Caffeine and ventricular arrhythmias: an electrophysiological approach

Article Abstract:

Medical care providers have worried about the effects of caffeine on abnormal heart rhythms (ventricular arrhythmias), especially rapid heartbeat and fibrillation (random and ineffective heartbeats), so patients are often advised not to drink any beverages containing caffeine. Previous studies have used different measures for both the amount of caffeine and for the arrhythmias, and different sample selection criteria. Not unexpectedly, the findings have also varied. The authors attempted to measure the effect of caffeine on the underlying cause of ventricular rhythms, using programmed electrical stimulation to produce the rhythms. Pacing was accomplished with a catheter in the right ventricular apex of the hearts of 22 volunteers (average age, 60), all habitual coffee drinkers who were undergoing angiography. Baseline measures were obtained during which arrhythmias were induced. Then the subjects consumed coffee containing the equivalent in caffeine of two to three cups of regular coffee, or four to eight cans of soda, and arrhythmias were once again induced. This amount of caffeine did not lead to or intensify abnormal heart rhythms in these patients, but electrophysiological testing may not be a good measure of this effect. The differing results of other researchers suggest caution in making recommendations on coffee or soda drinking. Also, a few patients did exhibit more easily induced and more severe rhythm disturbances, and these patients may represent a subgroup of people who are more sensitive to the effects of caffeine. This sample was small, and the effects may simply not have been measurable in so small a group. Therefore, on the basis of this study the authors cannot recommend that no limitations be placed on caffeine. However, they believe that so many restrictions are placed on patients with a history of ventricular tachycardia or fibrillation, that complete caffeine restriction, onerous for so many, does not seem warranted. To be on the safe side, patients should limit themselves to two cups of coffee or the equivalent (150 to 200 mg of caffeine) per day until research results indicate otherwise. (Consumer Summary produced by Reliance Medical Information, Inc.)

Physiological aspects, Caffeine

---

Astemizole-induced cardiac conduction disturbances in a child

Article Abstract:

Astemizole is a newly available medication given to relieve the symptoms of seasonal allergic rhinitis (runny nose) and chronic idiopathic urticaria (hives for no apparent reason). This drug has been available in Europe for many years; there have been several reports of heart arrhythmias occurring in teenagers or young adults. A case is reported of a three-year old girl who ate 10 of her mothers astemizole pills; the total dose for the child was 8 milligrams per kilogram of body weight, well below the lethal dose. The child was found soon after the ingestion and was lethargic and had stomach pain. The child had gastric lavage (washing out of the stomach contents) at the emergency room and an abnormality was noted in her heart rhythm. Many different types of heart dysrhythmias (abnormal rhythms) and impulse conduction defects were observed, including second degree heart block, right bundle branch block, and atrioventricular dissociation. She was admitted to the Pediatric Intensive Care Unit where her status was monitored. Within seven hours, and without the use of anti-arrhythmia heart medication, the electrocardiogram readings (record of electrical activity of the heart) returned to normal. No further abnormalities were observed and, at discharge, the child had a normal physical examination and electroencephalogram (record of the electrical activity of the brain). (Consumer Summary produced by Reliance Medical Information, Inc.)

Case studies, Drugs, Complications and side effects, Overdose, Children's accidents, Heart conduction system, Astemizole

---

Deaths associated with a purported aphrodisiac - New York City, February 1993-May 1995

Article Abstract:

Five men in New York City became ill after eating a compound that was marketed as an aphrodisiac and four died. Their symptoms occurred 30 minutes to several hours after ingesting the substance and included vomiting, low blood pressure and low heart rate. All four men died of heart arrhythmias and the chemical digoxin was detected in blood samples from all five men. Further analysis of the aphrodisiac obtained from family members revealed chemicals similar to digoxin called bufadienolides. The aphrodisiac was chemically identical to a Chinese remedy called Chan Su, which is used as a topical anesthetic and heart drug. In New York City, the substance can be purchased in grocery stores, smoke shops and from street vendors. Consumers should use caution when eating any non-traditional health product.

Health aspects, Aphrodisiacs

Similar abstracts:

• Abstracts: Percutaneous ethanol injection therapy for hepatocellular carcinoma: a histopathologic study. Continuous hyperthermic peritoneal perfusion for the treatment of peritoneal dissemination in gastric cancers and subsequent second-look operation
• Abstracts: Ascorbic acid requirements for smokers: analysis of a population survey. Vitamin C and cardiovascular risk factors
• Abstracts: The efficacy and clinical impact of brain imaging in neurologically symptomatic AIDS patients: a prospective CT/MRI study
• Abstracts: Clinical and epidemiological features of HIV infection at a referral clinic in Zambia. Epidemiology of acquired immune deficiency syndrome in persons aged 50 years or older
• Abstracts: Sonographic growth measurements in triplet pregnancies. Maternal left ventricular dimension in pregnancies complicated by fetal growth retardation

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.