardiac reflex.

INTRODUCTION: We investigated surgeon-modified factors in the oculocardiac reflex (OCR) including repeating tension after return to baseline pulse (fatigue) or modifying the tension place on the extraocular muscle (EOM). METHODS: A control group of 842 adult and pediatric strabismus cases underwent controlled, 200 gram, 10-second square wave tension on at least two EOM. The effect of TENSION was studied in 90 random cases by placing a tension of 50 grams on one of the later muscles and a tension of 400 grams on another subsequent muscle. The effect of FATIGUE was studied in 30 cases when the initial tension elicited a profound bradycardia. The heart rate was allowed to return to within 96% of pre-tension levels, and the same muscle had a second identical tension. RESULTS: For the 842 control cases, aged 12 +/- 16 (s.d.) years, initial 200 gram OCR was -16.9 +/- 19% and the second muscle 15 +/- 7 minutes later was significantly less percent change -14.6+/- 17%, paired t=3.9, p= .0001. TENSION: OCR was a similar reduction of 16-18% for 200 gram and 400 gram tension but had a modest reduction of 10% for 50 gram EOM tension. FATIGUE: For cases with profound initial OCR, waiting 3 minutes produced only a 17% reduction in OCR severity. CONCLUSION: A surgeon can reduce oculocardiac reflex by exerting very gentle 50 gram tension on the EOM or waiting for return to baseline heart rate before fatiguing the reflex. These reductions are of less clinical value than pharmacologic intervention.

Adult↗
PubMed1993

[Blepharoplasty and oculocardiac reflex].

100 patients have undergone electrocardiograph before and during blepharoplasty and after anaesthesia. The results show that the positive rate of oculocardiac reflex is 65%. The mechanism of occurrence of oculocardiac reflex is analysed. It has also been pointed out that great attention should be paid to the phenomenon and appropriate measures should be taken to prevent the occurrence of oculocardiac reflex.

Adult↗
PubMed1986

Quantitative analysis of the oculocardiac reflex by traction on human extraocular muscle.

The oculocardiac reflex was quantitatively studied in 15 patients with strabismus. The reflex was observed in all patients when the medial rectus and inferior oblique muscles were stretched; the medial rectus muscle had a lower threshold than the inferior oblique. Bradycardia was evoked in 7 of the 15 patients when the lateral rectus was tractioned with tensions of 50 g and 600 g. The oculocardiac reflex was a graded phenomenon as a function of tension applied to the extraocular muscles. As tension was increased, bradycardia occurred rapidly and became deep. Systemic administration of atropine prevented completely the bradycardia from occurring. The results suggest that the response of the extraocular muscles to stretch are critically mediated through a polysynaptic path to the heart, resulting in suppression of the heart rate.

Arrhythmias, Cardiac↗
PubMed1998

Oculocardiac reflex during laser in situ keratomileusis.

PURPOSE: To evaluate the occurrence of oculocardiac reflex during laser in situ keratomileusis (LASIK). SETTING: Merida Ophthalmological Hospital, Mexico City, Mexico. METHODS: This study included 20 patients who were given an electrocardiogram prior to, during, and after LASIK. Heart rate was noted before the procedure and during the preparation, placement of the patient under the microscope light, blepharostat application, and suction and laser treatment. The results in 1 eye of each patient were recorded. RESULTS: In 4 of the 20 patients (20%), the heart rate decreased during suction. In 2 of the 4, the decrease was 30% of baseline. In an additional 4 patients (20%), the heart rate increased more than 20% of baseline. This increase was detected prior to application of the suction ring. In the remaining 12 patients (60%), the heart rate did not change. CONCLUSIONS: Electrocardiographic changes compatible with oculocardiac reflex occurred in 20% of patients in this study. The same percentage showed an increase in heart rate attributable to surgical stress.

Adult↗
PubMedDate not supplied

The oculocardiac reflex in eye-surgery anesthesia.

A case of oculocardiac reflex occurring during general anesthesia for cataract removal is presented. The prevention and treatment of such reflexes is discussed with particular attention to the importance of ECG monitoring at all times in ophthalmic surgery.

Aged↗
PubMed2002

The attenuating effect of intraglossal atropine on the oculocardiac reflex.

INTRODUCTION: Bradycardia during strabismus surgery is reduced better by intravenous than by intramuscular (deltoid) anticholinergics, but recent studies suggest that injection into the tongue works faster than into the deltoid. We sought to study this using the suppression of the oculocardiac reflex during eye surgery as a parameter. METHODS: 804 children and adults underwent calibrated extraocular muscle tensioning during controlled, inhalational general anesthesia. A systemic anticholinergic agent was distributed by different routes to patient-subject sub-groups: preoperative oral, or induction intravenous, intramuscular (deltoid) and intraglossal (submucosal at the base of the tongue). A large control group received no anticholinergic. RESULTS: The control group had an oculocardiac reflex averaging 17.2% heart rate reduction (bradycardia), 6% of whom had greater than a 50% heart rate reduction. This oculocardiac reflex bradycardia was reduced to only a 6.7% heart rate reduction by oral and intradeltoid routes and was essentially eliminated by both intravenous (-2.3%) and intraglossal (-0.9%) routes. CONCLUSION: Intraglossal atropine is an effective alternative for oculocardiac reflex prophylaxis when intravenous access is not readily available in strabismus surgery. The intraglossal route is in fact slightly more effective in this regard that the intravenous route per se.

Adolescent↗
PubMed1999

Oculocardiac reflex in sedated patients having laser in situ keratomileusis.

PURPOSE: To eliminate stress as a variable in assessing the frequency of the oculocardiac reflex during laser in situ keratomileusis (LASIK). SETTING: Merida Ophthalmological Hospital and Oftalmedica, Mexico City, Mexico. METHODS: A pulse oximeter registered the heart rate of 30 sedated patients having LASIK. Sedation was accomplished with a combination of midazolam and fentanyl. The heart rate was noted before and during suction. The results in 1 eye of each patient were recorded. Oculocardiac reflex was defined as a decrease of 10% or more of the basal heart rate. RESULTS: Fourteen patients (46.7%) had a 10% or more decrease in heart rate when suction was applied. Ten of the 14 had a decrease in heart rate between 10% and 19%, 3 between 20% and 29%, and 1 of more than 30%. Two patients (6.6%) had an increase in the basal heart rate of more than 10%. CONCLUSIONS: The findings suggest that the oculocardiac reflex occurs more frequently in sedated patients than in nonsedated patients.

Adult↗