[Effect of infrared laser on pituitrin-induced bradycardia in rabbits].

OBJECTIVE: To observe the effect of infrared laser stimulation on Neiguan (PC 6) for bradycardia of rabbits induced by injection of pituitrin. METHODS: 10.6 microm CO(2) infrared laser, 650 nm semiconductor red laser and the compound laser of their aggregation were sent out by a compound laser sanatory instrument to stimulate Neiguan (PC 6) respectively for the purpose of analyzing the differences of the effects exerted by infrared laser and red laser as well as the changes of the effects after their aggregation. RESULTS: After 30 min and 40 min of the injection of pituitrin, the heart rate showed no significant difference between 10.6 microm CO(2) infrared laser group and the normal control group (P>0.05). However, the heart rate showed significant difference between the 650 nm semiconductor red laser group and the normal control group (P<0.05). After 30 min of the injection of pituitrin, the heart rate of the compound laser group were significantly different to that of the untreated group (P<0.05), and it was not significantly different to that of the normal control group (P>0.05). However, the heart rate of non-acupoint stimulated by the compound laser group showed no significant difference to that of the untreated group (P>0.05), and it was significantly different to that of the normal control group (P<0.05). CONCLUSION: Stimulation on Neiguan with 10.6 microm CO(2) infrared laser can evidently improve the bradycardia induced by injection of pituitrin, while the 650 nm semiconductor red laser has no such function, but they have coordinating effect. The thermal effect produced by CO(2) infrared laser stimulating acupoint is probably beneficial for semiconductor laser penetrating skin as well as the biochemical reactions it carries. The improvement of heart rate produced by the laser stimulation on Neiguan (PC 6) has relative specificity.

Effect of different LLLT on pituitrin-induced bradycardia in the rabbit.

The objective of this paper was to observe the effect of low-level combined- or single-laser irradiation on bradycardia produced by pituitrin in rabbits. A combined-laser apparatus was made. A 10.6-microm CO2 laser and a 650-nm semiconductor laser, transmitted by different optical fibers, converged to output and irradiate on the Neiguan (PC6) acupuncture point in rabbits with bradycardia produced by pituitrin. Thirty minutes after the model was set, the heart rates of the combined-laser Neiguan group made quicker recoveries than those of the model control group, the laser-control group, or the single-laser Neiguan group (P<0.05), and the heart rates of the single-CO2-laser Neiguan group were similar to those of the normal group (P>0.05). However, there were significant differences between the 650-nm-laser Neiguan group and the normal control group (P<0.05). The combined-laser irradiation certainly has a curative effect on bradycardia produced by pituitrin. A single CO2 laser could accelerate the recovery from bradycardia, while single 650-nm-laser irradiation on the Neiguan acupoint does not produce such an effect.

Prenatal diagnosis and treatment of fetal long QT syndrome: a case report.

We report a case of a fetus presenting with bradycardia, intermittent atrioventricular (AV) block, ventricular tachycardia (VT) and the signs of fetal congestive heart failure (ascites and scrotal hydrocele) during mid-gestation. Prenatal treatment with beta-adrenergic blocker (propranolol) and digitalis glycosides was prescribed because of suspicion of long QT syndrome occurring with fetal congestive heart failure. The male baby was born at 39 weeks of gestation and showed a prolonged QT interval (QTc = 492 ms) and frequent variable AV block or alternating left and right bundle branch block, depending on the atrial rate. Prenatal administration of lidocaine failed to correct the fetal VT. Conversely, propranolol decreased the attack frequency of fetal VT. Postnatal administration of the K(+) channel opener (nicorandil) successfully shortened the QT interval and improved the outcome.