Visceral chest pain from the heart and esophagus. Effects of transcutaneous electrical nerve stimulation (TENS)

Abstract

Although a substantial proportion of patients with visceral chest pain referred to hospital show signs of coronary artery disease, many may suffer from esophageal dysfunction. Dysfunction in these two viscera may be impossible to differentiate between; they may appear simultaneously; or dysfunction in one organ may induce dysfunction in the other organ by viscero-visceral reflexes. The aim of the present thesis was to study patophysiology of visceral pain from the heart and esophagus and treatment effects of TENS.Thirty patients with unstable angina were randomized to active TENS (n=14) or placebo TENS (n=16) as additional treatment in the Coronary Care Unit, and studied for 24 hours. TENS was found applicable in these patients as additional treatment (main end-point), and seemed to reduce silent ischemic STC-VM episodes (p=0.02 and p=0.01, for no. of episodes and duration, respectively), by mechanisms possibly unrelated to pain reduction.Eighteen consecutive patients referred for esophageal evaluation for unknown chest pain, were studied with esophageal manometry and balloon distention, on two different occasions, with active TENS and placebo TENS, respectively. TENS reduced esophageal pain sensitivity for mechanical stimulation by balloon distention (p<0.05). This study also suggests a relationship between increased peristaltic waves and visceral pain sensitivity in the esophagus. Balloon distention may be a non invasive method of measuring individual visceral pain sensitivity.Twenty patients with Syndrome X (anginal pain, objective ischemia signs and normal coronary angiography) were studied with regard to esophageal dysfunction. Twelve/Eighteen patients showed abnormality on 24-h pH measurements. Esophageal dysmotility was found in 7/20 (35%), most often nutcracker esophagus (n=5). Visceral hypersensitivity for mechanical stimulation (balloon distention) in 13/20 (65%) and for chemical stimulation (acid provocation test) in 9/19 (47%), were found. The study show a high percentage of esophageal dysfunction in Syndrome X and suggests that visceral hypersensitivity may be an important factor for the development of pain in patients with Syndrome X. Acid-suppression ameliorated pain in many patients with signs of esophageal dysfunction.Nutcracker esophagus was found in 14.3% of patients referred for esophageal evaluation 1993-98 because of unknown chest pain, compared to 4.5% of patients with other symptoms of referral (p<0.0001). Forty-five nutcracker patients (= high amplitude contractions >180 mmHg in the distal esophagus), were studied retrospectively regarding results of the accompanying 24-h pH measurements. No differences between different types of nutcracker-definitions (i.e. segmental or diffuse spreading of high amplitude contractions) could be seen, with regard to age, gender or clinical data. Signs of acid related disorder were found in 30/43 of nutcracker patients (70%). Acid-suppressive treatment improved symptoms in a majority of patients; at least as well in the nutcrackers with chest pain as in those with other symptoms. This study confirms the correlation between acid reflux and nutcracker esophagus. The results indicate that esophageal manometry should be part of the investigation of unknown chest pain, as nutcrackers are frequent in these patients. The role of acid-suppression in symptom relief needs to be confirmed in a randomized, placebo controlled study.