Coronary heart disease in marathon runners

A Framework for Understanding the Role of Psychological Processes in Disease Development, Maintenance, and Treatment: The 3P-Disease Model

Health psychology is multidisciplinary, with researchers, practitioners, and policy makers finding themselves needing at least some level of competency in a variety of areas from psychology to physiology, public health, and others. Given this multidisciplinary ontology, prior attempts have been made to establish a framework for understanding the role of biological, psychological, and socio-environmental constructs in disease development, maintenance, and treatment. Other models, however, do not explain how factors may interact and develop over time. The aim here was to apply and adapt the 3P model, originally developed and used in the treatment of insomnia, to couch the biopsychosocial model in a way that explains how diseases develop, are maintained, and can be treated. This paper outlines the role of predisposing, precipitating, and perpetuating factors in disease states and conditions (the 3Ps) and provides examples of how this model may be adapted and applied to a number of health-related diseases or disorders including chronic pain, gastrointestinal disorders, oral disease, and heart disease. The 3P framework can aid in facilitating a multidisciplinary, theoretical approach and way of conceptualizing the study and treatment of diseases in the future.

Physical fitness cannot be used to predict the likelihood of acute coronary syndromes in ED patients with chest pain

OBJECTIVE

The objective of the study was to explore the association between physical fitness and the likelihood of acute coronary syndrome (ACS) in patients presenting to the emergency department (ED) with chest pain (CP). We hypothesized that the likelihood of ACS would be lower in physically fit patients and higher in patients with exercise-induced CP.

METHODS

The study involved a prospective, descriptive cohort in an academic suburban ED. Subjects were ED patients with CP admitted for suspected ACS. Demographic and clinical data were collected by trained research assistants using standardized forms. Patients were surveyed on level of fitness and whether they had ever experienced anginal type symptoms during exercise. Acute coronary syndrome was considered present if the patient had electrocardiographic evidence of infarction or ischemia; elevated troponin I levels; greater than 70% stenosis of culprit coronary artery; or a positive nuclear, echocardiographic, or treadmill stress test result. Patients readmitted within 30 days for reinfarction, cardiogenic shock, or arrhythmias were also considered to have ACS. The association between physical fitness and ACS was determined using χ(2) tests and odds ratios (ORs).

RESULTS

One hundred patients were enrolled. Mean age was 55.8 (±15.3) years; 36% were female; 85% were white. Thirteen (13%) patients had positive troponins, 22 of 36 catheterized patients had greater than 70% coronary artery stenosis, and 6 (6%) had abnormal stress test results. There were no deaths or reinfarctions within 30 days. The rate of ACS was similar in patients who were physically fit and those who were not (24% vs 37%; OR, 0.5 [95% confidence interval, 0.2-1.3]) and in patients who had experienced exercise-induced CP and those who had not (32% vs 29%; OR, 1.2 [95% confidence interval, 0.4-3.2]). Neither the frequency nor the intensity of exercise was associated with ACS.

CONCLUSIONS

Physically fit patients with CP were as likely to have ACS as those not physically fit. A history of exercise-induced CP was not associated with an increased likelihood of ACS.

Chest pain in athletes

The symptom of chest pain in the athlete can represent anything from a nonspecific musculoskeletal strain to a life-threatening condition such as tension pneumothorax. For the physician charged with evaluating this patient population, a thorough knowledge of the possible etiologies, their usual diagnostic algorithms, available imaging modalities, and potential therapeutic options is essential. Although the vast majority of patients with traumatic chest pain will not harbor significant pathology, the clinician must be prepared for those few who do have such conditions, and be prepared to intervene in an appropriate, time-sensitive fashion.

Characteristics of conditioned and sedentary men with acute coronary syndromes

To evaluate the role of habitual exertion in the development and manifestation of coronary artery disease, 36 well-conditioned men with acute coronary syndromes (4 with unstable angina, 23 with acute myocardial infarction and 9 survivors of sudden ischemic death) related to sports were compared with 36 sedentary men with the same syndromes occurring at rest. The mean age of the study subjects was 48 years (range 25 to 65). Patients exercised on average 6 hours/week (range 2 to 15) for > or = 10 years (range 10 to 45). Coronary angiography was performed within 4 hours after the onset of symptoms. The well-conditioned men had fewer risk factors than the inactive men (control subjects): fewer of them smoked (58 vs 94%, odds ratio 0.08) or had serum total cholesterol levels > or = 240 mg/dl (14 vs 56%, odds ratio 0.13, both p < 0.05). In addition, these men had less diseased (28 vs 72%, odds ratio 0.15, p < 0.02) and less severely stenotic (36 vs 78%, odds ratio 0.16, p < 0.03) coronary arteries. The association between activity levels and angiographic disease severity remained significant after correction for risk factors. Lesion morphology, site of the lesion and presence of thrombus of the culprit artery and diameter and dominance of all coronary arteries did not differ between the well-conditioned men and control subjects. This study suggests that regular strenuous exercise can reduce coronary artery disease and shows a common pathogenesis for acute coronary syndromes related and unrelated to sport.

Clinical and angiographic observations on resuscitated victims of exercise-related sudden ischemic death

The clinical and angiographic findings of 17 resuscitated victims of exercise-related sudden ischemic death are reported in an attempt to elucidate the mechanism(s) of these deaths. Ten survivors developed cardiac arrest during or after sporting activities (group A) and 7 others during or after an exercise stress test (group B). There were 15 men and 2 women. The mean age of group A was 46 years and of group B 55 years. Coronary risk factors, as well as previous angina and myocardial infarction, were more frequent in group B. Only 3 of the 17 survivors had anginal symptoms before sudden death. Sudden death in group A was associated with acute myocardial infarction in 8 and unstable angina in 2 and was associated in group B with acute myocardial infarction in 2, unstable angina in 3 and silent ischemia in 2. Coronary angiography was acutely performed in 15 patients. In most patients the ischemia-related coronary artery was totally or subtotally occluded. Clinical and angiographic findings indicate that exercise-related sudden ischemic death was due to an acute coronary event--in most cases unexpected and unpredictable. It is suggested that exercise-induced intracoronary changes were probably responsible for the development of acute coronary (sub)occlusion and sudden death.

Clinical characteristics and coronary angiographic findings of patients with unstable angina, acute myocardial infarction, and survivors of sudden ischemic death occurring during and after sport

The clinical characteristics and coronary angiographic findings of 42 well-conditioned subjects with an acute ischemic event related to sport are reported. Five patients had unstable angina, 25 had acute myocardial infarction (AMI), and 12 were resuscitated victims of sudden ischemic death. Twenty-two events occurred during sport (group A) and 20 after sport (group B). There were two women and 40 men. The mean age was 46 years (range 25 to 65). Twelve out of 30 patients who smoked cigarettes had an adjunctive risk factor for coronary artery disease. Twelve others (28%) had no identifiable risk factor. Prodromal cardiac symptoms were detected in three patients (group A). Two patients had previous myocardial infarction (group B). Coronary angiography was performed acutely in 39 patients. The distribution of the ischemia-related coronary artery was comparable in both groups. The lesion morphology of 35 culprit coronary arteries was described as concentric in six patients and eccentric with regular borders (type I lesion) in 11 and irregular borders (type II lesion) in 18. Eccentric lesions consistent with ruptured plaques prevailed in both groups. Associated coronary artery disease was present in 10 patients. There was no relationship between the number of risk factors and the extent of diseased coronary arteries. Clinical characteristics and coronary angiographic findings of patients with unstable angina, AMI, and sudden death either during or after sport are similar and indicate a common pathogenesis. The probable mechanism of a coronary event related to sport is exercise-induced plaque rupture. In most instances such an event is unexpected and unpredictable. Identification of some subjects at risk is possible.

The effect of regular physical exercise on sensitivity to ischaemia in the rat's heart

The effect of different training regimes (three programmes of both swimming and running exercise) on the heart hypertrophy index and some biochemical indices was evaluated and compared individually with the sensitivity of the corresponding heart to ischaemia in order to elucidate the significance of training intensity and observed changes in the development of heart ischaemic injury. The sensitivity of the heart to ischaemia, evaluated by the rate of development of ischaemic contracture 48 h after completing the exercise programme, increased in parallel with an increase in the heart hypertrophy index. Experiments with different swimming programmes showed that the extent of cardiac hypertrophy increased together with an increase in the duration of everyday swimming bouts. Hypertrophied hearts from trained rats were characterized by greater mobilization of glycogen and increased incorporation of 32P into ATP when investigated 10 min after isoprenaline administration. During total ischaemia the development of ischaemic contracture was accelerated in catecholamine-stimulated trained hearts due to more rapid hydrolysis of ATP compared with that in the hearts from sedentary animals. It is suggested that the observed difference between hearts from sedentary and trained animals is, at least partially, connected with the higher sensitivity of myofibrils to Ca2+ in trained hearts.

Effect of selective and nonselective beta-adrenoceptor blockade on thermoregulation during prolonged exercise in heat

The effect of selective and nonselective beta-adrenoceptor blockade on the thermoregulatory responses of 11 physically active, healthy, young adult men was studied during 2-hour block-stepping in heat. The trial consisted of 3 periods of 6 days each during which propranolol (160 mg/day), atenolol (100 mg) or matching placebo was administered in a randomized, double-blind crossover fashion. Propranolol and atenolol induced similar, significant (p less than 0.001) increases in subjective ratings of perceived exertion. The mechanism of this increased fatigue was not evident from the documented alterations in serum electrolyte, blood glucose and blood lactate levels or ventilatory parameters. Propranolol did, however, induce a postexercise delayed serum-potassium reversion. Although rectal and mean skin temperature responses were essentially unaltered by beta-adrenoceptor blockade during block-stepping, an increased total sweat loss was observed with propranolol (p less than 0.01 versus placebo) and to a lesser degree with atenolol (p = not significant versus placebo). This indicates that persons receiving beta-adrenoceptor blockers have an increased need to adhere to a strict fluid-replacement regimen during exercise. This potentially adverse response was minimal with atenolol in contrast to propranolol, and this in turn suggests the use of beta1-selective adrenoceptor blockers during prolonged exercise when adequate fluid replacement is not possible.

Severe aortic-valve stenosis unmasked by amateur running

Three men aged 35, 55, and 60 years had asymptomatic underlying aortic-valve stenosis unmasked by amateur running or jogging. All three men underwent aortic-valve replacement and two of the three have resumed mild exercise programs. Congenitally abnormal aortic valves were found in two of the three patients. Amateur exercise may uncover an underlying cardiovascular abnormality perhaps sooner than might be apparent without exercise.

Elevated serum creatine kinase MB and creatine kinase BB-isoenzyme fractions after ultra-marathon running

To determine the incidence and range of serum creatine kinase MB (CK-MB) isoenzyme activity after ultra-marathon running, a popular test kit was used to measure total serum creatine kinase (CK) and CK MB-activity in 75 athletes immediately after they had completed an 88-km running race. Total serum CK activity was markedly elevated after the race (mean value: 637 U X 1(-1) and 45 (60%) runners showed abnormal CK-MB isoenzyme activities (greater than 4% of total CK activity - range 1-19%). Electrophoresis of 31 sera with either CK-MB to total CK activity greater than 4% or with total CK activity greater than 854 U X 1(-1) showed that 31 (100%) had visible CK-MM bands, 21 (68%) had visible CK-BB bands, but only 14 (44%) had visible CK-MB bands. We conclude that prolonged exercise increases the serum activity of all three CK-isoenzymes, and that the CK-MB test kit used in this study identified a greater number of sera with elevated post-race CK-MB isoenzyme activity than did electrophoresis. This discrepancy could result either from cross-reaction of elevated CK-BB activity with the test kit, or from relative insensitivity of the electrophoresis. The tissue source and long-term significance of the elevated serum CK-MB and CK-BB isoenzyme activity induced by ultra-marathon running are uncertain. Until these issues are resolved, these biochemical findings in ultra-marathon runners must be interpreted with the appropriate caution.

Significance of abnormal electrocardiograms in highly trained athletes

Electrocardiographic and other abnormalities of highly trained athletes are well recorded but not well enough known, and the more extreme changes still cause diagnostic confusion. This problem was exemplified by 10 athletes, all referred to us by cardiologists because of a diagnosis of organic heart disease. After thorough investigation, including catheter studies, all but 1 of these patients was regarded as normal and all returned to competitive sports. The criteria for diagnosing heart disease in athletes are discussed in light of the findings in 10 patients. Exercise electrocardiography and echocardiography help to exclude organic disease, but left heart catheterization is justified when doubt still exists.

Heart Disease in Marathon Runners

Most physicians agree that endurance exercise benefits the heart, but they vigorously debate the particulars: Does marathon running immunize people to heart disease? Or is it just one of many risk factors?

Hypertrophic cardiomyopathy associated with sudden death during marathon racing

An experienced marathon runner died suddenly during a competitive race. At necropsy, ventricular hypertrophy but no asymmetrical septal hypertrophy was found. Histological studies showed features of hypertrophic cardiomyopathy. The coronary arteries were normal. We propose that the runner died from myocardial ischaemia, precipitated by marathon running on a background of hypertrophic cardiomyopathy. Excess cardiac work, induced by marathon running in the presence of mild congenital cardiac defects, could have contributed to the development of the cardiomyopathy.