Significance of nausea and vomiting during acute myocardial infarction

The Relieving Effects of a Polyherb-Based Dietary Supplement ColonVita on Gastrointestinal Quality of Life Index (GIQLI) in Older Adults with Chronic Gastrointestinal Symptoms Are Influenced by Age and Cardiovascular Disease: A 12-Week Randomized Placebo-Controlled Trial

Chronic gastrointestinal symptoms (CGS) negatively affect the quality of life in about 15–30% of the population without effective drugs. Recent studies suggest that dietary supplement may improve CGS, but inconsistent results exist. The goal of this study is to evaluate the effect of a polyherbal-based supplement ColonVita on the gastrointestinal quality of life index (GIQLI) in 100 old adults with CGS (63.1 ± 9.6 years) who were randomly assigned to daily ColonVita or placebo tablets (n = 50/group) for 12 weeks in a double-blind, randomized controlled trial design. No significant fibrdifferences were found between ColonVita and placebo in the baseline total GIQLI score (101.12 ± 16.87 vs. 101.80 ± 16.48) (P > 0.05) or postintervention total GIQLI score (114.78 ± 9.62 vs. 111.74 ± 13.01) (P > 0.05). However, ColonVita significantly improved 16 scores of the 19 core GI symptoms compared with 10 items improved by placebo. The ColonVita group significantly improved the remission rate of 5 core GI symptoms compared to placebo and significantly improved the total GIQLI scores (118.09 ± 7.88 vs. 109.50 ± 16.71) (P < 0.05) and core GI symptom scores (64.61 ± 3.99 vs. 60.00 ± 8.65) (P < 0.05) in people ≥60 years of age (n = 49) but not in those under 60 y (n = 51). ColonVita significantly improved the total GIQLI scores and core GI symptom scores in people without cardiovascular diseases (CVD) (n = 56) (116.74 ± 9.38 vs. 110.10 ± 14.28) (P < 0.05) and (63.11 ± 4.53 vs. 59.93 ± 8.03) (P=0.07), respectively, but not in those with CVD (n = 44). Thus, ColonVita was beneficial for old adults with CGS, especially those ≥60 years of age and without CVD. Because a heterogenous pathogenesis of CGS-like irritable bowel syndrome (IBS) and inflammatory bowel disease (ISD) is differentially associated with CVD, different comorbidities may have influenced the outcomes of different trials that should be controlled in further studies.

Heart failure mice exhibit decreased gastric emptying and intestinal absorption

Our recent study showed that intravenously administered B-type natriuretic peptide (BNP) decreases gastric emptying and intestinal absorption in mice. We aimed to test whether acute myocardial injury and heart failure have similar effects. Wild-type (WT) and natriuretic peptide receptor type A (NPR-A) knockout (KO) mice underwent cryoinfarction (myocardial infarction [MI]) of the left ventricle (LV) versus sham. LV dysfunction was confirmed by echocardiography. Percent gastric emptying and intestinal absorption were measured and analyzed one and two weeks after infarction, by gavage feeding the mice with fluorescein-isothiocyanate-dextran. Ejection fraction was 48 ± 3% versus 64 ± 2% ( P < 0.05) and fractional shortening was 24 ± 2% versus 35 ± 2% ( P < 0.01), MI versus sham, respectively. BNP levels (pg/mL) were 4292 ± 276 one week after MI versus 105 ± 11 in sham ( n = 5, P < 0.05) and 1964 ± 755 two weeks after MI ( n = 5, P < 0.05). Gastric emptying was significantly decreased, 68 ± 6% in MI versus 89 ± 3% in sham ( n = 5, P < 0.05) one week after MI and 82 ± 0.5% versus 98 ± 0.4%, MI versus sham ( n = 5, P < 0.05), two weeks post-MI. Absorption, measured in relative plasma fluorescence units in WT mice, was 350 ± 79 in MI versus 632 ± 121 in sham ( n = 6, P < 0.05). KO mice did not show a significant difference in emptying or absorption compared with sham. These findings suggest that MI and LV dysfunction decrease gastric emptying and absorption in mice through a mechanism that involves NPR-A.

Relation of nausea and vomiting in acute myocardial infarction to location of the infarct

To determine whether the incidence of nausea and vomiting in patients with acute myocardial infarction (AMI) varies with infarct location, we studied 180 patients who had been admitted to our hospital for ST-segment elevation AMI or AMI associated with left bundle branch block. The presenting symptoms (chest pain, nausea, and vomiting), initial electrocardiographic findings, and additional demographic, clinical, laboratory, and outcome data were extracted from the medical records and correlated with the infarct location. Of the 180 patients with AMI, 108 (60%) had inferior and 72 (40%) had anterior infarcts. Nausea was reported in almost 2/3 of all patients, and vomiting in nearly 1/3. Both nausea and vomiting showed a trend toward a greater incidence in patients with inferior than with anterior infarcts (69% vs 56% and 33% vs 26%, respectively). However, the differences were not statistically significant. In conclusion, nausea and vomiting are common presenting symptoms in patients with either inferior or anterior wall AMI, but their frequency is unrelated to the infarct location.

Analgesic treatment in acute myocardial infarction. A double-blind comparison of ketobemidone + the spasmolytic A29 (Ketogan) and morphine

The analgesic effect of ketobemidone hydrochloride + the spasmolytic component A29 (Ketogan) and morphine hydrochloride was compared double-blindly in patients with suspect acute myocardial infarction. The test drugs were administered i.v. in an initial dose of 0.5 ml (2.5 mg Ketogan, 5 mg morphine) followed, if necessary, by additional injections of 0.25 ml. Altogether, 309 patients participated in the trial. The total consumption of the test drugs showed that 5 mg Ketogan was equipotent with 10 mg of morphine. Treatment with Ketogan resulted in a significantly higher proportion of patients who were completely free of pain 15 and 30 min after the initial injection: 16% and 15% more, respectively, compared to morphine. Within 2 hours after the initial injection, approximately 15% of the patients in both treatment groups had reported nausea and about 7% had vomited (patients who vomited or were nauseated before treatment were not included in this analysis). The frequency of other side-effects was low, with no differences between the two treatment groups. Morphine caused a greater reduction of the systolic blood pressure than Ketogan. The effect of both drugs on pulse rate and respiration was the same.

Patterns of coronary compromise leading to bradyarrhythmias and hypotension in inferior myocardial infarction

BACKGROUND

Occlusion and reperfusion of the acutely occluded right coronary artery may result in abrupt bradycardia and hypotension, attributed to Bezold-Jarisch cardio-inhibitory reflexes arising from the ischemic left ventricle. Given that right ventricular infarction, a result of proximal right coronary artery occlusion, predisposes to bradycardia and hypotension, we hypothesized that proximal right coronary occlusions would be more likely to result in bradycardia-hypotension compared to more distal occlusions.

METHODS

In 216 patients with acute inferior myocardial infarction undergoing primary angioplasty of the right coronary artery, we retrospectively analyzed the incidence of bradyarrhythmias and hypotension during occlusion and with reperfusion.

RESULTS

Occlusion proximal to the right ventricular branches was identified in 151 (70%) of cases, with occlusions distal but compromising the left ventricular and atrioventricular nodal branches in 65 (30%) others. During occlusion, those with proximal occlusions were more likely to suffer hypotension (41 versus 15%, P=0.0002), advanced atrioventricular block (21 versus 3%, P=0.0008) and hypotension with bradycardia (25 versus 9%, P=0.01). Similarly, reperfusion of proximal occlusions more frequently resulted in abrupt hypotension (42 versus 19%, P=0.002), bradycardia (34 versus 14%, P=0.004) and hypotension with bradycardia (27 versus 12%, P=0.02).

CONCLUSIONS

These data demonstrate that during right coronary artery occlusion and with reperfusion, bradycardia and hypotension develop more commonly in patients with proximal occlusions compared with those with distal occlusions. These findings suggest that reflexes arising from the ischemic right ventricle may play a role in bradyarrhythmias and hypotension.

Continuous PC6 wristband acupressure for relief of nausea and vomiting associated with acute myocardial infarction: a partially randomised, placebo-controlled trial

OBJECTIVES

To assess the effectiveness of continuous PC6 acupressure as an adjunct to antiemetic drug therapy in the prevention and control of nausea and vomiting in the first 24h after myocardial infarction (MI).

DESIGN

Partially randomised, partially blinded placebo-controlled, exploratory clinical study.

SETTING

Coronary Care Unit, Torbay Hospital, Torquay, Devon.

PARTICIPANTS

A total of 301 consecutive patients (205 males, 96 females) admitted following acute MI.

INTERVENTION

The first 125 patients recruited received no additional intervention. Subsequent patients were randomised to receive either continuous PC6 acupressure or placebo acupressure.

OUTCOME MEASURES

(1) Incidence of post-MI nausea and/or vomiting, (2) severity of symptoms, (3) use of antiemetic drugs, over 24h.

RESULTS

There were no significant differences between the groups for the whole 24-h treatment period. However, the PC6 acupressure group experienced significantly lower incidence of nausea and/or vomiting during the last 20h (18%), compared with the placebo (32%) or control (43%) groups (P<0.05). The severity of symptoms and the need for antiemetic drugs were also reduced in the acupressure group, but these differences were not statistically significant.

CONCLUSIONS

Continuous 24-h PC6 acupressure therapy as an adjunct to standard antiemetic medication for post-MI nausea and vomiting is feasible and is well accepted and tolerated by patients. In view of its benefits, further studies are worthwhile using earlier onset of treatment.

Roles of substance P and NK(1) receptor in the brainstem in the development of emesis

The emetic response is primarily a protective reflex occurring in a wide variety of vertebrates in response to the ingestion of toxic compounds. The role of the nuclei in the brainstem, including the area postrema, nucleus tractus solitarius, the dorsal motor nucleus of the vagus, and the central pattern generator for vomiting, as well as the involvement of the abdominal visceral innervation relevant to the emetic reflex, have all been discussed by many researchers. The introduction of serotonin 5-HT(3)-receptor antagonists into clinical practice allowed for a dramatic improvement in the management of vomiting. However, vomiting still remains a significant problem. The mechanism of the emetic response is even more complicated than was first thought. This review attempts to bring together some of the evidence suggesting the roles of substance P and its receptor, neurokinin NK(1) receptor, in the brainstem nuclei in the development of emesis. Accordingly, NK(1)-receptor antagonists might represent novel drugs for the management of major types of emesis.

Impairment of the arterial baroreflex during symptomatic and silent myocardial ischemia in humans

OBJECTIVES

The aim of this study was to assess whether transient episodes of symptomatic or silent myocardial ischemia after baroreceptor modulation of heart rate.

BACKGROUND

Animal and human studies have shown that myocardial infarction is accompanied by an impairment of the baroreceptor influences on the sinus node. However, whether this also occurs during transient myocardial ischemia has never been documented.

METHODS

In 12 patients undergoing coronary angiography, systolic blood pressure (intraarterial catheter) was reduced by an intravenous bolus of nitroglycerin during a spontaneous episode of transient chest pain and myocardial ischemia (ST segment depression on the electrocardiogram) and 30 min after recovery. The slope of the linear regression between the decrease in systolic blood pressure and the RR interval shortening was taken as the measure of baroreflex sensitivity.

RESULTS

During ischemia, baroreflex sensitivity was 1.3 +/- 0.3 ms/mm Hg (mean +/- SEM), whereas after recovery it was markedly and significantly greater (2.6 +/- 0.5 ms/mm Hg, p < 0.01). Similar results were obtained in eight other patients who experienced a silent ischemic episode either spontaneously or during coronary angioplasty. The reduction in baroreflex sensitivity was similarly pronounced during inferior (10 patients) and anterior (10 patients) ischemia, and its magnitude showed little or no relation to the ischemia-dependent changes in blood pressure and heart rate.

CONCLUSIONS

Transient myocardial ischemia is associated with marked baroreflex impairment. The impairment occurs even during symptomless ischemic episodes and is therefore not related to pain or to other nonspecific influences on the baroreflex.

Behavioral studies of emetic sensitivity in the ferret

The ferrets' responsiveness to several known and putative emetic agents was evaluated using a variety of agents that were injected subcutaneously and/or intravenously. Apomorphine was consistently emetic at relatively high doses (100 micrograms/kg) when injected subcutaneously in large male ferrets (> or = 1.4 kg). The responsiveness to apomorphine was anomalous in that subcutaneous injections produced a more consistent response than intravenous ones. In addition, ferrets rapidly become tolerant or tachyphylactic to subcutaneously administered apomorphine. Area postrema ablation, but not abdominal vagotomy, rendered ferrets refractory to the emetic effects of apomorphine. This species, relative to dog and humans, proved to be insensitive to a variety of pharmacologic agents including angiotensin II, gastrin, histamine, Leu-enkephalin, neurotensin, serotonin, and vasopressin. Cisplatin elicited forceful retching and emesis. Emetic responses were obtained with substance P and Met-enkephalin in individual animals but were inconsistent. Sensitivity to DAGO [D-Ala2,MePhe4,Gly-ol5 enkephalin] was variable. Results of this study indicate that the ferret is not an optimal model for all forms of emesis.

A critical review of the afferent pathways and the potential chemical mediators involved in cardiac pain

There is considerable evidence that on the anterior surface of the heart (which is usually supplied by the left anterior descending and the proximal part of the left circumflex coronary arteries), sympathetic efferent reflexes characterized by tachycardia and/or hypertension predominate following experimental or pathological perturbations. These cardiovascular reflexes are accompanied by an increase in presumed nociceptive afferent traffic and, in pathological condition, by pain. In these experiments, there is generally no effect of vagotomy on afferent nerve traffic, and lower cervical and upper thoracic sympathectomies help provide relief from angina. On the other hand, experimental or pathological perturbations involving the inferior-posterior surface of the heart (supplied by the right and distal parts of the left circumflex coronary arteries), are characterized by vagal efferent reflexes, resulting in bradycardia and/or hypotension. These reflexes are accompanied by an increase in vagal afferent nerve traffic and, in pathological conditions, by pain. In these experiments, vagotomy generally abolishes such cardiovascular reflexes, and lower cervical and upper thoracic sympathectomies are not effective in the relief from angina. Although cardiac sympathetic afferents are unquestionably involved in the central transmission of nociceptive information from the heart, it is also likely that there is a contributing role from the vagus in cardiac pain. It is important experimentally to understand the natural stimulus that gives rise to angina. In the clinical situation, a decrease in coronary blood flow or an increase in the metabolic demands of the myocardium due to increased work are obvious precipitating factors which lead to myocardial ischemia. In the experimental situation, occlusion of the coronary arteries is often used as a stimulus which mimics myocardial ischemia. As people who frequently experience angina have varying degrees of coronary artery disease, it is difficult to accept that the state of the coronary arteries of the normal experimental animal bear any resemblance to the state of the coronary arteries under pathological conditions. That is, the gain of homeostatic reflexes, the basal concentrations of neuroactive substances in the plasma, the myocardium and the afferent terminals, the excitability of the afferents, access of chemical mediators (e.g. bradykinin, 5-HT, adenosine, histamine, prostaglandins, potassium, lactate), to afferents, and the overall function of the animal are all significantly different. We have no idea how control mechanisms have been altered in the person with severe coronary artery disease compared to the normal patient or the "normal" experimental animal.(ABSTRACT TRUNCATED AT 400 WORDS)

Nausea and vomiting during acute myocardial infarction and its relation to infarct size and location

Nausea and vomiting occurring during myocardial ischemia is believed to be associated with inferior wall infarction. However, data supporting such an association are limited, and an alternative hypothesis that cardiac vomiting is related to infarct size has also been advanced. The 2 hypotheses were tested in a cross-sectional study of 265 patients consecutively admitted to the coronary care unit. Nausea or vomiting was a good predictor of myocardial infarction (p less than 0.0001). The odds of having an infarction was 3.14 times greater for patients with nausea or vomiting than for those without these symptoms. Nausea was not a good predictor for inferior wall infarction (p = 0.14): 51% of patients with inferior infarcts had nausea or vomiting and 66% with anterior infarcts had these symptoms. Using peak serum creatine kinase level as an index of infarct size, nausea or vomiting was a good predictor of larger infarction. While 55% of all patients with infarction had nausea or vomiting, for patients with infarctions that produced a peak creatine kinase level of more 1,000 IU/liters, 78% had nausea or vomiting. Sex was a marginally important variable. After adjusting for sex, the presence of nausea or vomiting still predicted infarct size (p less than 0.001). Thus, cardiogenic nausea and vomiting are associated with larger myocardial infarctions but do not suggest infarcts in a particular location.

Lack of association between prodromes nausea and vomiting, and specific electrocardiographic patterns of acute myocardial infarction

We conducted an observational study on 164 patients consecutively admitted to our coronary care unit in order to evaluate the predictive role of cardiac prodromes nausea and vomiting, in distinguishing a particular electrocardiographic pattern (Q wave versus non-Q wave and localisation) of an acute myocardial infarction. Patients with the prodromes made up 47.0% of all Q wave myocardial infarction and 59.4% in those without Q wave myocardial infarction. Furthermore, patients had nausea and vomiting in 25.0% of all Q wave myocardial infarction and in 31.2% of all non-Q wave infarction. No significant differences were found in the patients who experienced nausea and vomiting in the localisation (anterior versus inferior) of myocardial infarction. Our findings indicate that the cardiac prodromes of nausea and vomiting do not play any particular role in predicting a specific electrocardiographic pattern of acute myocardial infarction.

Reflexes unique to myocardial ischemia and infarction

Although arrhythmias caused by myocardial ischemia are a well recognized cause of sudden death, the potential influence of cardiogenic reflexes originating in areas of ischemia has received less attention. In this study, 12 patients with well documented single vessel coronary artery spasm, with a total of 2,240 episodes of transient transmural ischemia, are described. Continuous electrocardiographic and hemodynamic recordings were analyzed to determine possible relations between the anatomic area of ischemia and patterns of change in blood pressure and heart rate. Of seven patients with ischemia of the posterior or inferior left ventricular wall, six had associated bradycardia and hypotension, an apparent Bezold-Jarisch response. Only one of five patients with anterior ischemia had a similar response. A hypertensive, tachycardiac response resembling the James reflex was seen in two of the patients with anterior ischemia, with an increase in blood pressure of 36/22 +/- 12/6 mm Hg and an increase in heart rate of 8 +/- 3 beats/min. This increase began before the onset of chest pain and was seen even in asymptomatic episodes. These reflexly mediated hemodynamic responses may modulate the direct effects of myocardial ischemia and could play a role in sudden cardiac death.

The Bezold-Jarisch reflex revisited: clinical implications of inhibitory reflexes originating in the heart

The concept of depressor reflexes originating in the heart was introduced by von Bezold in 1867 and was later revived by Jarisch. The Bezold-Jarisch reflex originates in cardiac sensory receptors with nonmyelinated vagal afferent pathways. The left ventricle, particularly the inferoposterior wall, is a principal location for these sensory receptors. Stimulation of these inhibitory cardiac receptors by stretch, chemical substances or drugs increases parasympathetic activity and inhibits sympathetic activity. These effects promote reflex bradycardia, vasodilation and hypotension (Bezold-Jarisch reflex) and also modulate renin release and vasopressin secretion. Conversely, decreases in the activity of these inhibitory sensory receptors reflexly increase sympathetic activity, vascular resistance, plasma renin activity and vasopressin. Long regarded as pharmacologic curiosities, it is now clear that reflexes originating in these inhibitory cardiac sensory receptors are important to the pathophysiology of many cardiovascular disorders. This paper reviews the role of inhibitory cardiac sensory receptors in several clinical states including 1) bradycardia, hypotension and gastrointestinal disorders with inferoposterior myocardial ischemia and infarction, 2) bradycardia and hypotension during coronary arteriography, 3) exertional syncope in aortic stenosis, 4) vasovagal syncope, 5) neurohumoral excitation in chronic heart failure, and 6) the therapeutic effects of digitalis.